Abstract
Background: Colorectal cancer is one of the major health problems worldwide. However, limited studies have been reported from ASEAN countries. This study was conducted to evaluate clinical characteristics and survival of colorectal cancer cases aged <65 years and ${\geq}65$ years in the central region of Thailand. Materials and Methods: Clinical information, histological features, endoscopic findings and treatment outcome were collected and reviewed from Thammasat University Hospital, Pathumthani, Thailand between November 2011 and October 2015. Results: A total of 121 colorectal cancer patients, comprising 69 men and 52 women with a mean age of 65.8 years, were included. There were 57 aged <65 years and 64 aged ${\geq}65$ years. Common presenting symptoms were abdominal pain (37%), weight loss (34%) and anemia (32%). Mean duration of symptoms prior to diagnosis was 173 days. However, longer diagnosis time was demonstrated in patients aged <65 years than age more than ${\geq}65$ years (119.4 vs 58.4 days, P-value=0.30). Colonic fungating mass was the most common endoscopic finding (64.4%) and the location was significantly more commonly left than right side of the colon, both in younger and elderly groups (87.7% vs 12.3%, P=0.02 and 70.3% vs 29.7%, P=0.02, respectively). Adenocarcinoma with moderated differentiated was the most common histology (67.3%). More than half of the patients presented with advanced stage (28.9% with TNM stage 3 and 38.8% TNM stage 4, respectively). Overall 1-year and 5-year survival rates were 76.9% and 5%. Conclusions: Most colorectal cancer patients in Thailand have adenocarcinomas and present at advanced stage with poor prognosis. Screening of high risk patients and early detection might be essential factors to improve the treatment outcome and overall survival rate of colon cancer patients in Thailand and other ASEAN countries.