Sarcoma: Causes, Types, Symptoms, Diagnosis, and Treatments

They are cancerous tumors that arise from the cells that hold the body together (connective tissue).

It is known as rhabdomyosarcoma if it affects the muscles, osteosarcoma if it develops in the bones, and liposarcoma if it is found in the nerves, blood vessels, and fat.

Because these connective tissues are found in different parts of the body, sarcoma cancer can occur anywhere.

However, the most frequently affected limbs are the extremities where most of the body’s connective tissues are found.

They can be seen in the head, the back of the abdominal cavity, and internal organs.

Sarcomas comprise a complex family of cancers that cover a wide variety of different diseases that are classified into two broad areas: soft tissue and bone.

A sarcoma is a malignant tumor and a rare type of cancer that occurs at any age.

However, sarcoma in adults is very rare, accounting for approximately 1% of all adult cancers.

Sarcoma is more common in children and is responsible for about 20% of all childhood cancers.

Causes of the condition

As with other types of cancer, the reasons why sarcomas develop are not yet fully understood.

However, scientists have identified the common characteristics that sarcoma patients share.

Specific attributable factors cannot be related to causing soft tissue or bone sarcomas.

However, there are some factors that can increase the chances of developing sarcomas:

  • Family history of sarcoma. In addition to the presence of hereditary diseases, including Gardner syndrome, neurofibromatosis or Li-Fraumeni syndrome.
  • Exposure to Agent Orange. Exposure to certain chemicals (such as arsenic, vinyl chloride, herbicides that contain phenoxyacetic acids, and wood preservatives that contain chlorophenols).
  • Exposure to ionizing radiation. Radiation treatments can also be a possible influencing factor for the risk of developing bone sarcoma. Exposure to high doses of radiation for the treatment of another type of cancer may represent a risk factor.
  • Paget’s disease.
  • Age: Although sarcoma can occur in people of any age, it is often diagnosed in adults under the age of 50.
  • Weakened immune system: Some HIV patients develop Kaposi’s sarcoma, a malignant tumor that arises from cells that line lymph and blood vessels.

In general, sarcoma patients tend to be younger than most cancer patients.

16% of patients with bone or soft tissue sarcoma are under 30 years old, while 37% are under 50 years old.

Types of sarcomas

Sarcomas are divided into two main groups: soft tissue and bone sarcomas.

Soft tissue sarcomas

Soft tissue sarcomas are malignant tumors that occur in the connective tissue of the tendon, ligament, or muscle and are the most common sarcomas.

There are almost 100 to 75 subtypes of various soft tissue sarcomas.

These subtypes differ in terms of their tissue of origin, genetic alterations, clinical behavior or sensitivity to certain therapies, age of onset, aggressiveness, and growth pattern.

Soft tissue sarcomas are more common than bone sarcomas.

Soft tissue sarcomas are subdivided based on their location.

Some of these include:

  • Synovial sarcoma: is a type of soft tissue sarcoma that occurs in the extremities, often near the tendon sheaths and joint capsules.
  • Uterine sarcoma: It is a type of sarcoma that can also affect other parts of the female reproductive system, including the vagina, ovaries, and fallopian tubes.
  • Gastrointestinal Stromal Tumors: This is a common type of sarcoma that develops in the gastrointestinal tract. It can also affect the small intestine and stomach.

Bone sarcomas

Bone sarcomas are rare forms of cancer that form in the bone (including the upper arm, shoulder, ribs, and legs).

There are four types of primary bone cancer: osteosarcomas, chondrosarcomas, the Ewing family of tumors, and giant cell tumor of bone.

Osteosarcoma and Ewing’s sarcoma occur most often in children and adolescents; chondrosarcoma and giant cell tumor of bone occur most often in adults.

Both soft tissue and bone sarcomas are rare, appearing in a small percentage of juvenile and adult populations.

While only 1% of adult cancers are diagnosed as soft tissue, approximately 15% of childhood cancers are soft tissue sarcomas.

Bone sarcoma is less common than soft sarcomas.

An example of a bone sarcoma is Ewing’s Sarcoma, this commonly occurs in the bones, but it can also affect the muscles and cartilage.

It is often diagnosed in the pelvis, thighs, shoulder blades, and ribs.

Symptoms

Sarcoma symptoms are hardly noticeable at the beginning or when malignant tumors begin to form.

If the tumor grows large, patients may experience pain as the tumor puts pressure on nearby nerves and muscles.

Different subtypes of sarcoma also have other symptoms.

For example, Gastrointestinal Stromal Tumors can cause obstruction in the gastrointestinal system, blood in the stool or vomit, fatigue, fever at night, and anemia, while uterine sarcoma can cause vaginal bleeding.

Pain is the most common symptom of sarcoma, as is swelling and tenderness, especially in a tumor that is in or near a joint, causing difficulty in normal movement (limited mobility).

Another symptom can be weight loss.

Anyone with apparent sarcoma symptoms should consult with their doctor and do not assume they have cancer, as these symptoms are general and could be attributed to another medical condition.

