Nivolumab combined with brentuximab vedotin with or without mediastinal radiotherapy for relapsed/refractory primary mediastinal large B-cell lymphoma.

Not available.

Management of non-metastatic anal cancer in the elderly: ancillary study of the French multicenter prospective cohort FFCD-ANABASE.

BACKGROUND: Standard care for non-metastatic squamous cell carcinoma of the anus (SCCA) is chemoradiotherapy, data about elderly patients are scarce. METHODS: All consecutive patients treated for non-metastatic SCCA from the French multicenter FFCD-ANABASE cohort were included. Two groups were defined according to age: elderly (≥75 years) and non-elderly (<75). RESULTS: Of 1015 patients, 202 (19.9%) were included in the elderly group; median follow-up was 35.5 months. Among the elderly, there were more women (p = 0.015); frailer patients (p < 0.001), fewer smokers (p < 0.001) and fewer HIV-infected (p < 0.001) than in the non-elderly group. Concomitant chemotherapy and inguinal irradiation were less frequent (p < 0.001 and p = 0.04). In the elderly group; 3-year overall survival (OS), recurrence-free survival (RFS) and colostomy-free survival (CFS) were 82.9%, 72.4% and 78.0%, respectively; complete response rate at 4-6 months was 70.3%. There were no differences between groups for all outcomes and toxicity. In multivariate analyses for the elderly, PS ≥ 2 and locally-advanced tumors were significantly associated with poor OS (HR = 3.4 and HR = 2.80), RFS (HR = 2.4 and HR = 3.1) and CFS (HR = 3.8 and HR = 3.0); and treatment interruption with poor RFS (HR = 1.9). CONCLUSION: In the FFCD-ANABASE cohort, age did not influence tumor and tolerance outcomes of non-metastatic SCCA. Optimal curative treatment should be offered to elderly patients.

Extranodal nasal-type NK/T lymphoma treated with chemotherapy and radiotherapy: case series from a European tertiary referral center and review of the literature.

PURPOSE: Extranodal nasal-type NK/T-cell lymphoma (ENKTL) is very rare in western countries and few data are available regarding the prognosis and the outcome of patients treated for this disease. We aimed to evaluate the prognosis, the pattern and risk factors of disease failure after combined therapy and also performed a review of the literature. PATIENTS AND METHODS: We retrospectively analyzed 20 patients with (ENKTL) who underwent L­Asparaginase based chemotherapy followed by (chemo-) radiotherapy between 2010 and 2020 in our center. Data on clinical characteristics and irradiation were collected. Failure patterns were recorded as local (tumor site), regional (regional lymph nodes) or distant failure (metastasis and/or nonregional lymph nodes). RESULTS: During a median follow-up period of 46 months, disease failure was observed in 8 patients (40%). The 3­year progression-free survival (PFS) and overall survival (OS) rates were 62.5 and 83.0%, respectively. The failure patterns were local (n = 6, 30%), regional (n = 3, 15%) and distant (n = 4, 20%). Among patients with local failure, all failures occurred within the radiation fields (100%). Univariate analysis showed that bilateral regional lymph node involvement (p = 0.0002), initial circulating EBV viral load ≥ 3.5 log (p = 0.03) and no negativation of EBV PCR after induction CT (p = 0.0497) were independent predictors of PFS. CONCLUSION: Patients with bilateral lymph node involvement and/or high EBV viral load have a significant recurrence rate despite multimodal therapy. These results need to be confirmed by larger studies. Given the high rate of local recurrence within radiotherapy fields, the value of dose escalation should be considered. Patients at risk of relapse should be included in dedicated trials.

Association of Radiochemotherapy to Immunotherapy in unresectable locally advanced Oesophageal carciNoma-randomized phase 2 trial ARION UCGI 33/PRODIGE 67: the study protocol.

