Incidence Rates of Early-Stage Breast and Colorectal Cancer Increased Following Enactment of ACA

The incidence rates of early-stage breast and colorectal cancer increased after the initiation of the Affordable Care Act (ACA), according to a study published in JAMA Oncology.

In addition to expanding insurance coverage, the ACA puts emphasis on preventive care. Through the ACA, cost sharing for services given an “A” or “B” grade by the US Preventive Services Task Force (USPTF) is eliminated.

“Although these policies have improved preventive care generally, their impact on cancer screening specifically is uncertain,” wrote the authors.

The authors of the study analyzed incidence rates in early-stage breast, colorectal, and cervical cancer following the implementation of major ACA policies on January 1, 2014.

The 3 types of cancers all have “A” or “B” screening grades from the USPSTF.

Age-adjusted incidence rates of the 3 types of cancers were compared in the first 9 months of 2013 (pre-ACA) and the last 9 months of 2014 (post-ACA), with an intervening 6-month “wash-in” period.

Incidence rates were per 100,000 person-years and were age adjusted. The authors computed the incidence rate ratios (IRRs) and associated 95% confidence intervals to assess for change between the pre- and post-ACA periods. Weighted least squares with a log link were used to see if the relative difference in IRRs for early-stage disease varied significantly compared with locally advanced/metastatic disease. To find the relative difference in IRRs, the authors exponentiated the difference-in-differences of the log IRRs.

The authors found that from pre- to post-ACA, the incidence of early-stage breast cancer increased from 55.5 to 56.9 cases per 100,000 person-years, with an IRR of 1.025. The incidence of early-stage colorectal cancer increased from 13.5 to 15.3 cases per 100,000 person-years, with a pre- to post-ACA IRR of 1.132.

The difference in IRRs was significantly greater for early versus locally advanced/metastatic stages in both early-stage breast cancer and colorectal cancer. However, this pattern was not seen in cervical cancer.

These results showed that following the adoption of the ACA, the incidence of early-stage breast and colorectal cancer increased, but did not vary for late-stage breast and colorectal cancer. While the screening itself was not assessed, these findings are consistent with increased breast and colorectal cancer screenings since the ACA was enacted.

The absent change in detection of early-stage cervical cancer is consistent with a previous report that the dependent coverage expansion to age 26 years did not affect the use of the Papanicolaou test in that population.

“These results are consistent with a small but positive impact of the ACA on use of recommended cancer screening, which may vary by cancer site,” concluded the authors.