The effect of comorbidity on the use of adjuvant chemotherapy and type of regimen for curatively resected stage III colon cancer patients.

Postsurgical chemotherapy is guideline-recommended therapy for stage III colon cancer patients. Factors associated with patients not receiving adjuvant chemotherapy were identified in numerous studies; comorbidity was recognized as an important factor besides patient's age. We assessed the association between comorbidity and the use of adjuvant chemotherapy and type of chemotherapy regimen. Stage III colon cancer patients who underwent surgical resection were obtained from ten Centers for Disease Control and Prevention (CDC)-NPCR Specialized Registries which participated in the Comparative Effectiveness Research (CER) project. Comorbidity was classified into no comorbidity recorded, Charlson, non-Charlson comorbidities, number, and severity of Charlson comorbidity. Pearson chi-square test and multivariable logistic regression were employed. Of 3180 resected stage III colon cancer patients, 64% received adjuvant chemotherapy. After adjusting for patient's demographic and tumor characteristics, there were no significant differences in receipt of chemotherapy between Charlson and non-Charlson comorbidity. However, patients who had two or more Charlson comorbidities or had moderate to severe disease were significantly less likely to have chemotherapy (ORs 0.69 [95% CI, 0.51-0.92] and 0.62 [95% CI, 0.42-0.91], respectively) when compared with those with non-Charlson comorbidity. In addition, those with moderate or severe comorbidities were more likely to receive single chemotherapy agent (P < 0.0001). Capecitabine and FOLFOX were the most common single- and multi-agent regimens regardless of type of comorbidity grouping. Both the number and severity of comorbidity were significantly associated with receipt of guideline-recommended chemotherapy and type of agent in stage III resected colon cancer patients. Better personalized care based on individual patient's condition ought to be recognized.

Impact of race/ethnicity and socioeconomic status on adjuvant chemotherapy use among elderly patients with stage III colon cancer.

BACKGROUND: It is well recognized that stage III colon cancer patients who received chemotherapy postoperatively can have a reduced risk of recurrence and an improved survival rate. This study examined the impact of race/ethnicity and socioeconomic status (SES) on receipt of chemotherapy within 4 months after resection among stage III colon cancer patients enrolling in Medicare Parts A and B and trends of utilizing adjuvant chemotherapy. METHODS: Stage III colon cancer patients diagnosed between 2000 and 2007 were obtained from the Surveillance, Epidemiology, and End Results-Medicare data. Multilevel logistic regression was used to estimate the association between predictor variables and adjuvant chemotherapy, and the Cochran-Armitage test was used to assess for linear trends. RESULTS: Of 13,608 stage III colon cancer patients aged 66 and older, 56 percent received adjuvant chemotherapy within 4 months of surgical resection. Blacks or patients residing in the least affluent areas were less likely to receive the adjuvant chemotherapy within 4 months after resection, both before and after adjusting for race/ethnicity and other independent variables. A significantly decreasing trend was observed, from 58 percent in 2000 to 53 percent in 2007, for all patients combined. Trends of receiving chemotherapy within 4 months after resection were varied more in racial/ethnic groups than in SES groups. CONCLUSIONS: After adjusting for demographic and clinical factors, there are persistent racial/ethnic and SES disparities in the use of adjuvant chemotherapy among Medicare-insured elderly patients with stage III colon cancer. The shortage of chemotherapy drugs and the change of Medicare drug administration reimbursement could be attributive factors in the decline of using adjuvant chemotherapy within 4 months of surgical resection.