Combination Of Radiotherapy Research Articles

Efficacy and safety of SBRT combined with sintilimab and IBI305 in patients with advanced HCC and previously failed immunotherapy: study protocol of a phase 2 clinical trial

IntroductionHepatocellular carcinoma (HCC) is a leading cause of cancer-related death in China. The combination of immune checkpoint inhibitors (ICIs) and antiangiogenic drugs, such as bevacizumab and tyrosine kinase inhibitors, has...

Alleviating lung injury and pulmonary fibrosis in radiotherapy-immunotherapy combination: The role of low-dose radiation therapy.

e14632 Background: Lung cancer continues to be the primary cause of cancer-related mortality on a global scale. The integration of radiotherapy and immunotherapy has yielded significant advancements in the treatment of locally advanced non-small cell lung cancer. However, the occurrence of treatment-associated pneumonia remains the predominant adverse event necessitating treatment cessation and permanent medication discontinuation. The immune-modulating effects of radiation therapy on the body contribute to a complex interplay between radiation and inflammation. Low-dose radiotherapy (LD-RT) has historically been utilized for the management of benign inflammatory conditions. Recently, LD-RT was found to be effective in treating severe pneumonia in patients with severe COVID-19 as well as acute respiratory distress syndrome (ARDS). This investigation seeks to examine the impact of LD-RT on lung tissue morphology and the inflammatory immune microenvironment in preclinical models of lung injury induced by high-dose radiotherapy combined with programmed death-1(PD-1) inhibitor therapy. Methods: 6-8 week old C57BL/6 mice were treated with a single high-dose thoracic radiotherapy (15Gy) and the PD-1 inhibitor (once a week), with or without the low-dose radiotherapy (1.0/1.5Gy) four weeks later. Lung tissue was collected one and a half months and three months respectively after the initial high-dose radiotherapy for evaluation using HE and Masson staining, Image J software for analysis of collagen volume fraction (CVF), and immunohistochemical staining for CD3+ and CD8+ T lymphocytes. Cytokine transforming growth factor (TGF)-β1、interleukin (IL)-6 and tumor necrosis factor (TNF)-α level in lung tissue was detected by ELISA. Statistical analysis was performed using GraphPad Prism 9.5.0 software. Results: The radiotherapy-immunotherapy combination (iRT) group exhibits notable lung injury characterized by the proliferation of alveolar type II epithelial cells, thickening of alveolar septa, interstitial edema, pulmonary congestion and bleeding, increased infiltration of inflammatory cells, and significant deposition of interstitial collagen fibers. In contrast, the iRT+ LD-RT group demonstrates a significant decrease in lung tissue damage, interstitial fibrosis, collagen volume fraction (CVF), levels of IL-6 and TGF-β, as well as the infiltration of CD3+ and CD8+T cells compared to the iRT group. Conclusions: Low-dose radiation has the potential to ameliorate lung injury induced by the combination of radiotherapy and PD-1 inhibitors by modulating the inflammatory milieu, thereby potentially mitigating the development of pulmonary fibrosis.

Comparing toripalimab combined with chemoradiotherapy versus chemoradiotherapy alone for locally advanced esophageal squamous cell carcinoma: A multicenter, open-label, randomized phase II clinical trial.

4079 Background: Esophageal squamous cell carcinoma (ESCC) is the predominant histological subtype in Asia, representing approximately 90% of all esophageal cancer cases. Despite definitive chemoradiotherapy (CRT) being the standard treatment for unresectable locally advanced ESCC, the prognosis remains poor. The introduction of PD-1 inhibitors has shown significant improvement in survival outcomes for advanced ESCC. This study aims to evaluate the efficacy and safety of combining induction and consolidation toripalimab (a PD-1 inhibitor) with CRT in patients with locally advanced ESCC (Clinical trial information: NCT04084158). Methods: Patients aged 18-75 years with unresectable, locally advanced ESCC and an ECOG performance status of 0-1 were eligible. Participants were randomly assigned (1:1) to either two cycles of toripalimab (3mg/kg q2ws) followed by concurrent CRT with 50.4Gy+weekly paclitaxel and carboplatin (TC), TC consolidation, and toripalimab (study arm), or standard CRT alone (control arm). The primary endpoint was progression-free survival (PFS), with secondary endpoints including overall survival (OS) and objective response rate (ORR). Results: Between September 2019 and July 2020, 46 ESCC patients (40 males) were screened for eligibility across four participating centers in China. Forty-four patients were eligible for survival analysis, all with histopathologically confirmed ESCC. Median ages were 64 years (range 49-75) in the study arm and 61 years (range 47-74) in the control arm, with similar clinical AJCC stages. As of the February 1, 2024 cutoff, the median follow-up was 50.6 months. Median PFS was 10.0 months in the study arm and 17.8 months in the control arm (HR: 1.567, 95% CI: 0.755-3.251, p=0.228). Median OS was 23.7 months and 25.9 months, respectively (HR: 1.140, 95% CI: 0.536-2.427, p=0.733). ORR rates were 64% and 86% (p=0.164), respectively. The incidence of grade 3 or worse treatment-related adverse events was similar between groups, with the most common adverse event being lymphopenia. Conclusions: Our findings indicate no significant benefit in adding induction and consolidation immunotherapy to CRT for treating locally advanced ESCC. However, the combination of radiotherapy and immunotherapy warrants further exploration. Ongoing analyses of biomarker correlates of response and survival will provide additional insights. Clinical trial information: NCT04084158 .

