Consolidation Radiotherapy Research Articles

Long-term follow-up of bulky classic Hodgkin lymphoma managed with ABVD and PET-guided RT demonstrates excellent outcomes in PET-negative cases.

The outcome of 221 patients with bulky (≥10 cm) classic Hodgkin lymphoma (cHL) treated with doxorubicin, bleomycin, vinblastine, dacarbazine and consolidative radiotherapy (RT) only in those with a positive end-of-treatment (EOT) positron emission tomography (PET) scan was evaluated. With a median follow-up of 9.6 years, 5- and 10-year progression-free survival (PFS) in EOT PET-negative cases were 94.0% and 90.4%, respectively, and in PET-positive cases, 5/10-year PFS was 64.6% (p < 0.001), with 15% overall receiving RT. Five-year PFS for Deauville (D) score DX/D1-3 was 93.6%, compared with D4 66.7% (p < 0.001) and D5 33.3% (p < 0.001). Omission of RT in EOT PET-negative cases is associated with excellent long-term outcomes in bulky cHL.

Nivolumab+AVD in Advanced-Stage Classic Hodgkin’s Lymphoma

BackgroundIncorporating brentuximab vedotin into the treatment of advanced-stage classic Hodgkin’s lymphoma improves outcomes in adult and pediatric patients. However, brentuximab vedotin increases the toxic effects of treatment in adults, more than half of pediatric patients who receive the drug undergo consolidative radiation, and relapse remains a challenge. Programmed death 1 blockade is effective in Hodgkin’s lymphoma, including in preliminary studies involving previously untreated patients.MethodsWe conducted a phase 3, multicenter, open-label, randomized trial involving patients at least 12 years of age with stage III or IV newly diagnosed Hodgkin’s lymphoma. Patients were randomly assigned to receive brentuximab vedotin with doxorubicin, vinblastine, and dacarbazine (BV+AVD) or nivolumab with doxorubicin, vinblastine, and dacarbazine (N+AVD). Prespecified patients could receive radiation therapy directed to residual metabolically active lesions. The primary end point was progression-free survival, defined as the time from randomization to the first observation of progressive disease or death from any cause.ResultsOf 994 patients who underwent randomization, 970 were included in the intention-to-treat population for efficacy analyses. At the second planned interim analysis, with a median follow-up of 12.1 months, the threshold for efficacy was crossed, indicating that N+AVD significantly improved progression-free survival as compared with BV+AVD (hazard ratio for disease progression or death, 0.48; 99% confidence interval [CI], 0.27 to 0.87; two-sided P=0.001). Owing to the short follow-up time, we repeated the analysis with longer follow-up; with a median follow-up of 2.1 years (range, 0 to 4.2 years), the 2-year progression-free survival was 92% (95% CI, 89 to 94) with N+AVD, as compared with 83% (95% CI, 79 to 86) with BV+AVD (hazard ratio for disease progression or death, 0.45; 95% CI, 0.30 to 0.65). Overall, 7 patients received radiation therapy. Immune-related adverse events were infrequent with nivolumab; brentuximab vedotin was associated with more treatment discontinuation.ConclusionsN+AVD resulted in longer progression-free survival than BV+AVD in adolescents and adults with stage III or IV advanced-stage classic Hodgkin’s lymphoma and had a better side-effect profile. (Funded by the National Cancer Institute of the National Institutes of Health and others; S1826 ClinicalTrials.gov number, NCT03907488.)

Long-term efficacy and safety of dose-dense and dose-intense ABVD without consolidation radiotherapy in patients with advanced Hodgkin lymphoma: A 15-year follow-up of the ABVDDD-DI phase II study.

We demonstrated that dose-densified and dose-intensified ABVD (doxorubicin, bleomycin, vinblastine, dacarbazine; ABVDDD-DI) was safe and effective. Here, we present a post hoc long-term analysis of the 82 patients enrolled in the original study. The median observation time was 175 months (IQR 159-197). At 15 years, progression-free and overall survival rates were 81.2% (95% CI, 69.9%-88.7%) and 92.7% (95% CI, 82.6%-97.0%), respectively. Four patients with multiple cardiovascular risk factors experienced delayed G3 cardiac events. The cumulative incidence of second malignancies at 20 years was 6.1%. Fertility and childbearing potential were unaffected. Data support an ongoing benefit for ABVDDD-DI without uneven late toxicities.

