Breast Cancer Provider Interval Length in Fukushima, Japan, After the 2011 Triple Disaster: A Long-Term Retrospective Study

Background To minimize the interval from symptom onset to treatment commencement is essential for a favorable outcome among breast cancer patients. This study examined whether provider interval (time elapsed from first consultation to treatment onset) lengthened among breast cancer patients following Japan’s 2011 earthquake, tsunami, and nuclear disaster in Fukushima. Factors associated with the length of post-disaster interval and whether interval was associated with breast cancer stage, were also investigated. Materials and Methods So-so District (study site), was an area damaged by the 2011 disasters. Data of all breast cancer patients who made their first medical consultation and received initial treatment at the core medical institutions in the area five years pre- or post-disaster, were extracted from the patients’ medical records. We employed several regression approaches to fulfill our study objectives. Results We included 263 patients (140 pre-disaster and 123 post-disaster). After adjustment for covariates, the interval did not significantly change post-disaster compared with pre-disaster. Those with 4 or 5 cohabiting family members experienced shorter interval post-disaster than those with 0 or 1 cohabiting family members (relative length 0.47, 95% confidence interval 0.28–0.78). Those with >60 days interval had lower odds of stages III or IV cancer than those with Conclusion Overall, the total interval did not lengthen post-disaster. However, those with restricted cohabiting family members might have experienced a longer total interval. Cancer stage may not necessarily reflect the influence of provider interval on the patients’ outcome. Micro Abstract This study assessed provider interval among breast cancer patients in a post-disaster setting. The participants were patients diagnosed in Fukushima, Japan, either five years before or after the 2011 disasters. Although statistically significant change in the provider interval post-disaster was not observed after adjusting for covariates, the number of cohabiting family members might be associated with longer intervals.