Radiation‐associated sarcoma after breast cancer in a nationwide population: Increasing risk of angiosarcoma

Abstract

Radiation‐associated sarcoma (RAS) is a rare complication of radiation therapy (RT) to breast cancer (BC). This study explored RAS after RT to BC in a nationwide population‐based material. The Finnish Cancer Registry was queried for patients with BC treated during 1953‐2014 who were later diagnosed with a secondary sarcoma in 1953‐2014. Registry data, patient files, and sarcoma specimens were analyzed to confirm diagnosis and location of RAS at or close to the RT target volume. A total of 132 512 patients were diagnosed with invasive BC during the study period. A subsequent sarcoma was diagnosed in 355 patients. After exclusion, 96 RAS were identified. Angiosarcoma (AS) was the most prevalent histology in 50 (52%) of 96 patients. However, the first radiation‐associated AS was diagnosed in a patient treated for BC with breast‐conserving surgery in 1984, and thereafter, the proportion of AS continuously increased. The 5‐year sarcoma‐specific survival was 75.1% for RAS treated with a curative intent. The distribution of histologic subtypes of RAS has changed during the 60 years of this registry study. The first radiation‐associated AS was diagnosed in 1989, and presently, AS is the most common histologic subtype of RAS. It is possible that changes in BC treatment strategies are influencing the characteristics of RAS.

Postoperative radiotherapy-induced leiomyosarcoma in breast cancer: a case report and literature review

“…Yap et al reported that in sarcomas occurring in the radiation field, angiosarcoma accounted for 56.8%, malignant fibrous histiocytoma accounted for 15.9%, fibrosarcoma and chondrosarcoma accounted for 6.8%, and leiomyosarcoma accounted for 4.5% [7]. Sal et al reported that among 96 patients with radiation-related sarcoma, the most common angiosarcoma accounted for 52% [8].…”

“…The main cause of RIS is radiotherapy, its pathogenesis is thought to be due to non-fatal chromosome damage in non-tumor connective tissue cells, leading to sarcoma in the radiation field [11,12]. Most series report radiation doses ranging from 16-112 Gy [8,[13][14][15], and median doses for breast irradiation are approximately 50 Gy [8,[11][12][13][14][15]. It has been reported that radiotherapy dose is significantly associated with the risk of subsequent sarcoma, and higher radiation doses increase the risk of bone and soft tissue sarcoma.…”

“…In 1922, Beck [6] first reported the case of osteosarcoma after the breast cancer radiotherapy. The histological type of most RIS is angiosarcoma [7,8]. There is a long latent period between the occurrence of RIS and radiation therapy, usually 10 years after radiotherapy [9].…”

Treatment and Prognosis of Radiation-Associated Breast Angiosarcoma in a Nationwide Population

“…RAASB histopathology for the majority of cases was confirmed in a previous study. 5 Radiation-Associated Angiosarcoma of the Breast (RAASB) Treatment and Follow-Up Assessment Patient records and pathology reports were assessed to document the planned surgical side margins according to the surgery report (cm), pathological surgical margins (cm), removed tissues (skin, subcutaneous tissue, mammary gland, pectoral fascia, pectoral muscle), and possible surgical reconstruction. The pathological surgical margin was defined as the measurement stated in the original pathology report.…”

“…4 In recent years, angiosarcoma has been the most common subtype of radiation-associated sarcoma of the breast. 5 A newly published population-based study estimated the risk of RAASB to be approximately 0.1%. 6 It has been postulated that the shift from radical mastectomies to breast-conserving surgery has resulted in secondary angiosarcomas arising in the breast.…”