Assessment of tumor regression in patients with rectal carcinoma treated with neoadjuvant chemoradiotherapy

ABSTRACT

Introduction: Colorectal cancer is the third most common cancer diagnosis among both genders worldwide and the second in developed countries. The high incidence of local recurrence (20-70%) remains perhaps the major complication of surgery for rectal cancer, besides the persistent high rate of distant metastasis (30-35%) in this disease. Object The aim of the present study was to assess the impact of neoadjuvant chemoradiotherapy in pathologic characteristics of rectal cancer patients, analyzing the possible morphological parameters influencing the response to preoperative treatment. Material and Methods: We retrospectively selected all the patients who had received neoadjuvant chemoradiotherapy followed by excisional surgery for rectal carcinoma between 2003 and 2009 in Hospital São Marcos, Teresina - Piauí - Brazil. The clinical and pathological features for each patient were retrieved. The correlation between tumor regressiongrade (TRG) and other parameters were studied with the Pearson chi-square test. All statistical analyses were conducted using SPSS 19.0. Results: From January 2003 to December 2009, 79 patients with rectal cancer were treated with neoadjuvant chemoradiotherapy. Pathologicexamination of resected specimens revealed complete tumor regression (TRG1) in 18%, partial tumor regression (TRG2-4) in 71% and no regression (TRG5) in 11% of the patients. Of all the patients, 48% had their tumor downstaged at the time of pathologic examination. We found correlation (p < 0.05) between different levels of tumor regression and necrosis, histological type, differentiation grade and metastasis. Conclusion: Pathological complete response was 18% and was positive correlated with high histological differentiated, usual adenocarcinoma and absence of necrosis and metastasis