Phyllodes Tumor of the Breast: 307 Treated Cases, the Largest Mexican Experience at a Single Breast Disease Institution.

Background: Phyllodes tumor (PT) of the breast in Hispanic patients is more frequently reported with large tumors and with more borderline/malignant subtypes compared with other populations. The objective of this study was to describe characteristics of patients with PT and to identify differences among subtypes in a Mexican population.

Methods: A retrospective study was conducted on patients with PT. Sociodemographic, histopathologic, and treatment characteristics were compared among subtypes, including only surgically treated cases due the complete surgical-specimen study requirement for appropriate WHO classification.

Results: During 10 years, 346 PT were diagnosed; only 307 were included (305 patients), with a mean age of 41.7 yr. Self-detected lump took place in 91.8%, usually discovered 6 months previously, with median tumor size of 4.5 cm. Local wide excisions were done in 213 (69.8%) and mastectomies in 92 (30.1%). Immediate breast reconstruction took place in 38% and oncoplastic procedures in 23%. PT were classified as benign in 222 (72.3%) cases, borderline in 50 (16.2%), and malignant in 35 (11.4%), with pathological tumor size of 4.2, 5.4, and 8.7 cm, respectively (<0.001). Patients with malignant PT were older (48 yr), with more diabetics (14.3%), less breastfeeding (37.1%), more smokers (17.1%), with more postmenopausal cases (42.9%), and older age at menopause (51.5 years) compared with the remaining subtypes (<0.05). Relapse occurred in 8.2% of patients with follow-up.

Conclusion: In comparison with other Hispanic publications, these Mexican patients had similar age, with smaller tumors, modestly higher benign PT, fewer malignant PT, and lower documented relapse cases.