Sarcomas can spread to surrounding tissues and even distant organs in the body, resulting in a condition called metastatic sarcoma.

Overall, the 5-year survival rate for localized soft tissue and bone sarcoma is approximately 65%.

Diagnosis

After discussing the patient’s medical history and conducting a physical exam, the images will help establish a diagnosis, which will need to be confirmed by laboratory analysis of a tumor sample.

The following physical characteristics should prompt a physician to investigate:

  • A mass larger than 2 inches in diameter or growing in size.
  • The characteristics of being fixed, immovable or deep.
  • Be painful
  • Return of a previously removed tumor.

Soft tissue tumors are diagnosed with a surgical biopsy, in which a sample of tissue is removed from the tumor and analyzed under a microscope.

Osteosarcoma, on the other hand, is diagnosed by imaging tests that include magnetic resonance imaging (MRI) and bone scans.

Since the disease has a tendency to spread to other parts of the body, chest x-rays and computed tomography (CT) of the lungs are also performed to detect lung metastases.

Medical images help locate, characterize, and provide more information about a tumor to guide diagnosis.

It can also be used to measure the success of treatment or to detect the spread of cancer.

Imaging techniques include X-rays, computed tomography, magnetic resonance imaging, ultrasound, and positron emission tomography.

The results of diagnostic tests provide doctors with crucial information about the severity of the condition, allowing them to plan treatment carefully and effectively.

Knowing the histological grade of the sarcoma is essential, since it allows the tumors to be classified from the least to the most aggressive according to how quickly they grow (cell division) and the appearance they present.

Sarcoma treatment and care

A treatment plan should be developed based on the grade and stage of the tumor, previous treatments received (if applicable), cancer progress, biopsy analysis, and other individualized factors.

Oncologists will recommend drugs for cancer treatment if necessary.

Treatment of sarcoma tumors involves a multidisciplinary team made up of cancer specialists (physicians and radiation therapists), surgeons, pharmacists, physician assistants, and other healthcare professionals.

Chemotherapy is the most important treatment available for sarcomas because it is the only form of treatment that prevents and controls the spread of cancer to the lungs, vital organs, and other parts of the body.

In the past, chemotherapy was highly toxic and had significant side effects.

Currently in chemotherapy treatments, side effects have been significantly reduced and are practically non-existent in many cases.

The new treatments protect the heart and kidney, substantially reduce infections and the need for blood transfusions, and virtually eliminate nausea and vomiting for most patients.

Chemotherapy is an art and a science, and the correct combinations of treatments aggressively kill cancer, prevent recurrence, and maintain a patient’s quality of life through treatment.

More than 50% of patients are able to work during chemotherapy and maintain their daily routine activities and exercise throughout their treatment.

Surgery can be a particularly effective option after initial chemotherapy to shrink sarcoma tumors.

With the advent of newer adjuvant chemotherapy, improved technique in surgery, and the availability of internal prostheses, amputation is now avoided in approximately 95% of sarcoma cases.

Radiation is another effective tool used to fight sarcomas in specific localized areas.

Radiation works by sterilizing tumor cells and making them unable to divide and continue to grow.

Malignant sarcomas, like other cancers, are often treated with a combination of therapies including surgical removal of the tumor and adjuvant therapy (either chemotherapy or radiation therapy).

Small, low-grade sarcomas are often removed only with surgery, which means that patients no longer need to undergo chemotherapy.

However, for those with high-grade tumors that are larger than 2 inches, multimodal therapy (surgery and chemotherapy or surgery and radiation therapy) is often necessary.

Chemotherapy and radiation therapy can be used before or after surgery.

They are often recommended before the surgical procedure if the tumor is large enough and must be reduced first.

Biological therapy, which stimulates the patient’s immune system to fight cancer, is also used to treat some sarcomas.

Most bone and joint sarcomas are often removed using a surgical method called a limb sparing technique to help ensure that the patient does not suffer from long-term disability.

The removed portion of the bone is replaced with an allograft (bone taken from a cadaver) or a metal implant or a combination of two.

Occasionally, due to the size and location of the tumor, amputation is necessary for a complete healing.

New therapies are continually being discovered to improve the prognosis of sarcoma.

One of them is the use of olaratumab (a monoclonal antibody), which is used in combination with doxorubicin, to treat soft tissue sarcomas in adults.

This medicine is recommended in patients who are not healthy enough to undergo surgery or radiation therapy.

This treatment blocks growth-promoting signals in cancer cells.

Throughout the treatment process, various tests are performed on a regular basis to monitor the patient’s health with a special focus on their liver, kidneys, and heart.

Your body’s response to treatment is also monitored and, if necessary, adjustments are made to achieve optimal results or minimize side effects.

According to the National Cancer Institute, the 5-year survival rates for people with sarcoma are:

  • 56% for localized sarcoma.
  • 19% for regional sarcoma.
  • 16% for metastatic sarcoma.

It is important to note that despite successful treatment, patients are still at risk for recurrence.

Sarcoma can develop again in the original site or in other parts of the body.

Therefore, it is important that they undergo regular follow-up examinations even after a long period of remission.