Frequent Missed Opportunities for Earlier Diagnosis of Advanced-Stage Colorectal or Lung Cancer

Missed and delayed cancer diagnoses worsen patient outcomes. Overlooking cancer-related diagnostic signals may result in advanced-stage presentations. To develop and implement a digital quality measure of the proportion of advanced-stage cancer diagnoses in the US and assess the rate of missed diagnostic opportunities. This cohort study used electronic health records and a cancer registry of patients with cancer diagnosed from 2016 to 2020 at 2 integrated health care systems, Department of Veterans Affairs (VA) health system and Geisinger Health System. Patients with incident colorectal cancer (CRC) or non-small cell lung cancer, with at least 1 primary care visit in the 2 years before cancer diagnosis, were included. A random sample of 100 advanced-stage cases per cancer type and health system was manually reviewed using a 2-year look-back period. Data were analyzed from January 27 to June 9, 2025. The primary outcome was a digital quality measure for advanced stage cancer and a descriptive analysis (by health system and cancer type) of the rate of missed opportunities in diagnosis, dates of investigation initiation and completion, and factors associated with missed opportunities. There were 37 691 patients from the VA health system and 2914 patients from Geisinger with lung cancer, and there were 14 674 patients from the VA health system and 627 patients from Geisinger with CRC. For lung cancer, the advanced stage comprised 45.9% at the VA health system and 58.3% at Geisinger. Advanced CRC stage was 33.2% at the VA health system and 36.2% at Geisinger. Notably, 58.9% (95% CI, 48.6%-68.5%) of patients from the VA health system and 77.8% (95% CI, 68.6%-84.8%) of patients from Geisinger with advanced-stage lung cancer had missed opportunities in diagnosis. For CRC, 66.3% (95% CI, 56.3%-75.0%) of patients at the VA health system and 69.7% (95% CI, 60.0%-77.9%) of patients at Geisinger had missed opportunities. Patients with missed opportunities had notable delays in diagnosis (eg, the median time from diagnostic signal to workup completion ranged from 1 to 20 months). Lack of screening was associated with 6.1% to 16.7% of late-stage cancers across health systems and cancer types. For lung cancer, missed opportunities were associated with problems in patient-clinician encounters and performing and interpreting diagnostic tests. For CRC, missed opportunities were primarily associated with patient-related factors and problems performing and interpreting diagnostic tests. This study found high rates of missed diagnostic opportunities among patients with advanced-stage cancer. By using advanced stage as a digital quality measure, health systems, payers, and other stakeholders can better identify care gaps and track initiatives to reduce preventable delays in cancer diagnosis.