ABSTRACT
OBJECTIVE: To evaluate the clinical significance of primary tumor volume(PTV) by preoperative highresolution MRI measurement in subgroup of cT3 low rectal cancer. METHODS: A total of 99 patients with low rectal cancer who confirmed by pathology and assessed at stage-cT3 by MRI,did not undergo neoadjuvant chemoradiotherapy(nCRT) treated in Department of Colorectal Surgery,Fujian Medical University Union Hospital from June 2010 to December 2012 were adopted in the study. The relations between PTV and the depths of tumor infiltration out of mesorectum were analyzed through Spearman correlation analysis. The receiver-operating characteristic(ROC) curve was used to analyze the PTV and 3-year disease-free survival. Cox proportional hazard model was performed for influence factors analysis. RESULTS: The depth of tumor infiltration mesorectum and the PTV were revealed significantly correlated(P 15 cm~3 or PTV≤14.8 cm~3/>14.8 cm~3. The difference between groups revealed significant in the 3-year disease-free survival rate,the local recurrence rate and the distant metastases rate.COX regression analysis was utilized for 3-year disease-free survival,and the multivariate analysis indicated that PTV was an independent impact factor(HR=0.180,95%CI 0.078-0.415,P<0.05). CONCLUSION: The primary tumor volume (PTV) by preoperative high-resolution MRI measurement might be used as a new prognostic parameter for cT3 low rectal cancer.
ABSTRACT
Objective:To investigate the prognosis of cT3 and the subgroups of low rectal cancer patients who underwent neoadju-vant chemoradiotherapy (CRT) and evaluate whether all patients with cT3 low rectal cancer should undergo CRT. Methods:A total of 223 patients with cT3 low rectal cancer treated in the Department of Colorectal Surgery of Fujian Medical University Union Hospital from January 2008 to December 2012 were divided into neoadjuvant chemoradiotherapy group (CRT group) (115 cases) and no neoad-juvant chemoradiotherapy group (nCRT group) (108 cases) according to whether the patients underwent CRT. Afterward, the patients were retrospectively divided into three subgroups (mrT3a, mrT3b, and mrT3c) according to the proposed criteria of the Radiologic Soci-ety of North America (RSNA) by measuring the depth of mesorectal invasion (DMI) (DMI10 mm). The prog-noses of the two groups and their subgroups were compared. Results:The CRT and nCRT groups revealed no significant differences in the 3-year disease-free survival rate and the local recurrence rate for all the mrT3 patients (78.2%vs. 71.9%, P=0.608;4.4%vs. 8.5%, P=0.120) and mrT3a patients (82.4%vs. 81.8%, P=0.837;5.8%vs. 5.9%, P=0.658). On the contrary, for the mrT3b patients, the CRT and nCRT groups revealed significant differences in the 3-year disease-free survival rate (84.4%vs. 42.4%, P=0.032) and local recurrence rate (0.0%vs. 18.2%, P=0.014). For the mrT3b,c patients, the CRT and nCRT groups revealed no significant difference in the 3-year dis-ease-free survival rate (72.8%vs. 42.4%, P=0.060) but revealed a significant difference in the local recurrence rate (2.4%vs. 18.2%, P=0.021). COX regression analysis was utilized for 3-year disease-free survival, DMI and circumferential resection margin (CRM) were significant in the univariate analysis. Additionally, the multivariate analysis indicated that CRM is an independent impact factor (OR=2.249, CI 1.067-4.742, P=0.033). Conclusion:CRT can improve the prognosis of patients with mrT3b,c low rectal cancer but may not significantly influence the prognosis of patients with mrT3a and CRM-negative low rectal cancer;surgical treatment can be performed in these patients without CRT.