Sequential Radiotherapy Research Articles

MODERN EFFECTIVE TREATMENT OF BRAIN METASTASES OF SKIN MELANOMA. THE EXAMPLE OF CLINICAL OBSERVATION

Introduction. Melanoma of the skin has the highest potential for metastasis to the brain, ranking 15th in the frequency of occurrence among all malignant tumors – it is in third place in the incidence of intracerebral metastases. Modern methods of treatment of metastases of skin melanoma to the brain include neurosurgical treatment, radiation therapy and radiosurgery, antitumor drug therapy, including targeted therapy, immunotherapy and chemotherapy. The article discusses the indications for different methods of treatment, provides data on patient survival when using these methods of treatment alone or in combination. Additionally, a clinical case of long-term survival of a patient with skin melanoma with progression in the form of extra- and intracranial metastasis is discussed.Purpose. Evaluation of the result of using modern methods of antitumor treatment in real clinical practice in a patient with skin melanoma metastases in the brain. Materials and methods. On a clinical example, a possible sequence of an individual approach to the treatment of a patient with extracranial and intracerebral metastases of skin melanoma based on modern methods of treatment and examination is considered.Results. The use of modern methods of anticancer therapy has increased the overall survival and disease-free survival of patients with metastases of skin melanoma to the brain and reduces the need for neurosurgical interventions. As a confirmation of this, the life expectancy of the patient after the progression of skin melanoma in the form of metastases to the brain against the background of all the antitumor treatment carried out to date was 5.5 years, while neurosurgical treatment was not carried out at the request of the patient, although it was shown, but were used the possibilities of modern anticancer therapy, including sequential radiation therapy, targeted therapy and immunotherapy.Conclusion. Modern methods of anticancer therapy can significantly increase the survival rate of patients with melanoma brain metastases and individualize the treatment plan.

Clinical Outcomes of Patients with Anaplastic Large Cell Lymphoma, Anaplastic Lymphoma Kinase-Negative (ALCL, ALK-): Analysis of 203 Patients Prospectively Registered in the International T-Cell Project

Introduction: Anaplastic Large Cell Lymphoma, Anaplastic Lymphoma Kinase-negative (ALCL, ALK-) is a clinically aggressive lymphoid neoplasm with characteristic histologic and genetic features. The analysis from a retrospective International T-cell Lymphoma Project reported intermediate outcomes for ALCL, ALK- patients with 5-year event-free survival (EFS) and overall survival (OS) rates of 39% and 46%, respectively (Savage et al. Blood 2008 ). In this analysis, we sought to study clinical features and outcomes of 203 patients prospectively enrolled into the international T-cell lymphoma registry, the T-cell Project (TCP).Methods: The T-Cell Project prospectively registered consecutive patients with newly diagnosed peripheral T-cell lymphomas (PTCL) from 74 centres, in 14 countries, across 4 continents from Sep 2006 -Dec 2015. Demographic, clinical, and pathologic characteristics at the time of diagnosis, as well as treatment details and survival outcomes were collected. A key aim of this global collaborative project was to more precisely define clinical characteristics and outcome of patients with various subtypes of PTCL.Results: From a total of 1,429 evaluable PTCL cases, 203 (14.8%) were confirmed as ALCL, ALK- following international histopathologic panel review. As anticipated, these cases, as a proportion of all PTCL cases, varied across geographical regions (Asia 4.6%, South America 29.3%, U.S.A 12.7%, and Europe 14.7%). The median age at diagnosis was 55 (range, 18-89) years with a slight male predominance (63%). Stage III/IV disease was identified in 61% of patients, whilst bulky disease >5cm (25%) and BM involvement (9%) were uncommon. 65% of patients presented with low IPI score. Data on therapy was available in 155 (76%) patients, of whom 142 (92%) received chemotherapy (CHT) as part of first-line treatment. 23 (14.8%) patients additionally received concurrent or sequential radiotherapy (RT), whilst 12 patients (7.7%) underwent high-dose therapy as consolidation. Eleven (7%) patients received palliative care only. Of 142 patients treated with chemotherapy, 137 (96.5%) received anthracycline-containing regimens. There was no significant variation in anthracycline use by global geographic regions. The investigator-assessed overall response rate was 72%, with 84 (58%) patients achieving complete remission. With a median follow-up of 41 (range, 31-51) months, the median PFS (n=114) was 35 (95% CI 16-53) months, and 3-year and 5-year PFS rates were 48% and 40%, respectively. The median OS (n=203) was 52 (95% CI, 29-76) months, and 3-year and 5-year OS rates were 57% and 47%, respectively (Fig.1). At the time of data cut off, 84 (41%) patients died. Cause of death was most commonly attributable to lymphoma (72%) and infection (8%).Conclusions: This is the largest-to-date prospective international registry study of ALCL, ALK- patients describing epidemiology, clinical features, treatment approaches, and outcomes. With a mature follow-up, we report comparable results to previously reported from the retrospective International T-Cell Lymphoma Project. The long term survival rates after modern treatment approaches are disappointing with more than half of the patients not surviving past 5 years from diagnosis. This study underscores the urgent need for improved frontline therapies for ALCL, ALK- patients, and provides a robust platform for designing and interpreting future clinical trials. Recent results of incorporating novel CD30-targeting agent into initial therapy protocols are encouraging, and confirmatory randomized trial analysis is underway.Figure 1. Kaplan Meier estimates of overall (A) and progression-free (B) survival among ALCL, ALK- patients enrolled into the prospective TCP registry. [Display omitted] DisclosuresShustov:Celgene: Other: Publication assistance; Spectrum Pharmaceuticals: Consultancy, Research Funding. Horwitz:ADCT Therapeutics: Research Funding; Mundipharma: Consultancy; Kyowa-Hakka-Kirin: Consultancy, Research Funding; HUYA: Consultancy; Infinity/Verastem: Consultancy, Research Funding; Millenium/Takeda: Consultancy, Research Funding; Celgene: Consultancy, Research Funding; Forty-Seven: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Aileron Therapeutics: Research Funding; BMS: Consultancy. Radford:Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Consultancy; Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Research Funding; Novartis: Speakers Bureau; Millennium Pharmaceuticals, Inc., a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Speakers Bureau; Seattle Genetics: Speakers Bureau; GSK: Equity Ownership; AstraZeneca: Equity Ownership. Chiappella:Nanostring: Speakers Bureau; Amgen: Speakers Bureau; Pfizer: Speakers Bureau; Celgene: Speakers Bureau; Roche: Speakers Bureau; Teva: Speakers Bureau; Janssen: Speakers Bureau. Federico:takeda: Honoraria, Research Funding.

