Document Type: Research Articles
Department of Breast Surgery, Fujita Medical University, 1-98 Dengakugakubo, Kutsukakecho, Toyoake, Aichi 470-1192, Japan.
Department of Digestive Surgery, Breast and Thyroid Surgery, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 890-8520, Japan.
Background: Human T-cell lymphotropic virus type 1 (HTLV-1) is a retrovirus that causes adult T-cell leukemia/
lymphoma (ATL), an aggressive form of T-cell malignancy. The relationship between HTLV-1 infection and cancer
progression is controversial. HTLV-1 encodes oncogenic protein TAX1 and it is hypothesized that HTLV-1 infection
is associated with breast cancer progression. In this study, we evaluated the relationship between HTLV-1 infection
and clinicopathological factors in breast cancer patients. Methods: We retrospectively analyzed 610 patients with
primary breast cancer who underwent surgical treatment without preoperative chemotherapy at Kagoshima University
Hospital between January 2001 and January 2015. Results: When patients with and without HTLV-1 infection were
compared, no differences in clinicopathological factors were observed, except for age. Disease-free survival and
overall survival rates did not differ between groups. Conclusions: HTLV-1–positive patients were significantly older
than HTLV-1–negative patients. It was supposed to be due to the fact that the HTLV-1 infection rate is decreasing. Any
effect of HTLV-1 infection on breast cancer progression appears to be negligibly small.