Statistical estimation of the number of breast cancer patients with disabilities resulting from surgery.

BACKGROUND: The prolongation of the post-operative life of cancer patients brings new medical demands. The purpose of this paper is to estimate the total number of women patients with breast cancer who will have disability resulting from surgical treatment from 2000 to 2020 in Japan.
METHODS: The estimation was carried out using four indices: the number of cases of women diagnosed with breast cancer, the proportion of surgical operations, the frequency of disability from surgical treatment, and the crude survival rate of the patient group. The crude survival rates of surgically-treated breast cancer patients were estimated by the Weibull model. The frequencies of iatrogenic disabilities were calculated from several reports of complaints of pain in the chest wall or axilla and lymphedema of the arm, and 95% confidence intervals were calculated by the Monte Carlo simulation. RESULTS AND DISCUSSION: The number of women patients with disability from breast cancer treatment from 2000 to 2020 was estimated to be 42,016 (95% CI: 41,236, 42,796) people in 2000 and 72,514 (95% CI: 71,196, 73,832) people in 2020 for pain in the chest wall or axilla, and 22,486 (95% CI: 22,148, 22,823) people in 2000 and 38,692 (95% CI: 38,094, 39,290) people in 2020 for lymphedema of the arm. Treatment supports required for the disability are medication and social support. Cancer patients with disability after treatment need long-term support in their daily life.