The effectiveness of adjuvant therapy in adult patients with spindle cell/sclerosing rhabdomyosarcoma: A single-center retrospective study.

e23550 Background: In recent years, the WHO classification of soft tissue tumours has classified spindle cell/sclerosing rhabdomyosarcoma (RMS) as a novel subtype of RMS. However, the prognosis and standard treatment modalities for operable spindle cell/sclerosing RMS patients remain unclear. This study aims to investigate the effectiveness and influencing factors of postoperative adjuvant therapy in adult patients with spindle cell/sclerosing RMS. Materials and Methods: This single-center retrospective study enrolled adult patients with spindle cell/sclerosing RMS who underwent surgery and subsequent adjuvant therapy at West China Hospital, Sichuan University, from August 2014 to March 2023. The included patients initially underwent surgical excision, followed by one of the adjuvant treatments: radiotherapy, chemotherapy, or a combination of radiotherapy and chemotherapy. Disease-Free Survival (DFS) and Overall Survival (OS) were calculated for the included patients in this study. Univariate analysis and multivariate COX regression were conducted to determine prognostic factors. Results: This study included a total of 17 patients diagnosed with spindle cell/sclerosing RMS. Among them, 10 (58.8%) patients received postoperative adjuvant chemoradiotherapy, while 7 (41.2%) patients underwent postoperative chemotherapy alone. 12 (70.6%) patients received chemotherapy following the VAC regimen, and 5 (29.4%) patients received non-VAC chemotherapy. The prognosis analysis indicates that the median DFS was not reached, with a 1-year DFS rate of approximately 87.8% and a 2-year DFS rate of approximately 52.4%. The median OS was not reached, with a 1-year OS rate of 100% and a 2-year OS rate of approximately 92.9%. Univariate analysis shows that compared to undergoing non-R0 resection, undergoing R0 surgical resection significantly improves patient DFS (P = 0.02). Compared to no postoperative radiotherapy, receiving postoperative prophylactic radiotherapy significantly improved both DFS (P = 0.01) and OS (P = 0.02). In contrast, using VAC as adjuvant chemotherapy did not significantly increase DFS and OS compared to non-VAC regimens (P = 0.83 and 0.57, respectively). Multivariate Cox regression analysis demonstrated that the receipt of postoperative prophylactic radiotherapy independently predicted DFS (P = 0.03). Conclusions: In adult patients with spindle cell/sclerosing RMS, R0 resection, when compared with non-R0 resection, delays disease recurrence but does not enhance overall survival. Long-term outcomes may be improved in patients who receive postoperative adjuvant radiotherapy. However, choosing a VAC regimen as adjuvant chemotherapy may not contribute to an improved long-term prognosis when compared with a non-VAC regimen. Keywords: adjuvant therapy, spindle cell, sclerosing, rhabdomyosarcoma, effectiveness

Rethinking rectal cancer management through COVID: Real word evidence in a public hospital in the south of Brazil.

e15620 Background: Treatment of locally advanced rectal cancer is based on a combination of radiotherapy and chemotherapy, either as adjuvant, neoadjuvant or total strategies. Short course radiotherapy followed by neoadjuvant chemotherapy, as described in the RAPIDO trial, was chosen by our Oncology, Radiotherapy and Coloproctological tumor board at Hospital de Clínicas de Porto Alegre during the COVID19 pandemic as a measure to reduce hospital visits and thus the possibility of transmission and infection by the SARS-COV-2 virus. Methods: We performed an observational analysis, including all patients treated with short course radiotherapy for locally advanced rectal cancer, at the Hospital de Clínicas de Porto Alegre in the period between January 2020 and March 2023. Metastatic patients were included, either treated with curative or palliative intent. Demographic characteristics, clinical staging, timing of chemotherapy, radiotherapy and surgery were analyzed. Clinical response was evaluated through sigmoidoscopy and clinical rectal exam. Patients with complete clinical response were offered the watch and wait strategy or surgery, after careful discussion of the possible benefits and risks. Results: Ninety-six patients were submitted to short course radiotherapy in the period described. Seven (7) patients were excluded; 89 patients were included in the final analysis. Fifty-five percent were male; mean age was 62 ±12.5 years; 52.8% were ECOG 1 at the diagnosis. Median CEA value at diagnosis was 7 ng/mL (CI 95%:4.4 - 9.8). Sixty-four percent were stage III, 31.4% stage IV, 3.3% stage II. Ninety-eight percent completed the programmed radiotherapy treatment. Only two patients received less than 25Gy. Forty-nine percent of patients completed the whole planned chemotherapy treatment; 15.7% were treated with palliative intent chemotherapy and 5.6% couldn’t receive chemotherapy for other reasons. Clinical response data were available in 62 patients: the main reason for unavailable clinical response was metastatic disease. Disease control was achieved in 98.4% of the cases, with only 1 patient having progressive disease during treatment (1.6%). The overall clinical response rate was 72.6%, 25.8% had stable disease and 24.2% complete clinical response. Fifteen of the 16 patients that presented with complete clinical response opted into a watch and wait strategy, achieving a 1-year disease free survival of 86.6%. Conclusions: Adopting the RAPIDO approach had a positive outcome in our advanced rectal cancer population. Short course radiotherapy followed by chemotherapy achieved excellent rates of disease control. Almost 25% of the non-metastatic patients undergoing RAPIDO treatment achieved complete clinical response opting into a watch and wait program.