EP.09A.05 Consolidative Thoracic Radiotherapy Induced Lymphopenia in Metastatic NSCLC Is Predicted by EDIC and Associated with Poor Clinical Outcomes

EP.09A.05 Consolidative Thoracic Radiotherapy Induced Lymphopenia in Metastatic NSCLC Is Predicted by EDIC and Associated with Poor Clinical Outcomes

Using Deauville Scoring to Guide Consolidative Radiotherapy in Diffuse Large B-Cell Lymphoma

Background: The most common aggressive lymphoma in adults is diffuse large B-cell lymphoma (DLBCL). Consolidative radiotherapy (RT) is often administered to DLBCL patients but guidelines remain unclear, which could lead to unnecessary RT. We aimed to evaluate the value of end-of-treatment PET-CT scans, interpreted using the Deauville score (DV), to guide the utilization of consolidative RT, which may help spare low-risk DLBCL patients from unnecessary RT. Methods: We included all DLBCL patients diagnosed between 2010 and 2022 at the National Cancer Centre Singapore with DV measured at the end of the first-line chemoimmunotherapy. The outcome measure was time-to-progression (TTP). The predictive value of DV for RT was assessed based on the interaction effect between the receipt of RT and DV in Cox regression models. Results: The data of 349 patients were analyzed. The median follow-up time was 38.1 months (interquartile range 34.0–42.3 months). RT was associated with a significant improvement in TTP amongst the DV4-5 patients (HR 0.33; 95%CI 0.13–0.88; p = 0.027) but not the DV1-3 patients (HR 0.85; 95%CI 0.40–1.81; p = 0.671) (interaction’s p = 0.133). Multivariable analysis reported that RT was again significantly associated with improved TTP among the DV4-5 patients (adjusted HR 0.29; 95%CI 0.10–0.80; p = 0.017) but not the DV1-3 group (HR 0.86; 95%CI 0.40–1.86; p = 0.707) (interaction’s p = 0.087). Conclusion: Our results suggests that DLBCL patients with end-of-treatment PET-CT DV1-3 may not need consolidative RT. Longer follow-up and prospective randomized trials are still necessary to investigate long-term outcomes.

Safety and efficacy of consolidative stereotactic radiotherapy for oligo-residual EGFR-mutant non-small cell lung cancer after first-line third-generation EGFR-tyrosine kinase inhibitors: a single-arm, phase 2 trial

Prospective data is limited on the efficacy and safety of consolidative stereotactic radiotherapy (SRT) in metastatic epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients harboring oligo-residual disease (ORD) after first-line third-generation EGFR-tyrosine kinase inhibitors (TKIs). In this single-arm, phase II trial, 61 patients from two academic centers were enrolled from March 2021 to March 2023. All these patients had metastatic EGFR-mutant NSCLC and harbored ORD after first-line third-generation EGFR-TKIs. Consolidative SRT was performed and EGFR-TKIs were not held during SRT. The primary endpoint was progression-free survival (PFS) and the secondary endpoints included overall survival and treatment-related adverse events (TRAEs). A prespecified propensity score matched (PSM) comparison was conducted with a contemporary cohort of patients who developed ORD but received EGFR-TKIs alone. This trial was registered with ClinicalTrails.gov, NCT04764214. All patients received consolidative SRT. With a median follow-up of 21.1 months, the median PFS was 29.9 (80% CI 22.4-32.4) months and the lower boundary exceeded the predefined threshold, meeting the primary endpoint. TRAEs occurred in 43 (70%) patients, with pneumonitis (27.9%) and esophagitis (26.2%) being the most common toxicities. Four patients (6.6%) reported grade ≥3 TRAEs, each for pneumonitis, esophagitis, leukopenia, and cranial radiation necrosis. PSM analysis showed significantly prolonged PFS in EGFR-TKI+SRT group compared to EGFR-TKI group (HR 0.46, 80% CI 0.20-0.61; p=0.002). Consolidative SRT is associated with an encouraging PFS in first-line third-generation EGFR-TKI-treated metastatic NSCLC patients harboring ORD, with generally acceptable toxicities. Further confirmatory studies are warranted. Hui Lan Public Welfare and the Chinese Society of Clinical Oncology Foundation.

