Is there a role for adjuvant chemotherapy in a young healthy patient with a large malignant phyllodes tumor of the breast?

The management malignant phyllodes tumor (MPT) is hampered by the rarity of which it occurs, and case reports and small series is all we have. The definitive treatment is surgical resection, with intent of achieving > 1 cm margins. Overall, about 25% of MTP will develop distant metastases, with the commonest sites being lungs (> 60%) and bones (> 25%).  The benefits of adjuvant radiation are largely unknown, however, large tumors (i.e., greater 5 cm) or close surgical margins have tended to receive adjuvant radiation with anecdotal evidence of decrease in local failures (Mishra et al ISRN Surgery Volume 2013 Article ID 3611469, 10 pages). Likewise, the benefits of adjuvant  chemotherapy are unknown, but sarcoma drugs including anthracyclines, ifosfamide, cisplatin, etoposide are used. Although, the majority will estrogen or progesterone receptor positive there is no established role for anti-estrogens.  My anecdotes of 1 or 2 cases is that we gave adjuvant radiation to close margins, but no adjuvant chemotherapy.