Impact of comorbidity on outcome and treatment choice in patients with head and neck squamous cell carcinoma (HNSCC).

e18033 Background: Most patients (pts) with HNSCC are elderly and suffer from other diseases that, similarly to cancer, are related to smoking and alcohol habit. Therefore, these pts often may present at diagnosis with both comorbidities and other primary tumour with which they share the same risk factors. Several studies have shown that in cancer pts, the presence of comorbidities is a strong negative prognostic factor that can predict worse survival and a factor involved in changing cancer treatment choices. The Charlson Comorbidity Index (CCI) is a known tool for assessing the comorbidity burden of pts, with broad and validated prognostic value in the HNSCC population. Methods: The aim of this study is to retrospectively analyze, in a single cohort of HNSCC pts, the role of comorbidity burden on treatment choice and pts outcome.Data from the medical records of pts treated at Spaziani Hospital, FR, Italy from May 2019 to Jan 2023 for an HNSCC were collected. All pts had received a variable combination of surgery, chemo and radiotherapy for their tumor. All pts were staged according to CCI and divided into four groups of comorbidity burden. Data on treatment choice (trimodal (variable combination of surgery+chemotherapy+radiotherapy) vs non-trimodal) were also recorded for stage III-IVA pts. Results: 54 consecutive pts were enrolled. The disease sites included the oral cavity (14 pts), oropharynx (18 pts), larynx (9 pts), nasal cavity/paranasal sinuses (6 pts), occult primary (4 pts) and hypopharynx (4 pts).Of the 54 pts the 22.2% and 77.8% were female and male, respectively. Most pts (39 pts, 72.2%) had stage III-IVA disease. 35 and 40 pts, respectively received a surgical and nonsurgical primary therapy. 13 pts received a trimodal approach. The median observed PFS was 22.4 months (95% CI: 12.6-32.2). No significant differences in DFS were observed according to age (<65 vs ≥ 65 years, p 0.99), sex (p 0.45), comorbidity burden (CCI 0, CCI 1-2, CCI 3-4, CCI≥5; p 0.99), RT (yes vs no, p 0.90), CT-RT (yes vs no, p 0.62), smoking (p0.91). In our cohort, only an ECOG Performance Status 0 (0 vs ≥1; p 0.028) and HPV status (pos vs neg; p 0.002) were correlated with a better DFS. A high comorbidity burden (CCI score) was present in >85% of pts. In general, those who undergo trimodal treatment among stage III-IV pts are those with PS 0 vs ≥ 1 (40% vs 23.5%), with age < 65 vs ≥65 years (40.0% vs 26.3%), with a CCI ≤1 vs CCI >1 (47.6% vs 16.7%), absence vs presence of CV morbidity (40.6% vs 0%), female vs male (50% vs 27.6%), in the HPV+ vs HPV- (100% vs 25%). Among these, the presence of CV comorbidities (p 0.039), CCI (p 0.041) and HPV (p 0.018) are statistically significant. Conclusions: Our analysis suggests that in pts with Stage III-IVA, the presence of a higher comorbidity burden and CV morbidity are capable of influencing the choice of a trimodal treatment. A broader test is necessary due to the small sample size considered.

