Most patients with advanced cancer still not receiving genomic testing, study finds

A majority of patients with the most common advanced cancers in the United States did not undergo next-generation sequencing (NGS), according to a large cohort study published April 7 in JAMA Network Open. The study also found that socioeconomic status, race and ethnicity, and insurance coverage were associated with significant delays in testing among those who did receive it.

Chadi Hage Chehade, M.D., from the Huntsman Cancer Institute at the University of Utah, and team analyzed electronic health record data from approximately 280 cancer clinics and 800 sites of care through the Flatiron Health Research Database. The study included 63,294 patients diagnosed with metastatic breast, metastatic prostate, advanced non-small cell lung, metastatic colorectal, or metastatic pancreatic cancers between January 2018 and December 2022.

Although the one-year cumulative incidence of NGS testing increased across all five cancer types for patients diagnosed in 2022 compared with 2018, testing rates remained low. Among patients with metastatic breast cancer, 34.5% received NGS after diagnosis. Rates were higher for advanced non-small cell lung cancer (61.4%) and metastatic colorectal cancer (62.9%) but still left substantial portions of patients untested. Metastatic prostate cancer (44.5%) and metastatic pancreatic cancer (51.2%) fell in between.

The study used multivariable cause-specific Weibull accelerated failure time models to evaluate associations between social determinants of health and the time from diagnosis to NGS testing, with death treated as a competing risk. A time ratio (TR) was calculated such that a value greater than 1 means that group waited longer to receive NGS compared with the reference group. For example, a TR of 1.4 for Black patients in the aNSCLC cohort means they waited roughly 40% longer from diagnosis to testing than White patients. A TR of 2.0 for Medicaid in metastatic prostate cancer means those patients waited about twice as long. A TR less than 1 means faster time to testing.

Across multiple cancer types, patients in the lowest socioeconomic quintiles experienced significantly longer times to NGS compared with those in the highest quintile. In advanced non-small cell lung cancer, patients in the lowest socioeconomic group had a time ratio of 1.6, indicating they waited roughly 60% longer to receive testing. Similar patterns emerged in metastatic breast and colorectal cancers.

Racial and ethnic disparities were also evident. Black patients experienced significantly longer times to NGS in advanced non-small cell lung cancer (time ratio, 1.4), metastatic colorectal cancer (time ratio, 1.4), and metastatic pancreatic cancer (time ratio, 1.5). Hispanic patients faced delays in metastatic breast cancer (time ratio, 1.4), metastatic prostate cancer (time ratio, 1.6), and metastatic colorectal cancer (time ratio, 1.4).

Insurance type was another consistent predictor of delayed testing. Medicare coverage was associated with significantly longer times to NGS across all five cancer types, with time ratios ranging from 1.1 to 1.5. Medicaid coverage was associated with a twofold delay in metastatic prostate cancer.

The authors noted that patients treated in academic practice settings also experienced longer times to NGS compared with those in community settings, with time ratios as high as 3.1 in metastatic pancreatic cancer. They suggested this finding may reflect the study's focus on multigene NGS panels, which would not capture single-gene or hotspot assays that may be more commonly used at academic centers.

According to Chehade and his co-authors, potential causesof these disparities include lower referral rates for genomic testing, reduced attendance at genetic counseling appointments, limited awareness of NGS among both clinicians and patients, historical mistrust of the health care system among minoritized populations, and the high cost of testing combined with inconsistent insurance coverage.

Chehade called for healthcare policies aimed at improving access to genomic testing, increasing awareness of guideline-recommended testing, and promoting education on level-1 evidence supporting precision oncology. They described their findings as benchmark data that could inform efforts to bridge existing gaps in NGS utilization across the most common advanced cancers in the United States.