Elderly patients with colon cancer have unique tumor characteristics and poor survival

The incidence of colon cancer increases with age, and colon cancer predominantly affects individuals >65 years old. However, there are limited data regarding clinical and pathologic factors, treatment characteristics, and survival of older patients with colon cancer. The objective of this study was to determine the effects of increasing age on colon cancer.

Patients diagnosed with colon cancer between 1988 and 2006 were identified through the Los Angeles County Cancer Surveillance Program, in Southern California. Patients were stratified into 4 age groups: 18-49, 50-64, 65-79, and ≥80 years. Clinical and pathologic characteristics and disease-specific and overall survival were compared between patients from different age groups.

A total of 32,819 patients were assessed. Patients aged 18 to 49 and 65 to 79 years represented the smallest and largest groups, respectively. A near equal number of males and females were diagnosed with colon cancer in the 3 youngest age groups, whereas patients who were ≥80 years old were more commonly white and female. Tumor location was different between groups, and the frequency of larger tumors (>5 cm) was greatest in youngest patients (18-49 years). The oldest patients (≥80 years) were administered chemotherapy at the lowest frequency, and disease-specific and overall survival rates decreased with increasing age.

This investigation demonstrates that older age is associated with alterations in clinical and pathologic characteristics and decreased survival. This suggests that the phenotype of colon cancer and the efficacy of colon cancer therapies may be dependent on the age of patients.