ViTR-SP: A CT-based vision transformer model for prediction of pneumonitis in patients with non-small cell lung cancer who received thoracic radiotherapy and immunotherapy.

e20034 Background: The combination of thoracic radiotherapy (TRT) and immunotherapy accompanied by the accumulation of pulmonary toxicity. This study aimed to construct a deep radiomics model based on sequential computed tomography (CT) images for radioimmune-associated pneumonitis prediction in non-small cell lung cancer (NSCLC) patients treated with TRT and immune checkpoint inhibitors (ICIs). Methods: Three models were constructed based on a vision transformer (ViT) network using sequential chest CT images, tumor-mask and lung-mask as inputs, respectively. NSCLC patients treated with TRT and ICIs at Shandong Cancer Hospital and Qilu Hospital were included for model training and external validation, respectively. The image-level model was trained based on ViT to identify predictive images, and the image-level probability distribution were performed. Then, a ViT-Recursive Neural Network (ViT-RNN) model framework was constructed at the patient-level to integrate the image-level information to derive the final prediction, which was evaluated in an independent validation cohort. Results: A total of 230 NSCLC patients from Shandong Cancer Hospital were randomly assigned in a 7:3 ratio for model training and validation, respectively. Another 42 patients from Qilu Hospital were used as an independent external validation cohort. The ViT-RNN model for symptomatic pneumonitis (ViTR-SP) based on sequential CT images achieved better area under curve (AUC), sensitivity, and specificity of 0.725, 0.750, and 0.886 than lung-mask based model (0.575, 0.625, and 0.705) and tumor-mask based model (0.658, 0.667, and 0.773) in the internal validation set. In the external validation set, the proposed model achieved the AUC, sensitivity, and specificity of 0.654, 0.818, 0.727, while the lung-mask and tumor-mask based models had the AUC, sensitivity, and specificity of 0.540, 0.545, 0.677, and 0.630, 0.545, 0.742, respectively. The performance of the model was improved after integrating clinical features, with internal and external validation AUC of 0.782 and 0.672, respectively. Conclusions: In conclusion, the clinical combined ViTR-SP neural network risk prediction model based on sequential chest CT images can be used for predicting the risk of developing radioimmune-associated pneumonitis in NSCLC patients.

Radiotherapy improved the efficacy of immunotherapy for advanced esophageal cancer.

e16063 Background: The development of immunotherapy has changed treatment methods for advanced esophageal cancer (EC).However, the efficacy of ICIs in advanced EC is not ideal, and the clinical research on the combination of ICIs and Radiotherapy(RT) in advanced EC remains insufficient. This study aimed to evaluate the effectiveness and safety of radiation in first-line immunotherapy for advanced EC. Methods: We conducted 201 advanced EC patients who received first-line ICIs in West China Hospital. The enrolled patients were divided into 2 groups based on whether they received radiation therapy. Results: The analysis included data from 201 patients. The radiotherapy (RT) group had 103 patients (51.2%), whereas the non-radiotherapy (NRT) group included 98 individuals (48.8%). The RT sites include esophagus lesions (83, 80.6%), metastatic lymph nodes (11, 10.7%), liver metastases (4, 3.9%), bone metastases (2, 1.9%), brain metastases (2, 1.9%), lung metastases(1, 0.97%). The median radiation dose was 50.4 Gy (range, 12-68). The RT group had a median OS of 22.8 months (95% CI, 17.8-NA), which was longer than the NRT group's 14.6 months (95% CI, 12.8-26.5) (p = 0.038). And the median PFS was 12.9 months (95% CI, 11.2-14.0) in the RT group versus 7.3 months (95% CI, 6.3-9.7) in the NRT group (p = 0.006). Patients in the RT group had a higher disease control rate (DCR) (99.0% vs. 76.5%, P < 0.001). However, a higher proportion of patients in the RT group developed grade 3-4 myelosuppression (37.86% V.S. 20.20%, P = 0.006), and there was no significant difference in the other AEs. Conclusions: In the first-line immunotherapy for advanced esophageal cancer, radiotherapy has been attributed to improved survival with tolerable toxicity.

Pediatric and Adolescent Hodgkin Lymphoma: Paving the Way for Standards of Care and Shared Decision Making.

Hodgkin lymphoma (HL) is a treatable cancer with an incidence peak in adolescent and young adult years. Treatment strategies have been developed to balance the intensity of therapy needed to maintain disease-free survival while simultaneously preserving overall survival. Risk-based, response-adapted frontline therapy has long used a combination of chemotherapy and radiotherapy (RT). Successive clinical trials over the past three decades have safely reduced cumulative alkylator, anthracycline, and RT exposures for many patients. The advent of checkpoint inhibitors and the CD30-targeted antibody drug conjugate, brentuximab vedotin, has provided new options for de-escalation of conventional therapies associated with late effects in survivors treated at a young age. The ability to evaluate novel agents has been accelerated in collaborative trials inclusive of children and adolescents within the US National Clinical Trials Network and between the Children's Oncology Group and the EuroNet Pediatric Hodgkin Lymphoma Consortium. With numerous treatment options, patients with HL and their clinicians have an opportunity for shared decision making from diagnosis, through cancer treatment, and into survivorship. Given excellent survival outcomes, decisions about treatment in classic HL should be collaborative and attention to long-term survivorship needs should remain a high priority. Patient-reported outcomes remain an important tool to aid clinicians working with survivors to optimize health status and related quality of life for decades after HL therapy.

