Michaela Dinan, PhD, Yale School of Public Health, Yale Cancer Center, New Haven, CT, discusses results from a study which investigated real-world adherence and outcomes associated with oral anticancer agent use in patients with metastatic renal cell carcinoma (RCC).
These results were presented at the virtual 2021 ASCO Genitourinary Cancers Symposium.
My name is Michaela Dinan. I'm an associate professor at the Department of Epidemiology Chronic Diseases at the Yale School of Public Health. I also co‑lead the Cancer Prevention and Control Program for the Yale Cancer Center.
Thank you for the opportunity to discuss this important work that we are very excited about sharing. This is an analysis that was recently presented at the ASCO GU Conference.
This analysis is part of a larger R01 study that I'm currently leading, which is funded by the National Cancer Institute, to examine disparities in both access and adherence to oral anticancer agents, or OAAs, for patients with kidney cancer.
The study, as a whole, examined multiple levels of influence, including the patient, provider, and systems or structural levels, to see if ultimately, we can identify places to intervene in order to reduce disparities and outcomes for these patients with kidney cancer.
This particular analysis was looking at patient‑level factors associated with adherence to OAAs, and then the impact that adherence to OAAs had on survival.
Another one of our analyses, which was also presented at ASCO GU, was looking specifically at access or utilization of OAAs. I believe you were talking to Dr. Stephanie Wheeler from UNC, the first author of that study, separately.
The main premise here is that multiple oral anticancer agents, or OAAs, are now approved for the treatment of patients with metastatic renal cell carcinoma, based on improvement and overall and progression‑free survival that was observed in randomized clinical trials previously.
No one has really examined what adherence to these drugs looks like in the real world outside of the context of largely controlled trial environments, and then how real‑world adherence is translating to real‑world outcomes for these same patients.
This was a retrospective study using the SEER‑Medicare data for patients with metastatic renal cell carcinoma who received treatment with an OAA between 2007 and 2015.
Our measure of adherence was the proportion of days covered, or PDC, within 3 months of OAA initiation. We calculated the PDC for each patient, with adherent use of OAAs being defined as a PDC greater than 80%.
We examined factors associated with one, adherence, and then two, overall and disease‑specific 2-year survival, which we landmarked at 3 months after OAA initiation.
For this analysis, a total of 905 patients met our study criteria, of whom 445 patients, or only about 50%, were categorized as adherent to initial OAA treatment, based on that PDC of greater than 80% that I already mentioned.
In multivariable analysis, where we adjusted for patient, clinical, and demographic factors, we found that factors associated with decreased odds of adherence included one, living within an impoverished neighborhood based on ZIP code, and two, out‑of‑pocket cost greater than $200 per month.
Another important observation was that there was no significant association between race, ethnicity, marital status, or number of comorbidities and OAA adherence. It was more these socio‑economic factors that were driving adherence to these drugs.
We also found that adherence itself was associated with improved 2‑year survival in univariate analysis, and we observed a nonsignificant trend towards an association with decreased all‑cause and RCC‑specific mortality in multivariable analysis. Again, these findings did not reach statistical significance.
The three most important takeaways from this study are that, one, ZIP code‑based poverty level and high out‑of‑pocket costs of greater than $200 per month were associated with poor OAA adherence. Two, that low OAA adherence was associated with poor survival in univariate survival comparison with consistent trends and adjusted analyses.
Three, that these points taken together show that efforts to improve outcomes and mitigate disparities in the broader metastatic renal cell population should incorporate considerations of OAA adherence and how economic factors are impacting patients' abilities to be adherent to these drugs.
Dinan MA, Wilson LE, Greiner MA, et al. Oral anticancer agent (OAA) adherence and survival in elderly patients with metastatic renal cell carcinoma (mRCC). Presented at: the virtual 2021 ASCO Genitourinary Cancers Symposium; February 11-13, 2021. Abstract 280.