Borderline And Malignant Phylloides Tumors Of The Breast: A Retrospective Analysis Of 37 Cases

Phylloides tumors (PT) of the breast are rare fibroepithelial neoplasms. After surgical resection, borderline and malignant PT may benefit from an adjuvant treatment such as radiation therapy (RT). We analyzed retrospectively 37 patients with borderline or malignant PT treated in our institution between1970-2003 and compared it to the population of epithelial breast cancer. We collected clinical data on age at diagnosis, tumor diameter, histological characteristics, and clinical outcome. PT patients were compared with the 5596 epithelial breast cancer patients treated at our institution at the same period. Disease-free survival (DFS) was calculated using Kaplan Meier method. In univariate analysis we analyzed Histological tumor size, margin involvement, histologic grade, and age at diagnosis. Log Rank test was used to assess differences in survival. Median follow-up was 13 years. Median age was 49 years (14-88), median tumor diameter 5 cm (0.5-33). 31 patients were treated only by surgery (9 mastectomy, 22 lumpectomy). In the lumpectomy group, 7 had microscopically involved margins and 4 of them underwent a salvage surgery. 3 patients received adjuvant anthracycline-based chemotherapy. 1 patient received neoadjuvant chemotherapy, then mastectomy and RT (50 Gy). 1 patient received preoperative RT (40 Gy), and then mastectomy. 1 elderly patient refused surgery receiving only RT. 36 patients had a complete response. 5 local recurrences occurred, after a median period of 10 months (8-49). All of them were treated by surgery. 3 of them developed additional local recurrences, treated with surgery, RT, and/or chemotherapy. 3 patients developed a different breast tumor in the same region of the PT, dying all of them from metastases (brain and/or lung). The 1, 5, and 10 year Disease Free Survival rates were 89, 78, and 78%. The crude comparison of PT with epithelial breast cancer patients showed a better survival of PT (0.01) in the univariate analysis; PT patients were younger, their tumor size was larger and their grade was smaller. After adjustment of the main patients’ characteristics (period of diagnosis, age, clinical T and histology grade), the survival difference becomes nonsignificant (p = 0.09) with an estimated HR of 2. The univariate analysis showed a significant favorable effect of tumor size of less than 5 cm (p = 0.05). In malignant and borderline PT small tumor size influenced the survival in the univariate analysis. Wide excision surgery is the preferred treatment, followed by RT to improve local control and chemotherapy in selected patients. Compared to epithelial breast cancer, PT patients were younger and presented a larger tumor size with lower grade. Careful follow-up is recommended to diagnose local relapses, metastasis, and potential epithelial breast cancer.