Fifteen-Year Experience of a Single Institution: Outcomes for Early-Stage Hodgkins Lymphoma Comparing Chemotherapy Alone Versus Combined Modality Therapy

Doxorubicin, bleomycin, vinblastine, dacarbazine (ABVD) chemotherapy is the current standard treatment for early-stage Hodgkins lymphoma (HL). The use of consolidative radiation therapy (RT) in addition to chemotherapy may lead to better survival rates but is controversial because of concerns about long-term toxicity. The aim of this study is to compare outcomes of patients receiving ABVD chemotherapy alone (CTX alone) versus ABVD with consolidative RT (CMT). A single-institution, retrospective review of patients with HL diagnosed from 2000 to 2014 was conducted. Patients were identified from the National Cancer Database. Inclusion criteria included patients aged ≥18 years, with stage I or II HL, who received ABVD with a complete response with/without CMT. Consolidative RT must have been started within 90 days of completing chemotherapy. Institutional review board approval was obtained. Follow-up details and treatment responses were collected from medical record reviews. Standard statistical analysis and Kaplan-Meier curves were used to estimate relapse-free survival (RFS). One hundred and 8 patients with early-stage HL were identified. The median age at diagnosis was 31 years (range, 19-72). Most patients were female (63%) and Caucasian (65%). stage II HL was present in 89%of patients, 89% had an Eastern Cooperative Oncology Group score of 0 or 1, 35% had B symptoms, and 9% had extranodal involvement. A total of 52.8% received CMT (n = 57) and 47.2% received CTX alone (n = 51). The CMT group had fewer cycles of chemotherapy compared to the CTX-alone group (mean cycles, 5.2 vs 5.7, P = 0.045). Twenty-four relapse events occurred in the CTX-alone group, while no relapse events occurred in the CMT group. RFS at 10 years was significantly improved in the CMT group (100%) compared to CTX alone (47.4%, P < .0001; HR = .03, P < .001). ABVD with consolidative RT was associated with improved RFS. Further studies of toxicity comparisons, advanced stages, and nonfavorable HL are warranted.

Effect of consolidation radiation therapy on treatment outcomes of early-stage favorable Hodgkin lymphoma

Background. Early (stage I–II) classical Hodgkin lymphoma is a highly treatable malignant neoplasm. For many years, the standard treatment of early Hodgkin lymphoma has been combination therapy: polychemotherapy with subsequent consolidating radiation therapy. Aim. To retrospectively evaluate the results of treatment of stage I–II classical Hodgkin lymphoma in a favorable prognosis group using monotherapy and combination therapy (chemotherapy followed by consolidating radiotherapy). Materials and methods. The study included 58 patients aged 19–81 years (median age 36 years) diagnosed with stage I–II classical Hodgkin lymphoma with favorable prognosis; 23 (39.7 %) patients were men, 35 (60.3 %) were women. Depending on the treatment received, the patients were divided into two groups: 40 (69 %) patients received ABVD polychemotherapy, and 18 (31 %) patients received polychemotherapy followed by consolidating radiation therapy to the initial lesion zones with standard fractionation regimen (total dose 30 Gy). The Kaplan–Mayer method was used to evaluate overall, progression-free, recurrence-free, and event-free survival. Odds ratios and their 95 % confidence intervals were also calculated. The statistical significance of differences in survival was assessed using the log-rank test. The level of statistical significance was 0.05. Statistical data processing was carried out using the IBM SPSS Statistics 27 software and Microsoft Excel. Results. According to the results of our study, while in the total patient group a clear numerical advantage in survival (overall, progression-free, relapse-free and event-free survival) was observed in the combination therapy group compared to chemotherapy group (5.5, 13.2, 9.2 and 23.9 %, respectively), no preferred tactics were identified in the total patient group. However, considering a subgroup of patients with mediastinum involved in the tumor process, a statistically significant advantage of combined treatment over single-mode chemotherapy was determined for 2-year event-free survival (92.9 ± 6.9 % vs. 62.5 ± 9.9 %, respectively, p = 0.046). The risk of an adverse event is reduced by &gt;80 % (odds ratio 0.197; 95 % confidence interval 0.036–0.977) when using consolidating radiation therapy after chemotherapy.

