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Sarcomas
Essentials
- Sarcomas are divided into soft tissue sarcomas and bone sarcomas. The two groups behave differently and thus the treatment principles also differ, both between and within the groups.
- In the early stages sarcomas often cause few symptoms. Bone sarcomas cause pain, swelling or, rarely, locally increased skin temperature. Pathological fractures may occur, or a tumour in the joint area may restrict joint mobility. Soft-tissue sarcomas are usually painless, a lump being the most common symptom.
- Sarcomas spread mainly via the bloodstream, more rarely to local lymph nodes. Sarcomas send metastases most typically to the lungs.
- Surgery is often the curative treatment of localized sarcomas. It can be combined with radiotherapy and cytotoxic chemotherapy as adjuvant treatment, as necessary. In advanced disease, medication is used to slow down the progression of the disease.
Diagnostic work-up
- The management of both soft tissue sarcomas and bone sarcomas, starting with the diagnosis, should be centralized to multiprofessional specialized teams at tertiary level hospitals.
- The histopathological diagnosis requires special examinations and expertise. Even differentiating between benign tumours and malignant sarcoma can be difficult.
Bone sarcomas
- Osteosarcoma, chondrosarcoma and Ewing's sarcoma are the most common histological subtypes.
- The annual incidence of each subtype is no more than 0.3/100 000 (and concerning osteosarcoma and Ewing's sarcoma, somewhat higher in the younger population) http://www.annalsofoncology.org/article/S0923-7534(19)31712-0/fulltext.
- Pain, swelling, sometimes warmth, restricted movement of the adjacent joint, or a pathological fracture arouse suspicion of bone sarcoma.
- Osteosarcoma and Ewing's sarcoma typically occur in young individuals, chondrosarcoma in older population.
- The establishment of a diagnosis is based on multidisciplinary cooperation with combined consideration and interpretation of clinical, radiological, histopathological and molecular biological findings. The patient's age and the localization of the lesion affect the probability of the different diagnostic alternatives.
- Most bone tumours are metastases of primary cancers at other sites, myelomas or benign neoplasms.
- The diagnosis and treatment of all bone tumours should be performed at tertiary level hospitals with multiprofessional teams. The prognosis is good if appropriate treatment is given from the very beginning.
- The treatment of osteosarcoma and Ewing's sarcoma is started with effective, internationally agreed regimens of combination chemotherapy through which the tumour size can be decreased before surgery and possible (micro)metastases can be concomitantly treated (neoadjuvant therapy). After initial treatment, a radical operation is performed or radiotherapy is given while cytotoxic chemotherapy is continued as adjuvant treatment.
- Radical surgery is usually sufficient in bone sarcomas with a low degree of malignancy.
- Operative treatment aims to achieve radical removal, while preserving functionality.
- Amputation is rarely necessary. Experienced surgeons can perform even radical surgery such that the function of the limb can be spared by using prostheses or transplants.
- Radiotherapy may lower the risk of local relapses if the operation was not radical or the surgical margin remained narrow.
- Some subtypes of osteosarcomas can be treated with targeted treatment modalities.
Soft-tissue sarcomas
- Several subtypes include, for example, undifferentiated pleomorphic sarcoma, liposarcoma and leiomyosarcoma.
- Globally, the annual incidence is about 1-4/100 000 http://academic.oup.com/book/25326/chapter-abstract/192393065.
- Soft-tissue sarcomas typically occur in the older population.
- Most tumours are in the limbs or superficially on the trunk.
- A soft-tissue sarcoma is generally an asymptomatic lump that grows. Sarcoma should be suspected especially if the lump is under muscle fascia, attached to the underlying tissue, hard and/or over 5 cm in diameter (picture ).
- If soft-tissue sarcoma is suspected, the patient should be referred to a specialized centre for consultation by a sarcoma team.
- Soft-tissue sarcomas are removed surgically with a wide margin (2-3 cm, or less if an undamaged natural surface, such as muscle fascia, is reached). Radiotherapy is given after nonradical surgery or in the case of an insufficient surgical margin or if surgery is not possible for reasons such as the location of the sarcoma. Cytotoxic chemotherapy is used in metastasized cases if local treatment did not give sufficiently good results, if radiotherapy is no longer possible or to reduce the size of the tumour before surgery. There are targeted treatment modalities for some subtypes.
- In addition to surgical treatment, some patients receive cytostatic adjuvant therapy to reduce the risk of recurrence.
- Metastases of soft-tissue sarcomas, particularly lung metastases, should be removed by surgery, as far as possible. Removal of metastases may in some cases be a curative intervention.
Follow-up examinations
- Rehabilitation, prostheses and assistive devices are an essential part of further treatment of sarcoma patients. Many patients live long and recover well.
- Sarcomas are monitored in specialized care at 2-18-month intervals for 5-10 years. Frequent monitoring is used at first, with the intervals extended later.
- The follow-up protocol depends on the type and grade of tumour.
- Local recurrence and lung metastases, particularly, are sought because in these cases early treatment often gives good, sustainable results.
- A further aim of the monitoring is to ensure good results of rehabilitation through physiotherapy, supportive products and psychological support, for instance.
- Of sarcoma patients who have received appropriate treatment, 50-80% are free of disease after 5 years.