The 2017 Assisi Think Tank Meeting on rectal cancer: A positioning paper

Abstract

Background and purposes: To describe current practice in the management of rectal cancer, to identify uncertainties that usually arise in the multidisciplinary team (MDT)'s discussions ('grey zones') and propose next generation studies which may provide answers to them. Materials and methods: A questionnaire on the areas of controversy in managing T2, T3 and T4 rectal cancer was drawn up and distributed to the Rectal-Assisi Think Tank Meeting (ATTM) Expert European Board. Less than 70% agreement on a treatment option was indicated as uncertainty and selected as a 'grey zone'. Topics with large disagreement were selected by the task force group for discussion at the Rectal-ATTM. Results: The controversial clinical issues that had been identified within cT2-cT3-cT4 needed further investigation. The discussions focused on the role of (1) neoadjuvant therapy and organ preservation on cT2-3a low-middle rectal cancer; (2) neoadjuvant therapy in cT3 low rectal cancer without high risk features; (3) total neoadjuvant therapy, radiotherapy boost and the best chemo-radiotherapy schedule in T4 tumors. A description of each area of investigation and trial proposals are reported. Conclusion: The meeting successfully identified 'grey zones' and, in the light of new evidence, proposed clinical trials for treatment of early, intermediate and advanced stage rectal cancer.

ESTRO/ACROP IORT recommendations for intraoperative radiation therapy in primary locally advanced rectal cancer

“… The tendency of T4 stage to recur in anterior pelvic structures, although IOERT has also been reported to promote high local control rates in this disease category. The excellent local results obtained in more favourable disease risk factors, which might make it advisable to reconsider the need for radiation treatment intensification and implement strategies with short-course preoperative pelvic irradiation including an IOERT component [33] , [34] The use of adjuvant chemotherapy should be recommended after IOERT treatment in patients with proven adverse local features. In-vivo-dosimetry and intra-operative imaging could improve the accuracy, reproducibility and documentation and provide data for evaluation and tailoring of IOERT Tailored IOERT may be further defined by establishing correlations between biological equivalent dose (BED) calculations, topographic patterns of recurrence, and prognostic features for local effects.…”

“… The tendency of T4 stage to recur in anterior pelvic structures, although IOERT has also been reported to promote high local control rates in this disease category. The excellent local results obtained in more favourable disease risk factors, which might make it advisable to reconsider the need for radiation treatment intensification and implement strategies with short-course preoperative pelvic irradiation including an IOERT component [33] , [34] The use of adjuvant chemotherapy should be recommended after IOERT treatment in patients with proven adverse local features. …”

“…The excellent local results obtained in more favourable disease risk factors, which might make it advisable to reconsider the need for radiation treatment intensification and implement strategies with short-course preoperative pelvic irradiation including an IOERT component [33] , [34] …”

Neoadjuvant Chemotherapy in Locally Advanced Rectal Cancer

“…Patients with surgical complications after conventional CRT, particularly those having an abdomino-perineal resection, may have delayed postsurgical recovery and may not receive timely postoperative chemotherapy. Moreover, TNT could have an impact on the complete response rate, and it has potential as an option in patients eligible for organ preservation strategies [22].…”

Adjuvant Chemotherapy in Elderly Colorectal Cancer Patients

“…The risk of local recurrence has in rectal cancer decreased thanks to the use of pre-operative (chemo)radiotherapy (RT/CRT), precise surgery, improved preoperative staging using magnetic resonance imaging (MRI), and multidisciplinary team meetings [41]. Systemic recurrences have only marginally decreased [42] and now contribute to the majority of rectal cancer deaths after radical surgery.…”