Octogenarians present with several distinct characteristics of colorectal cancer and have overall worse outcomes, compared with younger patients with the disease, according to a study published in the World Journal of Gastroenterology.
Hadar Goldvaser, MD, from the Princess Margaret Cancer Center and the Department of Medicine at the University of Toronto in Canada, and colleagues, conducted a retrospective, single center cohort study to better define the growing entity of patients aged 80 years or older with colorectal cancer. The study population was diagnosed between 2008 and 2013 and was matched by year of diagnosis with a control group of consecutive patients younger than 80 years at diagnosis. Clinical-pathological characteristics, treatment, and outcome were compared between the groups.
A total of 350 patients were included in the study, with 175 patients in each group. Significant differences between the groups included a higher proportion of Ashkenazi Jews in the octogenarian group (64.8% v 47.9% of controls) and fewer Arab patients (0% v 7.1%) or other ethnicities (1.7% v 8.3%), a higher incidence of second malignancies (22.4% v 13.7%), a lower rate of family history of colorectal cancer (14.4% v 27.3%), and a lower smoking prevalence (24.6% v 44.3%); 5.7% of octogenarians were diagnosed by screening compared with 20% in the control group.
Octogenarians were more likely than controls to have tumors located in the right colon (45.7% v 34.3%) and have a lower prevalence of well-differentiated histology (10.4% v 19.3). Octogenarians with metastatic disease were treated with fewer chemotherapy lines: 34.6% did not receive any treatment, 42.3% received one line, and 23.1% received at least two lines, compared with 8.8%, 38.2%, and 53%, respectively, in the control group.
The median follow-up time was 40.2 months; during this time, 120 patients died of colorectal cancer and 230 remained alive or died of other causes. Octogenarians had a worse 5-year cancer-specific survival (63.4% vs 77.6%), both for metastatic disease (21% vs 43%) and for nonmetastatic disease (76% vs 88%).
“Our study indicates that octogenarians with colorectal disease display several differences in clinical and tumor characteristics, supporting the hypothesis of a unique clinical entity in this population, possibly with a distinct pathogenesis,” said the authors. “They were less likely to receive treatment despite adequate performance status and their outcome was worse.”
- Goldvaser H, Katz Shroitman N, Ben-Aharon I, et al. Octogenarian patients with colorectal cancer: Characterizing an emerging clinical entity. World J Gastroenterol. 28 February 2017. doi: 10.3748/wjg.v23.i8.1387