Factors associated with first course chemotherapy among older patients with newly diagnosed non-Hodgkin's lymphoma: National SEER-Medicare study

Abstract

6118 Background: Chemotherapy (CT) is indicated for some non-Hodgkin's lymphoma (NHL) patients (pts) with initial diagnosis. We describe clinical and nonclinical factors associated with receipt of first course CT. Methods: Using the National Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database, we identified newly diagnosed NHL pts (1991–1999), age ≥66 years, with continuous non-HMO Medicare part A and B benefits. First course CT was defined as a claim within 5 months of diagnosis (Dx) and whether cyclophosphamide with either doxorubicin or mitoxantrone (CH/CN) was given was determined. Univariate and multivariate analyses were performed using Pearson's Chi-Square test and SAS logistic regression methods. Results: Of 35,063 pts with NHL, 15,014 met inclusion criteria, and 7536 (50%) received CT (63% CH/CN). Among all 15,014 pts, factors multivariately associated (p≤0.05) with receiving CT were: diffuse large cell (DLC) histology, advanced (adv) stage, younger age, white race, Charlson comorbidity index (CCI) =0, no renal disease, no anemia, no radiation therapy, SEER site and Dx year. The largest associations were for DLC vs follicular histology (Odds Ratio (OR)=3.3, 95%CI: 2.9, 3.6) and age 66–70 years vs ≥86 years (OR=4.7, 95%CI: 4.1, 5.4). Among 2457 adv stage pts with DLC histology, 1660 (68%) received any CT, of whom 1154 (70%) received CH/CN. On multivariate analysis, older pts and those with CCI>0 or anemia were significantly (p≤0.05) less likely to receive CT. Multivariately, receipt of CH/CN was significantly (p≤0.05) less likely with advancing age, CCI>0, anemia, heart disease, and radiation therapy. SEER site and Dx year were independently associated with receiving CH/CN. Of particular interest was the rate (only 68%) of CT use in adv stage DLC lymphoma. Conclusions: Nonclinical factors (younger age, white race, Dx year and SEER site) and clinical factors (DLC histology, adv stage, no radiation therapy and less comorbidity) were independently associated with receiving first course CT in this population-based study. Author Disclosure Employment or Leadership Consultant or Advisory Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Amgen, Inc. Amgen, Inc. Amgen, Inc. Amgen, Inc.