Consolidation chemotherapy for locally advanced mid- or low rectal cancer after neoadjuvant concurrent chemoradiotherapy: A multicenter, randomized controlled trial (KONCLUDE).

Abstract

TPS813 Background: Chemoradiotherapy (CRT) followed by total mesorectal excision (TME) has been a standard treatment option for locally advanced mid or low rectal cancer with improved local control. However, systemic recurrence after the standard therapy is the most important failure of treatment, and several efforts have been trying to overcome it. Consolidation chemotherapy is adding several cycles of chemotherapy between neoadjuvant CRT and TME. It could increase the proportion of pathologic complete response (pCR), subsequently could show better oncologic outcomes. Methods: Patients with advanced mid or low rectal cancer who received neoadjuvant CRT will be included after screening. They will be randomized and assigned to underwent TME followed by adjuvant chemotherapy of 8 cycles (control arm) or receive 3 cycles of chemotherapy before TME, and receive 5 cycles of chemotherapy (experimental arm). The primary endpoints are pathologic complete response and 3-year disease-free survival, and the secondary endpoints are radiotherapy-related complications, R0 resection, tumor response rate, surgery-related morbidity, and peripheral neuropathy 3 year after the surgery. The authors hypothesize that the experimental arm would show a 15% improvement in two primary endpoints, compared with the control arm. Based on the superiority design, an one-sided log-rank test with α-error of 0.025 and a power of 90% was conducted. Allowing for a drop-out rate of 10%, 316 patients (158 per arm) will need to be recruited. The accrual period is 2 years and the follow-up period is 3 years. Discussion: KONCLUDE (A Korean society of coloproctology trial: cONsolidation Chemotherapy for Locally advanced mid or low rectal cancer after neoadjUvant concurrent chemoraDiothErapy: A multicenter, randomized controlled trial) is expected to provide evidence to support clear treatment guidelines for patients with locally advanced rectal cancer. Clinical trial information: 02843191.