National surgical patterns of care for primary surgery and axillary staging of phyllodes tumors.

Phyllodes tumors (PT) are rare and unique in their suspected stromal and epithelial origin, and their propensity to recur despite surgical resection. Current surgical treatment of PT does not include sampling of regional lymph nodes (LNs) as malignant PT infrequently spread to LNs. We hypothesize that, because of substantial experience with common epithelial lesions of the breast, surgeons are more prone to sample LNs in PT patients. We reviewed national surgical patterns of care of axillary LN sampling for PT using the Surveillance Epidemiology & End Results (SEER) registry. SEER data for LN evaluation are available from 1988. The public-access SEER data-base was queried for patients presenting over all 17 registries between 1988 and 2003 with PT of the breast. Data were collated by type of surgery and number of LNs examined, and further analyzed by tumor size of the primary lesion where available; 1,035 cases of PT were identified for the 16-year period. Patients had a median age of 50 (range 12-96). Of the specimens with SEER grade listed, 117 were well-differentiated, 186 moderately differentiated, 79 poorly differentiated, and 132 undifferentiated; 612 (59.1%) cases had specific surgical procedures reported: 191 partial, 251 simple, 5 subcutaneous, 154 modified radical, and 6 radical mastectomies, with 5 mastectomies (NOS) documented. The remainder of cases had surgery that was coded as "undocumented" or unknown. When surveyed by LNs examined, 25.5% of patients (n=264) underwent some degree of regional lymphadenectomy; the median number of LNs examined in these patients was 7 (range 1-37). Of all PT patients, 9.0% of patients underwent axillary sampling of 10 LN or more. Only nine patients (3.4%) had positive LNs. When assessing axillary sampling rate by tumor size, smaller lesions were less likely to undergo sampling than larger lesions (19.3% for lesions <2 cm, 20.5% for lesions 2-4.9 cm, 27.9% for 5-9.9 cm); although this was nonsignificant. In spite of the lack of supporting data for LN examination axillary staging continues to be performed for many cases of PT.