Page 17 - Delaware Medical Journal - March 2016
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CASE REVIEW
Early biopsy of suspicious lesions is suggested as this is an aggressive tumor requiring early intervention.
Currently surgical resection is the mainstay for treatment of RAAS of the breast. This can take the form of total mastectomy, or wide local excision in some cases. Currently there is no standard as to what constitutes an adequate margin. Case reports and retrospective studies have suggested that margins ranging from 1-4 cm are adequate.17-20 R0 (negative margin) resections have been shown to have increased survival when compared to either R1 microscopic positive margin) or R2 (gross positive margin) resection.21 Seinen
et al. showed that mastectomy as upfront surgery was more likely
to produce an R0 resection, however even with an R0 resection
they found local recurrence in 14 of 23 patients within six months.22 RAAS acts like a typical sarcoma and spread to lymphatics is rare, and currently axillary dissection is not considered appropriate in this patient population.23
RADIATION
Reirradiation is not standard of care for RAAS. The toxicity of further
have been studies showing improved local and distant control with either reirradiation +/- hyperthermia. Ghareeb et al. demonstrated improved local and distant free disease control with adjuvant radiation; 24 This study also showed an improved disease free survival, 71 percent vs
21 percent, when comparing surgery plus adjuvant radiation versus surgery alone respectively.24 Similar results for local and distant disease control were shown using hyperfractionated and accelerated chemotherapy.25 De Jong et al. demonstrated local response rate
of 75 percent in patients with unresectable disease by combining reirradiation with hyperthermia treatment.26
Smith et al. have shown impressive results on 14 consecutive patients who received hyperfractionated accelerated re-irradiation (HART).25 Typical therapy consisted of three treatments a day ten year survival rates of 79 percent and 71 percent, respectively.25 Side effects experienced were listed as follows: skin desquamation, telangiectasia. These results suggest that there could be a potential role for additional radiation in the treatment of RAAS.
Accelerated Partial Breast Irradiation (APBI) is an alternative to whole breast radiation. With this modality of treatment radiation is supplied to a limited area within the breast, sparing the patient
additional radiation exposure. At the time of this article no case
to APBI. APBI has been demonstrated to be equivalent to whole breast radiation in selected patient populations. The incidence of RAAS could potentially be reduced by decreasing the total number of women receiving whole breast radiation.
CHEMOTHERAPY
et al. showed a decreased local recurrence rate, but were unable to show improved disease free survival or overall survival.12 Perhaps the best data is from the ANGIOTAX trial which was been able to demonstrate nonprogression rates of 74 percent and 45 percent after two and four cycles of paclitaxel respectively for unresectable or locally advance angiosarcoma.27 Clinical trials will be needed to evaluate for utility of chemotherapy.
GENE TESTING / C-MYC
Radiation associated angiosarcoma is a distinct entity both
for primary angiosarcoma of the breast and atypical vascular proliferation of the breast. Mentzel et al. were able to show
a proto-oncogene found on chromosome 8q.24-28 This study patients studied. This data was reproduced by Wade et al. in 2015 showing that diffuse FLT4 gene expression using FISH was associated with RAAS.29 FLT4 could have the potential for targeted therapy. In the future, genetic testing could identify patients at risk for RAAS and spare them irradiation.
Recent studies have demonstrated pathways for the development of
PRDM1 a down regulator of C-Myc expression.30
CONCLUSION
Radiation associated angiosarcoma of the breast is an aggressive tumor whose prevalence can be expected to increase with increased usage of breast conserving surgery. Understanding its clinical presentation and prognosis will be important in its treatment. Surgery with negative margins remains the mainstay of therapy;
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