BACKGROUND: In case of locally advanced and/or non-metastatic unresectable esophageal cancer, definitive chemoradiotherapy (CRT) delivering 50 Gy in 25 daily fractions in combination with platinum-based regimen remains the standard of care resulting in a 2-year disease-free survival of 25% which deserves to be associated with new systemic strategies. In recent years, several immune checkpoint inhibitors (anti-PD1/anti-PD-L1, anti-Program-Death 1/anti-Program-Death ligand 1) have been approved for the treatment of various solid malignancies including metastatic esophageal cancer. As such, we hypothesized that the addition of an anti-PD-L1 to CRT would provide clinical benefit for patients with locally advanced oesophageal cancer. To assess the efficacy of the anti-PD-L1 durvalumab in combination with CRT and then as maintenance therapy we designed the randomized phase II ARION (Association of Radiochemotherapy with Immunotherapy in unresectable Oesophageal carciNoma- UCGI 33/PRODIGE 67). METHODS: ARION is a multicenter, open-label, randomized, comparative phase II trial. Patients are randomly assigned in a 1:1 ratio in each arm with a stratification according to tumor stage, histology and centre. Experimental arm relies on CRT with 50 Gy in 25 daily fractions in combination with FOLFOX regimen administrated during and after radiotherapy every two weeks for a total of 6 cycles and durvalumab starting with CRT for a total of 12 infusions. Standard arm is CRT alone. Use of Intensity Modulated radiotherapy is mandatory. The primary endpoint is to increase progression-free survival at 12 months from 50 to 68% (HR = 0.55) (power 90%; one-sided alpha-risk, 10%). Progression will be defined with central external review of imaging. ANCILLARY STUDIES ARE PLANNED: PD-L1 Combined Positivity Score on carcinoma cells and stromal immune cells of diagnostic biopsy specimen will be correlated to disease free survival. The study of gut microbiota will aim to determine if baseline intestinal bacteria correlates with tumor response. Proteomic analysis on blood samples will compare long-term responder after CRT with durvalumab to non-responder to identify biomarkers. CONCLUSION: Results of the present study will be of great importance to evaluate the impact of immunotherapy in combination with CRT and decipher immune response in this unmet need clinical situation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT: 03777813.Trial registration date: 5th December 2018.

Treatment, outcome, and prognostic factors in non-metastatic anal cancer: The French nationwide cohort study FFCD-ANABASE.

INTRODUCTION: International guidelines regarding the treatment of squamous cell carcinoma of the anus (SCCA) recommend intensity-modulated radiotherapy (IMRT) combined with mitomycin-based chemotherapy (CT). The French FFCD-ANABASE cohort aimed at evaluating clinical practices, treatment, and outcomes of SCCA patients. METHODS: This prospective multicentric observational cohort included all non-metastatic SCCA patients treated in 60 French centers from January 2015 to April 2020. Patients and treatment characteristics, colostomy-free survival (CFS), disease-free survival (DFS), overall survival (OS), and prognostic factors were analyzed. RESULTS: Among 1015 patients (male: 24.4 %; female: 75.6 %; median age: 65 years), 43.3 %presented with early-stage(T1-2, N0) and 56.7 % with locally advanced stage (T3-4 or N + ) tumors. IMRT was used for 815 patients (80.3 %) and a concurrent CT was administered in 781 patients, consisting of mitomycin-based CT for 80 %. The median follow-up was 35.5 months. DFS, CFS, and OS at 3 years were 84.3 %, 85.6 %, and 91.7 % respectively in the early-stage group compared to 64.4 %, 66.9 %, and 78.2 % in the locally-advanced group (p < 0.001). In multivariate analyses, male gender, locally-advanced stage, and ECOG PS ≥ 1 were associated with poorer DFS, CFS, and OS. IMRT was significantly associated with a better CFS in the whole cohort and almost reached significance in the locally-advanced group. CONCLUSION: Treatment of SCCA patients showed good respect for current guidelines. Significant differences in outcomes advocate for personalized strategies by either de-escalation for early-stage tumors or treatment intensification for locally-advanced tumors.