Clinical Outcomes of Patients with Anaplastic Large Cell Lymphoma, Anaplastic Lymphoma Kinase-Positive (ALCL, ALK+): Data from 119 Patients Prospectively Registered in the International T-Cell Project

Introduction: Anaplastic Large Cell Lymphoma, Anaplastic Lymphoma Kinase-positive (ALCL, ALK+) is a clinically aggressive lymphoid neoplasm with reported outcomes that compare favorably to other peripheral T-cell lymphoma (PTCL) subtypes. Pathogenesis of ALCL, ALK+ has been linked to perpetual activation of the ALK-kinase and numerous downstream signaling molecular events, that result from the recurrent genetic alteration, t(2;5)(p23;q35), in the majority of cases. In this study, we sought to analyze demographic characteristics, presenting clinical features, and treatment outcomes of 116 patients with ALK+ ALCL prospectively enrolled into the international T-cell lymphoma registry, the T-cell Project (TCP).Methods: The T-Cell Project prospectively registered consecutive patients with newly diagnosed PTCLs from 74 centers, in 14 countries, across 4 continents from Sep 2006 -Dec 2015. A key aim of this global collaborative project was to more precisely define clinical characteristics and outcomes of patients with various PTCL subtypes.Results: From a total of 1,429 evaluable PTCL cases, 119 (8.3%) were confirmed as ALCL, ALK+ following international histopathologic panel review. As anticipated, these cases, as a proportion of all PTCL cases, varied across geographical regions (Asia 4.4%, South America 8.0%, U.S.A 9.3%, and Europe 9.1%). The median age at diagnosis was 34.5 (range, 18-84) years with a slight male predominance (58%). Stage III/IV disease was found in 68.7% patients, whilst bulky disease >10cm (8.4%) and bone marrow involvement (14.5%) were uncommon, and 78.6% of patients had low risk IPI score (0-1). Data on therapy was available in 81 (68%) patients, of whom 80 (99%) received chemotherapy (CHT) as part of first-line treatment. Ten patients (12.3%) additionally received concurrent or sequential radiotherapy (RT), whilst 4 patients (4.9%) underwent high-dose therapy as consolidation. One patient (1.2%) received palliative care only. Of 80 patients treated with chemotherapy, 76 (91%) received anthracycline-containing regimens. The investigator-assessed overall response rate was 82.6%, with 57 patients (71%) achieving complete remission. With a median follow-up of 28 (range, 19-37) months, the median PFS for (n=114) ALK+ ALCL patients was not reached, and 3-year and 5-year PFS rates were 66% (95% CI, 55-75) and 59% (95% CI, 47-70), respectively. The median OS (n=116) was not reached, and 3-year and 5-year OS rates were both 77% (95% CI, 66-85) (Fig.1). At the time of data cut off, 20 patients died. Cause of death was most commonly attributable to lymphoma (65%) and infection (15%).Conclusions: This is the largest prospective international registry study to-date of ALCL, ALK+ patients, describing epidemiology, clinical features, treatment approaches and clinical outcomes. The use of anthracycline-based CHT regimens remains a standard of care front-line approach across global geographic regions. With a median follow up of >2 years, we observed favorable OS outcomes compared to other PTCLs despite presence of advanced stage disease in the majority of patients. However, the rates of PFS leave room for improvement. These findings are consistent with previous report from the retrospective International T-cell Project. Incorporation of recently developed CD30-targeting and ALK-kinase targeting agents into front-line regimens is underway to further improve outcomes for high-risk patients.Figure 1. Kaplan-Meier estimates of overall (A) and progression-free survival (B) among ALCL, ALK+ patients enrolled into the prospective TCP registry. [Display omitted] DisclosuresShustov:Celgene: Other: Publication assistance; Spectrum Pharmaceuticals: Consultancy, Research Funding. Pileri:Takeda Pharmaceuticals: Speakers Bureau. Horwitz:Mundipharma: Consultancy; ADCT Therapeutics: Research Funding; Celgene: Consultancy, Research Funding; BMS: Consultancy; Millenium/Takeda: Consultancy, Research Funding; Kyowa-Hakka-Kirin: Consultancy, Research Funding; Aileron Therapeutics: Research Funding; Infinity/Verastem: Consultancy, Research Funding; Seattle Genetics: Consultancy, Research Funding; Forty-Seven: Consultancy, Research Funding; HUYA: Consultancy. Carson:Seattle Genetics: Honoraria. Federico:takeda: Honoraria, Research Funding.

134 - Sequential chemo radiation (SCRT) in locally advanced NSCLC: a review of outcomes in a single institution practice

134 - Sequential chemo radiation (SCRT) in locally advanced NSCLC: a review of outcomes in a single institution practice

Demographical differentials of lung cancer survival in Bangladeshi patients.

