Racial Differences in Germline Genetic Testing Completion Among Males With Pancreatic, Breast, or Metastatic Prostate Cancers.

BACKGROUND: Germline genetic testing is a vital component of guideline-recommended cancer care for males with pancreatic, breast, or metastatic prostate cancers. We sought to determine whether there were racial disparities in germline genetic testing completion in this population. PATIENTS AND METHODS: This retrospective cohort study included non-Hispanic White and Black males with incident pancreatic, breast, or metastatic prostate cancers between January 1, 2019, and September 30, 2021. Two nationwide cohorts were examined: (1) commercially insured individuals in an administrative claims database, and (2) Veterans receiving care in the Veterans Health Administration. One-year germline genetic testing rates were estimated by using Kaplan-Meier methods. Cox proportional hazards regression was used to test the association between race and genetic testing completion. Causal mediation analyses were performed to investigate whether socioeconomic variables contributed to associations between race and germline testing. RESULTS: Our cohort consisted of 7,894 males (5,142 commercially insured; 2,752 Veterans). One-year testing rates were 18.0% (95% CI, 16.8%-19.2%) in commercially insured individuals and 14.2% (95% CI, 11.5%-15.0%) in Veterans. Black race was associated with a lower hazard of testing among commercially insured individuals (adjusted hazard ratio [aHR], 0.73; 95% CI, 0.58-0.91; P=.005) but not among Veterans (aHR, 0.99; 95% CI, 0.75-1.32; P=.960). In commercially insured individuals, income (aHR, 0.90; 95% CI, 0.86-0.96) and net worth (aHR, 0.92; 95% CI, 0.86-0.98) mediated racial disparities, whereas education (aHR, 0.98; 95% CI, 0.94-1.01) did not. CONCLUSIONS: Overall rates of guideline-recommended genetic testing are low in males with pancreatic, breast, or metastatic prostate cancers. Racial disparities in genetic testing among males exist in a commercially insured population, mediated by net worth and household income; these disparities are not seen in the equal-access Veterans Health Administration. Alleviating financial and access barriers may mitigate racial disparities in genetic testing.

Development and Validation of a Tool to Identify Patients Diagnosed With Castration-Resistant Prostate Cancer.

PURPOSE: Several novel therapies for castration-resistant prostate cancer (CRPC) have been approved with randomized phase III studies with continuing observational research either planned or ongoing. Accurately identifying patients with CRPC in electronic health care data is critical for quality observational research, resource allocation, and quality improvement. Previous work in this area has relied on either structured laboratory results and medication data or natural language processing (NLP) methods. However, a computable phenotype using both structured data and NLP identifies these patients with more accuracy. METHODS: The Corporate Data Warehouse (CDW) of the Veterans Health Administration (VHA) was used to collect PCa diagnoses, prostate-specific antigen test results, and information regarding patient characteristics and medication use. The final system used for validation and subsequent analysis combined the NLP system and an algorithm of structured laboratory and medication data to identify patients as being diagnosed with CRPC. Patients with both a documented diagnosis of CRPC and a documented diagnosis of metastatic PCa were classified as having mCRPC by this system. RESULTS: Among 1.2 million veterans with PCa, the International Classification of Diseases (ICD)-10 diagnosis code for CRPC (Z19.2) identifies 3,791 patients from 2016 when the code was created until 2022, compared with the combined algorithm which identifies 14,103, 10,312 more than ICD-10 codes alone, from 2016 to 2022. The combined algorithm showed a sensitivity of 97.9% and a specificity of 99.2%. CONCLUSION: ICD-10 codes proved to be insufficient for capturing CRPC in the VHA CDW data. Using both structured and unstructured data identified more than double the number of patients compared with ICD-10 codes alone. Application of this combined approach drastically improved identification of real-world patients and enables high-quality observational research in mCRPC.

Cetuximab-Based vs Carboplatin-Based Chemoradiotherapy for Patients With Head and Neck Cancer.

Importance: Cetuximab-based and carboplatin-based chemoradiotherapy (CRT) are often used for patients with locally advanced head and neck cancer who are ineligible for cisplatin. There are no prospective head-to-head data comparing cetuximab-based and carboplatin-based regimens for radiosensitization. Objective: To compare survival with cetuximab-based and carboplatin-based CRT in locally advanced head and neck squamous cell carcinoma (HNSCC). Design, Setting, and Participants: This cohort study included US veterans who received a diagnosis of HNSCC between January 2006 and December 2020 and were treated with systemic therapy and radiation. Data cutoff was March 1, 2022 and data analysis was conducted from April-May 2022. Exposures: Cisplatin, cetuximab, or carboplatin-based systemic therapy as captured in VA medication data and cancer registry. Main Outcomes and Measures: Overall survival by systemic therapy was estimated using Kaplan-Meier methods. We used propensity score and inverse probability weighting to achieve covariate balance between cetuximab-treated and carboplatin-treated patients and used Cox regression to estimate cause-specific hazard ratios of death associated with carboplatin vs cetuximab. We also performed subgroup analyses of patients with oropharynx vs nonoropharynx primary sites. Results: A total of 8290 patients (median [IQR] age, 63 [58-68] years; 8201 men [98.9%]; 1225 [15.8%] Black or African American and 6424 [82.6%] White individuals) with nonmetastatic HNSCC were treated with CRT with cisplatin (5566 [67%]), carboplatin (1231 [15%]), or cetuximab (1493 [18%]). Compared with cisplatin-treated patients, patients treated with carboplatin and cetuximab were older with worse performance status scores and higher comorbidity burden. Median (IQR) overall survival was 74.4 (22.3-162.2) months in patients treated with cisplatin radiotherapy (RT), 43.4 (15.3-123.8) months in patients treated with carboplatin RT, and 31.1 (12.4-87.8) months in patients treated with cetuximab RT. After propensity score and inverse probability weighting, carboplatin was associated with improved overall survival compared with cetuximab (cause-specific hazard ratio, 0.85; 95% CI, 0.78-0.93; P = .001). This difference was prominent in the oropharynx subgroup. Conclusions and Relevance: In this cohort study of a US veteran population with HNSCC undergoing treatment with CRT, almost a third of patients were ineligible to receive treatment with cisplatin and received cetuximab-based or carboplatin-based radiosensitization. After propensity score matching, carboplatin-based systemic therapy was associated with 15% improvement in overall survival compared with cetuximab, suggesting that carboplatin may be the preferred radiosensitizer, particularly in oropharynx cancers.