Potential association of prolonged patient interval and advanced anatomic stage in breast cancer patients in the area affected by the 2011 triple disaster in Fukushima, Japan: Retrospective observational study

For five years after the 2011 triple disaster (earthquake, tsunami, and nuclear disaster) in Japan, the proportion of patients with undiagnosed symptomatic breast cancer remained elevated in the coastal area of Fukushima. These individuals experienced a prolonged interval from first symptom recognition to initial medical consultation (hereafter referred to as the patient interval). We aimed to investigate how this prolonged patient interval affected disease staging.Using patient records, we retrospectively extracted females with newly and pathologically diagnosed breast cancer who initially presented to Minamisoma Municipal General Hospital from March 2011 to March 2016. We estimated the proportion with advanced-stage disease (III, IV) according to the patient interval duration (