1452P Camrelizumab plus chemotherapy combined with consolidative radiotherapy as first-line treatment for oligometastatic esophageal squamous cell carcinoma (ESCORT-1ST-RT): A single-arm, open-label, phase II trial

1452P Camrelizumab plus chemotherapy combined with consolidative radiotherapy as first-line treatment for oligometastatic esophageal squamous cell carcinoma (ESCORT-1ST-RT): A single-arm, open-label, phase II trial

1799P Efficacy and safety of integrating consolidative thoracic radiotherapy with immunochemotherapy in ES-SCLC: A real-world retrospective analysis

1799P Efficacy and safety of integrating consolidative thoracic radiotherapy with immunochemotherapy in ES-SCLC: A real-world retrospective analysis

Omission of Radiotherapy in Primary Mediastinal B-Cell Lymphoma: IELSG37 Trial Results.

The role of consolidation radiotherapy in primary mediastinal B-cell lymphoma (PMBCL) patients is controversial. The IELSG37 trial, a randomized non-inferiority study, aimed to assess whether irradiation can be omitted in PMBCL patients with complete metabolic response (CMR) after induction immunochemotherapy. Primary endpoint was progression-free survival (PFS) at 30 months post-randomization. Patients with CMR were randomly assigned to observation or consolidation radiotherapy (30 Gy). With a non-inferiority margin of 10% (assuming a 30-month PFS of 85% in both arms), a sample size of 540 patients was planned with 376 expected to be randomized. The observed events were considerably lower than expected, therefore, primary endpoint analysis was conducted when ≥95% of patients were followed for ≥30 months. Of 545 patients enrolled, 268 were in CMR after induction and were randomized to observation (n=132) or radiotherapy (n=136). The 30-month PFS was 96.2% in the observation arm and 98.5% in the radiotherapy arm, with a stratified hazard ratio of 1.47 (95%CI, 0.34 to 6.28) and absolute risk difference of 0.68% (95%CI, -0.97% to 7.46%). The 5-year overall survival was 99% in both arms.Non-randomized patients were managed according to local policies. Radiotherapy was the only treatment in 86% of those with Deauville score (DS) 4 and in 57% of those with DS 5. The 5-year PFS and OS of patients with DS 4 (95.8% and 97.5%, respectively) were not significantly different from those of randomized patients. Patients with DS5 had significantly poorer 5-year PFS and OS (60.3% and 74.6%, respectively). This study, the largest randomized trial of radiotherapy in PMBCL, demonstrated favorable outcomes in patients achieving CMR with no survival impairment for those omitting irradiation.

Real-world comparison of chemo-immunotherapy and chemotherapy alone in the treatment of extensive-stage small-cell lung cancer

Small cell lung cancer (SCLC) is a high-grade neuroendocrine carcinoma responsible for 200,000 deaths per year worldwide. Platinum-etoposide-based chemotherapy has been the standard of treatment for the past 40 years, with an overall survival of 10 months. Since 2019, the addition of immunotherapy (atezolizumab or durvalumab) to chemotherapy has become the standard of care for first-line treatment of extensive-stage SCLC following the demonstration of an improvement in overall survival in phase 3 studies. We aimed to evaluate the efficacy and safety of chemo-immunotherapy compared with chemotherapy alone in a "real-world" setting. Retrospective observational study including patients undergoing first-line treatment for extensive-stage SCLC between 2014 and 2022. We separated the study population into two arms (chemo-immunotherapy/chemotherapy). For each arm, progression-free survival (PFS), overall survival (OS) and serious side effects were collected. Associations between treatments and survival outcomes were adjusted for potential confounders. Consolidative palliative thoracic radiotherapy was introduced in the models as a time-dependent variable. A total of 118 patients with a median age of 63 years were included. 65.2 % of patients were performance status 0 or 1. In univariate analysis, PFS and OS were not significantly different between the chemo-immunotherapy and chemotherapy alone groups (p = 0.70 and 0.24 respectively). In multivariate analysis, the addition of immunotherapy to chemotherapy was not significantly associated with better PFS (HR 0.76, IC (0.49 - 1.19), p = 0.23), but it was significantly associated with better OS (HR 0.61, IC (0.38 - 0.98), p = 0.04). Consolidative palliative thoracic radiotherapy (time-dependent variable), when applied (almost only in the chemotherapy alone group), was significantly associated with better PFS and OS. In this real-world study, chemo-immunotherapy was associated with slightly better OS compared to chemotherapy alone as a first-line treatment in ES-SCLC patients in multivariate analysis, which is not explained by a benefit in PFS. However, consolidative palliative thoracic radiotherapy seems to be significantly associated with better OS and PFS, suggesting that we should also consider using it in patients receiving chemo-immunotherapy.

