Treating Sarcoma, the Orphan Disease

Sarcoma, a form of soft-tissue cancer, doesn’t receive much attention from researchers, says Meena Bedi, MD, Sharon K. Wadina Professor in Sarcoma Research and associate professor of radiation oncology at the Medical College of Wisconsin (MCW), and sarcoma specialist with the Froedtert & MCW Clinical Cancer Center.

“Sarcomas account for about 1 percent of all adult cancers, so it’s really rare,” she explains, adding that the disease is much more common in childhood cancers.

But its effects are devastating, she continues, and if it’s not detected early or spreads to other parts of the body, the prognosis is not good for patients.

“Sarcoma is analogous to an orphan disease,” says Dr. Bedi, who spent her first ever rotation treating patients of the disease. “Because so few people are diagnosed with it, it receives little dedicated research funding compared to other cancers such as breast cancer, colorectal cancer and brain tumors. Correspondingly, the treatment of sarcomas is far behind these other cancers in viable treatments.”

For a while now, the standard of care for sarcoma has been radiation and surgery with or without chemotherapy, followed by regular surveillance where CT scans or MRIs are used to check whether the disease has returned or spread to other areas of the body.

Although CT scans and MRIs are useful, according to Dr. Bedi, there still may be microscopic disease in the bloodstream that we are unable to see on imaging. Unfortunately, once medical providers identify disease on imaging, it may have already spread to other areas of the body. Once the cancer spreads, or becomes metastatic, the chances of survival dwindle.

However, there have been some advances in treatment thanks to passionate researchers – such as Dr. Bedi – who are hoping to push the envelope even further.

Dr. Bedi is currently leading a team of researchers from MCW and Froedtert Hospital in piloting a new project aimed at creating a blood test for soft tissue sarcomas. Hers is the only group in the United States focusing its research on circulating tumor DNA (ctDNA) for sarcomas. ctDNA is DNA originating from the tumor that is present in the blood. The team’s hope is that the study will lead to the biggest recent breakthrough in treatment for sarcoma.

For each patient, the cause of his/her sarcoma varies, Dr. Bedi explains. The key to determining why lies within the tumor’s genetic code.

“We are assessing each patient’s biopsy and tracking the specific mutation through ctDNA at various points. The goal is to eventually be able to detect sarcoma prior to appreciating it on surveillance imaging,” Dr. Bedi says.

In addition, once those genetic mutations are identified, doctors can attack those specific mutations with tailored therapies that have been proven to stem their development.

“The goal is to be able to intervene sooner with early detection,” Dr. Bedi explains.

The study will involve two cohorts of 25 patients each. One group will have a localized form (stage I-III) of sarcoma and the other group will have metastatic disease (stage IV). The goal in patients with stage I-III disease is to assess if ctDNA can detect local or distant recurrence sooner than seen on surveillance. In addition to this, the goal in patients with stage IV disease is to assess if systemic therapies decrease the concentration of ctDNA within the blood.

“We are hopeful that this marker will allow for early detection and therefore translate to improve the chances of survival in this patient population,” Dr. Bedi says.

“This test could be a game-changer in terms of monitoring and treating sarcoma,” Dr. Bedi concludes. “Sarcoma research doesn’t get much attention, but that could change because of the work of passionate researchers who are dedicated to helping those who suffer from it.”