The clinical and pathological characteristics of pure mucinous carcinoma of the breast

Aim To study the clinical and pathological characteristics of pure mucinous carcinoma of the breast,and to analyze the association between it and prognosis by comparing the pure mucinous cancer with invasive ductal carcinoma.Methods 23 cases of operable pure mucinous carcinoma of the breast patients were analyzed retrospectively and 863 controlled records of invasive ductal carcinoma patients during the same duration were also analyzed.Results The proportion of pure mucinous cancer of breast in all the breast cancer is less than 2.6%.Pure mucinous cancer patients were older than all patients(median age 62 y versus 51 y) and the median tumor size is larger too(3.0 cm vs.2.5 cm).The differences of age,tumor size,axliary lymph nodes status,ER and HER-2 statuses between pure macinous and invasive ductal carcinoma were obvious.It also showed that the proportion of ER+PR+ and ER+PR-subgroups were higher in the pure mucinous group than that in invasive ductal carcinoma patients.In the median follow-up time of 17.6 months,no case relapsed or died in 23 mucious patients while 2 patients died and 4 patients recurred or metastasized in 863 invasive ductal carcinoma patients.Conclusions Pure mucinous carcinoma of the breast has better clinical and pathologic characteristics than invasive ductal breast cancer,which indicates its advantage in prognosis and survival.Moreover,the patients of pure mucinous breast cancer are always ER+ and elderly.Adjuvant endocrine therapy may be more effective to them.