The evolution of cardiac function in patients with non-Hodgkin’s lymphoma under chemotherapy

In clinical practice, the treatment of non-Hodgkin’s lymphoma (NHL) often involves the combination of several chemotherapy agents, radiotherapy and immunotherapy. While these multimodal approaches improve the efficacy of pathology-specific treatment, they also increase the risk of cardiovascular complications, the most common of which is ventricular dysfunction induced by anti-tumor therapy. Aim of the study: Evaluation of the impact of anti-tumor treatment of NHL on the trajectory of left and right ventricular echocardiographic function. Materials and methods: 127 randomly selected patients from the hematology departments of the PSMI Institute of Oncology were included in the study. Patients were investigated during 3 visits by comprehensive echocardiography, the first visit was up to the onset of anti-tumoral treatment, the 2nd visit was 1 month after initiation and the 3rd visit at 6 months after the debut of chemotherapy. Results: During the anti-tumor treatment, a statistically significant decrease in left ventricular systolic indicators was attested by following parameters: left ventricular ejection fraction (LV EF), mean left ventricular S’, the ratio between the maximum velocity of the E wave and the flow propagation velocity (E/Vp), with an ANOVA p-value <0.001. Regarding the right ventricular systolic function, the indices reflected by TAPSE and S’ right ventricular free wall were reduced statistically significantly also (p ANOVA <0.001). The given analysis confirmed the impairment of ventricular relaxation throughout the treatment, the increase in left ventricular filling pressures, the ratio E/A and E/e’ showed a statisticallysignificant increase, parameters such as the deceleration time of the E wave, the relaxation isovolumetric time, the ratio e’/a’ did not register a statistically significant dynamic (p ANOVA = 0,897; 0,705 and 0,145 respectively). 6 months after the start of treatment, cardiac dysfunction associated with cancer therapy (CTRCD) was found in 18 patients (14,2%), 8 (6,3%) presented a moderate asymptomatic form, 7 (5,7%) had a mild asymptomatic form and 3 (2,4%) a symptomatic one.Conclusion: The left ventricular systolic function was statistically significantly reduced under the impact of the applied treatment, which was confirmed by the LV EF, the mean S’ value at the LV and the E/Vp ratio, the diastolic function having an impact through the E/A and E/e’ ratio. Regarding the function of the right ventricle, we attested statistically significant changes only in the longitudinal contraction parameters. CTRCD was confirmed in 18 patients.

Endoscopic surgery combined chemoradiotherapy and PD-1 blockade in patients with sinonasal mucosal melanoma.

e21552 Background: Primary sinonasal mucosal melanoma (SNMM) is a rare and aggressive disease different from cutaneous melanoma. The best treatment modality including the role of immune checkpoint blockade in SNMM has not been defined. Methods: Between 2021 and 2023, patients with previously untreated sinonasal melanoma were enrolled by three single-center investigator-initiated phase II clinical trials (ChiCTR2100046498 / ChiCTR2100045797/ ChiCTR2100049031). Eligible patients in ChiCTR2100045797 trial received postoperative radical chemoradiotherapy combined with toripalimab (a PD-1 inhibitor) for a year or until the disease progressed. Eligible participants in ChiCTR2100046498 study received surgery combined with radiation without immunotherapy. And for patients in ChiCTR2100049031 study, preoperative radiation was carried out firstly. The locoregional control, distant metastasis-free survival (DMFS), and overall survival (OS) were the main efficacy goals. Results: Fifty-four patients were enrolled (mean age 62 years, 33 males [61.1%] and 21 women [38.9%]) with 2y-OS rate 62.3±7.9%, 2y-RFS rate 67.1±8.2%, and 2y-DMFS rate 63.9±8.1%. Patients with T3 (n = 23), T4a (n = 14), and T4b (n = 17) stages, including12 patients with node-positive disease, were included at baseline. During a median follow-up of 11 months, 19 patients ultimately died, 10 experienced relapses, and 17 developed metastases. Tumor T staging was demonstrated to be an independent prognostic predictor according to the Cox univariate analysis. The primary factor contributing to a poor prognosis and the primary cause of death for 73.7% of patients was distant metastases. Preoperative radiation had an improved long-term survival with 2y-OS rate of 85.7±13.2%, and it can considerably lower the risk of distant metastases (p≤0.05). The overall survival rate for patients receiving postoperative chemoradiotherapy combined with immunotherapy was higher than that for patients not receiving immunotherapy (2y-OS rate 74.1±11.4% vs. 39.3±15.8%), although the difference was not statistically significant due to a small number of patients (p = 0.16). No immune-related adverse effects grade≥3 was recorded. Conclusions: The primary cause of the poor prognostic performance of SNMM is distant metastasis. The risk of distant metastases might be considerably decreased by preoperative radiation treatment. Surgery combined with radiation and immunotherapy could bring promising survival benefit. The way forward may involve investigating the combination of immunotherapy and preoperative radiotherapy. Clinical trial information: NCT04879654 ; NCT05009446 .