10570 Background: Lung Cancer is the leading cause of cancer-related mortality and most common cancer in worldwide with more than a million deaths annually. 20.8% cancer related death caused by lung cancer and more than half of lung cancer occurred in Asia. Differences In the epidemiology of lung cancer among the developing country may shed light on possible genetic and demographical influences on lung cancer survival. Demographic stratification of lung cancer patients of Bangladesh is remain unclear due of lack of data We tried to figure out the demographic pattern and its impact on survival in Bangladeshi lung cancer patient. Methods: Previously diagnosed primary lung cancer patients attending Medical Oncology department of National Institute of cancer research and Hospital, a tertiary care center of Bangladesh, between 2018 and 2019 were included. Demographic and clinical data were collected retrospectively from the medical records. Results: A total of 1868 consecutive patient (1580 males, 288females) diagnosed to have lung cancer; Mean age was 60 years which quite early compare to other countries. Older than 70-year age groups had worse survival outcome (hazard ratio 1.04: 95% confidence interval: 1.17–1.68). Below 50-year group had better outcome with standard adjuvant or palliative chemotherapy whereas older groups had better survival with sequential radiotherapy and chemotherapy or concurrent chemo radiation (Hazard Ratio 0.45; 95% confidence interval: 0.30–0.67). Sex was not a predicting factor for overall survival (Hazard ratios 1.04 95% confidence interval 0.89- 1.22, P = 0.621). But, Male had better treatment response than the female (Hazard ratio and 95% confidence interval: 0.51 and 0.42-0.61, P = < 0.001). Education level had significant impact on survival outcome (Hazard ratio 0.58 and 95% confidence interval: 0.47-0.71, P = < 0.001). Underweight group had worse survival than the normal BMI group (Hazard ratio1.18 and 95% confidence interval 1.05-1.31, P = 0.005). Having the Comorbid condition at the time of diagnosis had shorter survival (Hazard ratio 1.16 and 95% confidence interval 1.04-1.30 P = 0.007). Histological variation had no survival benefit among the squamous, small cell or other histological types (p = 0.214, 0.494, 0.658 respectively). But adenocarcinoma or small cell carcinoma had better treatment response outcome. Eastern Cooperative Oncology Group performance status (ECOG-PS) 4 had worse outcome (Hazard ratio 1.95, 95% confidence interval 1.37–2.79; P = < 0.001). Conclusions: The socio-demographic related survival in lung cancer needs to be fully elucidated because of its implication in the design of experimental protocols for targeted chemoprevention, early disease screening, molecular marker based staging, and individualized treatment. Due to its extraordinary disease burden and the international variability in demographic variables, the lung cancer requires continual monitoring.

The impact of multimodality therapies in marginally inoperable soft tissue sarcomas (STS): The Toronto Sarcoma Program (TSP) experience.

11548 Background: The mainstay therapy of operable STS remains surgery, which may include (neo)adjuvant therapies. Within the TSP, marginally inoperable STS are often treated with sequential chemo (CTX) and radiation (RT) therapy, followed by surgery (SX). Herein we present our experience of multi-modality therapies for marginally inoperable STS patients (pts). Methods: This was a dual-center, single program, retrospective review. Pts were included if deemed to have marginally inoperable primary or recurrent STS, as determined at the TSP tumor board. Pts included must have had CTX with the intent of having RT and SX after. Pts demographics, treatment details and clinical outcomes data were collected. Relapse free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Multivariate analysis of the influence of disease characteristics and treatment on outcomes was assessed using Cox regression. Results: From June 2005 to May 2019, 75 pts were identified. Median age was 52 years (range 16-72). Pts were predominantly male (55%). Histological subtypes included dedifferentiated liposarcoma (29%), leiomyosarcoma (27%), synovial sarcoma (19%) and others (25%). Primary tumor was located in the retroperitoneum (48%), extremity (23%), pelvis (12%), thorax (9%), and other sites (8%). All pts had doxorubicin and ifosfamide CTX (median 4 cycles; range 1-6), while RT dose delivered was 50.4Gy/28 fractions in 58 (77%) of cases. Twenty three pts (31%) achieved partial response, 40 pts (53%) had stable disease and 12 pts (16%) had progression of disease (PD) on CTX, of which half (8%) did not undergo further treatment. Nine pts (12%) underwent CTX followed by SX due to significant response, 9 pts (12%) underwent CTX and RT without SX due to persistent tumor unresectability or PD. The final 50 pts (67%) completed multi-modality treatment (CTX, RT & SX). Overall, 59 pts (79%) had SX; negative margins were achieved in 53 (71%). 19 pts (25%) had postoperative complications, causing death in 2 pts (2.7%). With a median follow-up of 72 months, median RFS and OS were 26.9 months (95% CI: 0-86.0), and 65 months (95% CI: 13.5-116.4). Extremity location was associated with superior RFS (median not reached [NR], HR 0.28 95% CI 0.09-0.83, p = 0.022), and OS (median NR, HR 0.29 95% CI 0.09-0.90, p = 0.032). Receipt of RT was associated with superior RFS (median NR, HR 0.23 95% CI 0.10-0.52, p < 0.001); and OS (median NR, HR 0.21 95% CI 0.09-0.50, p < 0.001). Pts who had PD after CTX were associated with poor outcomes - RFS (median 4.7 months, HR 2.03 95% CI 0.61-6.76, p = 0.24); and OS (median 21.9 months, HR 2.48 95% CI 0.73-8.47, P = 0.144). Conclusions: Multi-modality approach resulted in successful resection for most pts with marginally inoperable STS. Extremity location and RT administration were associated with better RFS and OS, while progression on CTX confers worse survival outcomes.

Retrospective cohort of total neoadjuvant therapy (TNT) in high-risk locally advanced rectal cancer (HR-LARC): Additional sintilimab (PD-1) in tri-modality approach.

e15604 Background: TNT is an emerging practice adapted to ensure all patients (pts) receive of systemic therapy, particularly for pts with high risk recurrence. Our previous phase II trial of TNT in MRI stratified HR-LARC demonstrated high down-staging rate and improved complete response with acceptable toxicity (manuscript under review). The aim of this retrospective cohort study was to evaluate the feasibility of sintilimab in combination with chemotherapy in TNT tri-modality treatment of pts with HR-LARC. Methods: HR-LARC pts who were given 3 cycles of sintilimab (200mg, iv, q3w) in combination with CapeOx followed by sequential long-course radiotherapy (IMRT GTV50.6 Gy/CTV 41.8 Gy/22f), 2 cycles CapeOx and surgery were enrolled from Beijing Cancer Hospital, CHN. The high risk was defined as middle to low RC (≤8cm to ARJ or 12 cm per sigmoidoscopy) with ≥1 factor from MRI features: clinical stage T3c/d-T4a/b, or N2 or MRF (+) or EMVI (+). The clinical outcomes included pathological response, major response rate (cCR+MPR), R0 resection rate, and toxicity. Results: From Feb 2019 to Oct 2020, 19 cases were identified with median distal location 4 cm (3-7), T2/T3/T4 1/15/3, N1/N2a/N2b 7/4/8, MRF+ 8/11, EMVI+ 8/11. Other characteristics were pMMR/MSS 100%, age 67y (47-78), male 57.9%, PS 1 100%, c-stage III 100% (18), median diameter of primary lesion 5.1 cm (2.1-7.5). As of 30th Dec 2020, 84.2% (16/19) received neoadjuvant therapy and completed surgical resection, with R0 resection rate 100%. One pts denied surgery and two chose watch & wait since achieving cCR 10.5% (2/19). Of 16 resection pts, 13 had sphincter-sparing surgery (LAR or TaTME). One had Hartmann procedure, and two had abdominal perineal resection. The sphincter preservation rate was 84.2% (16/19). The pCR was 26.3% (5/19), and MPR was 47.3% (9/13). The major response rate was 57.9% (11/19), 4/2/13 of which completed intact TNT schema, induction and RT, and induction phase only, respectively. Treatment related adverse events (TRAE) occurred in 6 pts (31.6%) in grade (gr) 1-2 (CTCAE 5.0) without any gr 3-5 events occurred. Immune-related AEs were found in 2 pts with hypothyroidism (gr 1,2). Postoperative complications included two gr2 (Clavien-Dindo) events of anastomtic bleeding and infection. Of note, 3 pts with anastomotic stenosis got stoma reversion after dilation. Conclusions: Given the impressive response rate (57.9%), this retrospective analysis suggested a potential enhanced anti-cancer activity and good tolerability in pMMR/MSS HR-LARC from sintilimab in combination with TNT. The encouraging results warrant further evaluation of this approach in prospective trial.

