Prognostic value of tumor response to neoadjuvant therapy in rectal carcinoma.

Background: Neoadjuvant treatment in the multimodal therapy concept of rectal carcinoma has considerable effects on prognosis appraisal.

Objective: This study aimed to evaluate the tumor response specified as an improvement by at least one stage defined in terms of the International Union Against Cancer stages as a prognostic factor.

Design: This investigation was designed as a prospective cohort study.

Setting: This study was performed at a community-based hospital with a specialized colorectal unit.

Patients: One hundred seventy-four patients with locally advanced rectal carcinoma, treated in the Dresden-Friedrichstadt hospital from 1997 to 2009, who received long-term preoperative chemoradiotherapy and underwent curative resection, were included in this study.

Main Outcome Measures: The main outcome measures were cause-specific and disease-free survival with respect to T and N category, International Union Against Cancer stage, venous and lymphatic invasions, grading, CEA level, complete pathologic response, tumor regression grading, International Union Against Cancer stage shift, T, N, and CEA shift, types of neoadjuvant therapy, adjuvant therapy, interval between completion of neoadjuvant chemoradiotherapy and surgery, and number of extracted lymph nodes in resected specimens. Univariate and multivariate analyses were performed.

Results: Median follow-up was 45 months. One hundred twenty-one patients (69.5%) showed a response to the treatment, whereas 53 (30.5%) did not. Five-year cause-specific and disease-free survival for responders (n = 121) vs nonresponders (n = 53) were 92.6% and 73.7% vs 84.9% and 47.9%. In the univariate analysis, ypN category, venous and lymphatic invasion, tumor regression grading, International Union Against Cancer stage shift, and T and N shift were significantly predictive for cause-specific and disease-free survival. Furthermore, ypUICC stage, ypT category, grading, and complete pathologic response had an impact on disease-free survival. In the multivariate analysis, only the International Union Against Cancer stage shift kept its independent explanatory power for cause-specific P = .012, HR 3.10 (95% CI 1.28-7.51) and disease-free survival P < .001, HR 3.85 (95% CI 1.98-7.51).

Limitations: The determination of International Union Against Cancer stage shift depends on the pretreatment staging modalities.

Conclusion: Our investigation demonstrates that the response of tumor to neoadjuvant therapy is an independent prognostic factor in patients with rectal carcinoma.