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Atypical vascular lesions including angiosarcoma after breast conservation.

689 Background: The development of angiosarcom (AS) after breast conservation and radiotherapy (BCT) is a rare complication of breast cancer (BC) treatment carrying a poor prognosis. We have observed an increase in the diagnosis of atypical vascular proliferation (AVP) which does not meet pathologic criteria for AS, but may represent a precursor lesion. We review our experience with AVP and AS, to further elucidate the clinical course and outcomes for patients with these lesions.


METHODS
Patients who underwent BCT for BC with a secondary AVP or AS of the ipsilateral breast were identified from patient records at our institution from January 1982 to May 2003. BC and AVP or AS treatment details were recorded and vascular lesion pathology reviewed.


RESULTS
20 patients were identified, 15 had AS and 5 had AVP. Median age at initial BC diagnosis was 54 yrs (30-68). All patients had whole breast radiotherapy. Fifty-five percent (10/18) had adjuvant chemotherapy and 69% (9/13) took tamoxifen after BCT. Median age at AS and AVP diagnosis was 63 (47-74) and 53 (40-65) yrs respectively. Median time to diagnosis of AS post BC diagnosis was 81 mos (38-137) and 76 mos (54-63) for AVP. Treatment of AS was wide local excision (WLE) in 2 patients; both are NED. Total mastectomy (TM) was performed in 87% (13/15). 23% (3/13) of these women had additional chemotherapy and 7.7 % had adjuvant RT. Only 23% (3/13) experienced no recurrence at a median f/u of 21 mos (1-108). Of the 6/13 with local recurrence, 3 remain alive with disease (AWD) and 3 are NED. Of the 4/13 with distant recurrence, 3 are dead of disease (DOD), one is AWD. 8/15 patients with AS were NED at last f/u. Median f/u for patients with AVP is 15 mos (12-65). Treatment of AVP was TM in 1 patient followed by chemotherapy, she is NED. 80% (4/5) were treated with WLE. Of these, one developed recurrent AVP 1 year later.


CONCLUSIONS
Post BCT AS has a grave prognosis in spite of multimodality therapy. Further follow-up is needed to better elucidate the malignant potential of AVP. With increasing use of BCT, clinicians should be aware of the spectrum of vascular lesions and the possibility that AVP is a precursor lesion with capacity to recur. No significant financial relationships to disclose.