Treatment Outcomes in Primary Mediastinal Large B-Cell Lymphoma. Experience of the AF Tsyb Medical Radiological Research Center (Obninsk)

AIM. To assess chemotherapy outcomes in patients with primary mediastinal large B-cell lymphoma (PMBCL) treated at the AF Tsyb Medical Radiological Research Center from 2016 to 2023. MATERIALS &amp; METHODS. The analysis focused on the data from 58 patients with the morphologically verified diagnosis of PMBCL. The patients were aged 17–62 years (median 34 years), there were 39 women and 19 men. The median follow-up was 51.2 months (range 0.4–200.9 months). Depending on drug chemotherapy regimens, patients were divided into 3 groups: R-NHL-BFM-90 (n = 9), R-CHOP (n = 17), and R-MACOP-B (n = 32). Most patients (90 %) received mediastinal radiotherapy of total 30–46 Gy. RESULTS. The 5-year overall survival in the therapy groups was 66.7 %, 88.2 %, and 100 %, respectively (p = 0.007), progression-free survival was 66.7 %, 70.6 %, and 96.9 % (p = 0.006), and event-free survival was 66.7 %, 54.7 %, and 90.6 % (p = 0.038). On the whole, the toxicity profile of chemotherapy was quite acceptable. Neither low blood values nor other adverse events essentially affected a complete implementation of chemoradiotherapy program. The intermediate outcomes were based on PET-CT data after 2–4 therapy cycles in 37 (64 %) patients. PET-CT showed that at the stage of drug chemotherapy, complete response (CR) was achieved in 27 (73 %) patients, and partial response (PR) was achieved in 4 (11 %) patients. With respect to the CR and PR criteria, there were 6 (16 %) non-responders. CONCLUSION. PMBCL is one of extranodal lymphomas with thymic B-cells being primary source of tumor growth. PMBCL is characterized by aggressive course and extreme heterogeneity of clinical manifestations. Up to now, the first-line chemotherapy decision making in PMBCL has remained an issue with practical importance. This paper reports immediate and long-term outcomes of the program chemoradiotherapy regimen R-MACOP-B with subsequent consolidation radiotherapy. The results obtained can be termed quite satisfactory and noninferior to the data from national and international sources. Nevertheless, more effective chemoradiotherapy programs for PMBCL continue to be elaborated. In this context, immune checkpoint inhibitors as part of therapy programs seem to hold promise for the treatment of newly diagnosed PMBCL.

PRIMARY VITREORETINAL LYMPHOMA MASQUERADING AS POSTOPERATIVE ENDOPHTHALMITIS IN A PREGNANT PATIENT WITH LONG-STANDING IDIOPATHIC PANUVEITIS.

To report primary vitreoretinal lymphoma after surgical 0.59 mg fluocinolone acetonide implant (FAi) exchange in a patient treated with adalimumab for idiopathic bilateral panuveitis. Retrospective case review. A 37-year-old woman with bilateral idiopathic panuveitis, who had favorable responses to previous FAi surgical implants, presented with right eye recurrent intraocular inflammation and cystoid macular edema that partially responded to systemic adalimumab. Her FAi was replaced, given her previous favorable response. She developed postoperative ocular inflammation transiently responsive to two serial vitreous taps and injections of intravitreal antimicrobials and then worsening inflammation and new layered flocculant material. Diagnostic vitrectomy showed a few atypical lymphocytes and cultures were negative. At postdiagnostic vitrectomy Month 1, flocculant material recurred. Aqueous cytology and flow cytometry revealed large CD45-positive B cells suspicious for lymphoma. Postoperatively, she revealed that she was pregnant. She was treated with eight monthly intravitreal methotrexate injections and postpartum consolidation radiotherapy. Subsequent repeat cytology, flow cytometry, and corneal pathologic examination revealed large B cells that were CD20 positive, and next-generation sequencing detected a dominant monoclonal B-cell population, diagnostic of PVRL. Nineteen months after FAi exchange, she developed an area of enhancement in the lateral aspect of the right frontal lobe on brain MRI, consistent with central nervous system involvement. The authors present a unique case of PVRL masquerading as postoperative endophthalmitis after FAi exchange in an eye with chronic panuveitis treated with adalimumab immunosuppressive therapy. The authors hypothesize that there may be a causal relationship between adalimumab and PVRL.

Benefit of consolidative radiation in patients with extranodal limited-stage diffuse large B-cell lymphoma: a multicenter retrospective study in China.