Abstract PO-044: Exploiting a radiotherapy induced immunologic double bind in advanced prostate cancer

Abstract An evolutionary double bind occurs in cancer when resistance to a commonly used therapy increases the sensitivity to a second therapy. Typically, the second therapy is most effective in the recurrent setting and less effective when given up front. There is a tremendous need for novel second-line therapies able to exploit these new sensitivities. Prostate cancer remains one of the most treatable cancers, however, advanced disease is typically metastatic and currently incurable. Radiation therapy (RT) is often used in the resistant setting. Given locally, RT induces double-strand DNA breaks in tumor cells. This results in cellular stress responses that either trigger apoptosis and cell death, or DNA repair and cell survival. Radiosensitivity is related to the DNA repair capabilities of a tumor. Activation of DNA damage response pathways, which are mediated by ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and Rad3-related protein (ATR), induces changes in surviving cancer cells. Most notably, it has been shown that RT, as well as other DNA damaging agents, can increase natural killer cell (NK) ligand expression on tumor cells. Here we utilize an isogenic cell line model of radioresistant prostate cancer. Our pre-clinical model shows that alterations in DNA repair pathways required to maintain resistance to RT correlate with changes in NK-cell ligands, including: major histocompatibility complex class I chain-related protein A/B (MICA/B), Nectin-2 (CD112), and poliovirus receptor (PVR). This results in a 2-fold increase in sensitivity to NK-cell mediated killing in the radiation resistant cell line. An “evolutionary game assay” was performed by preparing mixtures of parental and radiation-resistant cell lines at 4 different ratios: 100:0, 90:10, 10:90 and 0:100. This was repeated for six treatment scenarios: untreated, 6Gy radiation, 1:1 NK cells, 5:1 NK cells, 6Gy with 1:1 NK cells, and 6Gy with 5:1 NK cells. Comparison of monotypic growth rates to coculture mixtures of parental and radiation-resistant cell lines enable quantification of competitive interactions through the use of evolutionary math models. This assay quantifies effective fitness (growth rate) to experimentally determine the frequency-dependent gradient of selection. Preliminary results indicate the emergence of three qualitatively unique evolutionary scenarios: 1) dominance of resistance (radiation therapy), 2) dominance of sensitive (5:1 NK), and 3) coexistence (untreated; 1:1 NK). These results suggest the existence of an evolutionary double-bind when NK-cell administration follows radiation. This was experimentally validated and confirmed by repeating the evolutionary assay with sequential radiation and NK therapy. Importantly, there is a minimum threshold of NK cells required to achieve the double-bind. Direct measurement of the fitness landscape underlying radiation and NK treatment enabled the discovery and validation of an evolutionary strategy to re-sensitize tumors after radiation treatment. Citation Format: Kimberly Luddy, Jeffrey West, Mark Robertson-Tessi, Alexander Anderson, Laure Marignol, Robert Gatenby, Cliona O'Farrelly. Exploiting a radiotherapy induced immunologic double bind in advanced prostate cancer [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr PO-044.

A Multi-Institutional Analysis of Adjuvant Chemotherapy and Radiation Sequence in Women With Stage IIIC Endometrial Cancer.

Our purpose was to evaluate the effect of sequence and type of adjuvant therapy for patients with stage IIIC endometrial carcinoma (EC) on outcomes. In a multi-institutional retrospective cohort study, patients with stage IIIC EC who had surgical staging and received both adjuvant chemotherapy and radiation therapy (RT) were included. Adjuvant treatment regimens were classified as adjuvant chemotherapy followed by sequential RT (upfront chemo), which was predominant sequence; RT with concurrent chemotherapy followed by chemotherapy (concurrent); systemic chemotherapy before and after RT (sandwich); adjuvant RT followed by chemotherapy (upfront RT); or chemotherapy concurrent with vaginal cuff brachytherapy alone (chemo-brachy). Overall survival (OS) and recurrence-free survival (RFS) rates were estimated by the Kaplan-Meier method. A total of 686 eligible patients were included with a median follow-up of 45.3 months. The estimated 5-year OS and RFS rates were 74% and 66%, respectively. The sequence and type of adjuvant therapy were not correlated with OS or RFS (adjusted P = .68 and .84, respectively). On multivariate analysis, black race, nonendometrioid histology, grade 3 tumor, stage IIIC2, and presence of adnexal and cervical involvement were associated with worse OS and RFS (all P < .05). Regardless of the sequence of treatment, the most common site of first recurrence was distant metastasis (20.1%). Vaginal only, pelvic only, and paraortic lymph node (PALN) recurrences occurred in 11 (1.6%),15 (2.2 %), and 43 (6.3 %) patients, respectively. Brachytherapy alone was associated with a higher rate of PALN recurrence (15%) compared with external beam radiation therapy (5%) P < .0001. The sequence and type of combined adjuvant therapy did not affect OS or RFS rates. Brachytherapy alone was associated with a higher rate of PALN recurrence, emphasizing the role of nodal radiation for stage IIIC EC. The vast proportion of recurrences were distant despite systemic chemotherapy, highlighting the need for novel regimens.

Pathologic Response Rates after Neoadjuvant Therapy for Sarcoma: A Single Institution Study.

