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.

Secondary breast angiosarcomas are a well-known entity generally characterized by a poor outcome, especially in patients with advanced disease. Among the drugs with demonstrated activity, taxane derivatives are one of the most effective histology-driven treatments against angiosarcomas. We report two cases of secondary breast angiosarcoma, both characterized by a very peculiar behavior towards paclitaxel. Both patients showed local recurrence of angiosarcoma after primary surgery, and they achieved complete remission following treatment with weekly paclitaxel. When a locoregional recurrence was observed as a result of a brief treatment interruption or a treatment delay, a new complete remission was rapidly achieved with the resumption of the drug, without evidence of any significant adverse effects.

e22174 Background: Uncommon breast tumors are often neglected by large clinical trials, even if their incidence is not so low. Methods: We investigated stage, treatment and outcome of 112 patients affected by uncommon breast cancer, out of 2,185 breast cancer patients diagnosed and followed in our Institution from January 1985 to October 2008. Results: Rare subtypes were represented as follows: tubular 2.7% (58 pts), mucinous 1.1% (25 pts), medullary 1% (21 pts), papillary 0.4% (8 pts). Median age at diagnosis was 56.5 years among patients with tubular histotype, 68.9 years for mucinous, 55 and 61.7 years for medullary and papillary, respectively. Stage I tumors were 87.7% among patients with tubular differentiation, 60% for mucinous, 26.3% for medullary and 50% for papillary, (compared to 45.7% in invasive ductal carcinoma: 1,626 pts). Stage II represented 12.3% among patients with tubular carcinoma, 32% for mucinous, 57.9% for medullary and 37.5% for papillary. Surgical option for stage I and stage II was usually conservative surgery (quadrantectomy, lumpectomy) plus local radiotherapy, followed by estrogenic blockade. In stage III radical mastectomy was often performed, followed by hormonal suppression. Median DFS for patients with tubular cancer was 4.1 years, for mucinous 3.7 years, 10.5 and 5.1 years for medullary and papillary, respectively. Median OS for patients with tubular cancer was 4.3 years, whereas for mucinous 4.2 years, for medullary 11 years and 5.3 years for papillary. Conclusions: In our retrospective analysis, uncommon breast tumors are often diagnosed at limited stages, resulting in good prognosis, with standard treatment. Further studies are warranted for a better management of these diseases. No significant financial relationships to disclose.

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Aims and background Often neglected by large clinical trials, patients with uncommon breast malignancies have been rarely analyzed in large series. Patients and methods Of 2,052 patients diagnosed with breast cancer and followed in our Institution from January 1985 to December 2009, we retrospectively collected data on those with uncommon histotypes, with the aim of investigating their presentation characteristics and treatment outcome. Results Rare histotypes were identified in 146 patients (7.1% of our total breast cancer population), being classified as follows: tubular carcinoma in 75 (51.4%), mucinous carcinoma in 36 (24.7%), medullary carcinoma in 25 (17.1%) and papillary carcinoma in 10 patients (6.8%). Whereas age at diagnosis was not significantly different among the diverse diagnostic groups, patients with medullary and papillary subtypes had a higher rate of lymph node involvement, similar to that of invasive ductal carcinoma. Early stage diagnosis was frequent, except for medullary carcinoma. Overall, in comparison with our invasive ductal carcinoma patients, those with rare histotypes showed a significantly lower risk of recurrence, with a hazard ratio of 0.28 (95% CI, 0.12–0.62; P = 0.002). Conclusions According to our analysis, patients with uncommon breast malignancies are often diagnosed at an early stage, resulting in a good prognosis with standard treatment.