E1405. Phyllodes Tumor of the Breast: Race-Related Differences in Presentation, Pathology and Prognosis
  1. Courtney Lee; Albert Einstein Medical Center
  2. Zi Zhang; Albert Einstein Medical Center
Phyllodes tumors (PT) are fibroepithelial breast neoplasms often distinguished by their rapid growth rate and large size. The presentation and behavior of PT by race remains largely unknown. We aimed to investigate the race-related differences in clinical, radiological and pathological presentation and prognosis of PT.

Materials and Methods:
We identified cases of PT confirmed by excisional biopsy at our institution from May 2012 to May 2022. A retrospective chart review was then conducted. For benign PT, resection margins > 0.1mm were considered negative and 0.1mm were close. For borderline/malignant PT, margins >2mm were negative and 0.1-2mm were close. Statistical analysis was performed using Pearson’s chi-squared test and one-way ANOVA test.

All 62 cases of PT occurred in women of average age 41+/-15.2 years at the time of presentation. Among them, 21.0% were Caucasian (13/62), 32.3% African American (20/62), 17.7% Hispanic (11/62) and 29.0% Asian/Other (18/62). 22.6% presented through screening mammogram (14/62) and 77.4% presented with a palpable mass (48/62). The average tumor size was 3.5+/-2.6 cm. 66.1% were benign (41/62), 22.6% borderline (14/62) and 11.3% malignant (7/62). Of the 41 benign PT, 29.3% had negative resection margins (12/41), 14.6% had close margins (6/41) and 53.7% had positive margins (22/41). 26.8% were re-excised (11/41), 26.8% had short-term follow-up (11/41), and 17.0% lost to follow-up (8/41). The recurrence rate was 12.1% (4/33). Of the 14 borderline PT, 14.3% had negative margins (2/14), 28.6% had close margins (4/14) and 57.1% had positive margins (8/14). 35.7% underwent re-excision (5/14), 7.1% underwent mastectomy (1/14), 14.3% received radiation (2/14), and 21.4% had short-term follow-up (3/14). None were lost to follow-up. The recurrence rate was 7.1% (1/14). Of the 7 malignant PT, 42.9% had negative margins (3/7), 28.6% had borderline margins (2/7) and 28.6% had positive margins (2/7). 42.9% were re-excised (3/7), 42.9% underwent mastectomy (3/7), 42.9% received radiation (3/7), and 14.3% had short-term follow-up (1/7). None were lost to follow-up. 1 instance of metastasis occurred (14.3%). There were no significant differences in age of presentation, malignancy rate, treatment, resection margins, recurrence rate and follow-up rate by race. However, minorities were significantly more likely to present with palpable concerns compared to Caucasian (p=0.031). Among 48 women presenting with a palpable concern, 14.6% were Caucasian (7/48), 29.2% African American (14/48), 20.8% Hispanic (10/48) and 35.4% Asian/Other (17/48). Additionally, the average tumor size was 2.8+/-1.5cm in Caucasian women, 4.1+/-2.8cm in African American women, 3.2+/-3.1cm in Hispanic women and 3.7+/-2.7cm in Asian/Other women (p=0.094).

Minority women diagnosed with PT were more likely to present with a palpable concern than Caucasian women. This may be related to the various barriers to screening mammography experienced by minority populations. However, these distinctions did not significantly affect treatment and recurrence based on a mean follow-up of 2.5 years.