Simple SummaryFor high-grade soft tissue sarcomas (STS), combined modality treatment with surgery and radiation therapy is the standard of care. The addition of chemotherapy has been shown to decrease the risk of local recurrence and improve survival. Evaluating treatment response with surrogate modalities such as MRI, CT and PET imaging have substantial limitations. Pathologic necrosis of the surgical specimen is a direct indicator of the effect of treatment on tumor cells. Studies in STS and other malignancies have shown that increasing rates of treatment-induced tumor necrosis correlate with improvement of oncological outcomes and survival. However, the relationship between pathologic response and outcomes of specific neoadjuvant treatments for STS remains indeterminate. We hypothesized that sequential neoadjuvant chemotherapy and radiation yields higher rates of pathologic complete response (pCR) than neoadjuvant radiation or chemotherapy alone. Our results indicate that neoadjuvant chemotherapy and radiation yields superior pCR compared to other neoadjuvant regimens.(1) Background: Pathologic necrosis of soft tissue sarcomas (STS) has been used to determine treatment response, but its relationship to neoadjuvant treatments remains indeterminate. In this retrospective, single institution study, we hypothesized that neoadjuvant chemoradiation (NA-CRT) yields higher rates of pathologic complete response (pCR) than neoadjuvant radiation (NA-XRT) or chemotherapy (NA-CT) alone. (2) Methods: Patients with extremity STS between 2011–2020 who received neoadjuvant treatment were included. pCR was defined as percent necrosis of the surgical specimen greater than or equal to 90%. (3) Results: 79 patients were analyzed. 51.9% of the population were male with a mean age of 58.4 years. 49.4% identified as Non-Hispanic White. Twenty-six (32.9%) patients achieved pCR while 53 (67.1%) did not. NA-CT (OR 15.82, 95% CI = 2.58–96.9, p = 0.003 in univariate (UVA) and OR 24.7, 95% CI = 2.88–211.2, p = 0.003 in multivariate (MVA), respectively) and NA-XRT (OR 5.73, 95% CI = 1.51–21.8, p = 0.010 in UVA and OR 7.95, 95% CI = 1.87–33.7, p = 0.005 in MVA, respectively) was significantly associated with non- pCR when compared to NA-CRT. The analysis also demonstrated that grade 3 tumors, when using grade 2 as reference, also had significantly higher odds of achieving pCR (OR 0.23, 95% CI = 0.06–0.80, p = 0.022 in UVA and OR 0.16, 95% CI = 0.04–0.70, p = 0.015 in MVA, respectively). (4) Conclusion: NA-CRT yields superior pCR compared to other neoadjuvant regimens. This extends to higher grade tumors.

P49.03 Chemoradiation with Cisplatin-Etoposide versus Carboplatin-Etoposide in Limited-Stage Small Cell Lung Cancer

There are limited data on the comparison between etoposide plus cisplatin or carboplatin in patients with limited-stage small-cell lung cancer (SCLC). Although the guidelines and published randomized trials have included only cisplatin-based chemotherapy, the COCIS (Carboplatin- or Cisplatin-Based Treatment for SCLC) meta-analysis showed no significant differences in efficacy based on platinum drug used for either limited or extensive-stage SCLC (J Clin Oncol 2012; 30: 1692-8). We conducted a retrospective study to compare the outcomes in patients with stage III SCLC treated with thoracic radiation therapy with etoposide and either cisplatin or carboplatin. Patients diagnosed with limited-stage SCLC at Washington University between January of 1997 and May of 2019 were retrospectively screened for this study. Those with stage III, who were treated with radiation therapy and chemotherapy, including etoposide plus either cisplatin or carboplatin, were included in this analysis. The Kaplan-Meier method and multivariate Cox Proportional Hazard models were used to estimate progression-free survival (PFS) and overall survival (OS). Fischer exact tests were used to test group differences for categorical variables. Among the 244 patients evaluated, 150 (61.4%) met the eligibility criteria. 69 patients (28.3%) were excluded due to stage I, II or unavailable, 17 (7.0%) due to lack of radiation therapy, and 8 (3.3%) due to the use of other chemotherapy regimens. Among the 150 patients, 68 were treated with cisplatin and 82 with carboplatin. The median age was 58 years in the cisplatin group and 67 years in the carboplatin group. While most patients were treated with concurrent chemoradiation, more patients received sequential radiation in the carboplatin group when compared to the cisplatin one (18.3% vs. 2.9%, P=0.004). There were no significant differences between the two groups regarding gender, race, or smoking status. At a median follow-up of 19 months, there was no statistical difference in PFS or OS between both groups. The median PFS was 13 months in the cisplatin group and 9 months in the carboplatin group (P=0.33). The median OS was 33 months in the cisplatin group and 26 months in the carboplatin group (P=0.1). On multivariate Cox regression analysis, chemotherapy type was not significantly associated with PFS or OS. However, increasing age at diagnosis and sequential radiation were both independently associated with increased mortality (HR:1.03 [1.00-1.05], P=0.02, and 1.97 [1.03-3.78], P=0.04, respectively). Our findings suggest that among patients with stage III SCLC treated with chemoradiotherapy, there are no significant differences in outcomes based on the platinum drug used. Although there are no ongoing randomized studies directly comparing the platinum drugs, some allow carboplatin, and their results may further clarify its role in the management of limited-stage SCLC.

Abstract PS15-09: Adverse events in breast cancer patients treated with concurrent or sequential radiation therapy and CDK 4/6 inhibitors in metastatic setting

