Temporal trends in receipt of adjuvant chemotherapy for veterans with colorectal cancer.

Abstract

e19171 Background: For patients with National Comprehensive Cancer Network (NCCN) high risk stage II or stage III colorectal cancer (CRC), adjuvant chemotherapy improves disease free (DFS) and overall survival (OS). Rates of use vary significantly across health care settings. Several demographic and healthcare factors are associated with decreased receipt of chemotherapy; however, few studies have assessed utilization patterns over time. We evaluated receipt of chemotherapy from 2000-2015 among patients treated at a Southeast Regional Veterans Health Administration (VHA) facility to determine local targets for quality improvement initiatives. Methods: We reviewed 1,107 electronic medical records of patients undergoing colorectal surgery from January 1, 2000 to December 31, 2015 at VHA Tennessee Valley Healthcare System. We included patients with NCCN eligible pathologic high risk stage II (T4/perf, R1, < 12LN, LVI) or stage III CRC and excluded for age ≥80, age ≥75 hospitalized in the prior year with a major co-morbidity, and death or hospice within 30 days of surgery. The primary predictor was year of surgery, partitioned 2000-2005 (N = 60), 2006-2010 (N = 64), 2011-2015 (N = 56) to reflect changes in NCCN guidelines. The primary outcome was receipt of any chemotherapy. Results: Of 1,107 colorectal surgeries, we excluded 623 for non-cancers, 212 for stage I or low-risk stage II cancer, 47 for metastatic disease, and 45 for age, co-morbidity, death, and hospice, yielding a final cohort of 121 colon and 59 rectal cancers. Most patients were male (96%), white (79%), with median age 64 years [Interquartile Range 60, 70]. Overall, 117 of 180 (65%) received chemotherapy with a median time to treatment of 50.5 days [40,64]. Adjusting for known correlates, receipt of chemotherapy decreased over time; 2000-2005 (72%), 2006-2010 (69%), 2011-2015 (53%) p = 0.02. Regardless of CRC stage, more patients declined chemotherapy in 2011-2015 (27%) compared to 2000-2005 (6%) and 2006-2010 (8%) p < 0.01. Conclusions: We identified decreased utilization of adjuvant chemotherapy in a non-elderly veteran cohort, which appeared to be due to patients declining chemotherapy regardless of cancer stage. Understanding patient and provider decisions around adjuvant chemotherapy and evaluating trends outside the VHA may offer important insights to implementing quality improvement measures.