Adjuvant chemotherapy for rectal cancer: Current evidence and recommendations for clinical practice.

While adjuvant chemotherapy is an established treatment for pathological stage II and especially stage III colon cancer, its role in the multimodal management of rectal cancer remains controversial. As a result, there is substantial variation in the use of this treatment in clinical practice. Even among centres and physicians who consider adjuvant chemotherapy as a standard treatment, notable heterogeneity exists with regard to patient selection criteria and chemotherapy regimens. The controversy around this topic is confirmed by the lack of full consensus among national and international clinical guidelines. While most of the clinical trials do not support the contention that adjuvant chemotherapy may improve survival outcomes if pre-operative (chemo)radiotherapy is also given, these suffer from many limitations that preclude drawing definitive conclusions. Nevertheless, in the era of evidence-based medicine, physicians should be guided by the available data and refrain from extrapolating results of adjuvant colon cancer trials to inform treatment decisions for rectal cancer. Patients should be informed of the evidence gap, be given the opportunity to carefully discuss pros and cons of all the possible management options and be empowered in the decision making. In this article we review the available evidence on adjuvant chemotherapy for rectal cancer and propose a risk-adapted decisional algorithm that largely relies on informed patient preferences.

Grey areas and evidence gaps in the management of rectal cancer as revealed by comparing recommendations from clinical guidelines.

BACKGROUND: While the management of nonmetastatic and oligometastatic rectal cancer has rapidly evolved over the last few decades, many grey areas and highly debated topics remain that foster significant variation in clinical practice. We aimed to identify controversial points and evidence gaps in this disease setting by systematically comparing recommendations from national and international clinical guidelines. METHODS: Twenty-six clinical questions reflecting practical challenges in the routine management of nonmetastatic and oligometastatic rectal cancer patients were selected. Recommendations from the ESMO, NCCN, JSCCR, Australian and Ontario guidelines were extrapolated and compared using a 4-tier classification system (i.e., identical/very similar, similar, slightly different, different). Overall agreement between guidelines (i.e., substantial/complete disagreement, partial disagreement, partial agreement, substantial/complete agreement) was assessed for each clinical question and compared against the highest level of available evidence by using the χ2 statistic test. RESULTS: Guidelines were in substantial/complete agreement, partial agreement, partial disagreement, and substantial/complete disagreement for 8 (30.8%), 2 (7.7%), 7 (26.9%), and 9 (34.6%) clinical questions, respectively. High level of evidence supported clinical recommendations in 3/10 cases (30%) where guidelines were in agreement and in 10/16 cases (62.5%) where guidelines were in disagreement (χ2 = 2.6, p = 0.106). Agreement was frequently reached for questions regarding diagnosis, staging, and radiology/pathology pro-forma reporting, while disagreement characterised most of the treatment-related topics. CONCLUSIONS: Substantial variation exists across clinical guidelines in the recommendations for the management of nonmetastatic and oligometastatic rectal cancer. This variation is only partly explained by the lack of supporting, high-level evidence.