Combine Immunotherapy, Radiation…Fight Sarcoma

University of Maryland School of Medicine researchers are priming the immune system to fight soft-tissue sarcomas, combining two immunotherapy drugs with radiation therapy to stimulate the immune system to destroy the main tumor and tiny, leftover cancer cells that may cause additional tumors to grow.

Vincent Y. Ng, M.D., an assistant professor of orthopedics at the University of Maryland School of Medicine, told OTW, “Cancer and tumors have the ability to evolve and one of the exciting things about immunotherapy is that the body’s immune system is dynamic and can potentially adapt to various challenges, including cancer.”

“Checkpoint inhibitors are drugs that give the immune system a boost in the fight against cancer. Combining two drugs that work in different ways may help the immune system more than a single drug. Also, in combination with state-of-the-art proton beam or GRID [spatially fractionated radiation therapy] radiation, immunotherapy may have an added benefit in fighting the tumor not only at the primary site of disease, but also elsewhere in the body.”

“The best opportunity to overcome high-risk soft tissue sarcoma is with the first treatment. Once it becomes advanced stage or metastatic, the prognosis is poor. Localized high-risk soft tissue sarcoma can be cured, but it requires careful surgery with clear margins combined with radiation.”

“We have not seen dramatic improvements in cure rates with adding traditional chemotherapy with surgery and radiation over several decades and some chemotherapy agents have significant side effects on other organ systems. Immunotherapy has made great strides in other fields of oncology and I am excited about the prospect of immunotherapy helping high risk soft tissue sarcoma patients above and beyond the approximately 50-60% survival rate with current standard radiation and surgery. Anything we can do to significantly tip the odds in our favor would save that many more patients’ lives.”

According to the September 20, 2017 news release, the 35 patients Dr. Ng plans to enroll will receive two immunotherapy drugs, durvalumab and tremelimumab, in addition to the standard of care.

“In patients with advanced disease, the immune system may be exhausted by the large amount of cancer or weakened by other treatments,” said Dr. Ng in the news release. “The presence of the main tumor during immunoradiotherapy may be able to assist the immune system in recognizing the molecular signature of the particular sarcoma and identify other cancerous cells throughout the body, similar to a cancer vaccine.”

Dr. Ng told OTW, “Orthopaedic surgeons, and all physicians for that matter, should be aware that any soft tissue mass could potentially be a sarcoma. Common misconceptions are that if a mass is not painful or not growing that it is not a sarcoma can lead to misdiagnosis and delay in care. These conditions should be managed by an orthopaedic oncologist/musculoskeletal tumor surgeon, starting from the biopsy to the definitive surgery, in conjunction with a multidisciplinary team of medical oncologists, radiation oncologists, radiologists and pathologists.”