Treatment Trends in Stage II and III Colorectal Cancer in the United States
As reported by Murphy et al in the Journal of the National Cancer Institute, an analysis of Surveillance, Epidemiology, and End Results (SEER) data from patients with stage II or III colorectal cancer indicated that the use of adjuvant chemotherapy in colon cancer declined slightly between 2005 and 2010 and that the use of radiotherapy in stage II or III rectal cancer steadily increased between 1990 and 2010.
Colon Cancer
The study involved data from 7,057 patients aged ≥ 20 years randomly sampled from the periods 1990–1991, 1995, 2000, 2005, and 2010. The use of adjuvant chemotherapy in patients with colon cancer increased from 22.5% in stage II disease and 56.3% in stage III in 1990 to 32.1% and 72.4% in 2005 and decreased to 29.3% and 66.4% in 2010.
Overall, older age (risk ratio [RR] = 0.81, 95% confidence interval [CI] = 0.71–0.91, for 75–79 years, and 0.37, 95% CI = 0.28–0.47, for ≥ 80 years vs < 55 years) and Charlson comorbidity score ≥ 2 vs 0 (RR = 0.56, 95% CI = 0.35–0.87) were associated with reduced likelihood of receiving chemotherapy in patients with stage III colon cancer.
Rectal Cancer
The use of radiation therapy in patients with rectal cancer increased from 45.5% in 1990 to 66.1% in 2010, and the use of chemoradiation increased from 37.2% to 66.6%. The use of surgery followed by chemoradiation increased from 35.2% in 1990 to 45.1% in 1995 and decreased from 41.6% in 2000 to 18.7% in 2010. The use of preoperative chemoradiation increased over time, including an increase from 11.2% in 2005 to 20.8% in 2010. Increased age (RR = 0.59, 95% CI = 0.47–0.74, for 75–79 years, and 0.33, 95% CI = 0.25–0.45, for ≥ 80 years vs < 55 years) was associated with reduced likelihood of chemoradiation use.
The investigators concluded: “Our findings demonstrate increased adoption of chemotherapy and radiation therapy for colon and rectal cancer patients and differences in therapy by age, comorbidity, and diagnosis year. Increased receipt of these therapies in the community may further reduce colorectal cancer mortality.”
The study was supported by the National Institutes of Health. The authors declared no potential conflicts of interest.
Caitlin C. Murphy, MPH, of the University of North Carolina at Chapel Hill, is the corresponding author of the Journal of the National Cancer Institute article.
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