Proton Therapy giving hope to patients affected by rare cancers

Complex cases coupled with limited treatment options have historically translated into a bleak prognosis for many patients diagnosed with a rare cancer. Now, however, novel therapies developed in recent years at The University of Texas MD Anderson Cancer Center are enabling clinicians to successfully treat a range of uncommon tumors offering increasing numbers of patients new hope. Proton therapy is one such tool advanced by specialists at MD Anderson’s Proton Therapy Center.

Proton therapy is often used to treat rare cancers such as sarcomas and pediatric malignancies and tumors in sensitive areas of the body including the head and neck and liver. These and other rare cancers benefit from proton therapy’s ability to deliver radiation precisely to the tumor — destroying cancer cells while sparing surrounding healthy tissue from damage. As a result, proton therapy patients can receive a stronger, more effective radiation dose, while simultaneously protecting vital quality of life functions such as neurocognitive function, vision, swallowing, taste and speech.

Proton therapy’s advantage is often realized in treating uncommon or inoperable cancers or tumors that are unresponsive to standard radiation and chemotherapy. Ongoing MD Anderson research studies are comparing long-term survival benefit for patients whose rare cancers are treated with proton therapy versus other non-operative therapies (see sidebar an example with liver cancer).

“Individually, rare diseases affect too few patients to benefit from research funding and major clinical trial advances,” said Christopher Crane, M.D., professor of Radiation Oncology and Gastrointestinal Section Chief at MD Anderson. “MD Anderson is standardizing proton therapy as an effective treatment for not just one, but a variety of rare cancer types where viable options are limited. While our goal is always to provide the optimal treatment solution for every patient, we have the opportunity to impact rare cancers as a whole.”

When combined, rare cancers account for more than 50% of all cancer diagnoses in the U.S. Specialists at MD Anderson continue to evolve innovative treatments, like proton therapy, to rare disease-sites, offering new options for these patients.

A significant portion of the 30,640* patients diagnosed with liver cancer in the U.S. each year are not candidates for aggressive surgery and traditional radiation therapy that offers limited therapeutic benefit. In these cases, as well as scenarios where the disease has spread or there is cirrhosis of the liver, the best treatment option, though not always available, is transplanting a new liver.MD Anderson estimates that 30% of its patients diagnosed with liver cancer may benefit from proton therapy. The MD Anderson Proton Therapy Center is one of two proton centers in the U.S. with the technological capability to treat liver cancer with high-powered doses of proton therapy, precisely targeting the tumor and limiting radiation exposure to the healthy liver tissue and surrounding organs (such as the gallbladder and pancreas). This regimen has resulted in tumor control and long-term survival in individual cases documented at MD Anderson Proton Therapy Center.MD Anderson is currently leading a clinical trial of 50 liver cancer patients in cooperation with the Massachusetts General Hospital Francis H. Burr Proton Therapy Center in Boston. This study, the only one of its kind done in the U.S., has yielded impressive preliminary results with median survival rates of over 30 months among patients treated with proton therapy in comparison with 12 months for patients treated with other non-operative therapies. MD Anderson hopes to design and conduct a national randomized trial based on these results.Listen to Christopher Crane, M.D., professor of Radiation Oncology and Gastrointestinal Section Chief at MD Anderson, discussing proton therapy for liver cancer patients in this podcast.