Determinants of treatment in patients with stage IV renal cell carcinoma.

Abstract

486 Background: Although there have been significant advances in the detection and treatment of renal cell carcinoma (RCC), many elderly patients—particularly those with stage IV disease—likely receive no treatment. The purpose of this research was to study treatment patterns for elderly patients with stage IV RCC and determine patient and disease characteristics associated with receiving no treatment. Methods: Data from the Surveillance Epidemiology and End Results (SEER) and Medicare linked data set were analyzed. We identified 949 stage IV RCC patients over age 65 years diagnosed between 2007 and 2011. Surgery was identified using Medicare Part A and B claims, and use of systemic therapy was identified from Part D claims in addition to Part A and B claims. Treatment approach, including no treatment, was modeled using multinomial logistic regression controlling for several patient and disease characteristics, allowing us to identify significant risk factors for no treatment. We also performed landmark analyses at 3 and 6 months to account for early death as a potential cause for no treatment. Results: Of the 949 patients with stage IV RCC, 26.2% received surgery and 34.1% received systemic therapy within 6 months of diagnosis. Of 324 patients who received systemic therapy, most received sunitinib (57.1%), temsirolimus (21.3%), or sorafenib (12.3%). Over half of patients (51.2%) had no evidence of receiving surgery or systemic therapy. Of the 618 patients who survived at least 3 months, 38.3% received no treatment within 3 months, and among the 447 patients who survived at least 6 months, 26.6% received no treatment within 6 months. Older patients and those with a higher Charlson Comorbidity Index had lower odds of being treated with surgery, systemic therapy, or both; married patients had higher odds of being treated. These results were largely sustained in 3- and 6-month landmark analyses. Conclusions: Many elderly patients with stage IV RCC did not receive surgery or systemic therapy despite surviving at least 6 months from diagnosis. Several factors appear to be associated with this phenomenon. Further investigation should determine reasons why physicians and/or patients are reluctant to use systemic therapy in patients.