Invasive apocrine carcinoma of the breast: clinicopathologic features of 57 patients.

Apocrine carcinoma is a rare, unique, and morphologically distinctive type of invasive ductal carcinoma (IDC). The features of invasive apocrine carcinoma (IAC) and their possible prognostic implications have not been fully investigated. To this end, we examined the clinicopathologic characteristics and outcome of patients with IAC and compared these factors with those of patients with IDC. Out of 2,055 breast cancer patients who had undergone breast surgery between 1995 and 2005, 57 patients of IAC and 1,583 patients of IDC were analyzed. The mean ages of the patients with IAC and of those with IDC were 58.5 +/- 10.9 years and 54.4 +/- 11 years, respectively (p = 0.006). The percentages of patients with axillary nodal metastasis and lymphatic invasion were significantly lower in the IAC group than in the IDC group (p = 0.03 and 0.02, respectively). The percentage of estrogen and progesterone receptor negativity was higher in the IAC group than in the IDC group (p < 0.001). After a median follow-up period of 49 months (range, 1-133 months), seven (12%) patients with IAC and 244 (15%) patients with IDC had experienced recurrences. Three (5%) patients with IAC and 125 (8%) patients with IDC died of recurrent breast cancer. No significant differences in the relapse-free survival (p = 0.83) and overall survival (p = 0.75) rates were observed between the two groups. Although IAC and IDC have different clinicopathologic characteristics, the prognoses of patients with these diseases are similar.