A population-based study elicits a reverse correlation between age and overall survival in elderly patients with rectal carcinoma receiving adjuvant chemotherapy.

Colorectal cancer is the third most common cancer and the fourth most common cause of cancer-related death globally. This population-based study aimed to explore the predictive factors that affected the overall survival of rectal cancer patients receiving adjuvant chemotherapy plus radical surgery using a Cox proportional hazards modeling approach. A total of 619 patients with rectal cancer who underwent surgery were enrolled between October 2006 and May 2013. Clinical characteristics of the patients were compared among the groups and potential prognostic factors were analyzed using the spss program, version 19.0. Patients aged ≥ 70 years have distinctive characteristics such as lager tumour size (≥ 5 cm), damaged micturition and higher incidence of diabetes compared to younger and middle-aged patients. Male gender, tumour size (≥ 5 cm), poor differentiation, later stage, adjuvant chemotherapy, damaged micturition, hypertension or diabetes are associated with a worse prognosis for rectal cancer patients (P < 0.05). However, smoking is a favourable factor to the patients (P = 0.018). Age of ≥ 70 years is an independent prognostic factor for patients with rectal cancer after surgery (P = 0.000) and elderly patients with Stage II and III disease receiving adjuvant chemotherapy show a favourable prognosis. The elderly patients who suffered from diabetes receiving adjuvant chemotherapy have a poor prognosis. Further prospective and large population studies are warranted to confirm the findings of this study.