According to a study published in the October issue of the Journal of the American College of Surgeons, phyllodes tumors rare breast malignancies accounting for 0.5 to one percent of all breast tumors tend to be more prevalent in Hispanic patients. Population-based estimates indicate that the incidence of malignant phyllodes tumors is 2.1 cases per million women, with the highest frequencies in Hispanic women.
Previous studies have focused on race-related differences in biologic, pathologic, surgical and access-to-care factors in other benign and malignant pathologies of the breast. However, little is known about phyllodes tumors, which have unpredictable behavior and recurrence rates as high as 40 percent.
"We found substantial pathologic differences by race, with higher-grade tumors present more often in Hispanic patients," said lead study author Jose M. Pimiento, MD, surgical oncology fellow at Moffitt Cancer Center in Tampa, FL. "Although we did not determine that these variances could be translated into a survival difference by race, we believe that our findings can improve the understanding of this disease."
The authors of this retrospective study reviewed all patients treated for phyllodes tumors at Moffitt Cancer Center and the Cancer Therapy and Research Center, University of Texas Health Science Center San Antonio (UTHSCSA) between 1999 and 2010. Of the 124 patients studied, 71 (57 percent) were treated at MCC and 53 (42 percent) at UTHSCSA. Mean age at diagnosis was 44 years and 33 patients required mastectomy. Combining both cohorts, 42 percent of the patients were Caucasian, 43 percent were Hispanic and 12 percent were African-American.
Tumors were benign in 49 percent of patients, borderline in 35 percent and malignant in 16 percent, with a higher percentage of borderline and malignant tumors in Hispanic patients. Hispanic patients tended to have larger tumors and higher mitotic rates, the rate at which cells in the tumor are dividing. Patients showed a local recurrence rate of 6.4 percent during patient follow-up care (at approximately 13 months).
In light of these findings, the researchers noted that longer follow-up is also warranted to evaluate for later differences in local recurrence or survival, especially given the latent nature of this disease.