Oncologic Outcome to Neoadjuvant Chemoradiation for Rectal Carcinoma after Surgery (NCI -Cairo and Minia Oncology Center Experience)

摘要

Background: Surgery is the mainstay of curative treatment for carcinoma of the rectum. Neoadjuvant chemoradiotherapy (CRT) and an 8week hiatus may give a chance to spare a major surgical procedure in a subset of patients with rectal carcinoma. The current retrospective study studied the correlation between the clinical response assessment after neoadjuvant therapy and tumor regression grade in post-operative pathological examination. We tried to identify the category of patients who may benefit from” watch and wait “protocol to avoid the morbidity of surgical intervention. Patients and Methods: The current retrospective study included 124 patients with histologically proven stage II-III rectal adenocarcinoma treated at NCI-Cairo and Minia Oncology Center during the period between January 2010 and December 2015. All patients were to be treated by neoadjuvant CRT followed by surgical intervention. Post-operative pathological response was compared with the clinicopathologic characteristics as well as the pre-operative clinical response after neoadjuvant CRT. Results: Among the study group, 120 patients were subjected to surgery. In 30 patients (25%) there was no viable tumor cells in the surgical specimen (Group 3). Pathological examination documented mild response (Group 2) in 56 patients (46.7% ) and no response (Group 1) in 34 patients (28.3%). There was no statistically significant difference as regards the clinicopathologic characteristics of patients according to the degree of pathologic response to neo -adjuvant therapy. The correlation between the clinical response after neoadjuvant therapy and the pathologic response after surgical intervention was studied. It was found that out of the 6 patients who showed complete clinical remission, no viable tumor cells were documented in only one patient (17%). Moreover, out of the 54 patients who showed partial clinical remission, no viable tumor cells were documented in 24 patients (44 %). Among the 48 patients who showed clinically stable disease, no viable tumor cells were documented in 5 patients (11%). Thus, the majority ( 80% ) of patients with no viable tumor cells had partial clinical response while only 3.3 % had clinical complete remission and 16.7% had clinically stable disease after neo adjuvant therapy. As regards the overall survival rates, there was no significant difference in survival according the clinical response after neoadjuvant therapy. On the other hand, the degree of pathologic response significantly affected the survival (p-value 0.002). Conclusions: The extent of clinical response after neoadjuvant therapy is not always a true indicator for the pathologic response after surgical intervention. The “watch and wait” approach may be a valid option not only for patients achieving complete clinical remission but also for some patients, who show partial or even stable disease after neoadjuvant therapy if properly evaluated.