Sarcoma is a rare type of cancer, making up about 1 percent of all adult cancers and about 15 percent of pediatric cancers, according to the Liddy Shriver Sarcoma Initiative. Despite the high rate for childhood and adolescent cancers, the total number of pediatric sarcoma cases is far lower than adult cases because overall there are fewer cases of cancer in people younger than 20 than in adults. When detected early, many soft tissue sarcomas have a high rate of successful treatment, but there are still thousands of children and adults who pass away each year because of this disease. Worse yet, the survival rate for pediatric sarcomas is lower than the average survival rate for all childhood cancers. While some sarcomas are chemotherapy-sensitive, others defy traditional cancer treatment methods. This is why research into new detection and treatment methods has been ongoing for years, and researchers have made strides in creating better chemotherapy and other cancer-killing drugs.
Chemotherapy is a broad term for a number of drugs used to treat diseases – not just cancer. The purpose of chemo is to work throughout the entire body. For cancer, it not only stops the spread of the cancerous cells throughout the body, but it also kills them. There are many chemotherapy drugs, and the FDA has approved more medications that are focused on specific types of cancers in recent years. While these specific chemotherapy drugs are not the same as targeted therapies, they are made to be effective against certain types of cancers.
In October 2015, the U.S. Food and Drug Administration approved Trabectedin, also known as Yondelis, to treat two types of soft tissue sarcomas – liposarcoma (sarcoma in fat cells) and leiomyosarcoma (sarcoma in smooth muscle cells) – when patients cannot be treated with surgery or they previously had chemotherapy containing anthracycline. This is a major advancement for patients who didn’t respond to traditional chemo or targeted therapy.
Researchers have discovered which genes mutate in certain cancers, enabling them to develop drugs that target that specific gene or the proteins affected by the mutation. Some targeted drugs turn off the signal in a cancer cell that tells it to divide, others stop a cell from living an abnormally long time, and some kill the cancerous cells. The purpose of targeted drugs is to create more customized and effective medications to stop the spread of specific types of cancers.
Pazopanib is the only targeted drug approved to specifically treat soft tissue sarcoma and was approved by the FDA in 2012, according to the American Cancer Society. Pazopanib, brand name Votrient, blocks enzymes known as tyrosine kinases, which are necessary to cell division and survival. This helps stop the progression of the cancer, which can give patients more time to receive other treatments.
Angiogenesis is the growth of blood vessels between a tumor and surrounding tissue. It’s the blood flow through these vessels that carries oxygen and other nutrients to the tumor that allows the tumor to metastasize throughout the body. Researchers have developed anti-angiogenesis drugs that stop the development of the blood vessels to the tumor in some way, essentially cutting off the tumor’s food source. Different anti-angiogenesis agents perform this function in unique ways.
The drugs Avastin and Adriamycin have benefited sarcoma patients when given together, and Cediranib is a more recent anti-angiogenesis drug showing benefits for some types of soft tissue sarcoma, according to the American Cancer Society.
Biosimilar drugs are gaining importance in today’s health care landscape because they offer a less costly, similar version of a customized biologic drug. For patients suffering from sarcoma and other forms of rare cancer, the cost of treatment adds up quickly. A specific drug could cost them thousands of dollars every month.
Many cancer patients will now be able to receive Zarxio, a biosimilar drug of filgrastim, also known as Neupogen, which is a biologic drugs that helps patients manage their white blood cell count during chemo and other cancer treatments. Zarxio is the first biosimilar drug to ever be FDA approved in the U.S. and was approved for all of the same purposes as Neupogen.
For any type of cancer, detecting it as soon as possible is important to getting treatment and working toward remission. Sarcoma is no different and now people may be able to use genetic testing to determine if they are at risk or have the disease. For example, the retinoblastoma gene, RB1, was the first known inherited cancer susceptible trait. Genetic testing can determine if a person has a mutated RB1 gene, and if they do, the physician can discuss the patient’s higher risk for certain sarcomas – particularly if that person needs to undergo radiation. Patients with this mutated gene have a higher risk of tumors following radiation.
Other syndromes or gene mutations, like Li-Fraumeni syndrome, which involves the mutated TP53 gene, can be detected in genetic testing.
Genetic testing isn’t for everyone. It is often performed when individuals are experiencing medical issues, and it may be more appropriate for patients who have a family history of certain types of cancer or disorders. Individuals without any family history of cancer or other risk factors can develop sarcoma, but genetic testing for indicators of risk may not be helpful.