Quality indicators in the care of patients with rectal cancer in social security in Guatemala: Results of a retrospective population study.

e15518 Introduction: Rectal cancer is a serious condition affecting a significant number of patients worldwide. However, in the Guatemalan population, the epidemiology and clinical characteristics of this disease have not been widely studied. This study aims to address this knowledge gap by retrospectively analyzing patients with rectal cancer treated at the Guatemalan Social Security Institute between 2013 and 2018. Methods: A retrospective analysis of eighty-eight patients with rectal cancer treated at the Guatemalan Social Security Institute during the mentioned period was conducted. Descriptive statistical techniques, such as chi-square, as well as survival analysis using Cox regression and Kaplan-Meier, were employed to assess the relationship between clinical stages, treatments, and overall survival. Results: The mean age at diagnosis was 70 years +/- 20 years, and 71% of the patients were male. At the time of diagnosis, 14.28% of the patients had localized disease, 58.86% had regional spread, and 26.86% had metastatic disease. Patients in clinical stage I showed a 5-year survival rate of 100%, with a p-value < 0.001 and an HR of 0.01. Additionally, the combination of chemotherapy, radiotherapy, and surgery was found to be significantly associated with improved survival, with a p-value of 0.03 and an HR of 0.82. Conclusions: This study provides crucial information on the clinical characteristics and survival of Guatemalan patients with rectal cancer. The findings underscore the importance of early detection and multimodal treatment, including chemoradiotherapy followed by surgery, to improve outcomes in these patients. Sharing these results is essential to promote access to standard treatment and enhance survival outcomes in patients with rectal cancer in Guatemala.

Efficacy and Safety of Chidamide in Combination with PD-1 Inhibitor and Radiotherapy for HER2-Negative Advanced Breast Cancer: Study Protocol of a Single Arm Prospective Study.

As one of the most important breakthroughs in cancer therapy, immune checkpoint inhibitors have greatly prolonged survival of patients with breast cancer. However, their application and efficacy are limited, especially for advanced HER2-negative breast cancer. It has been reported that epigenetic modulation of the histone deacetylase (HDAC) inhibitor chidamide, as well as immune microenvironment modulation of radiotherapy are potentially synergistic with immunotherapy. Thus, the combination of chidamide, radiotherapy and immunotherapy is expected to improve prognosis of patients with advanced HER2-negative breast cancer. This is a single-arm, open, prospective clinical trial investigating the efficacy and safety of the combination of HDAC inhibitor chidamide, anti-PD-1 antibody sintilimab, and the novel immuno-radiotherapy, which aims to enhance efficacy of immunotherapy, in subsequent lines of therapy of HER2-negative breast cancer. Our study will include 35 patients with advanced breast cancer that has failed endocrine therapy and first-line chemotherapy. Participants will receive 30 mg of chidamide twice a week, 200 mg of sintilimab once every 3 weeks, combined with immuno-radiotherapy. Radiotherapy will be centrally 8 Gy for at least one lesion, and at least 1 Gy for the other lesions. We will complete three fractions of radiotherapy in one cycle. The primary endpoint is progression-free survival, and secondary endpoints are objective response rate, disease control rate and safety. Moreover, biomarkers including cytokines and lymphocyte subgroups will be explored. As a single-arm clinical trial, the analysis of the influence of each single treatment is limited. Besides, our study is an open study, which involves neither randomization nor blinding. In spite of the abovementioned limitations, this prospective clinical trial will give an insight into subsequent lines of therapy of HER2-negative advanced breast cancer, prolong the survival or achieve long remission for these participants, and identify potential responders.

An interpretable AI-derived radiology signature to identify patients at risk of progression on the PACIFIC regimen for unresectable non-small cell lung cancer.

