Is It Possible a Conservative Approach After Radiochemotherapy in Locally Advanced Rectal Cancer (LARC)? A Systematic Review of the Literature and Meta-analysis

Background: Locally advanced rectal cancer is usually treated with a preoperative approach with radiochemotherapy followed by surgery. Patients obtaining a pathologic complete response have a very favorable long-term prognosis. This study was intended to assess whether major surgery can reduce tumor recurrences and prolong survival of patients with a complete response after radiochemotherapy. Methods: Computerized literature search was performed to identify relevant articles. Comparative studies reporting the outcomes of non-operative and operative management in patients after neoadjuvant treatment were reviewed. Data synthesis was performed using Review Manager 5.0 software. Results: Twelve non-randomized comparative studies with a total of 1812 patients were suitable for analysis. There was no significant difference in overall survival at 3 and 5 years (odds ratio [OR] 1.31; 95% CI 0.64–2.69; p = 0.46 and 1.48; 95% CI 1.00–2.20; p = 0.50) and in disease-free survival at 3 and 5 years (odds ratio [OR] 1.20; 95% CI 0.68–2.14; p = 0.53 and 1.22; 95% CI 0.86–1.74; p = 0.26, respectively) between locally advanced rectal cancer patients treated with and without operative approach. Conclusions: Major surgery does not seem to improve prognosis in patients obtaining a complete response after radiochemotherapy. Clinical trials, using clear criteria to identify complete response patients, are needed to recommend non-operative approach.