Paclitaxel-dependent prolonged and persistent complete remission four years from first recurrence of secondary breast angiosarcoma.

Among angiosarcomas, radiation-induced breast sarcomas (RIBS) represent a well-known entity generally characterized by a poor outcome, especially in patients with advanced disease. Despite the unfavorable prognosis, some chemotherapeutic agents have been used to treat these malignancies, occasionally with success. Treatments with demonstrated activity against sarcomas include ifosfamide-based regimens and, more recently, taxane derivatives. We report a case of a patient having a secondary breast angiosarcoma recurring early after surgery, who achieved complete remission following treatment with weekly paclitaxel. After 4 years of maintenance therapy, with an interval between consecutive administrations of no longer than 3 weeks, the patient is still in complete remission. A locoregional recurrence was documented twice during this period, the first as a consequence of a brief treatment interruption and the second because of a treatment delay. Nonetheless, in both instances a new complete remission was rapidly achieved with the resumption of the same treatment, without evidence of any significant adverse effects. We discuss the highly unusual behavior of this malignancy and the possible role of the two different mechanisms of action of paclitaxel-antiangiogenic versus cytotoxic-depending on the schedule of administration, with evidence of "false" drug-resistance.