Clinical outcomes of adapted hypofractionated radiotherapy for bladder cancer in elderly patients.

OBJECTIVE: To investigate the feasibility, efficacy, and safety of trimodal therapy (TMT) using a bifractionated split-course hypofractionated radiotherapy (RT) for non-metastatic muscle-invasive bladder cancer (MIBC) in elderly patients. PATIENTS AND METHODS: We retrospectively reviewed the characteristics and outcomes of patients aged >75 years with non-metastatic MIBC suitable or not for radical cystectomy (RC) and treated with transurethral resection of bladder tumour followed by concomitant radio-chemotherapy (platinum salt and 5-fluorouracil) at two institutions (Saint Louis Hospital, Paris, France and European Georges Pompidou Hospital, Paris, France) between 1990 and 2021. RT consisted of an adapted bifractionated split-course hypofractionated RT. Acute toxicities were reported according to Common Terminology Criteria for Adverse Events version 5.0 and late toxicities were reported according to the Radiation Therapy Oncology Group/European Organisation for Research and Treatment of Cancer late radiation morbidity scoring schema. The primary end-point was overall survival (OS). Secondary end-points included other survivals outcomes and safety. RESULTS: A total of 122 patients were identified, with a median (range) follow-up of 51.1 (0.5-210.8) months. In all, 83.5% of patients completed radio-chemotherapy. The OS rate was 61.7% at 3 years and 51.2% at 5 years. In multivariate analysis, the completion of RT and concomitant chemotherapy were significantly associated with better OS and cancer-specific survival. For patients fit for RC, a complete histological response was achieved for 77 patients (91.7%) with radio-chemotherapy and the bladder conservation rate was 90.5%. Acute and late Grade ≥3 toxicities were <5%. CONCLUSION: Bifractionated split-course hypofractionated RT with concomitant chemotherapy regimen appears to be well-tolerated and effective. Trimodal treatment seems to be a curative option for elderly patients unfit for radical surgery compared with palliative care and may contribute to improved survival in these patients.

The 10-month mortality rate among older patients treated for digestive system cancer during the first wave of the COVID-19 pandemic: The CADIGCOVAGE multicentre cohort study.

INTRODUCTION: The coronavirus disease 2019 (COVID-19) pandemic has had a dramatic impact on cancer diagnosis and care pathways. Here, we assessed the mid-term impact of the COVID-19 pandemic on older adults with cancer before, during and after the lockdown period in 2020. MATERIALS AND METHODS: We performed a retrospective, observational, multicentre cohort study of prospectively collected electronic health records. All adults aged 65 or over and having been newly treated for a digestive system cancer in our institution between January 2018 until August 2020 were enrolled. RESULTS: Data on 7,881 patients were analyzed. Although the overall 10-month mortality rate was similar in 2020 vs. 2018-2019, the mortality rate among for patients newly treated in the 2020 post-lockdown period was (after four months of follow-up) significantly higher. A subgroup analysis revealed higher mortality rates for (i) patients diagnosed in the emergency department during the pre-lockdown period, (ii) patients with small intestine cancer newly treated during the post-lockdown period, and (iii) patients having undergone surgery with curative intent during the post-lockdown period. However, when considering individuals newly treated during the lockdown period, we observed lower mortality rates for (i) patients aged 80 and over, (ii) patients with a biliary or pancreatic cancer, and (iii) patients diagnosed in the emergency department. DISCUSSION: There was no overall increase in mortality among patients newly treated in 2020 vs. 2018-2019. Longer follow-up is needed to assess the consequences of the pandemic. A subgroup analysis revealed significant intergroup differences in mortality.

Phase II INTERACT-ION study: ezabenlimab (BI 754091) and mDCF (docetaxel, cisplatin, and 5-fluorouracil) followed by chemoradiotherapy in patients with Stage III squamous cell anal carcinoma.

