Second opinion on sarcoma

Sarcomas are malignant tumors that occur in either bone or soft tissue (muscle, fat, cartilage, connective tissue, and blood vessels). They appear in up to 100 varieties, with significant differences in the biological behavior, prognosis and therapy response between some subtypes. This is a rare cancer, presenting a major challenge in terms of diagnosis treatment planning, so sarcoma patients often have to seek a second opinion from reputable sarcoma experts.

Classification and differentiation of sarcomas

There are different types of tissues in the human body. Sarcomas are usually classified in accordance with the tissue from which they grow or to which they bear a close resemblance.

On this basis, three main groups with different frequence rates are distinguished:

• Soft tissue lesions: approximately 75 %.
• Bony masses: about 10 %.
• Gastrointestinal stromal tumors (GIST): a special soft tissue sarcoma of the gastrointestinal tract, accounting for about 15% of all sarcomas.

Within this classification, subtypes are distinguished according to their tissue of origin. For example, angiosarcoma is a blood vessel tumor, and  chondroscarcoma is the one arising from cartilage cells.

Degree of differentiation

Neoplasms can be classified not only according to the tissue from which they form. They can also be differentiated according to the degree of similarity to the original tissue. If this is still present, the tumor is called differentiated. If the malignant cells have degenerated to such an extent that the tissue that gave rise to them can no longer be identified, it is an undifferentiated tumor. The degree of differentiation as well as the size, location and presence of metastases are important for treatment planning.

Frequency

Sarcomas are rare malignant conditions, accounting for about 1 in 100 cancer cases. Notably, 3 out of 4 sarcomas are soft tissue sarcomas.

In children and adolescents, these malignancies are more common than in adults: out of every 100 pediatric cancer diagnoses, 6 are sarcomas of one kind or another.

Symptoms

Soft tissue sarcomas usually go undetected for a long time because they have no characteristic symptoms. The first, and sometimes the only, manifestation of the disease is a so-called solid mass, i.e. a lump, swelling or growth. In the early stages, it is often painless and only becomes sensitive as it gets bigger in size, putting pressure on surrounding tissue and affecting nerves.

Bone sarcomas are characterized by pain independent of exertion, and less frequently by swelling or feeling hot to the touch. In addition, as they are often detected in the late stages when the bone becomes unstable due to the tumor, a pathological (occurring without usual causes) fracture is a typical manifestation. Ewing's sarcoma also manifests itself with fever, general malaise, as well as weight loss and fatigue in later stages.

In principle, these lesions can occur in any part of the body. Most commonly affected are the extremities (43 %), while in other areas the disease is less frequent (internal organs 19%, abdomen 15%, trunk 10%, head and neck 9%).

For this reason, approximately 10-20 per cent of patients already have locally spread disease or metastases at the time of diagnosis.

Diagnosis

If a malignant soft tissue or bone lesion is suspected, the diagnostic algorithm includes a thorough physical examination and history taking, as well as various imaging studies, such as- X-ray, ultrasound, magnetic resonance and/or computed tomography. The final diagnosis is made with the help of biopsy. Only the examination of tissue samples can determine whether the tumor is benign or malignant, as well as establish the subtype of sarcoma and its degree of differentiation.

If it is suspected that your tumor may be a sarcoma, it is highly advisable to have biopsy specimens taken at a specialized facility. This is important both in terms of the appropriate conduct of the procedure and in view of the complex nature of the pathological examination of the obtained samples.

The correct choice of treatment strategy depends on an accurate understanding of the type of cancer. The role of the pathologist in this case can be compared to that of a pilot responsible for charting the right course. Their conclusions determine the course of subsequent therapy, which can vary considerably for different types of sarcomas. This requires a great deal of experience and specific knowledge. Therefore, it is sometimes a good idea to obtain a pathology second opinion, e.g. from a sarcoma reference laboratory, to ensure greater reliability of results.

Sarcoma treatment planning

Since the disease can vary greatly in its manifestations and specific features, there is no general treatment plan for sarcomas. For some subgroups, like bone sarcomas, there are separate treatment concepts. The approach to developing a therapy plan should be multidisciplinary, involving representatives from several medical specialties.

In general, surgery is the most important method. Depending on the tumor type, surgical removal may be preceded by neoadjuvant therapy to reduce the size of the mass or the tumor burden. For this purpose, radiation, chemotherapy or a combination of both is used. The cancer is then removed with closure of the resulting defect. After careful examination of the resection material, the case is again discussed by the tumor board to determines the further strategy (adjuvant treatment or disease monitoring).

Recovery chances

As a rule, it is not possible to give an accurate prognosis for the course of the disease in each individual case.

However, generally, it can be stated that in a significant proportion of patients with soft tissue sarcoma who have no metastases at the time of diagnosis, a long-time remission can be achieved with the help of properly selected treatment. The chances of cure under these conditions are high.

Cure means that after the tumor has been removed, no new growths appear for five years. After this time, the likelihood of recurrence or metastases is relatively low. However, there is still a chance of relapse, so regular check-ups should be continued.

If metastases have already formed at the time of initial diagnosis, the chances of getting rid of the disease are much lower. However, depending on the risk profile (tumor growth pattern, number, size and location of metastases, comorbidities), there may still be a chance of recovery under certain circumstances.