[6120] Retrospective review with long term follow up of 11.400 cases of pure mucinous breast carcinoma. DiSaverio S, Gutierrez J, Avisar E. Miller School of Medicine, University of Miami, Miami, FL Background Pure Mucinous Breast Carcinoma (PMBC) is a rare histologic type of mammary neoplasm. It has been associated with a better short term prognosis than Infiltrating Ductal Carcinoma (IDC) but long term survival curves have been reported as identical. The value of tumor size for TNM staging has been challenged because of the mucin content of the lesions. This study presents a large PMBC series with 20 years follow up as compared to IDC. The relative significance of a variety of common prognostic factors is calculated for this uncommon histology. Materials and Methods A retrospective analysis of all PMBC cases reported in the SEER database between 1973 and 2002 was conducted. Overall survival (OS) and disease specific survival (DSS) were calculated at 5,10, 15 and 20 years of follow up. Those curves were compared with all the IDC cases reported into the database during the same period. The prognostic significance of gender, race, laterality, age at diagnosis, T and N status, estrogen and progesterone receptors and administration of radiation therapy was calculated by univariate and multivariate analysis. Results There were 11422 PMBC patients reported. Median age at diagnosis was 71 years (Range 25-85). Fifty three percent of the tumors were well differentiated, 38% were moderately differentiated and the remainder 9% were poorly differentiated or anaplastic. The majority of the tumors were located in the upper outer quadrant (44%) the other 56% were roughly evenly divided between the upper inner, lower inner, lower outer and central quadrants. Eighty six percent of the patients had only localized disease at the time of surgery without nodal or distant disease while 12% had regional nodal involvement and 2% had distant metastases. Kaplan Meier overall survival curves revealed a 5 yr. survival rate of 94%. Although slowly decreasing with time, 10,15 and 20yr. survival were, 89%, 85% and 81% respectively compared to 58%, 45% and 36% for IDC. Multivariate analysis by Cox regression revealed the nodal status (N) to be the most significant prognostic factor followed by age, tumor size (T), progesteron receptors and nuclear grade. The addition of radiation therapy after surgery did not improve overall survival. Conclusions This large retrospective comparative analysis confirms the less aggressive behavior of PMBC compared to IDC. This favorable outcome is maintained after 20 years. This tumor presents typically in older patients and is rarely associated with nodal disease. Positive Nodal status appears to be the most significant predictor of worse prognosis. San Antonio Breast Cancer Symposium, 12/06 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.