Abstract Background. Radiation therapy (RT) is important modality in MBC patients, however, there is paucity of data on safety and feasibility in combining radiation and a cyclin-dependent kinase 4 and 6 inhibitors (CDK 4/6i). No sufficient data were gathered in clinical trials and a few small retrospective series were published; it is important to extend these data. Theoretically, concerns pertain both the augmentation of effect (toxicity) or decrease of treatment effectiveness. Methods. 116 patients with MBC were treated in our center with CDK 4/6i (ribociclib n=59, palbociclib n=57) between 2018-2020. 26 patients were also treated with RT and were included into further analysis. 10 patients were treated with concurrent RT and 16 patients with sequential RT. Median age of patients was 55 years (range 23-78). 11 patients (42%) were diagnosed with de novo MBC, whereas 15 patients (57%) with recurrent breast cancer. 16 patients received prior chemotherapy, 6 of them less than 1 year before CDK 4/6i treatment. 73% of patients received CDK 4/6i in first line setting. Bones were the main metastatic site in the majority of patients, whereas visceral metastasis were diagnosed in 9 patients (35%). Overall 32 RT treatments in 26 patients were performed. Various RT regimens were used, including 8 Gy in 1 fraction (n=10), 20 Gy in 5 fractions (n=9), 30 Gy in 10 fractions (n=3). SBRT was performed in 5 patients and chest wall irradiation in 3 patients. The majority of patients received palliative radiotherapy to the bones, including 6 patients (23%) with RT to the pelvic area. Results. Nineteen patients (73%) experienced G2 and G3 neutropenia, with no G4 case. Neutropenia G≥2 occurred during first cycle of CDK 4/6i treatment in 50% of patients (n=8) after sequential RT and signicantly more often in patients after concurrent RT (all treated, n=10; p= 0.0095). No neutropenia was observed in 7 patients after sequential RT (27%). 4 patients (15%) had CDK 4/6i dose reduction, including 1 patient treated with concurrent RT and 3 patients treated with sequential RT. In all 4 patients the cause of dose reduction was prolonged G3 neutropenia. Patients were treated as follows: 60yo patient received RT 8 Gy in 1 fraction for bone metastases in lumbar and thoracic spine and ribs; 31yo patient received RT 20 Gy in 5 fractions for central nervous system, then 20 Gy in 5 fractions for bone metastases in thoracic, lumbar and sacral spine (all of these treatments were performed during 4 weeks before CDK 4/6i first dose). The following two patients received additionally doxorubicin-based chemotherapy shortly before CDK 4/6i treatment. At median follow up of 17 months (range 9-20 months) none of these patients discontinued treatment because of toxicity: one patient continue ribociclib at first dose reduction level, two patients continue ribociclib at second dose reduction level and one patient continued ribociclib treatment for 11 consecutive months and then CDK 4/6i treatment was ended because of disease progression. There was no difference in neutropenia rate in patients treated previously with chemotherapy (n=16) and chemo-naïve patients (n=10; p=0.6680). No cases of acute radiation-induced enterocolitis or enhanced dermatologic toxicity were found. No other serious adverse events were observed. Conclusions. We found that concurrent RT leads to more frequent neutropenia than sequential RT, although it did not change treatment course in the majority of patients and appeared well-tolerated. Potential risk factors for radiation-induced CDK4/6i dose reduction might be extensive radiation fields and previous chemotherapy in metastatic setting. Until now, combined RT is not a part of adjuvant CDK 4/6i clinical trials protocols. Excellent tolerance of this combination supports future consideration of this scenario in clinical trial setting. Citation Format: Marcin Kubeczko, Agnieszka Badora-Rybicka, Anna Polakiewicz-Gilowska, Aleksandra Leśniak, Katarzyna Świderska, Marta Mianowska-Malec, Barbara Grandys, Barbara Łanoszka, Magdalena Stankiewicz, Marzena Gawkowska, Elżbieta Nowicka, Grzegorz Woźniak, Dorota Gabryś, Rafał Tarnawski, Leszek Miszczyk, Michał Jarząb. Adverse events in breast cancer patients treated with concurrent or sequential radiation therapy and CDK 4/6 inhibitors in metastatic setting [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS15-09.

Assessment of Prognostic Factors and Adjuvant Treatment Modalities in Adult Head and Neck Soft Tissue Sarcoma Patients Treated With Upfront Surgery

ObjectivesHead and neck soft tissue sarcomas (HNSTSs) are a heterogeneous group of rare tumors. Surgical resection with negative margins remains the standard primary treatment for patients with HNSTS. The role of chemotherapy (CT) and radiotherapy (RT) remains controversial. In this multicenter study, we aimed to demonstrate the real-world assessing prognostic factors and the effect of adjuvant treatment modalities in adult patients with HNSTS treated with upfront surgery.MethodsWe included a total of 47 patients who underwent curative-intent resection of a primary HNSTS between 2000 and 2019.ResultsThe median follow-up was 29 months. The median age of patients was 51 years, and 66% of patients were male. The median relapse-free survival (RFS) of the study population was 31 months (range: 1.0-61.1 months), and the median overall survival (OS) was 115 months (range: 60.8-169.2 months). The univariable analysis revealed that treatment modalities showed a significant impact on RFS (p = 0.021); however, no difference was found in its impact on OS (p = 0.137). R0 resection did not showed impact on RFS (p = 0.130), but a significant association was found with OS (p = 0.004). In multivariable analysis, T stage of the tumor (hazard ratio [HR]: 3.834; 95% CI: 1.631-9.008; p = 0.002) and treatment with surgery and sequential RT and CT (HR: 0.115; 95% CI: 0.035-0.371; p < 0.001) were independent factors associated with RFS. R0 resection was independently associated with OS (HR: 4.902; 95% CI: 1.301-18.465; p = 0.019).ConclusionOur study revealed that R0 resection improved OS, and T3-4 stage of tumor was a negative independent factor for RFS in surgically resected HNSTS patients. The use of sequential CT and RT after resection was associated with a better RFS, which emphasizes the importance of multidisciplinary evaluation of the treatment of HNSTS. Randomized prospective studies are needed

The Case Report of Malignant Pericardial Effusion in Recurrent Endometrial Cancer: An Emergency Treatable Condition

Malignant-related pericardial effusion from endometrial cancer is a considerably rare condition. Massive fluid accumulation can cause a cardiac tamponade, which could lead to a life threatening condition. Here, the author presented a case of 45-year-old woman diagnosed of stage IIIC2 endometrial cancer, with para-aortic lymph nodes metastases. Fourteen months after completion of systemic chemotherapy and adjuvant sequential radiotherapy, she had been suffering from acute shortness of breath, tachypnea, tachycardia, and hemodynamic instability. Massive pericardial effusion was confirmed by echocardiogram. Malignant tumor cells were found on the cytological analysis. Beside pericardial effusion, computed tomography scan also demonstrated pleural effusion and multiple enlarged para-aortic lymph nodes. Pericardial window was done on the second day of admission after the diagnosis was confirmed by pericardiocentesis. Six courses of systemic chemotherapy, carboplatin and paclitaxel, were administered, followed by hormonal therapy. The patient was scheduled for follow up, every month, for 10 consecutive times. Her physical performance was in good condition without any clinical potential recurrence. Pericardial window is a palliative surgical treatment in emergency circumstance and systemic chemotherapy should be considered with clinical response result. Keywords: Malignant pericardial effusion, Endometrial cancer, Treatment

