Survival of male breast cancer patients: a population-based study in Osaka, Japan.

BACKGROUND

Little information is available on the survival of male breast cancer patients because the disease is extremely rare in men. Recent studies indicated there were no gender-differences in the 5-year survival if patients' age and stage were matched. However, this problem has rarely been studied in Japan.

METHODS

Using the Osaka Cancer Registry's data, the 5-year survival was analyzed based on the reported 19,869 cases who lived in Osaka Prefecture excluding Osaka City and were diagnosed in 1975-1997, or who resided in Osaka City and were diagnosed in 1993-1997, because reliable follow-up information was available for them.

RESULTS

Breast cancer in males accounted for 0.49% of all cases during 1975-1997. The 5-year relative survivals were 71.1% in men and 81.6% in women. The survival in males decreased over older groups due to a lower proportion of localized stage, but not in females. The survival of males in the regional stage was significantly lower than that of females (49.1 versus 73.7%, P<0.05). Survival of males has increased since 1980-1984, while it has been stable in females. Compared with the survival of patients diagnosed in 1975-1979, male patients diagnosed in 1995-1997 had a noticeably lower risk of death after adjusting for age and cancer stage.

CONCLUSIONS

The results suggest male breast cancer patients at the regional stage had a worse 5-year survival rate compared to females. However, this gender-related difference seems to have disappeared with the increased survival of males during the 1990s. Further population-based studies are required with a greater number of male patients diagnosed after 1990.