Soft Tissue Sarcoma Diagnosis and Treatment

Advances in the diagnoses and treatment of soft tissue sarcomas have improved the quality of life—and saved the lives—of many soft tissue sarcoma patients. Thanks to advances in radiation, fewer patients with extremity soft tissue sarcoma need amputations. Additionally, recent trials show that the drug Gleevec works well on a type of soft tissue sarcoma. Despite this progress, there are still challenges for soft tissue sarcoma patients and specialists.

Soft tissue sarcomas are rare—there are six to eight thousand cases a year. Yet, there are more than 50 types of soft tissue sarcomas. These factors can make it hard to diagnose the condition. And diagnosing the condition is the important first step in deciding how to treat it.

Diagnosing Soft Tissue Sarcoma

"Correctly diagnosing the condition is absolutely critical for sarcomas. It is not trivial," said George Demetri, M.D., co-director of the Center for Sarcoma and Bone Oncology at the Dana-Farber Cancer Institute. Demetri is also a lead author on a study of Gleevec and gastrointestinal stromal tumor (GIST), a type of soft tissue sarcoma.

"The diagnosis has to be correct," added Murray Brennan, M.D., FACS, chairman, Department of Surgery at Memorial Sloan-Kettering Cancer Center. "We know a great deal about predicting outcomes from sarcoma. From the clinical presentation and the biopsy, you can predict what a person's risks are of either having a local recurrence in the future, or of actually getting metastasis (a spread)."

Both Brennan and Demetri stressed that it is important to work with doctors who have experience with soft tissue sarcomas, since it is so rare. According to Demetri, an expert diagnosis is "critical to understanding the disease, the way it might behave, and in choosing between treatment options."

"Sarcoma pathologists are, in many ways, the key ‘behind-the-scenes' players on the care team," added Demetri. (A pathologist is a specialized doctor who closely examines tissues and cells under a microscope. He or she then assigns a grade to a tumor.) "Most pathologists who do not specialize in sarcomas cannot and do not tell the difference between subtle groups of sarcomas. In this age of targeted therapies and evolving molecular diagnosis (diagnosing a disease on a molecular level), such distinctions can have real clinical impacts," he said.

Tumor Stages

In diagnosing your condition, your doctor will assign a stage to your tumor. The tumor's stage is based on many factors. These include the size of the tumor and whether the tumor has spread. It also includes the tumor's histologic grade. This is the grade of the tumor after the pathologist looks at part of it under a microscope. Your doctor will also carefully review physical, x-ray, lab, and biopsy results to determine the tumor's stage. Doctors assign tumors a stage, from I to IV. This chart shows the four tumor types, and the typical diagnoses and treatments for soft tissue sarcomas.

Treating Soft Tissue Sarcoma

It's common to use a combination of treatments for soft tissue sarcomas. This is called multi-modal (or modality) treatment. Multi-modal treatment includes using a main treatment and an additional treatment. Additional treatment is called adjuvant treatment. In treating soft tissue sarcomas, it's common for your doctor to suggest surgery as the main treatment and radiation and/or chemotherapy as the adjuvant treatment. The recommended combination depends on many factors, with the diagnosis being most important.

Surgery

The main goal of surgery is to completely remove the tumor and some of the tissue around it. The surgeon decides how to operate based on the tumor's location and grade. Depending on the tumor's location or if it has spread, the surgeon may not be able to remove the entire tumor or enough of the surrounding tissue. In this case, the surgeon may recommend an additional treatment, such as radiation and/or chemotherapy.

Radiation

There are two types of radiation used to treat soft tissue sarcoma.

1. External beam radiation. This is when a machine outside the body focuses radiation on the tumor site. External beam radiation is the most common type of radiation used to treat soft tissue sarcomas. It can be used before or after surgery. Using radiation before surgery helps shrink tumors. It is usually used on large, high-grade tumors. Using radiation after surgery helps destroy tumor cells that are left over from surgery.

2. Brachytherapy. This is when radiation is applied directly to the tumor site. The radiologist does this by placing radioactive seeds (or pellets or catheters) in the tumor site. Brachytherapy may be used alone or in combination with external beam radiation. Brachytherapy has been shown to decrease the chance the cancer will come back in that area. Brachytherapy also takes less time than external beam radiation. With brachytherapy, treatment can take five days. Along with surgery, it can take ten days. With external beam radiation, treatment can take up to six weeks as an outpatient. However, brachytherapy does not seem to work as well on low-grade tumors as it does on high-grade tumors.

Your doctor may recommend radiation instead of surgery if the tumor is in a place that's hard to operate on. Also, people in poor health, who can't have surgery, may just have radiation. Many times, doctors use radiation with surgery to reduce the chance of the tumor coming back or spreading. Advances in radiation have also allowed for better local control of soft tissue sarcoma. According to Brennan, 15 to 20 years ago, 50 percent of people with an extremity soft tissue sarcoma had amputations. Today, about five percent have amputations. Today, at least eighty percent of people are candidates for limb salvage surgery.

Chemotherapy

Using adjuvant chemotherapy to treat soft tissue sarcomas is controversial. While some studies have suggested that adjuvant chemotherapy is not effective for treating adult soft tissue sarcomas, others have shown an approximate ten percent survival advantage to people with large high grade tumors and no evident metastases.   However, adjuvant chemotherapy works well treating children's soft tissue sarcomas, including rhabdomyosarcomas and Ewing's sarcomas. Brennan and Demetri have their own theories. Brennan said that children respond better to adjuvant chemotherapy. He added that the types of soft tissue sarcomas found in children are rare in adults. It may be that children are able to better tolerate the high does of chemotherapy that are necessary to kill the tumor cells.   Demetri said that adult and childhood soft tissue sarcomas are different cancers. Nevertheless, most researchers agree that they need to do more studies on adjuvant chemotherapy for adult soft tissue sarcomas. Your doctor will tell you if it's best for your condition.

Your doctor may recommend chemotherapy as the main or adjuvant treatment. This depends on the type of soft tissue sarcoma you have and its stage. Adjuvant chemotherapy can be used before or after surgery to shrink tumors or destroy tumor cells. Chemotherapy is felt to be most effective in treating those at highest risk of developing metastases, that is, those with large, high grade tumors. Chemotherapy is usually not given to people with log grade tumors.  

Demetri said that doctors should consider trial results and each patient's condition when considering adjuvant chemotherapy and treatment options in general.

"(Treatment options) depend on the specifics of the individual," said Demetri. He added that doctors should base their practices on real data and solid, trial-based evidence. But, if there isn't evidence, doctors and patients need to talk about the patient's individual condition. They should also review available information on that condition. "This involves openness, honesty, and a lot of time and communication to evaluate the options between the patient and doctor," he said.