Angiosarcoma (AS) represents a rare and aggressive vascular sarcoma, posing distinct challenges in clinical management compared to other sarcomas. While the current European Society of Medical Oncology (ESMO) clinical practice guidelines for sarcoma treatment are applicable to AS, its unique aggressiveness and diverse tumor presentations necessitate dedicated and detailed clinical recommendations, which are currently lacking. Notably, considerations regarding surgical extent, radiation therapy (RT), and neoadjuvant/adjuvant chemotherapy vary significantly in localized disease, depending on each different site of onset. Indeed, AS are one of the sarcoma types most sensitive to cytotoxic chemotherapy. Despite this, uncertainties persist regarding optimal management across different clinical presentations, highlighting the need for further investigation through clinical trials. The Italian Sarcoma Group (ISG) organized a consensus meeting on April 1st, 2023, in Castel San Pietro, Italy, bringing together Italian sarcoma experts from several disciplines and patient representatives from \"Sofia nel Cuore Onlus\" and the ISG patient advocacy working group. The objective was to develop specific clinical recommendations for managing localized AS within the existing framework of sarcoma clinical practice guidelines, accounting for potential practice variations among ISG institutions. The aim was to try to standardize and harmonize clinical practices, or at least highlight the open questions in the local management of the disease, to define the best evidence-based practice for the optimal approach of localized AS and generate the recommendations presented herein.

Hemangiosarcoma is a mesenchymal neoplasm originating in the endothelial cells of blood vessels; they can be classified as non-visceral and visceral types. Non-visceral hemangiosarcomas can affect the skin, subcutaneous tissues, and muscle tissues; visceral hemangiosarcomas can affect the spleen, liver, heart, lungs, kidneys, oral cavity, bones, bladder, uterus, tongue, and retroperitoneum. Among domestic species, dogs are most affected by cutaneous HSA. Cutaneous HSA represents approximately 14% of all HSA diagnosed in this species and less than 5% of dermal tumors, according to North American studies. However, Brazilian epidemiological data demonstrate a higher prevalence, which may represent 27 to 80% of all canine HSAs and 13.9% of all skin neoplasms diagnosed in this species. Cutaneous HSA most commonly affects middle-aged to elderly dogs (between 8 and 15 years old), with no gender predisposition for either the actinic or non-actinic forms. The higher prevalence of cutaneous HSA in some canine breeds is related to lower protection from solar radiation, as low skin pigmentation and hair coverage lead to greater sun exposure. Actinic changes, such as solar dermatosis, are frequent in these patients, confirming the influence of solar radiation on the development of this neoplasm. There are multiple clinical manifestations of hemangiosarcoma in canines. The diagnostic approach and staging classification of cutaneous HSAs are similar between the different subtypes. The definitive diagnosis is obtained through histopathological analysis of incisional or excisional biopsies. Cytology can be used as a presurgical screening test; however, it has little diagnostic utility in cases of HSA because there is a high risk of blood contamination and sample hemodilution. Surgery is generally the treatment of choice for dogs with localized non-visceral HSA without evidence of metastatic disease. Recently, electrochemotherapy (ECT) has emerged as an alternative therapy for the local ablative treatment of different neoplastic types; the use of radiotherapy for the treatment of dogs with cutaneous HSA is uncommon. There is greater consensus in the literature regarding the indications for adjuvant chemotherapy in subcutaneous and muscular HSA; doxorubicin is the most frequently used antineoplastic agent for subcutaneous and muscular subtypes and can be administered alone or in combination with other drugs. Other therapies include antiangiogenic therapy, photodynamic therapy, the association of chemotherapy with the metronomic dose, targeted therapies, and natural products. The benefits of these therapies are presented and discussed. In general, the prognosis of splenic and cardiac HSA is unfavorable. As a challenging neoplasm, studies of new protocols and treatment modalities are necessary to control this aggressive disease.

Currently, there are no comprehensive breast sarcoma guidelines in the UK. There is therefore a need for guidelines to clarify surgical management, which we have based on data from our regional audit, current evidence, and consensus between West of Scotland Breast Cancer and Scottish Sarcoma Managed Clinical Networks. Methods and results: From 2007 to 2019, 46 patients were treated with breast sarcoma in the West of Scotland. Sarcoma Centre versus Peripheral Hospitals: Incomplete excision rate was 0% at sarcoma centre and 50% at peripheral hospitals (p = 0.0002, Odds Ratio 43). For angiosarcoma, 0% positive margin at the sarcoma centre versus 62.5% at the peripheral unit (p = 0.0036, odds ratio 39.3). Tumours treated at the sarcoma centre were larger than those treated at peripheral hospitals (92.5 versus 39.7 mm, p = 0.0009). WLE (wide local excision) versus mastectomy: Out of eight WLE patients, seven (87.5%) had positive margins, with 6 of these patients proceeding to mastectomy (i.e. 75% WLE patients ultimately had a mastectomy). The positive margin rate was significantly higher in WLE (87.5%) than in mastectomy (10.3%) (p = 0.0001, odds ratio 60.7). Survival: No difference was noted between the sarcoma centre and peripheral hospitals for overall survival (p = 0.43), stratified for tumours <5 cm (p = 0.16), and disease-free survival (p = 0.45). Conclusions: Our data strongly suggest that specific guidelines are needed for breast sarcoma, and that managing these patients according to breast carcinoma protocols in peripheral hospitals is sub-optimal. We recommend centralisation of breast sarcoma patient care to a specialist sarcoma centre, with WLE not recommended as a firstline surgical option given both the high rates of incomplete excision and subsequent need for completion mastectomy.

Kaposi sarcoma is a vascular sarcoma with 4 clinical variants: classic Kaposi sarcoma, which mainly affect the extremities of elderly patients and follows a chronic, generally indolent course; African Kaposi sarcoma; immunosuppression-associated Kaposi sarcoma; and AIDS-associated Kaposi sarcoma. Type8 human herpesvirus is the etiologic agent in all 4variants. Cutaneous angiosarcoma is a cutaneous neoplasm with a very poor prognosis. It carries a high probability of local relapse and has a 10% to 15% survival rate at 5years. There are 3 main variants of cutaneous angiosarcoma: idiopathic angiosarcoma of the face and scalp; Stewart-Treves syndrome; and postradiation angiosarcoma. The only potentially curative treatment is surgery with or without radiotherapy. However, its indistinct borders and multicentric nature mean that treatment is often palliative with chemotherapy, radiotherapy, or both.