Pelvic Insufficiency Fractures and Bone Pain after Radiation Therapy for Anal Cancer: Relation to Pelvic Bone Dose-Volume Parameters.

Purpose: Chemoradiation therapy is the primary treatment for anal cancer. Radiation therapy (RT) can weaken the pelvic bone structure, but the risk of pelvic insufficiency fractures (PIFs) and derived pain in anal cancer is not yet established. We determined the frequency of symptomatic PIFs after RT for anal cancer and related this to radiation dose to specific pelvic bone substructures. Methods and Materials: In a prospective setting, patients treated with RT for anal cancer had magnetic resonance imaging 1 year after RT. PIFs were mapped to 17 different bone sites, and we constructed a guideline for detailed delineation of pelvic bone substructures. Patients were interviewed regarding pain and scored according to Common Terminology Criteria for Adverse Effects. Dose-volume relationships for specific pelvic bone substructures and PIFs were determined for V20 to V40 Gy mean and maximum doses. Results: Twenty-seven patients were included, and 51.9% had PIFs primarily located in the alae of the sacral bone. Patients with PIFs had significantly more pelvic pain (86% vs 23%, P = .001) and 43% had grade 2 bone pain. Dose-volume parameters for sacral bone and sacral alae were significantly higher in patients with PIFs (P < .05). V30 Gy (%) for sacral bone and alae implied an area under the curve of 0.764 and 0.758, respectively, in receiver operating characteristic analyses. Conclusions: We observed a high risk of PIFs in patients treated with RT for anal cancer 1 year after treatment. A significant proportion had pain in the sites where PIFs were most frequently found. Radiation dose to pelvic bone substructures revealed relation to risk of PIFs and can be used for plan optimization in future clinical trials.

One-Year Treatment-Related Side Effects and Quality of Life After Chemoradiotherapy in Squamous Cell Carcinoma of the Anus.

PURPOSE: Patient-reported outcome (PRO) and National Cancer Institute-Common Terminology Criteria for Adverse Events (NCI-CTCAE) data for patients with squamous cell carcinoma of the anus (SCCA) treated with modern radiation therapy (RT) are lacking. The primary aim of this study was to report bowel and bladder PRO and NCI-CTCAE for patients with SCCA 1 year after RT. METHODS AND MATERIALS: From 2015 to 2020, we included patients in a prospective Danish national study. Data were collected before treatment (PT) and 1 year after treatment (1Y) using NCI-CTCAE version 4.0, as well as European Organisation for Research and Treatment of Cancer Quality of Life Questionnaires C30 and CR29. We evaluated the combined PRO scores according to the European Organisation for Research and Treatment of Cancer scoring guidelines, and classified changes according to score difference from PT to 1Y as no change (0-5), minor (5-10), moderate (11-20), and major (>20). Raw scores were reported as frequencies of each of the scores: Not at all, a little, quite a bit, and very much. RESULTS: Of the 270 patients, 81% had complete data sets, including PT and 1Y answers. Functional mean scores were equal to a matched normal population cohort at PT and 1Y. From PT to 1Y, C30 scores were stable despite minor improvements in global health status/quality of life (7.3), emotional functioning (9.3), insomnia (8.0), and appetite loss (7.8). For questionnaire CR29, bowel and bladder symptoms and sore skin improved with minor change (6.2), and buttocks, anal, or rectal pain improved with moderate change (18.3). Flatulence worsened moderately (12.6), and fecal incontinence had minor worsening (7.8). Agreement between PROs and NCI-CTCAE was generally only fair to moderate, especially for quantitative symptoms, such as pain (κ = 0.25). CONCLUSIONS: For patients with SCCA who underwent definitive RT, only a few patients had high scores (indicating quite a bit or very much frequency of bother) regarding bowel and bladder symptoms.

Intensified Induction Chemotherapy in Locally Advanced Squamous Cell Carcinoma of the Anus-A Population-Based Experience from the Danish Anal Cancer Group.

Locally advanced squamous cell carcinoma of the anus (LASCCA) has a poor prognosis with a high risk of treatment failure calling for intensified therapy. We present the long-term follow-up of a nationwide cohort of LASCCA treated with intensified induction chemotherapy (ICT). The study included patients with LASCCA (T3-4N0 or T1-4N+) treated with at least one cycle of ICT (cisplatin, ifosfamide, leucoverin, and 5-flourouracil) between 1998-2018. Data were retrospectively collected from medical records, and statistics were performed in STATA 16.1. In total, 166 patients with LASCCA were identified. Following ICT, 157 patients (95%) received primary curative treatment with either radiotherapy (70%), chemoradiotherapy (27%), or abdominal perineal resection (3%). The overall local tumor response rate after ICT was 76% with 20 (13%) achieving complete local tumor response. After the primary treatment, 123 patients (79%) obtained complete response, and 27 underwent salvage surgery due to persistent disease. The median follow-up time was 6 years, local and distant failure rates 22% and 13%, respectively. The 3- and 5-year disease-free survival rates were 70% and 67%, and the 3- and 5-year overall survival rates were 76% and 70%, respectively. Intensified ICT regimen could be a supplementary treatment option in the most advanced cases of LASCCA. Prospective randomized trials are needed to investigate this approach further.