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.

Low-grade Leiomyosarcoma of the Cavernous Sinus in an HIV Positive Patient: Case Report.

Primary leiomyosarcomas of the central nervous system are extremely rare tumors, with few cases reported in the literature. In this article we report the case of a patient with an intracranial leiomyosarcoma of the cavernous sinus. This is the case of a 23-year-old man with a history of human immunodeficiency virus (HIV) and Epstein-Barr virus infection, with clinical picture of headache and left palpebral ptosis, who underwent nuclear magnetic resonance imaging that showed a lesion that occupied the cavernous sinus. Excisional biopsy reported fusocellular mesenchymal neoplasm with smooth muscle differentiation by immunohistochemistry compatible with low-grade leiomyosarcoma. The patient was initially taken to a partial resection, without treatment. Subsequently, the patient presented progression of his disease, so the area of neurosurgery considered that the lesion was unresectable due to its location and the risk of sequelae. It was then decided to treat the patient with intensity-modulated radiation therapy technique external radiotherapy. At six months of treatment, the patient continues asymptomatic with a stable disease.

Abscopal Effect After Palliative Radiotherapy in a Patient with a Gastric Adenocarcinoma Disseminated to Retroperitoneal Space: Case Report from a Latin American Reference Center and Review of the Literature.

Radiation therapy is known to have a highly effective local and regional effect for cancer treatment; however, sporadic events of tumor regression in non-irradiated and irradiated fields have been observed over time, which is known as the "abscopal effect." In this report, we describe the case of a patient with a diagnosis of unresectable advanced gastric adenocarcinoma, who developed extensive retroperitoneal lymph node involvement and did not accept management with chemotherapy. Primary radiotherapy at the local level was offered to control hemostasis, reaching an important span of complete remission of the disease.

Primary Conjunctival Rhabdomyosarcoma in a Pediatric Patient.

Rhabdomyosarcomas are neoplasms with a high degree of malignancy and arise from the embryonic mesenchyme. They represent approximately 5% of all pediatric tumors and their main locations are the head and neck (45%), trunk (40%), and extremities (15%). Twenty-five percent to 30% of the head and neck rhabdomyosarcomas appear in the orbit; however, its origin from the conjunctiva is rare, with few case reports published in the literature. We present the case of a five-year-old girl with a diagnosis of primary embryonic rhabdomyosarcoma of the conjunctiva, treated with surgery and chemotherapy. After completing the treatment, it was followed up with controls for oncological ophthalmology, pediatric hematology-oncology, and radiotherapy oncology every six months with magnetic resonance of the orbits. Two years after the end of treatment, the patient is disease-free. Conjunctiva rhabdomyosarcoma is a rare lesion, with few previously reported cases. In the reported case, the histopathological findings and positivity of the different immunohistochemical markers allowed a definitive diagnosis of rhabdomyosarcoma. The excellent prognosis of this pathology is probably linked to the early diagnosis of the disease and the timely administration of radical treatment. It is essential to be able to identify conjunctival rhabdomyosarcoma from its clinical and histopathological characteristics in order to achieve early diagnosis and provide adequate treatment to patients.