SUO 2022: Geographic Variation in Utilization of Doublet Therapy for Metastatic Prostate Cancer

(UroToday.com) The 23rd Annual Meeting of the Society of Urologic Oncology held in San Diego, CA between November 30th and December 2nd, 2022 was host to a prostate cancer session. Dr. Samuel L. Washington III, MD, MAS presented the results of a population-based analysis evaluating geographic variations in the utilization of doublet therapy for metastatic prostate cancer patients.

Dr. Washington began his abstract presentation by noting that prostate cancer remains the most commonly diagnosed visceral organ malignancy in men within the United States, with incidence rates varying by state from 79.6 to 134.7 per 100,000 persons. There is strong level one evidence to support the use of combination therapies, in the form of doublet and triplet therapies,1,2 in men with metastatic prostate cancer with overall survival benefits demonstrated in multiple clinical trials. However, real-world utilization of these combination strategies (i.e. androgen deprivation therapy plus chemotherapy and/or androgen receptor axis-targeted agents), as well as its geographic variation, has not yet been fully evaluated in detail. Barriers to the adoption of doublet therapy in practice need to be further highlighted and addressed before we can realistically expect further treatment intensification to be adopted in clinical practice. In this study, Dr. Washington and colleagues used aggregated data from a national cohort of community and academic oncology practices to characterize the real-world utilization of doublet therapy and examine the factors associated with its use, including geographic region.

The authors identified patients with metastatic prostate cancer using the ConcertAI Real-World Data (RWD) dataset. Clinical data was procured from electronic medical records and linked with state-level measures of socioeconomic factors and healthcare resources from the Area Health Resources File. The following geographic-level clinical and community characteristics were evaluated: urban population levels, number of hospital beds, and urologist and radiation oncologist densities, per 1,000,000 persons. The association between clinical/community variables and receipt of doublet therapy, versus androgen deprivation therapy alone, within 90 days of diagnosis was evaluated using logistic regression analyses.

This study included 1,763 men with metastatic prostate cancer. Mean age at diagnosis was 68.6 years. Geographically, 48% of patients resided in a Southern region, 9.3% in the Northeast, 186% in the West, and 23.7% in the Midwest. With regards to race, 13.8% were black, 1.3% American Indian, and 1.1% Asian. Of the 1,763 patients, 37.8% received ADT alone. Interestingly, 88.3% had genomic testing performed within 90 days of treatment. Regression analysis was conducted on 1,604 men, of whom 84.6% received doublet therapy in the form of ADT plus novel hormonal therapy. Predictors of receiving doublet therapy included, with odds ratio (OR) >1 indicating increased odds of receiving doublet therapy: geographic region [vs Southern: Midwest, Odds Ratio: 0.6, 95% Confidence interval [CI]: 0.4 - 0.9; Northeast, OR: 0.4, 95% CI: 0.2 - 0.7], larger state population [(log-transformed) OR: 0.09, 95 CI%: 0.02 - 0.3], prior surgery or radiation (vs none, OR: 1.7, 95% CI: 1.3 - 2.3), greater urologist density [(log-transformed), OR: 0.1, 95% CI: 0.02 - 0.8] and radiation oncologist density [(log-transformed), OR: 12.9, 95% CI: 2.8 - 60.2].

The authors concluded that receipt of doublet therapy, compared to ADT alone, was associated with the geographic region and by the regional availability of specialty care (i.e. urologist and radiation oncologist density), emphasizing the relationship between regional medical expertise and care implementation. Notably, race and age were not significantly associated with receipt of doublet therapy amongst patients with access to treatment within a national cohort of community and academic oncologic practices. This study highlights how treatment remains influenced by where you live and the need for identifying actionable targets for intervention and organizational change at the regional level.

 

Presented by: Samuel L. Washington III, MD, MAS, Assistant Professor, Department of Urology, University of California in San Francisco, San Francisco, CA

Written by: Rashid Sayyid, MD, MSc – Society of Urologic Oncology (SUO) Clinical Fellow at The University of Toronto, @rksayyid on Twitter during the 23rd Annual Meeting of the Society of Urologic Oncology (SUO), Nov 30 – Dec 2, 2022. San Diego, CA

References:

  1. Smith MR, et al. Darolutamide and Survival in Metastatic, Hormone-Sensitive Prostate Cancer. N Engl J Med. 2022; 386:1132-1142
  2. Fizazi K, et al. Abiraterone plus prednisone added to androgen deprivation therapy and docetaxel in de novo metastatic castration-sensitive prostate cancer (PEACE-1): a multicentre, open-label, randomised, phase 3 study with a 2‚Äâ√ó‚Äâ2 factorial design. The Lancet. 2022;399(10336):1695-1707.