Radioresistant malignant myoepithelioma of the breast with high level of ataxia telangiectasia mutated protein

Abstract

Malignant myoepithelioma of the breast (MMB) is a rare and often aggressive disease with poor prognosis. Little is known regarding its optimal treatment and progression. We describe the clinical history of a woman following excision of a benign adenomyoepithelioma which recurred years later as a radioresistant malignant myoepithelioma with high levels of ataxia telangiectasia mutated protein and mutant p53 (Cys135Phe). MMB requires close follow-up and aggressive treatment. If adjuvant radiotherapy is adopted to improve local control, minimal postoperative delay and higher doses than for standard post-mastectomy radiation are recommended.

Radiotherapy in the Multidisciplinary Management of Adenomyoepithelioma of the Breast with an Axillary Lymph Node Metastasis: A Case Report and Review of the Literature

“…Another case report described recurrent AME (a fourth recurrence after excisional biopsy, repeat excisional biopsy, and mastectomy) treated with 60 Gy RT to the chest wall, resulting in 15 months of local control but then later progressing to develop lung metastasis [4]. Case reports of malignant AME have utilized RT (50 Gy in 25 fractions followed by a 9 Gy in three fraction boost) where, despite mastectomy, there was tumor progression [10]. Adjuvant RT was employed in our patient to achieve local control in the setting of AME with a lymph nodes metastasis after resection.…”

“…A link between upregulation of ATM protein in malignant AME and possible radioresistance has been reported [10]. Proponents of RT have advocated that if RT is to be employed, minimal postoperative delays, higher doses, and accelerated fractionation should be considered [10].…”

“…Proponents of RT have advocated that if RT is to be employed, minimal postoperative delays, higher doses, and accelerated fractionation should be considered [10]. In the case report here, RT was delivered at the standard post-mastectomy dose for our institution and has achieved disease control at the three-year follow-up period.…”

Adenomyoepithelioma of the breast: a review stressing its propensity for malignant transformation

“…Axillary lymph node dissection is not indicated for these lesions unless there is clinically detected lymphadenopathy because metastasis to nodes is unusual 14. There is little objective evidence to support a role for radiotherapy107 or chemotherapy in the management of AME.…”

Myoepithelial carcinoma of the head and neck: A report of 23 cases and literature review

“…A clinical study from the Peking University of China [24] gave similar results, with eight out of 12 patients developing a recurrence after postoperative radiotherapy. Fang et al found that high levels of ataxia telangiectasia-mutated protein (ATM) might induce radioresistance in MC, and recommended that an accelerated, high-dose approach should be delivered as soon as possible after surgery [31]. We believe that changing the fraction of radiation or using high-liner energy transmission (LET) radiotherapy, such as carbon particles and fast neutrons, may help to improve outcome.…”