Document Type: Research/Original Article
Colorectal Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
Colorectal Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
University of Kufa, College of medicine, Kufa, Iraq
Department of Radiation Oncology, Shiraz University of Medical Sciences, Shiraz, Iran
Background: Colorectal cancer causes many deaths worldwide and rectal cancer includes one-third of them. Surgical mesorectal excision along with preoperative neoadjuvant chemoradiotherapy is known as the standard treatment for rectal cancer. However, inaccurate preoperative staging is a main concern which leads to large number of patients not being treated with neoadjuvant therapy. Selection of the best treatment approach for these patients is controversial. Although significant better survival was observed is patients who received postoperative adjuvant chemoradiation compared with patients who treated with surgery alone, other studies did not find such results. Due to these contradictory results, this study was designed to further evaluate the survival outcomes in rectal cancer patients who received adjuvant chemoradiotherapy without neoadjuvant therapy. Methods: Totally 197 rectal cancer patients who received adjuvant chemoradiation were included in this study. The demographic and clinico-pathological characteristics of the patients were evaluated by statistical analysis. Results: Based on the univariate cox regression, poor disease free survival (DFS) was significantly associated with male sex and T3 stage. Poor overall survival (OS) was also associated with stage II/III, T3/T4, NI/NII, grade II/III, positive node number (> 3), perineural invasion, lymphovascular invasion, and margin involvement. According to the multivariate cox regression, independent predictive factors for DFS were T3 andT4 stage, and for OS were also T3/ T4 stage, grade II/ III and lymphovascular invasion. Conclusions: Taken together, obtained results indicated that combined adjuvant chemoradiation contributes to improve survival outcomes in the rectal cancer patients who did not received neoadjuvant therapy.