Transportation Insecurity and its Impact on Stage at Diagnosis in Breast Cancer

Introduction: Transportation insecurity is a worldwide but underrecognized problem. It is relatively unknown whether trips for preventative healthcare persist when individuals face this issue. Breast cancer (BC) screening may be especially impacted by transportation insecurity as it requires a separate appointment, as compared to other cancer screening that can be completed at a primary care visit or at home. We hypothesize that increased travel burden negatively impacts breast cancer screening rates, and therefore stage at diagnosis, however the literature surrounding this topic varies greatly in methodology and results.

Methods: We searched PubMed, TRID, Embase, Scopus, and Web of Science for relevant abstracts. Abstracts were screened for applicability, data was extracted, and quality assessment was conducted. Adjusted odds ratios were compared between studies where possible.

Results: We found 18 studies pertaining to BC stage at diagnosis. 17 studies reported patient travel distance/time, with 2 reporting additional aspects of transportation as well. Overall, 10/18 studies reported increased stage at diagnosis with increasing travel burden. There was little congruence in the definition of “late stage” as well as in the definition of reference groups.

Conclusion: Increasing travel burden appears to be associated with late stage at diagnosis; however, there remains a knowledge gap surrounding access to transportation and its relationship to BC stage at diagnosis. Future research should standardize the definition of late stage, benchmark travel burden against empiric patient patterns, and better identify sources of bias. Identifying definitive relationships between travel burden and cancer stage is requisite to inform public policy initiatives going forward.