Background: Chemoradiotherapy alone is the standard treatment for locally advanced squamous cell anal carcinoma (SCAC). However, up to 50% of patients will experience recurrence; thus, there is a need for new treatments to improve outcomes. Modified docetaxel, cisplatin and 5-fluorouracil (mDCF) is a treatment option for first-line metastatic SCAC, having shown efficacy in the Epitopes-HPV01 and -02 trials (NCT01845779 and NCT02402842). mDCF treatment also plays a role in the modulation of anti-tumor immunity, suggesting it may be a good combination partner for immunotherapy in patients with SCAC. Anti-programmed death protein-1 (PD-1) immunotherapy has been shown to be effective in metastatic SCAC. We therefore designed the INTERACT-ION study to assess the combination of mDCF with ezabenlimab (BI 754091), an anti-PD-1 antibody, followed by chemoradiotherapy, in patients with Stage III SCAC. Methods: INTERACT-ION is a pivotal, open-label, single-arm phase II study in patients with treatment-naïve Stage III SCAC. Patients will receive induction treatment with mDCF (docetaxel 40 mg/m2 and cisplatin 40 mg/m2 on Day 1, 5-fluorouracil 1200 mg/m2/day for 2 days) every 2 weeks for 4 cycles and ezabenlimab (240 mg given intravenously) every 3 weeks for 3 cycles. In the absence of disease progression at 2 months, two additional cycles of mDCF and one additional cycle of ezabenlimab will be administered. Patients with radiological objective response, pathological complete/near-complete response and biological complete response will then receive an involved-node radiotherapy with intensity-modulated radiation therapy and concurrent chemotherapy, followed by ezabenlimab alone for seven cycles. All other patients will receive standard chemoradiotherapy. The primary endpoint is the clinical complete response rate 10 months after the first cycle of mDCF plus ezabenlimab. Major secondary endpoints are major pathological response and biological complete response after induction treatment. An extensive ancillary biomarker study in tumor tissue and peripheral blood will also be conducted. Discussion: The addition of immunotherapy to chemotherapy is an area of active interest in metastatic anal cancer. This pivotal study will evaluate this combination in the locally advanced setting. Ancillary biomarker studies will contribute to the understanding of predictors of response or resistance to treatment. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT04719988, identifier NCT04719988.

ELANE neutropenia and solid tumors: Four cases from the French severe chronic neutropenia registry.

Neutropenia related to ELANE gene mutations predisposes patients to infection and leukemia/myelodysplasia, but little is known about the predisposition to cancer. Among a cohort of 147 patients, we identified four with malignant solid tumors (papillary thyroid cancer, anal squamous cell cancer, papillary renal cell carcinoma, and adrenocortical carcinoma), all aged 25-50 years. Three occurred with cyclic neutropenia, and one occurred with severe chronic neutropenia. Previous radiotherapy was identified as a risk factor in one patient. No genetic predisposition was identified in the three other patients.

What should be done in terms of fertility preservation for patients with cancer? The French 2021 guidelines.

AIM: To provide practice guidelines about fertility preservation (FP) in oncology. METHODS: We selected 400 articles after a PubMed review of the literature (1987-2019). RECOMMENDATIONS: Any child, adolescent and adult of reproductive age should be informed about the risk of treatment gonadotoxicity. In women, systematically proposed FP counselling between 15 and 38 years of age in case of treatment including bifunctional alkylating agents, above 6 g/m2 cyclophosphamide equivalent dose (CED), and for radiation doses on the ovaries ≥3 Gy. For postmenarchal patients, oocyte cryopreservation after ovarian stimulation is the first-line FP technique. Ovarian tissue cryopreservation should be discussed as a first-line approach in case of treatment with a high gonadotoxic risk, when chemotherapy has already started and in urgent cases. Ovarian transposition is to be discussed prior to pelvic radiotherapy involving a high risk of premature ovarian failure. For prepubertal girls, ovarian tissue cryopreservation should be proposed in the case of treatment with a high gonadotoxic risk. In pubertal males, sperm cryopreservation must be systematically offered to any male who is to undergo cancer treatment, regardless of toxicity. Testicular tissue cryopreservation must be proposed in males unable to cryopreserve sperm who are to undergo a treatment with intermediate or severe risk of gonadotoxicity. In prepubertal boys, testicular tissue preservation is: - recommended for chemotherapy with a CED ≥7500 mg/m2 or radiotherapy ≥3 Gy on both testicles. - proposed for chemotherapy with a CED ≥5.000 mg/m2 or radiotherapy ≥2 Gy. If several possible strategies, the ultimate choice is made by the patient.

