[Colorectal cancer: ten years of illusion of progress but advances are on the horizon]. / Le cancer colorectal : dix années d'illusion de progrès mais des avancées sont à l'horizon.

Recent years have basically been marked by a modest progress in digestive oncology. Biologic drugs such as anti-EGFR and antiangiogenic antibodies have improved the overall survival of patients with advanced colorectal cancer for a few months, but did not alter adjuvant treatment paradigms after curative resection of a locally advanced colon cancer or of liver metastases. With the exception of the RAS gene mutations, predictive of lack of effectiveness to anti-EGFR antibodies, our knowledge of colon cancer tumor biology has hardly evolved. Long-awaited novelties come rather from fundamental discoveries about the different genomic subtypes of colorectal cancer and new immunotherapy approaches which both announce hopefully real giant leaps in the near future.

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.