Phase II Trial Investigating Definitive Radiation Therapy in Lieu of Systemic Therapy for Oligometastatic Renal Cell Carcinoma

Background: The role of definitive radiation therapy (RT) in metastatic renal cell carcinoma (RCC) is controversial. We prospectively tested the feasibility, efficacy, and safety of definitive RT to defer systemic therapy for patients with oligometastatic RCC. Methods: This single-arm phase 2 study (NCT03575611) enrolled patients with histologically confirmed RCC, ≤5 metastatic lesions, and ≤1 prior systemic therapy. Patients were treated with definitive RT to all lesions and maintained off systemic therapy. Additional rounds of RT were allowed to treat new sites of progression. The co-primary endpoints were progression-free survival (PFS) and feasibility. Criteria for initiating systemic therapy were progression in >3 lesions, toxicity, local progression, or patient/provider preference. Findings: Thirty patients were enrolled in July 2018–September 2020 (median follow-up time 17.5 months). All patients had clear cell histology and had undergone nephrectomy before enrollment. Nine patients (30%) had received one prior systemic therapy. All patients completed initial RT and 13 (43%) received a second round. Median PFS was 22·7 months (1-year PFS rate 64%). All patients were alive at last follow-up, and one local failure was observed. The 1-year systemic therapy–free survival was 82%, with 7 patients (23%) initiating systemic therapy at a median 8.1 months from enrollment. Adverse events were grade ≥2 in six patients and ≥3 in three patients. At first follow-up, no viable tumor cells were detected in 5 of 14 biopsy samples obtained after RT (36%). For patients in whom viable tumor was present, the Ki-67 labeling index was significantly reduced (P =0·0068). Interpretation: Sequential definitive RT is a feasible and effective strategy for patients with oligometastatic RCC seeking to defer systemic therapy. Clinical Trial Registration: This study is registered with ClinicalTrials.gov as NCT03575611. Funding: Grant support from the Anna Fuller Foundation, the Cancer Prevention and Research Institute of Texas (CPRIT), and the National Cancer Center, National Institutes of Health (P30 CA016672, PI P. Pisters). Declaration of Interest: PM has received honoraria for service on scientific advisory boards for Mirati Therapeutics, Bristol- Myers Squibb, and Exelixis; consulting for Axiom Healthcare Strategies; non-branded educational programs supported by Exelixis and Pfizer; and research funding for clinical trials from Takeda, Bristol- Myers Squibb, Mirati Therapeutics, Gateway for Cancer Research, and UT MD Anderson Cancer Center. INCOMPLETE Ethical Approval: This protocol underwent full approval by the Institutional Review Board at MD Anderson. All patients provided written informed consent to participate.

Oxidation-reduction potential of tissues of the oral mucosal wound surface under the photodynamic action

On the mucous membrane of the cheeks of sexually mature female autocrats of Wistar rats (n=72) experimental models of wound surfaces with a diameter of 3 mm were formed. The animals were divided into groups: control (n=36) and experimental (n=36). In the experimental group, a single photodynamic exposure was carried out for the 1st postoperative day with a sequential combined light radiation at two wavelengths (660 nm and 405 nm) with a total dose of 15 J/cm2. Wound management was carried out traditionally in the control group of animals. The observation periods were 3, 7 and 14 days. Macroscopic examination of the wound surface indicated complete epithelialization of the wound on the 7th day in the experimental group of animals and on the 14th day in the control group. Significant and sharp decline in free-radical oxidation processes (Imax, S, Z index) intensity was recorded in the experimental animals at earlier periods in comparison with the initial data and control results, when analyzing the results of studies of homogenates of animal tissues. A similar pattern was observed in the evaluation of lipid peroxidation products, especially in the early days of observations. The reported results were supported by the activation of antioxidant enzymes in the experimental group compared to control data and baseline data. Thus, a combined photodynamic action using two wavelengths with a combined dose of 15 J/cm2 provides safety and low invasiveness for use on the oral mucous membrane and, may be used to stimulate regeneration of the wound surface, which requires further experimental testing.

Radiation to the Primary Tumor in Metastatic Anaplastic Thyroid Cancer.

Metastatic anaplastic thyroid cancer is associated with a dismal prognosis. We evaluated outcome and prognostic factors in patients receiving radiation to the primary tumor in metastatic anaplastic thyroid cancer (ATC). All consecutive patients with metastatic ATC (n=20) undergoing irradiation between 2009 and 2019 for anaplastic thyroid cancer were investigated. Median survival time and median progression-free survival were 2 (range=1-22) and 2 (1-20) months. In univariate analyses, surgery, concurrent or sequential chemotherapy and higher radiation dose escalation (>39 Gy) were correlated with longer overall survival (p=0.005, p=0.018 and p=0.038), respectively. Karnofsky performance status >70% showed a trend of longer survival time (p=0.062). Limited metastatic disease, surgery and concurrent/sequential chemotherapy are correlated with longer progression-free survival times (p=0.043, p=0.024 and p=0.039), respectively. Radiation to the primary tumor in metastatic anaplastic thyroid cancer is safe and offers durable local control. Treatment intensification including concurrent or sequential chemotherapy and radiation dose escalation were associated with longer survival rates and should be considered in selected patients with metastatic disease.

Clinical Study of 2 Radiotherapy Techniques for Semi-Hepatic Alternating Radiotherapy on Diffuse Liver Metastasis in Patients with Breast Cancer.

