Adjuvant treatment for locally advanced rectal cancer patients after pre-operative chemoradiotherapy: when, and for whom?

Background: The standard treatment for patients with locally advanced rectal cancer (clinical tumor, node, metastases [TNM] stage II or III) is radiotherapy before surgery (with or without concomitant fluoropyrimidine-based chemotherapy) followed by surgery. The role of adjuvant chemotherapy in this setting of patients is controversial in terms of the overall benefit on survival, the subgroup of patients who might not need it, and the best regimen (combination regimens vs. fluoropyrimidine alone). Patients and Methods: Based on the retrospective analysis of the clinical outcome of all patients with locally advanced rectal adenocarcinoma treated at our institute during the past 9 years, we comment on prognostic factors for local and distant metastases of patients who received neoadjuvant treatment followed by surgery, and the scientific evidence that can help to decide the adjuvant chemotherapy. Results: We conclude that pathological TNM stage after neoadjuvant chemoradiation (ypTNM) stage after surgery significantly affects disease-free and overall survival. In particular, patients with pathologically positive lymph nodes (ypN+) after surgery have a high probability of developing distant metastases. Conclusion: ypN+ patients are candidate for intensified adjuvant chemotherapy.