Approximately 40% of limited-stage (stage I and II) diffuse large B-cell lymphoma (LS-DLBCL) presents with extranodal disease. Extranodal LS-DLBCL may have significant biological differences and associated with worse outcomes than nodal disease. Although rituximab based chemoimmunotherapy is standard of first-line treatment, the role of consolidative radiotherapy (RT) in this particular subgroup is controversial. In this multicenter retrospective study, we evaluated the survival benefit of consolidative RT in patients diagnosed with extranodal LS-DLBCL and received rituximab-based chemoimmunotherapy with or without consolidative RT. A total of 328 patients were included, 129 patients (39.3%) received chemoimmunotherapy and consolidative RT, and 199 patients (60.7%) received chemoimmunotherapy alone. With a median follow-up of 5.1 years (range, 0.3-14.8 years), 5-year progression-free survival (PFS) and overall survival (OS) for all patients were 75.4% and 83.9%, respectively. In multivariate analyses, the addition of consolidative RT was associated with superior OS (P = 0.004) and PFS (P = 0.005). High stage-modified International Prognosis Index (SM-IPI) risk predicted worse OS (P = 0.001) and PFS (P = 0.005). Also, propensity score-matched analyses showed RT improved both OS (hazard ratio [HR] 0.228, 95% confidence index [CI] 0.111-0.467, P < 0.001) and PFS (HR 0.308, 95% CI 0.167-0.566, P < 0.001). Among patients who achieved CR, 49 patients (16.6%) developed disease relapse, of which 30.6% relapsed at local sites. Consolidative RT significantly reduced relapse risk (P = 0.002). Our results demonstrated that consolidative RT significantly improved outcomes in patients with extranodal LS-DLBCL in the rituximab era.

Advances in thoracic consolidation radiotherapy after first-line immunotherapy combined with chemotherapy for extensive stage small cell lung cancer

Small cell lung cancer (SCLC) accounts for about 13%~17% of primary bronchial lung cancer. Due to its rapid growth rate, aggressive behavior, early metastasis and poor prognosis, about 70% of patients were diagnosed with extensive-stage (ES) disease. Although most ES-SCLC patients are sensitive to initial chemotherapy, local recurrence and distant metastasis develop in the short term. Immunotherapy has brought the dawn to overcome it. At present, immune checkpoint inhibitor combined with chemotherapy has become an important strategy as first-line therapy for ES-SCLC. Nevertheless, patients are still at a high risk of chest lesion recurrence after initial systemic therapy. Whether the addition of thoracic consolidation radiotherapy (TRT) can reduce chest lesion recurrence rate remains to be determined. In this review, we summarized the latest research progress in the mode of first-line chemotherapy combined with immunotherapy followed by TRT in ES-SCLC, aiming to provide reference for clinical practice.

Camrelizumab plus chemotherapy combined with consolidative radiotherapy as first-line treatment for oligometastatic esophageal squamous cell carcinoma (ESCORT-1st-RT): A single-arm, open-label, phase 2 trial.

e16043 Background: Compared to chemotherapy alone, immunotherapy combined with chemotherapy as the first-line standard treatment for esophageal squamous cell carcinoma (ESCC) can increase progression-free survival (PFS) to 5.8-7.2 months. This study aimed to explore the feasibility and safety of combining camrelizumab and chemotherapy with consolidative radiotherapy in the treatment of advanced oligometastatic ESCC. Methods: This study included newly diagnosed patients with stage IV ESCC confirmed by histopathology and imaging examination who had ≤ 5 metastatic lesions in ≤ 3 organs. All patients were treated with camrelizumab combined with albumin paclitaxel and carboplatin for 4 cycles, followed by consolidative radiotherapy. The primary esophageal lesion and metastatic lymph nodes were treated with involved-field irradiation therapy, receiving 2.0 Gy per fraction over 25 daily sessions. For distant metastases in organs like the liver, lungs, brain, or bones, radiotherapy was tailored to individual clinical needs, often employing hypofractionated radiation therapy with doses starting at 3 Gy per fraction or above. The maintenance duration of camrelizumab treatment was limited to a maximum of 12 months. The primary endpoint was PFS. The secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety. Results: From October 26, 2021, to September 28, 2022, 29 patients with ESCC, median age 63 (range 51-74), were enrolled; 93.1% were male. All had an ECOG score of 0 or 1 and stage IV disease. 27 (93.1%) patients completed planned radiotherapy. Of 29 evaluated patients, 23 achieved an objective response and 6 maintained stable disease. Thus, the ORR and DCR were 79.3% (95% CI 78.2-80.4) and 100% (95% CI 100-100), respectively. With 23.3 months (95%CI 21.5-25.1) of follow-up, the median PFS was13.7 months (95% CI 9.9-17.5) , the median OS has not reached and the 1-year and 2-year OS rates were established at 72.4% (95% CI 52.3-85.1) and 61.4% (95% CI 41.1-76.5), respectively. The most common treatment-emergent adverse events (TEAEs) of grade 3-4 were lymphocyte count decreased (65.5%), neutrophil count decreased (27.6%), and white blood cell count decreased (20.7%). 1 patients discontinued camrelizumab treatment due to radiation esophagitis. No grade 5 TEAEs occurred. Conclusions: Consolidative radiotherapy following camrelizumab combined with chemotherapy showed potential efficacy and manageable tolerability in patients with advanced oligometastatic ESCC.

