A study was conducted to investigate the prognostic factors for colorectal cancer patients in order to improve future treat-ment. Patients who had undergone curative resection (n = 842) were divided into three groups according to age: young (40 years or younger), middle-aged (41 to 64 years), and older (65 years or above). Univariate survival and multivariate analysis were used to compare 35 clinical factors among the groups.
Overall five-year, 10-year, and 15-year survival rates were 66.3%, 54.2%, and 48.5%, respectively. In the young age group, the five-year survival rate was 53%, and the 10-year survival rate was 42.7%. These rates were lower than those in the middle-aged and older groups.
A Cox-proportional hazard regression model demonstrated that Dukes stage and a family history of cancer were common prognostic factors in both young and middle-aged patients. Chronic constipation was an independent prognostic factor in middle-aged patients. Bowel obstruction, the length of operating time, and the number of metastatic lymph nodes were prognostic factors in the older group. In the young group, the duration of symptoms was not shown to be a prognostic factor. Five-year and 10-year survival rates, respectively, were:
- Dukes A stage: 82.6°% and 64.5°%
- Dukes B stage: 73.3% and 67.4%
- Dukes C stage: 37.3% and 27%
- Dukes D stage: 33.3% and 22.2%
Survival rates in patients with Dukes A and B stages were similar; however, in Dukes C and D stages, survival rates were lower than those of the middle-aged and older patients with the same stage of disease.
In young colorectal cancer patients with a family cancer history, five- and 10-year survival rates were 73.1% and 64.5%, respectively. These rates were better than those of patients without a family history (48.1% and 37.3%).
Therefore, survival rates were lower in younger patients than in middle-aged and older patients. A family history of cancer and advanced Dukes stage were poor prognostic factors, whereas the duration of symptoms did not suggest a poor prognosis. The prognostic factors affecting survival after surgery may differ among the various age groups.