A systematic review of the impact of comorbidity on chemotherapy utilization and outcomes in solid tumors
e20646 Background: The management of cancer patients (pts) with comorbidities can be challenging as these individuals are underrepresented in oncology clinical trials. We conducted a systematic literature review to determine the impact of comorbidity on utilization, tolerability, and efficacy of chemotherapy among pts with solid tumors. Methods: Using MEDLINE and EMBASE databases, all English-language articles published from 1990–2008 that explored the association between comorbidity and chemotherapy were identified. MeSH and keyword search terms included “comorbidity,” “chemotherapy” and “cancer.” All abstracts were manually reviewed for eligibility based on inclusion and exclusion criteria. Two reviewers independently abstracted data on the design and results of each eligible study, and rated the quality of the article using the STROBE checklist. Results: Of 1,031 citations retrieved by the search, 29 articles met inclusion criteria. Study designs were too heterogeneous to permit a quantitative summary and the overall quality of articles was poor. Comorbidity was investigated most frequently among pts with lung (41%), breast (17%), or colon cancers (17%). Most studies were retrospective (72%), based on cancer registry data (48%), and assessed the effect of cumulative comorbidity based on an index score (76%). Fourteen studies (41%) investigated access and 26 (90%) addressed survival. For pts with comorbidities, the majority reported decreased access (50%) and inferior survival (65%). Of the 12 articles that included both parameters, 6 showed that comorbidity was independently associated with worse survival while 4 demonstrated that impaired access to treatment, not comorbidity, was the stronger predictor of inferior outcomes. Few studies addressed toxicity (24%), ability to complete chemotherapy (7%) or response rates (7%). Among them, no differences based on comorbidity were noted. Conclusions: The evidence regarding the impact of comorbidity on chemotherapy utilization and outcomes among cancer pts is limited and of poor quality. Further better-designed studies are warranted to determine the relationship between decreased access and inferior outcomes and to better define the tolerability and efficacy of chemotherapy in pts with comorbidities. No significant financial relationships to disclose.