The Role of Radiotherapy in Treating Kaposi's Sarcoma in HIV Infected Patients.

Kaposi's sarcoma (KS) is a radiosensitive cancer regardless of its form (classical, endemic, AIDS-related, and immunosuppressant therapy-related). Radiotherapy (RT) is an integral part of the therapeutic management of KS. RT may be used as the main treatment, in the case of solitary lesions, or as palliative therapy in the disseminated forms. The dose of RT to be delivered is 20-30 Gy by low-energy photons or by electrons. The complete response rate after RT is high, around 80-90%. This treatment is well tolerated. However, patients should be informed of the possible risk of the development of late skin sequelae and the possibility of recurrence. With the advent of highly active antiretroviral therapy (HAART), the indications for RT treatment in HIV-positive patients have decreased.

Intraoperative Radiotherapy for Breast Cancer in Elderly Women.

PURPOSE: To evaluate outcomes and postoperative toxicities after intraoperative radiotherapy (IORT) in elderly women. POPULATION: Women older than 65 years, with infiltrating ductal breast cancer ≤3 cm, expressing estrogen receptor (ER+) without Her2 overexpression, and with negative axillary nodes. TREATMENT: Treatment consisted of partial mastectomy with a sentinel lymph node biopsy (SLNB) procedure; in case of positive SLNB, IORT was cancelled. IORT consisted in a total dose of 20 Gy in 1 fraction delivered at the surface of the applicator with the Intrabeam® technique. RESULTS: IORT was planned to be administered to a total of 225 patients but was cancelled for 34 patients during surgery. Thus 191 patients were analyzed; mean age was 76 years, with 57 patients (30%) >80 years. Despite inclusion criteria, 15 had lobular carcinoma and 7 were triple negative. With a median follow-up of 40 months, we observed only 1 local recurrence, located in the skin over the initial tumor. The 5-year local relapse rate was 1.7%. A wound healing delay (>15 days) was observed in 21 patients (11%). Sixty-six patients (35%) had postoperative complications, mainly grade 2, resolving within a few days. Two patients needed surgical drainage for local abscesses. Long-term (>1 year) cosmetic outcome was evaluated in 120 patients and was judged excellent or good in 102 (91%). CONCLUSION: IORT can be safely given to elderly women, with a good local control rate and without major toxicities.

Effect of lockdown on digestive system cancer care amongst older patients during the first wave of COVID-19: The CADIGCOVAGE multicentre cohort study.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had a dramatic impact on cancer diagnosis and treatment. Most patients newly diagnosed with digestive system cancer are aged 65 and over. METHODS: We performed a retrospective, observational, multicentre cohort study based on prospectively collected electronic health records. All adults aged 65 or over and having been newly treated for a digestive system cancer between January 2018 until August 2020 were enroled. RESULTS: Data on 7882 patients were analysed. The first COVID-19 lockdown period led to a 42.4% decrease in newly treated digestive system cancers, and the post-lockdown period was associated with a 17% decrease. The decrease in newly treated digestive system cancer did not differ as a function of age, sex, comorbidities, primary tumour site, and disease stage. The proportion of patients admitted to an emergency department increased during the lockdown period. We do not observe a higher 3-month mortality rate in 2020, relative to the corresponding calendar periods in 2018 and 2019. CONCLUSION: To avoid a decrease in newly treated cancers during future lockdown periods, access to healthcare will have to be modified. Although 3-month mortality did not increase in any of the patient subgroups, the 2020 cohort must be followed up for long-term mortality.

