Effect of Time to Diagnostic Testing for Breast, Cervical, and Colorectal Cancer Screening Abnormalities on Screening Efficacy: A Modeling Study

Abstract

Patients who receive an abnormal cancer screening result require follow-up for diagnostic testing, but the time to follow-up varies across patients and practices. We used a simulation study to estimate the change in lifetime screening benefits when time to follow-up for breast, cervical, and colorectal cancers was increased. Estimates were based on four independently developed microsimulation models that each simulated the life course of adults eligible for breast (women ages 50-74 years), cervical (women ages 21-65 years), or colorectal (adults ages 50-75 years) cancer screening. We assumed screening based on biennial mammography for breast cancer, triennial Papanicolaou testing for cervical cancer, and annual fecal immunochemical testing for colorectal cancer. For each cancer type, we simulated diagnostic testing immediately and at 3, 6, and 12 months after an abnormal screening exam. We found declines in screening benefit with longer times to diagnostic testing, particularly for breast cancer screening. Compared to immediate diagnostic testing, testing at 3 months resulted in reduced screening benefit, with fewer undiscounted life years gained per 1,000 screened (breast: 17.3%, cervical: 0.8%, colorectal: 2.0% and 2.7%, from two colorectal cancer models), fewer cancers prevented (cervical: 1.4% fewer, colorectal: 0.5% and 1.7% fewer, respectively), and, for breast and colorectal cancer, a less favorable stage distribution. Longer times to diagnostic testing after an abnormal screening test can decrease screening effectiveness, but the impact varies substantially by cancer type. Understanding the impact of time to diagnostic testing on screening effectiveness can help inform quality improvement efforts. .

Timely follow‐up of positive cancer screening results: A systematic review and recommendations from the PROSPR Consortium

“…The PROSPR multimodel study used 2 separate CRC modeling strategies side by side. That study reported an RR from 1.01 to 1.02 for lifetime disease risk at 3 months (compared with immediate diagnosis), an RR of 1.05 at 12 months, an RR of 1.03 for late‐stage disease risk at 3 months, an RR from 1.11 to 1.12 at 12 months, and an estimated decrement of 2.0% to 2.7% in LYG with a 3‐month interval to diagnostic testing …”

“…That study suggested no difference in the lifetime risk of breast cancer for wait times of 90 days to 1 year, but the relative risk (RR) for late‐stage disease was 1.08 at 90 days and 1.26 by 1 year. The modeling yielded a 17.3% decrement in estimated life‐years gained (LYG) when diagnostic testing occurred at 90 days …”

“…The final literature search yielded 597 unique articles for CRC; after initial screening, 80 articles were selected for review, and 3 were deemed acceptable by the CRC team (see Supporting Material 3 for a list of final included articles), including 2 modeling studies …”

Mammography facilities serving vulnerable women have longer follow‐up times

“…However, because mammography is not 100% specific and can only identify suspicious lesions, all abnormal mammogram results require either subsequent imaging or biopsy until the abnormality is defined as either cancer or benign . This additional evaluation must be done in a timely manner in order to avoid delays in cancer diagnosis and to have the potential to achieve the benefits of screening …”

“…While there is no definitive definition of the length of time between an abnormal mammogram and resolution that constitutes a delay, there is evidence that more than 3 months between presentation and treatment initiation can lead to more advanced cancer at diagnosis . Additionally, a recent simulation study reported that, with each additional 3‐month delay between an abnormal mammogram and subsequent diagnostic testing, the distribution of breast cancers shifted toward a higher stage . Delays in resolution of abnormal mammogram results can cause women psychological distress, including anxiety and depression .…”