Overall Survival Benefit in Rectal Cancer After Neoadjuvant Radiotherapy and Adjuvant Chemotherapy: A...

Area of Science:

• Oncology
• Surgical Oncology
• Radiotherapy

Background:

• Neoadjuvant radiotherapy is known to reduce local recurrence in rectal cancer patients undergoing surgery.
• However, the oncologic efficacy and survival benefits of adjuvant chemotherapy following neoadjuvant radiotherapy remain unclear.

Purpose of the Study:

• To evaluate the survival benefit of adjuvant chemotherapy after neoadjuvant radiotherapy in rectal cancer patients.
• To develop a nomogram for predicting survival benefits associated with neoadjuvant radiotherapy.

Main Methods:

• A retrospective cohort study analyzed 22,008 rectal cancer patients from the SEER database (2004-2014).
• Propensity score matching was used to compare outcomes between groups receiving different treatment combinations.
• Overall survival was assessed using log-rank tests and Cox regression analysis.

Main Results:

• Adjuvant chemotherapy did not significantly impact overall survival when given after surgery alone or after neoadjuvant radiotherapy and surgery for Stage I-III rectal cancer.
• However, adjuvant chemotherapy significantly improved overall survival for patients who received neoadjuvant radiotherapy followed by surgery, across all stages (I-III).
• A predictive nomogram integrating clinicopathologic factors demonstrated promising performance in identifying patients who benefit from neoadjuvant radiotherapy.

Conclusions:

• Rectal cancer patients receiving neoadjuvant radiotherapy show acceptable outcomes.
• These patients are more likely to benefit from adjuvant chemotherapy in terms of overall survival.
• Findings support consistent guideline adherence for adjuvant chemotherapy use post-neoadjuvant radiotherapy.