Ten-Year Outcomes of Hypofractionated Postmastectomy Radiation Therapy of 26 Gy in 6 Fractions.

PURPOSE: To investigate the efficacy and long-term side effects of hypofractionated postmastectomy radiation therapy (HFRT-PM) of 26 Gy in 6 fractions over 5 weeks. METHODS AND MATERIALS: We retrospectively reviewed characteristics and outcomes of patients with stage I to III breast cancer treated with HFRT-PM between 2000 and 2009. Treatment provided 4 fractions of 4 Gy (days 1, 3, 15, 17) and then 2 fractions of 5 Gy (days 29 and 31) over 5 weeks. The treatment techniques were applied by using 3-dimensional conformal radiation therapy of the chest wall with regional nodal volume if required. RESULTS: We identified 454 patients with a median follow-up of 10.6 years (range, 0.5-22.9). Regional nodal irradiation was done in 84.1% of patients. At 10 years, the cumulative incidence of locoregional relapse was 15.1%. In multivariate analysis, regional lymph node involvement (≥4 nodes) was associated with worse locoregional control (hazard ratio, 1.68; 95% confidence interval, 1.06-2.67; P = .03) and overall survival (hazard ratio, 2.16; 95% confidence interval, 1.59-2.95; P < .001). The toxicities were acceptable. The incidence of cardiac disorders (3.3%), and symptomatic lung fibrosis (1.5%) was low during follow-up. At 10 years, the cumulative rate of arm lymphedema was 9.5% and considered severe in 20 patients (4.4%). CONCLUSIONS: The long-term results of this study show that HFRT-PM of 26 Gy in 6 fractions over 5 weeks seems safe, but locoregional recurrence seems slightly higher than that observed in the literature, highlighting the need for long-term follow-up and for randomized trials for hypofractionated radiation therapy postmastectomy.

Is There a Benefit of Oxaliplatin in Combination with Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer? An Updated Meta-Analysis.

BACKGROUND: Neoadjuvant fluoropyrimidine (5FU or capecitabine)-based chemoradiotherapy (CRT) has been considered the standard of care for locally advanced rectal cancer (LARC). Whether addition of oxaliplatin (OXP) will further improve clinical outcomes is still unclear. METHODS: To identify clinical trials combining oxaliplatin in preoperative CRT or perioperative chemotherapy for LARC published until March 2021, we searched PubMed and the Cochrane Library. We also searched for relevant ASCO conference abstracts. The primary endpoint was disease-free survival (DFS). Data were extracted from every study to perform a meta-analysis using Review Manager (version 5.3). RESULTS: A total of seven randomized clinical trials (ACCORD-12, CARO-AIO-04, FOWARC, JIAO, NSABP, PETACC-6, and STAR-01) with 5782 stage II or III rectal cancer patients were analyzed, including 2727 patients with OXP + 5FU regimen and 3055 patients with 5FU alone. Compared with the 5FU alone group, the OXP + 5FU regimen improved DFS (HR = 0.90, 95% CI: 0.81-0.99, p = 0.03) and pathologic complete response (pCR) (OR = 1.21, 95% CI: 1.07-1.37, p = 0.002). Patients treated with the OXP + 5FU regimen had significantly less metastatic progression (OR = 0.79; 95% CI, 0.67 to 0.94; p = 0.007). Considering adverse events (AEs), there was more grade 3-4 diarrhea with OXP + 5FU (OR = 2.41, 95% CI: 1.74-3.32, p < 0.00001). However, there were no significant differences grade 3-4 hematologic AEs (OR = 1.16, 95% CI: 0.87-1.57, p = 0.31). CONCLUSIONS: Our meta-analysis with long-term results from the randomized studies showed a benefit of the addition of OXP + 5FU regiment in terms of DFS, metastatic progression, and pCR rate that did not translate to improved OS.

Radiotherapy for gastric mucosa-associated lymphoid tissue lymphoma.

