No benefit after neoadjuvant chemoradiation in stage IV rectal cancer : A propensity score-matched analysis on a real-world population

Background: Stage IV rectal cancer occurs in 25% of patients and locoregional control of primary tumor is usually poorly considered, since priority is the treatment of metastatic disease. Aims: This study evaluates impact of neoadjuvant chemoradiation followed by surgery (nCHRTS) vs. upfront surgery on locoregional control and overall survival in stage IV rectal cancer. Methods: All patients diagnosed with stage IV rectal carcinoma between 2009 and 2019, undergone elective surgery at the National Cancer Institute of Milan (Italy), were included. Propensity score-based matching was performed between the two study groups. Loco-regional recurrence-free survival (LRRFS) and overall survival (OS) were analysed using Kaplan-Meyer method. Results: A total of 139 patients were analyzed. After propensity score matching, 88 patients were included in the final analysis. The 3-yr LRRFS rates were 80.3% for nCHRTS vs. 90.4% for upfront surgery patients (p = 0.35). The 3-yr OS rates were respectively 81.8% vs. 58% (p = 0.36). KRAS mutation (HR 2.506, p = 0.038) and extra-liver metastases (HR 4.308, p = 0.003) were both predictive of worse OS in univariate analysis. Conclusion: The present study failed to demonstrate a significant impact of nCHRTS on LRRFS or OS in stage IV rectal cancer.