8079 Background: Advances in the treatment of unresectable NSCLC have emerged through the combination of chemotherapy, radiotherapy, and immune checkpoint inhibitors (ICI), also known as the PACIFIC regimen. Despite this protocol’s benefits, it lacks predictive biomarkers and many patients will ultimately fail to respond. Artificial intelligence (AI) has shown promise in identifying patients responsive to ICI, but its ability to identify patients who may not benefit from such combination regimens remains underexplored. We introduce an AI-enabled approach leveraging interpretable imaging biomarkers, such as tumor heterogeneity and twistedness of the tumor-associated vasculature, to identify patients who will fail to benefit from chemo-radio-immunotherapy (CRIT) using pretreatment scans. Methods: We analyzed CT data from 148 NSCLC patients with predominantly stage III (91%) disease from two institutions. Target lesions were delineated by a trained radiologist. The Picture Health Px platform was utilized to segment the lungs and pulmonary vessels. Subsequently, a number of interpretable imaging features from the tumor and surrounding tissues were extracted. A Cox proportional hazards model of feature clusters was developed on the training set (n = 101) to stratify patients into benefit groups associated with progression-free survival (PFS). A cohort of 47 patients receiving CRIT were held out for testing. Results: The imaging-derived high-risk group defined by the model was associated with decreased PFS in the test set, with a hazard ratio (HR) of 4.99 (95% CI: 2.04-12.18; p < 0.005) and concordance index (C-index) of 0.66. The risk groups identified by the model outperformed PD-L1 negative status in identifying likely progressors (C-index = 0.52; HR = 1.49 [0.51-4.54], p = 0.47), and were additionally independently prognostic of PD-L1 status when compared in a multivariable analysis (p < 0.001). The primary features driving the model were measurements of the radius and tortuosity of the tumor-associated vasculature, as well as heterogeneity metrics of the tumor. Conclusions: An AI imaging tool that stratifies patients by risk after CRIT from baseline radiology was developed. The tool was able to strongly identify a subset of patients at very high risk of progression if treated with CRIT. These risk groups outperformed PD-L1 and thus may address biomarker gaps in the CRIT setting. With further clinical validation, radiology-based risk stratification could be used to identify a subset of unresectable NSCLC patients for whom alternatives to the standard of care should be explored.

Determinants of pathological complete response and tumor regression in high-risk breast cancer treated with neoadjuvant radiotherapy and chemotherapy.

e12652 Background: Pathological complete response (pCR) is a recognized prognostic indicator in breast cancer patients undergoing neoadjuvant systemic therapy (naST). Known determinants of pCR include intrinsic subtype, proliferation index, grading, clinical tumor and nodal stage, as well as the type of systemic therapy. Incorporating neoadjuvant radiotherapy (naRT) may enhance response rates, disease-free survival, toxicity profiles, and cosmetic outcomes compared to adjuvant radiotherapy. However, the factors influencing pCR and primary tumor regression with the addition of neoadjuvant radiotherapy to chemotherapy are not well-documented. Methods: A retrospective analysis was conducted on 341 patients (cT1-cT4/cN0-N+) who received naRT and neoadjuvant chemotherapy between 1990 and 2003. Treatment included naRT to the breast and, in most cases, to the supra-/infraclavicular lymph nodes, complemented by an electron or brachytherapy boost. NaST was administered either sequentially or concurrently with RT, utilizing various regimens. Univariate and multivariate regression analyses were employed to evaluate the impact of different subgroups and treatment modalities on pCR (ypT0/Tis and ypN0) and complete primary tumor response (ypT0/Tis). Receiver operating characteristic (ROC) analysis assessed the interval between radiotherapy (RT) and surgical resection (Rx), as well as the radiotherapy dose. Results: Out of 341 analyzed patients, 31.1% achieved pCR. Multivariate analysis revealed that pCR rates were affected by the planned type of resection, breast cancer subtype, primary tumor stage, and the interval between radiation and surgery. The biologically effective dose to the tumor did not significantly impact pCR. Univariate analysis identified age, resection type, breast cancer subtype, clinical tumor stage, and grading as significant factors for primary tumor regression. In the multivariate analysis, resection type, subtype, and clinical tumor stage remained significant. Radiation dose to the tumor and the interval from radiation to surgery were not significant for pCR. However, a longer interval from radiotherapy to resection significantly predicted pCR when treatment factors were included in the model. Conclusions: The factors associated with pCR following combined neoadjuvant chemotherapy and radiotherapy are akin to those identified with neoadjuvant chemotherapy alone. A prolonged interval to surgery may be linked to higher pCR rates. Escalating the dose beyond 60 Gy did not lead to increased response rates.

Phase II study of combination of radiotherapy with pembrolizumab plus chemotherapy in patients with previously untreated metastatic non-small cell lung cancer: North Japan Lung Cancer Study Group 1902.

Phase II study of combination of radiotherapy with pembrolizumab plus chemotherapy in patients with previously untreated metastatic non-small cell lung cancer: North Japan Lung Cancer Study Group 1902.

Transcriptomic and epigenetic landscape of nimorazole-enhanced radiochemotherapy in head and neck cancer