Combined modality for localized gastric diffuse large B-cell lymphoma: Long-term outcomes of 50 patients.

7079 Background: R-CHOP is the primary treatment for gastric diffuse large B-cell lymphoma (GDLBCL); for localized disease, the role of consolidative radiation therapy (RT) after chemotherapy remains underexplored. This study focuses on localized GDLBCL undergoing a combined modality therapy of R-CHOP followed by gastric RT, comparing outcomes between those receiving short-course (3-4 cycles) and full-course (6 cycles) R-CHOP. Methods: A retrospective analysis identified 50 consecutive PGDLBCL pts treated with R-CHOP followed by RT between 1/2000-1/2021. Baseline characteristics and follow-up data were collected. Lugano PET criteria and endoscopy (EGD) assessed overall response rate. Kaplan-Meier and univariable cox regression models estimated overall survival (OS) and (PFS). Results: Of the 50 pts with localized (Stage I-II) disease, 34 (68%) received 3-4 cycles of R-CHOP and 16 (32%) received 6 cycles. Pre-RT disease evaluation varied, with 36 (72%) undergoing EGD and PET, 4 (8%) EGD and CT, and 6 (12%) PET alone. One pt (3%) exhibited active DLBCL post 3-4 cycle R-CHOP, while 5 (31%) did so after 6 cycles (p=0.1). Median time from last R-CHOP dose to RT start date was 1.2 months with a median 3060 cGy delivered dose for both groups (range 2340-3060 in the 3-4 cycle group, 3000-4500 in the 6-cycle group). Median follow-up time from RT end is 58 months. No in-field failures occurred post-complete response (CR); however, 1 pt did not achieve a CR following R-CHOP and RT, progressing in the stomach and subsequently at new, out-of-field (OOF) sites. 3 pts had OOF progression without relapses in the stomach in a median time of 21 months. Low-grade lymphoma in the stomach post-DLBCL CR was observed in 2 pts, 3 and 22 months from RT end, with 1 OOF marginal zone lymphoma 2 years-post RT. OS and PFS did not significantly differ between the 3-4 and 6 cycle groups (96-month OS 70% vs. 86%, p=0.8; 96-month PFS 76% vs. 86%, p=0.7). OS and DLBCL PFS were analyzed for pts with evidence of residual DLBCL pre-RT compared to those without evidence of disease after R-CHOP. The 24-month DLBCL PFS was 92% in the CR group and 67% for those with incomplete response (p=0.14), with 92% and 67% 24-month survival probability (p=0.11). On univariate analysis, pre-RT evidence of active DLBCL by PET and/or EGD, pre-RT PET FDG uptake, and achieving CR on first-post-RT imaging were not statistically significant for DLBCL PFS. Conclusions: Recognizing the limitations of a retrospective study, our study documents the effectiveness of short-course R-CHOP followed by RT in localized GDLBCL, with similar outcomes to the full 6-cycle regimen. Excellent disease control was observed, with few instances of DLBCL or low-grade lymphoma relapse. Further analysis will include a cohort receiving R-CHOP alone without consolidative RT. This analysis aims to contribute to the evolving standard of care for GDLBCL, providing insights for future treatment strategies.