Objective: To compare the effects of 2 techniques of semi-hepatic alternating radiotherapy on diffuse hepatic metastasis in patients with breast cancer. Methodology: A total of 68 breast cancer patients with diffuse liver metastasis were randomly divided into Group A (semi-hepatic alternating radiotherapy) and Group B (semi-hepatic sequential radiotherapy). In Group A (semi-hepatic sequential radiotherapy), the liver was divided into the first semi-liver and second semi-liver and alternatively treated with semi-hepatic intensity-modulated radiation therapy (IMRT). The interval between the 2 instances of semi-hepatic radiotherapy was 6 h. The average radiotherapy dose to the semi-livers was both 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The total radiation therapy time in Group A was 15 days in Group B (semi-hepatic sequential radiotherapy), the livers were divided into the first semi-liver and second semi-liver and treated with semi-hepatic sequential IMRT, The first semi-liver was first treated in the initial stage of radiation therapy, the average radiotherapy dose to the semi-liver was 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The second semi-liver was treated next in the second stage of radiation therapy, the average radiotherapy dose to the semi-liver was 2 Gy/fraction, once a day, 5 times per week, with a total dose of 30 Gy for 15 days. The total radiation therapy time in group B was 30 days. Results: The objective response rate (complete response + partial response) of Group A and Group B were 50.0% and 48.5%, respectively (p = .903). The median survival time after metastasis (median survival of recurrence) of Group A and Group B was 16.7 months and 16.2 months, respectively (p = .411). The cumulative survival rates of 6 months, 1 year, 2 years, and 3 years of Group A and Group B were 90.6% (29 of 32) and 84.8% (28 of 33) (p = .478), 65.6% (21 of 32) and 60.6% (20 of 33) (p = .675), 31.2% (10 of 32) and 27.3% (9 of 33) (p = .725), and 15.6% (5 of 32) and 0 (0 of 33) (p = .018), respectively. The differences between the 2 groups showed no statistical significance in terms of cumulative survival rates in 1 year, 2 years, however, the 3-year survival rate was significantly different. The main toxic reactions were digestive tract reactions, abnormal liver functions, and myelosuppression. The incidence of I to II degree gastrointestinal reactions was 78.13% (25 of 32) in Group A and 72.73% (24 of 33) in Group B (p = .614). The incidence of I to II abnormal liver function was 53.13% (17 of 32) in Group A and 48.48% (16 of 33) in Group B (p = .708). The differences between the 2 groups showed no statistical significance. The incidence of I to II myelosuppression was 59.38% (19 of 32) in Group A and 51.52% (17 of 33) in Group B (p = .524), respectively. The differences between the 2 groups showed no statistical significance in terms of adverse effects. Conclusion: Semi-hepatic alternating IMRT was an effective palliative treatment for diffuse liver metastasis in patients with breast cancer. Semi-hepatic alternating radiotherapy showed a trend of prolonged survival time when compared with semi-hepatic sequential radiotherapy. Compared with the former, the latter showed a trend of lower incidences of side effects without any statistical differences. Moreover, the side effects from the 2 radiotherapy techniques can be controlled through appropriate management, which is worthy of further exploration and applications.

Association Between Preoperative Patient-Reported Symptoms and Postoperative Outcomes in Rectal Cancer Patients: A Retrospective Cohort Study

BackgroundRectal cancer patients undergoing preoperative radiotherapy experience a significant symptom burden. However, it is unknown whether symptoms during radiotherapy may portend adverse postoperative outcomes and healthcare utilization. MethodsA retrospective cohort study was performed of rectal cancer patients undergoing neoadjuvant radiotherapy and proctectomy in Ontario from 2007 to 2014. The primary outcome was a complicated postoperative course–a dichotomous variable created as a composite of postoperative mortality, major morbidity, or hospital readmission. Patient-reported Edmonton Symptom Assessment System (ESAS) scores, collected routinely at outpatient provincial cancer center visits, were linked to administrative healthcare databases. The receiver-operating characteristic analysis was used to compare ESAS scoring approaches and to stratify patients into low versus high symptom score groups. Multivariable regression models were constructed to evaluate associations between preoperative symptom scores and postoperative outcomes. Results1455 rectal cancer patients underwent sequential radiotherapy and proctectomy during the study period and recorded symptom assessments. Patients with high preoperative symptom scores were significantly more likely to experience a complicated postoperative course (OR 1.55, 95% CI 1.23-1.95). High preoperative ESAS scores were also associated with the secondary outcomes of emergency department visits (OR 1.34, 95% CI 1.08-1.66) and longer length of stay (IRR 1.23, 95% CI 1.04-1.45). ConclusionsRectal cancer patients reporting elevated symptom scores during neoadjuvant radiotherapy have increased odds of experiencing a complicated postoperative course. Preoperative patient-reported outcome screening may be a useful tool to identify at-risk patients and to efficiently direct perioperative supportive care.

Omental Metastasis from ALK-positive Lung Cancer \u2014 A Case Report

BackgroundNon-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide. In Ireland alone, there are over 2500 new cases of lung cancer diagnosed each year. It ranks fourth among the most common cancers and causes 21% of all cancer-related deaths.Lung cancers usually metastasize to the liver, brain, bone, and adrenal glands—rarely affecting the abdomen. To our knowledge, there are 8 previous studies in the literature to date which involve omental metastasis from NSCLC.Case presentationA 73-year-old lady presented with a history of productive cough for 18 months. A chest X-ray showed a suspicious 6 cm mass in the right lower zone. She went on to have an endobronchial biopsy which confirmed a moderately differentiated adenocarcinoma of the lung which was ALK positive. She went on to have staging PET and CT scans and was staged as cT3N2M0. She was not a suitable candidate for surgery so she had radical chemo-radiotherapy with 4 cycles of cisplatin pemetrexed followed by radical dose sequential radiotherapy. Post treatment CT showed the tumor to be more spiculated in appearance. She was ineligible for Durvalumab maintenance therapy due to the extensive pneumonitis following her radiotherapy which required a prolonged course of steroids. Interval scans every 3 months did not show any progression of disease.She presented to the hospital 13 months post her diagnosis with progressive abdominal swelling. Restaging CT scans showed extensive omental infiltration, the presence of multiple peritoneal nodules, and progression of her pulmonary disease with new brain metastasis. Cytological analysis of the ascitic fluid confirmed metastasis followed by omental biopsy which confirmed metastatic ALK-positive NSCLC. She went on to have targeted treatment with alectinib. She tolerated the treatment well. Restaging scans done 3 months later showed good partial response to therapy.ConclusionIn conclusion, ALK-positive NSCLC with metastasis to the omentum is very rare. However, in patients with atypical symptoms like ascites, the possibility of a metastasis must be considered and repeat biopsy is always recommended. A targeted therapy in the selected patients has shown a more durable response than chemotherapy.