Tumors associated with radiotherapy: a case series

BACKGROUND

Breast cancer is the cancer with the highest incidence and mortality worldwide. Its treatment is multidisciplinary with surgery, systemic therapy, and radiotherapy. In Colombia, according to Globocan 2018, there is an age-standardized incidence rate of 44 per 100,000 women. Radiotherapy improves local and regional control in patients with breast cancer, and it could even improve relapse-free survival and overall survival in patients with nodal disease. The toxicity of this treatment in most cases is mild and transient, but in a low percentage of patients, radiotherapy-induced tumors may develop.

CASE PRESENTATION

Seven Colombian patients treated for breast cancer at our institution developed radiotherapy-induced tumors between 2008 and 2018. The median age was 54.4 (range 35-72) years. Six patients had locally advanced tumors at the time breast cancer was diagnosed, and all of them received neoadjuvant or adjuvant chemotherapy and radiotherapy. The radiotherapy-induced tumors were five sarcomas, one of which was a well-differentiated angiosarcomatous vascular lesion with negative c-Myc (benign lesion), and the remaining patient had basal cell carcinoma associated with radiotherapy.

CONCLUSIONS

Sarcomas are the most common radiotherapy-induced tumors after breast cancer treatment. These are rare, aggressive tumors and represent between 0.5% and 5.5% of all sarcomas. Basal cell carcinoma has also been associated with breast cancer treatment. The management is individualized and multimodal, including surgical resection and chemotherapy. Different studies have shown that radiation therapy is a risk factor for the development of soft tissue tumors.

A radiation-induced and radiation-sensitive, delayed onset angiosarcoma arising in a precursor lymphangioendothelioma

An 83-year-old female was treated with mastectomy and postoperative radiotherapy for breast cancer 30 years prior to developing a new small patch of thickening and scaliness on her left upper back, within the previous radiotherapy field. Serial excision biopsies revealed this to be a lymphangioendothelioma with no suggestion of malignancy. In early 2006 the lesion began to enlarge and take on a more erythematous plaque-like appearance. She was reviewed by a specialist dermatologist and an excision biopsy revealed a low-grade cutaneous angiosarcoma; this was approximately 38 years after radiotherapy to this region, the longest reported period between irradiation and in-field angiosarcoma development (the previous being 16 years). To our knowledge, this is the first case of post-radiotherapy angiosarcoma with a diagnosed precursor lesion. The lesion was treated with surgical excision and adjuvant radiotherapy. After further in- and out of- field recurrences, low dose radiotherapy elicited a surprisingly rapid and complete response within the treated areas; this was unusual in that these tumours are characteristically radiation-resistant. The radiosensitive case we report here raises the possibility that radiation should be more widely considered in the therapy of this disease. Methods of treatment of this rare malignancy are discussed.

[Post-radiation atypical vascular lesions and angiosarcoma: 11 cases]

BACKGROUND

Post-radiation atypical vascular lesions of the skin display clinical and morphological overlap with well-differentiated angiosarcomas, and correct diagnosis may be difficult.

PATIENTS AND METHODS

We studied clinical, histological and immuno-histochemical aspects (CD31, CD34, D2-40 and VEGFR-3) of eight post-radiation atypical vascular lesions comparatively with three post-radiation angiosarcomas.

RESULTS

All patients were female and received radiation therapy for breast carcinoma. On average, atypical vascular lesions occurred 4.3 years after radiation therapy and presented as small papulonodules or erythematous plaques. The clinical course after simple excision was benign. Histologically, they were relatively circumscribed lesions and showed slit-like vessels dissecting dermal collagen in all cases. On average, angiosarcomas occurred 5 years after radiation therapy and presented as more extensive lesions with a more aggressive clinical course. The lesions showed histological overlap with atypical vascular lesions, but were poorly circumscribed, with deeper invasion, cytological atypia and mitosis. Although the immuno-histochemical profiles were similar, expression of VEGFR-3 was greater in two cases of angiosarcoma.

CONCLUSION

Post-radiation atypical vascular lesions are benign lesions that display clinical, histological and immuno-phenotypic overlap with well-differentiated angiosarcoma, and diagnosis requires good clinicopathological correlation. VEGFR-3 may be useful for differential diagnosis, as well as amplification of the MYC gene.

Tumour suppressor gene TP53 mutations in atypical vascular lesions of breast skin following radiotherapy

AIMS

Atypical vascular lesions (AVL) occurring at the site of radiotherapy represent an uncommon but well-documented complication in the setting of breast-conserving therapy for breast carcinoma. Although the biological behaviour of AVL has been regarded as benign, it has been suggested that AVL may represent a precursor of angiosarcoma. A better understanding of the biology of AVL is essential in order to assess appropriate patient management. The aim of the present study was to investigate alterations of tumour suppressor gene TP53 in a series of radiation-induced AVL and angiosarcomas (AS).

METHODS AND RESULTS

Direct sequencing analysis of the TP53 gene showed the presence of at least one variation in 10 of 12 (83.3%) AVL and in seven of eight (87.5%) AS. The most common alteration in both categories was the P72R polymorphism in exon 4. One angiosarcoma sample carried a pathogenetically relevant disruptive mutation c.592delG, a frameshift deletion in exon 6, causing a premature stop codon.

CONCLUSIONS

The presence of TP53 alterations suggests that its mutational inactivation may be implicated in the pathogenesis of radiation-associated vascular proliferations. The common mutational pathway suggested by our data supports the hypothesis that AVL and AS are biologically related entities, most probably representing the extremes of a morphological continuum.