Surgical margins for borderline and malignant phyllodes tumours

Abstract

Background Phyllodes tumours represent less than 1% of all UK breast neoplasms. Histological features allow classification into benign, borderline or malignant, which has a significant impact on prognosis and recurrence. Currently, there is no consensus for the optimal surgical excision margin. This systematic review aims to provide a comparative summary of outcomes (local recurrence, metastasis and survival) for borderline and malignant phyllodes tumours resected with either ≥1cm or <1cm margins. Methods MEDLINE and Embase were systematically searched (1990 to July 2019), in line with PRISMA guidelines. Study quality was assessed using the Newcastle–Ottawa scale. Results Ten retrospective studies were included (Newcastle–Ottawa scale mean score: 5.6, range: 8–4). Nine reported local recurrence rates, four reported distant metastasis and four reported survival. Meta-analysis pooling demonstrated no statistically significant difference between <1cm and ≥1cm margins in terms of local recurrence rates (relative risk [RR] 1.43, 95% confidence interval [95% CI] 0.70 – 2.93; p=0.33, n=456), distant metastasis (RR 1.93, 95% CI 0.35 – 10.63; p=0.45, n=72) or mortality (RR 1.93, 95% CI 0.42 – 8.77; p=0.40, n=58) for borderline and malignant tumours. Additionally, two studies demonstrated no significant difference in local recurrence for borderline tumours excised with <0.1cm margins compared to ≥1cm. Conclusion Current evidence suggests that margins <1cm may provide adequate tumour excision. This could enable breast conservation in patients with smaller breast-to-tumour volume ratios, with improved cosmetic outcomes and patient satisfaction. A prospective, multi-institutional trial would be appropriate to further elucidate the safety of smaller margins.

Surgical management in phyllodes tumors of the breast: a systematic review and meta-analysis

“…Ogunbiyi et al also found that margin ≥1 and <1 cm had no significant difference in the LR risk for borderline PT, which was consistent with the result of this study (48). Thind et al conducted a systematic review and meta-analysis on borderline and malignant PTs, and proposed that the correlation between margin width and LR was not statistically different as well (11). However, there were also studies indicated that borderline PT was resemble to malignant PT in terms of chromosomal variation and gene mutation and suggested that borderline PT should be given the same attention as malignant PT in making surgical decision (14,49,50).…”

“…As for malignant PT, no significant difference in the LR rate between margin ≥1 and <1 cm was found which was consistent with the meta-analysis conducted by Thind et al (11). Some studies also indicated that there was no real advantage to obtain ≥1 cm margins as thinner surgical excisions did not impact LR and the disease-free survival (13,28,35).…”

“…While some studies investigated that for benign PT, no significant difference of LR between <1 and ≥1 cm margins was found (10). Thind et al even indicated that margin <1 cm was also acceptable for borderline and malignant PTs (11). As for margin status, some studies suggested that positive margin was significantly related to the increase of LR risk (12,13).…”

A giant malignant phyllodes tumor of breast post mastectomy with metastasis to stomach manifesting as anemia: a case report and review of literature

“…According to Thind A., et al, a larger surgical margin of 1 cm or greater, compared with less than 1 cm, does not confer any statistically significant advantage as for local control, distant metastasis, or overall survival for borderline and malignant PTs [17]. Axillary dissection was not routinely performed since nodal metastases secondary to PT are very rare.…”

Retrospective study of malignant phyllodes tumors of the breast: Younger age, prior fibroadenoma surgery, malignant heterologous elements and surgical margins may predict recurrence

“…A meta-analysis showed that, between margins of <1 cm and ≥1 cm, there was no statistically significant difference between borderline and malignant PTs in terms of local recurrence, distant metastasis, and mortality. In addition, there was no significant difference in local recurrence among patients with borderline PT with margins of <1 cm and ≥1 cm[ 31 ]. Recently, Spanheimer et al.…”