Sarcoma

Sarcoma is a rare cancer and accounts for approximately 1 % of all diagnosed cancer cases in Europe. In 2022, 562 new cases of sarcoma were recorded in Norway.
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Sarcoma is cancer of connective and supporting tissues of the body and can occur in any location and organ. Soft tissue sarcomas constitute about 90 percent of all sarcomas, of which GISTS (tumors originating from the connective tissue of the gastrointestinal tract) is the largest histological subgroup. The rest are bone sarcomas.

A total of 562 people were diagnosed with sarcoma in Norway in 2022, including abdominal and retroperitoneal soft tissue sarcomas and gynaecological soft tissue sarcomas.

The diagnosis of sarcoma is based on tissue or cell samples. Histological diagnosis of sarcoma is difficult and requires specialist expertise. All tissue samples suspected of sarcoma must be primary or re-examined at one of the university hospitals. Immunohistochemical and molecular examinations will also often be necessary. It is necessary to distinguish different tumour types from each other and to be able to adapt the treatment for the patients.

Risk factors

According to helsenorge.no , there are some factors that can increase the risk of soft tissue cancer.

  • Chronic lymphedema (kreftforeningen.no) may be congenital or may occur after radiation therapy or removal of lymph nodes. Also, some benign connective tissue tumors can become malignant.
  • High-dose radiation therapy. Soft tissue sarcoma can occur in places where radiation therapy has previously been given to another form of cancer, but this is very rare. As a rule, this type of sarcoma takes at least five to ten years to develop after radiation therapy. However, the risk is very small due to improvements in radiation therapy.
  • Viruses are the cause of Kaposi's sarcoma – a rare form of soft tissue sarcoma in blood vessels, skin or mucous membranes. The cause is a special type of herpes virus called HHV-8. This can occur in older people and by weakened immune systems, for example in HIV-infected or organ transplant recipients.
  • Immunosuppressive medicine after transplants, which is supposed to prevent the new organ from being rejected, causes the immune system to be unable to repair cell damage, increasing the risk of soft tissue sarcomas.
  • Some chemicals are suspected of developing some forms of soft tissue sarcomas: vinyl chloride (PVC), certain types of herbicides (phenoxy acids) and dioxin.

In general, soft tissue sarcomas are very unlikely to be hereditary. Heredity has been demonstrated in connection with Li-Fraumeni syndrome, (sml.snl.no) where a congenital defect in a gene called P53 is central.

Source: helsenorge.no

Read about cancer prevention on kreftregisteret.no

New cases

562 people were diagnosed with sarcoma in Norway in 2022. 

Proportion of sarcomas in 2022 and 2020-2022 by location. From Fig. 3.3 in Annual Report Quality Register for Sarcoma 2022 (Norwegian only)

Most patients with sarcoma have abdominal and retroperitoneal sarcomas and sarcoma of the soft tissues of the extremities and trunk.

Aging

Number of bone and soft tissue sarcomas in 2022 by age.
From Fig. 3.5 in Annual Report Quality Register for Sarcoma 2022 (Norwegian only)

As expected, the majority of patients with soft tissue sarcoma are adults, and the number increases in each age group up to 80 years.

We see an indication that the number of bone sarcomas is greater in children and young adults and at 61-80 years than at 41-60 years. This is as expected from the literature. Note that the figure only shows the number of patients and that age-specific incidence rates cannot be deduced from the figure. Since the number of patients with cancer in children and young adults is low, for example, the age-specific incidence rates for bone sarcomas will be considerably higher in these groups than in patients from 61 to 80 years, even though the absolute number is similar.

Survival

5-year relative survival of sarcoma in Norway is at a good level compared to results reported internationally.

The survival rate for patients with soft tissue sarcoma is higher than for patients with bone sarcoma. Both bone sarcomas and soft tissue sarcomas have many subgroups and survival varies within the groups. 

5-year relative survival for bone sarcomas by regional health authority (catchment area), 2013-2022. Fromfig. 3.19 in the Annual Report Quality Register for Sarcoma 2022 (Norwegian only).

The prognosis for patients with bone sarcoma is related to several factors, such as histological subtype, degree of malignancy and metastatic status at diagnosis. The figure includes all subgroups and is thus an unselected cohort. We see that 5-year relative survival is 67 percent. There are some differences between the regions, but this is presumably due to small numbers and natural variation. The result is comparable to other European countries. A similar study from the Netherlands has shown that the 5-year survival rate for all patients with bone sarcoma is 58.9 percent.

