Adjuvant chemotherapy after neoadjuvant chemo-radiotherapy and surgery in locally advanced rectal cancer. A systematic review of literature with a meta-analysis of randomized clinical trials

Highlights: Although no definitive data exist in literature, adjuvant chemotherapy is usually recommended in patients with radically resected stage III rectal cancer treated with neo-adjuvant chemo-radiotherapy. We performed a systematic review of literature with direct and indirect comparisons to assess the role of adjuvant mono or poli-chemotherapy in radically resected rectal cancer treated with neoadjuvant chemo-radiotherapy. Neither chemotherapy (mono-or poli-chemotherapy) nor polichemotherapy with oxaliplatin-containing regimens seems to improve Overall Survival and Disease-Free Survival in patients with radically resected rectal cancer treated with neoadjuvant chemo-adiotherapy. Neither the entire population of patients radically resected after neoadjuvant chemotherapy, nor high risk patients seem to benefit from adjuvant chemotherapy. Our data seem to suggest the need of review the actual international guidelines that suggest the need of adjuvant chemotherapy at least in high risk rectal cancer treated with surgery and neoadjuvant chemo-radiotherapy.