Gastric mucosa-associated lymphoid tissue (MALT) lymphoma is a rare disease which is often associated with Helicobacter pylori (H. pylori) infection. First-line treatment of stage IE and IIE localized gastric MALT lymphoma is based on the eradication of H. pylori. The presence of H. pylori resistance factors such as translocation t (11;18), peri-gastric lymph node involvement and the degree of tumor infiltration of the gastric wall; or lack of response to antibiotic therapy are two main indications to treat with definitive radiotherapy (RT). RT is an effective treatment in localized gastric MALT lymphoma. A moderate dose of 30 Gy allows a high cure rate while being well tolerated. After treatment, regular gastric endoscopic follow-up is necessary to detect a potential occurrence of gastric adenocarcinoma.

Locoregional relapses in the ACCORD 12/0405-PRODIGE 02 study: Dosimetric study and risk factors.

PURPOSE: The aim of this study is to correlate locoregional relapse with radiation therapy volumes in patients with rectal cancer treated with neoadjuvant chemoradiation in the ACCORD 12/0405-PRODIGE 02 trial. PATIENTS AND METHODS: We identified patients who had a locoregional relapse included in ACCORD 12's database. We studied their clinical, radiological, and dosimetric data to analyze the dose received by the area of relapse. RESULTS: 39 patients (6.5%) presented 54 locoregional relapses. Most of the relapses were in-field (n = 21, 39%) or marginal (n = 13, 24%) with only six out-of-field (11%), 14 could not be evaluated. Most of them happened in the anastomosis, the perirectal space, and the usual lymphatic drainage areas (presacral and posterior lateral lymph nodes). Only patients treated for a lower rectum adenocarcinoma had a relapse outside of the treated volume. 2 patients with T4 tumors extending into anterior pelvic organs had relapses in anterior lateral and external iliac lymph nodes. CONCLUSIONS: Lowering the upper limit of the treatment field for low rectal tumors increased the risk of out of the field recurrence. For very low tumors, including the inguinal lymph nodes in the treated volume should be considered. Recording locoregional involvement, treated volumes, and relapse areas in future prospective trials would be of paramount interest to refine delineation guidelines.

What is the optimal treatment for T1N0 anal squamous cell carcinoma? Analysis of current practices in the prospective French FFCD ANABASE cohort.

INTRODUCTION: for localized T1N0 squamous cell carcinoma of the anus (SCCA) standard radiotherapy (RT) may result in overtreatment and alternative strategies are debated. METHODS: T1N0M0 SCCA treated between 2015 and 2020 by local excision (LE) or RT were analyzed from the French prospective FFCD ANABASE cohort. Treatment strategies, recurrence-free and colostomy-free survivals (RFS, CFS) and prognostic factors were reported. RESULTS: among 1135 SCCA patients, 99 T1N0M0 were treated by LE(n = 17,17.2%), or RT (n = 82,82.8%) including RT alone (n = 65,79.2%) or chemo-RT (n = 17, 20.7%). Median follow-up was 27.2 months [0.03-54.44]. Median tumor size were 11.4 mm [0.9-20] and 15.3 mm [2-20] in the LE and RT groups respectively. Mean RT tumor dose was 59.4 Gy [18-69.4 Gy]. One patient in LE group and 9 in RT group had a pelvic recurrence, either local (60%), nodal (10%) or both (30%). RFS and CFS at 24 months were 92.2%[95%CI,83.4-96.4] and 94.6%[95%CI,86.1-98.0], at 36 months 88.1%[95%CI,77.1-94.2] and 88.5%[95%CI,77.0-94.5], in LE and RT group respectively, without any significative difference (HR = 0.57;[95%CI,0.07-4.45];p = 0.60). By univariate analysis, male gender was the only prognostic factor(HR = 5.57;95%CI, 1.76-17.63; p = 0.004). CONCLUSION: this cohort confirms the heterogeneity of T1N0M0 SCCA management, questioning the place of RT alone, reduced dose or RT volume, and the safety of LE.