Patient, provider, and hospital factors associated with oral anti-neoplastic agent initiation and adherence in older patients with metastatic renal cell carcinoma

INTRODUCTION

Oral anti-neoplastic agents (OAAs) for metastatic renal cell carcinoma (mRCC) are associated with increased cancer-specific survival. However, racial disparities in survival persist and older adults have the lowest rates of cancer-specific survival. Research from other cancers demonstrates specialty access is associated with high-quality cancer care, but older adults receive cancer treatment less often than younger adults. We therefore examined whether patient, provider, and hospital characteristics were associated with OAA initiation, adherence, and cancer-specific survival after initiation and whether race, ethnicity, and/or age was associated with an increased likelihood of seeing a medical oncologist for diagnosis of mRCC.

PATIENTS AND METHODS

We used Surveillance, Epidemiology, and End Results (SEER)Medicare data to identify patients ≥65 years of age who were diagnosed with mRCC from 2007 to 2015 and enrolled in Medicare Part D. Insurance claims were used to identify receipt of OAAs within twelve months of metastatic diagnosis, calculate proportion of days covered, and to identify the primary cancer provider and hospital. We examined provider and hospital characteristics associated with OAA initiation, adherence, and all-cause mortality after OAA initiation.

RESULTS

We identified 2792 patients who met inclusion criteria. Increased OAA initiation was associated with access to a medical oncologist. Patients were less likely to begin OAA treatment if their primary oncologic provider was a urologist (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.49-0.77). Provider/hospital characteristics were not associated with differences in OAA adherence or mortality. Patients who started sorafenib (odds ratio [OR] 0.50; 95% CI 0.29-0.86), were older (aged >81 OR 0.56; 95% CI 0.34-0.92), and those living in high poverty ZIP codes (OR 0.48; 95% CI 0.29-0.80) were less likely to adhere to OAA treatment. Furthermore, provider characteristics did not account for differences in mortality once an OAA was initiated. Last, only age > 81 years was statistically and clinically associated with a decreased relative risk of seeing a medical oncologist (risk ratio [RR] 0.87; CI 0.82-0.92).

CONCLUSION

Provider/hospital factors, specifically, being seen by a medical oncologist for mRCC diagnosis, are associated with OAA initiation. Older patients were less likely to see a medical oncologist; however, race and/or ethnicity was not associated with differences in seeing a medical oncologist. Patient factors are more critical to OAA adherence and mortality after OAA initiation than provider/hospital factors.