Preoperative Radiochemotherapy in Rectal Cancer: Is There an Impact of Oxaliplatin on Pathologic Complete Response...

Area of Science:

• Oncology
• Gastrointestinal Cancer Research
• Clinical Trial Analysis

Background:

• Locally advanced rectal cancer (LARC) requires effective neoadjuvant treatment to improve outcomes.
• Fluorouracil-based neoadjuvant radiochemotherapy (nRCT) is a standard treatment, but its efficacy can be enhanced.
• The role of oxaliplatin in combination with fluorouracil during nRCT for LARC warrants further investigation.

Purpose of the Study:

• To evaluate the impact of adding oxaliplatin to fluorouracil-based nRCT on pathologic complete remission (pCR), disease-free survival (DFS), and overall survival (OS).
• To identify prognostic factors influencing survival outcomes in patients with advanced rectal cancer treated with nRCT.

Main Methods:

• Retrospective analysis of 414 patients with advanced rectal cancer who received nRCT between 2006 and 2021.
• Comparison between patients treated with fluorouracil/capecitabine (n=283) and those treated with fluorouracil/capecitabine plus oxaliplatin (n=131).
• Propensity score matching (PSM) was used to create balanced groups (114 patients each) for comparative analysis of outcomes.

Main Results:

• The addition of oxaliplatin to nRCT significantly increased the pCR rate (27% vs. 16%, p=0.033) after PSM.
• No significant differences were observed in 10-year OS (67.8% vs. 55.1%, p=0.703) or DFS (44.7% vs. 42.3%, p=0.184) between the groups post-PSM.
• Multivariate analysis identified Dworak grade 4 regression and age over 60 as independent predictors for OS.

Conclusions:

• Adding oxaliplatin to fluorouracil-based nRCT improves pCR rates in advanced rectal cancer.
• The addition of oxaliplatin does not significantly affect long-term overall survival or disease-free survival.
• Prognostic factors such as tumor regression grade and patient age are critical for predicting OS.