BackgroundHypoxia remains a challenge for the therapeutic management of head and neck squamous cell carcinoma (HNSCC). The combination of radiotherapy with nimorazole has shown treatment benefit in HNSCC, but the precise underlying molecular mechanisms remain unclear. PurposeTo assess and to characterize the transcriptomic/epigenetic landscape of HNSCC tumor models showing differential therapeutic response to fractionated radiochemotherapy (RCTx) combined with nimorazole. Materials/methodsBulk RNA-sequencing and DNA methylation experiments were conducted using untreated and treated HNSCC xenografts after 10 fractions of RCTx with and without nimorazole. These tumor models (FaDu, SAS, Cal33, SAT and UT-SCC-45) previously showed a heterogeneous response to RCTx with nimorazole. The prognostic impact of candidate genes was assessed using clinical and gene expression data from HNSCC patients treated with primary RCTx within the DKTK-ROG. ResultsNimorazole responder and non-responder tumor models showed no differences in hypoxia gene signatures However, non-responder models showed upregulation of metabolic pathways. From that, a subset of 15 differentially expressed genes stratified HNSCC patients into low and high-risk groups with distinct outcome. ConclusionIn the present study, we found that nimorazole non-responder models were characterized by upregulation of genes involved in Retinol metabolism and xenobiotic metabolic process pathways, which might contribute to identify mechanisms of resistance to nitroimidazole compounds and potentially expand the repertoire of therapeutic options to treat HNSCC.

Posterior fossa primary intracranial extraosseous Ewing’s sarcoma: case report

BackgroundPrimary intracranial Ewing’s sarcoma (ES) is a type of primitive neuroectodermal tumour and is a rare malignant tumour in children and adolescents. The imaging features of ES overlap with other central nervous system embryonal tumours, making it difficult to pinpoint a specific diagnosis. We aim to explore the clinical, neuroimaging and differential diagnoses of this entity.Case presentationWe describe a 6-month-old infant who presented with complaints of enlarging the head size and poor feeding. Imaging revealed a contrast-enhancing large solid-cystic mass lesion with internal calcification, focal bone erosion and haemorrhage in the posterior fossa. Histopathological examinations, immunohistochemistry, and molecular analysis confirmed ES.ConclusionsThe confirmative diagnosis of primary intracranial ES requires histological examination, immunohistochemical analysis, and genetic detection, along with radiological findings. Surgical excision followed by combined radiotherapy and chemotherapy is the treatment of choice.

Chemotherapy in pediatric low-grade gliomas (PLGG).

Pediatric low-grade gliomas (PLGG) are commonly treated with a combination of surgery, radiotherapy, and chemotherapy. Recent trends prioritize reducing long-term morbidities, particularly in younger patients. While historically chemotherapy was reserved for cases progressing after radiotherapy, evolving recommendations now advocate for its early use, particularly in younger age groups. The carboplatin and vincristine (CV) combination stands as a standard systemic therapy for PLGG, varying in dosage and administration between North America and Europe. Clinical trials have shown promising response rates, albeit with varying toxicity profiles. Vinblastine has emerged as another effective regimen with minimal toxicity. TPCV, a regimen combining thioguanine, procarbazine, lomustine, and vincristine, was compared to CV in a Children's Oncology Group trial, showing comparable outcomes, but more toxicity. Vinorelbine, temozolomide, and metronomic chemotherapy have also been explored, with varied success rates and toxicity profiles. Around 40-50% of PLGG patients require subsequent chemotherapy lines. Studies have shown varied efficacy in subsequent lines, with NF1 patients generally exhibiting better outcomes. The identification of molecular drivers like BRAF mutations has led to targeted therapies' development, showing promise in specific molecular subgroups. Trials comparing targeted therapy to conventional chemotherapy aim to delineate optimal treatment strategies based on molecular profiles. The landscape of chemotherapy in PLGG is evolving, with a growing focus on molecular subtyping and targeted therapies. Understanding the role of chemotherapy in conjunction with novel treatments is crucial for optimizing outcomes in pediatric patients with low-grade gliomas.

The Immunomodulatory Potential of Concurrent High-Dose Radiotherapy and Immune Checkpoint Inhibitor Cemiplimab in Advanced Cutaneous Squamous Cell Carcinoma: Initial Results.

In this retrospective case series, we investigate the synergistic effect and the immunomodulatory potential of combination radiotherapy and immunotherapy on 11 patients affected by locally advanced or metastatic cutaneous squamous cell carcinoma (CSCC), treated at our institution between 2020 and 2023. The primary endpoints of this study are objective tumor response, assessed by Immunotherapy Response Evaluation Criteria in Solid Tumors (iRECIST), and time to treatment failure (disease progression). In all patients, surgery was deemed not amenable, due to its potential functional and aesthetic impact. Therefore, upon multidisciplinary agreement, radiotherapy and immunotherapy with cemiplimab were alternatively administered. After 6 months, an early objective tumor response was observed in 9/11 patients, with 17/20 cutaneous lesions (85%) presenting either a complete or partial response. Only 2/11 patients, with a total of 3/20 cutaneous lesions (15%), had stable disease. These benefits persisted at a longer follow-up (21.4 ± 9.7 months), with no patients presenting disease progression. Despite the retrospective nature of this study and small sample size, our experience highlights the ability of concomitant radiotherapy and cemiplimab to promote an early objective response in patients with advanced CSCC. Moreover, in our population, the clinical benefits were also related to a longer progression-free survival, without any safety alert reported.