5-year relative survival for soft tissue sarcomas in extremities and trunks, distributed by catchment area, 2013-2022. From Fig. 3.33 of the Annual Report Quality Register for Sarcoma 2022 (Norwegian only).

The figure shows 5-year relative survival for soft tissue sarcomas in the extremities and trunk. All patients are included in the analysis, regardless of tumour size, location, degree of malignancy or metastatic status.

The 5-year relative survival is 76%, which is the same level reported internationally. 5-year relative survival in Western Norway Regional Health Authority appears to be higher than in the rest of the country. We have conducted supplementary analyses to examine details related to morphological diagnoses and metastatic status. The difference appears to mainly concern patients with localised disease, and we only see differences for certain morphological subgroups. We will conduct more analyses to increase our understanding of what affects survival in this patient group, and whether this may be related to the fact that more patients in Western Norway Regional Health Authority received additional treatment with drug cancer treatment.

Development over time

For bone sarcoma, the incidence rates are generally stable. 

For soft tissue sarcoma, the incidence rates have been somewhat more variable. On the whole, there has been a steady increase in the incidence of soft tissue sarcoma in both sexes during the time period. We do not know for sure the reason for this increase, and several factors may play a role. Some of the increase may be due to an increasing proportion of elderly in the population.

Increased use of diagnostic imaging and other diagnostic methods in recent decades may generally contribute to an increase in the number of diagnosed cancer cases.

Incidence of sarcoma cases in the period 2003-2022, by bone, soft tissue and gender. From Fig. 3.1 in the Annual Report Quality Register for Sarcoma 2022 (Norwegian only).

Quality registry for sarcoma

The quality registry for satcoma contains detailed data on patients in Norway with sarcoma. The registry started recording clinical information for patients with a diagnosis from 01.01.2018. The Quality Registry began collecting clinical information in January 2019.

The registry collects data on assessment and treatment of this patient group. The purpose is to use the data from the registry to illustrate practice in hospitals, which can be of help in assessing practice in individual hospitals and for the patient group as a whole.

Examples of results from the Sarcoma Registry's annual report 2022:

According to the National Action Programme with guidelines for diagnosis, treatment and follow-up of sarcoma, MRI is recommended for deep-seated tumours, for subcutaneous tumours > 5 cm on palpation, for clinical growth of unexplained superficial lesions, even if the lesions are small, and for tumours suspected of clinical malignancy. Patients with soft tissue tumours that are not lipoma should be referred to sarcoma centres and the images assessed there regardless of MRI findings. Patients should be referred without prior biopsy.

Referral of patients with soft tissue sarcomas (in extremities and trunks) to sarcoma centres, 2020-2022, distributed by regional health authority. From Fig. 3.22 of the Annual Report Quality Register for Sarcoma 2022 (Norwegain only).

More than half of the patients are referred to sarcoma centres after assessment at hospital. Local and regional conditions in the health regions have an impact on referral patterns. This may include proximity/accessibility to hospitals and X-ray institutes.

The figure shows the distribution in the various health trusts. In Western Norway Regional Health Authority, most of the patients are referred directly from their GP. In the other health regions, a lower number are referred by GPs. In the Central Norway Regional Norway Health Authority, 26.5 % are referred by GPs, while the corresponding percentages in South-Eastern Norway and Northern Norway Regional Health Authority are 34.2 % and 29.2 % respectively.

Steps you can take to reduce your risk of getting sarcoma

General advice is:

  • Be physically active
  • Have a healthy diet
  • Be smoke-free

Pay special attention if a bump

  • Growing fast
  • are larger than five cm in diameter
  • sitting deep (in the muscles or deeper)
  • Comes again after being removed

Source: helsenorge.no

More about cancer prevention on kreftregisteret.no

Questions about cancer

The Cancer Registry of Norway is a research institution. Our professionals therefore do not answer questions about diagnosis, assessment, treatment and follow-up from patients or their relatives.

Questions about this should be directed to your own GP, treating institution or the Cancer Society Advisory Service tel: 21 49 49 21

Useful Links

Facts about soft tissue sarcoma - kreftforeningen.no

Facts about bone sarcoma - kreftforeningen.no

Support association for all affected by sarcoma

Sarcoma - National action programme with guidelines for diagnosis, treatment and follow-up

Soft tissue sarcoma on National Cancer Institute website