TisCRT-LAPC: A phase II study of tislelizumab combined with nab-paclitaxel and gemcitabine (AG) followed by consolidative radiotherapy in locally advanced pancreatic cancer (LAPC).

e16350 Background: We have previously reported that consolidative chemoradiotherapy following induced chemotherapy is an optimal regimen for LAPC. This study aimed to evaluate the clinical benefit of tislelizumab (anti-PD-1) plus AG chemotherapy sequenced by consolidative radiotherapy for therapy-naive LAPC. Methods: Patients (pts) with LAPC were enrolled and received tislelizumab (TIS) 200mg Q3W, nab-paclitaxel 125 mg/m2 and gemcitabine 1,000 mg/m2 on days 1 and 8 every three weeks for 6 cycles. Those who did not progressed continued to receive radiotherapy and tislelizumab. After that, tislelizumab and gemcitabine were ongoing until progression. The primary endpoint was 12-month progression-free survival rate, and secondary endpoints included objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), overall survival (OS), safety and biomarker explore. Results: From April 2021 to December 2023, 30 pts were enrolled, 29 pts completed at least one efficacy assessment, 1 dropped out due to jaundice on liver damage for more than 6 weeks without medication. 17 males and 13 females with a median age of 58.5 years. 12.5% (3/24) progressed after TIS+AG treatment and did not receive radiotherapy, 87.5% (21/24) had completed radiotherapy and 5 pts were still receiving TIS+AG treatment. ORR was 31.0%, and DCR was 96.6%, respectively. The median follow-up time was 14.0 months, and the median PFS was 11.2 months (95%CI,7.6-26.6). The median OS was not reached. 6-month and 12-month PFS rates were 84.2% and 44.3%, respectively. Most patients (27/30) showed serum CA19-9 decline with different degrees.The most common treatment-emergent adverse events (TEAEs) were myelosuppression, rash, and fatigue. Grade 3/4 TEAEs were neutropenia in 5 patients, anemia in 1 patient, and rash in 1 patient. Immune-related AEs included 1 Grade-1 myocarditis, 1 Grade-1 pneumonia and 1 Grade-3 disfunction of liver. Conclusions: This study demonstrates the effectiveness and manageable safety of tislelizumab combined with AG chemotherapy sequenced by radiotherapy for LAPC. Exploratory analysis of correlative biomarkers suggests that KRAS ctDNA negative at baseline may be a pedictive markers benefit with treatments. Clinical trial information: ChiCTR2000040872.

JCOG2002: A randomized phase III study of thoracic radiotherapy for extensive stage small cell lung cancer.

TPS8132 Background: Consolidative thoracic radiotherapy (cTRT) has shown a marginal improvement in overall survival (OS) and progression-free survival (PFS) for extensive-stage small-cell cancer (ES-SCLC). Consequently, ASTRO and NCCN guidelines conditionally recommend the use of cTRT. Despite the recent establishment of anti-PD-L1 antibody (aPD-L1) combined with platinum-doublet chemotherapy as the standard first-line treatment for ES-SCLC, the impact of cTRT in the era of immunotherapy remains uncertain. Methods: The JCOG2002 study, a randomized, multicenter phase 3 trial, initiated in October 2021 to assess the superiority of additional cTRT in terms of OS for ES-SCLC following induction aPD-L1 plus platinum doublet chemotherapy. Eligibility patients must meet criteria for the first registration including ES-SCLC, no prior radiation or chemotherapy history, age 20 or older, ECOG performance status 0 or 1, and adequate organ function. Induction treatment involves atezolizumab + carboplatin + etoposide or durvalumab + cisplatin / carboplatin + etoposide. Responding patients proceed to the second registration, randomization (1:1 between 30 Gy in 10 fractions of cTRT plus aPD-L1 maintenance therapy and maintenance therapy only). The cTRT targets metastatic lymph nodes in stations #1-7 and ipsilateral stations #10-12 identified at diagnosis. The adjustment factors include response to induction treatment (CR/PR versus SD), presence of brain metastasis (yes versus no), participating institutions, and aPD-L1 type (atezolizumab versus durvalumab). The primary endpoint is OS, with secondary endpoints being PFS and safety. The study aims to enroll 240 randomized patients, with 330 in the first registration, providing 80 % power at a one-sided 5 % significance level to detect a hazard ratio of 0.69 with 3-year accrual period and 1-year follow-up. As of February 6, 2024, 239 patients initiated induction treatment, and 121 have been randomized. This trial is registered at Japan Registry of Clinical Trials as jRCTs031210393 (https://jrct.niph.go.jp/detail/jRCTs031210393). Clinical trial information: jRCTs031210393 .