Chemotherapy use in stage III colon cancer: A National Cancer Database analysis

Background: Although adjuvant chemotherapy in stage III colon cancer improves overall survival, prior studies have shown that it is underused. We analyzed different factors that may influence its use. Methods: This is a retrospective study of stage III colon cancer patients (n = 207,718) diagnosed between 2000 and 2011 in the National Cancer Data Base (NCDB). The NCDB contains ~70% of new cancer diagnosis from >1500 American College of Surgeons accredited cancer programs in the United States and Puerto Rico. The chi-squared test was used to determine any difference in characteristics of patients who did or did not receive chemotherapy. Results: A total of 35% of all stage III colon cancer patients, and 38% of stage III cases undergoing surgery, did not receive adjuvant chemotherapy. The use of chemotherapy had increased in recent years (64% in 2007–2011 versus 59% in 2000–2002; p < 0.0001). Its use was lower in whites (61%), females (60%), patients ⩾60 years (55%), patients with one or more comorbidities (55%), nonacademic centers (62%), those with medicare insurance (52%), lower education (61%) and income levels (59%, all p < 0.0001). The nonwhite and uninsured were more likely to be <60 years old. More than one-third did not receive adjuvant chemotherapy, although its use has increased in more recent years. Age was one of the most important determinants of chemotherapy use, which may explain higher rates in nonwhite and uninsured. In addition to patient characteristics, race, gender and socioeconomic factors influence chemotherapy use. These findings have important implications for healthcare reform.