Significant decline in cancer diagnostic testing in U.S. CMS population during the COVID-19 pandemic

ABSTRACT

Background: The COVID-19 pandemic has caused >400,000 infection related deaths in the US to January 2021. Actions taken to limit COVID-19 infection and mortality could potentially lead to unintended consequences, precipitating excess mortality due to other causes. One such cause is delayed cancer diagnosis. Significant decreases in presentation for cancer diagnosis at the primary care level have been noted in the UK. This study aimed to look for evidence of a similar effect in the US. Methods: CMS claims data from JAN18-JUN20 associated with primary diagnosis across 11 cancers (bladder, breast, cervical, colorectal, endometrial, lung, ovarian, pancreatic, prostate, sarcoma and thyroid) were analyzed for use of surgical pathology (SP), a procedure associated with initial diagnosis, and immunohistochemistry (IHC). Test volumes varied widely by test and cancer so were normalized to enable comparison across indications. This was done by dividing the month-on-month difference for the period JAN19-JUN19 vs JAN20-JUN20 by the median monthly test volume for the period JAN18-DEC19 (“pre-COVID period”). Extent and duration of declines in test rates and number of missing patients as the sum of these declines were then determined. The ratio of IHC to SP testing was taken to determine any decline in likely post-initial diagnosis testing. Results: There were significant (>10%) declines in test volumes for SP for all 11 cancers at some time in Q1- Q2 2020. Table. Extent, duration and return to preCOVID levels for SP testing across 11 cancers Median extent and duration of the decline was 56% (range 41.1%-80.4%) and 2 months (range 1- >4). This equates to 32,192 missing diagnoses across all cancers. SP test volumes for all cancers except lung and breast had returned to around pre-COVID levels by JUN20. There was no significant (>10%) increase in normalized SP test volume after the COVID dip for any cancer. While SP showed decreased test volumes across all cancers at some point during the first half of 2020, test volume ratios of IHC to SP showed increases for most cancers in the same time period. Conclusions: These data highlight that the decline in patients presenting to their primary care physicians with suspicion of cancer for diagnostic investigation was linked to COVID-19 prevention strategies. No evidence for increased, “catch up” testing to address presentational/diagnostic backlog was observed. Thus, it is predicted that these patients may subsequently present with a more advanced cancer. Potential excess morbidity, mortality and cost associated with absent or delayed diagnosis should be factored into cancer control programs going forward. (Table Presented).