What is Proton Therapy
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What are Secondary Malignancies?

What are Secondary Malignancies?

When battling cancer, your immediate concern is to treat the cancer you have. Nobody wants to think about the risk of developing new and different tumors caused by the cancer treatments – or “secondary malignancies” as they are often called.

Secondary malignancies can occur several years or decades after treatment is completed and are sometimes a consequence or side effect of the initial cancer treatment. Radiation can cause secondary malignancies when normal, healthy tissues are exposed to radiation during treatment.

“If the secondary cancer is within the original radiation field, it is generally assumed the secondary cancer is due to the radiation exposure,” says Dr. Ralph P. Ermoian, radiation oncologist and childhood cancer specialist at Seattle Cancer Care Alliance (SCCA) Proton Therapy Center.

Proton therapy may decrease the risk of treatment-related secondary malignancies by allowing oncologists to treat the cancerous areas with less radiation to surrounding healthy tissues. According to a 2009 study by the M.D. Anderson Cancer Center, proton therapy reduces the risk of secondary cancers by 26–39% compared with photon (x-ray) radiation therapy.

“When it comes to patients needing external radiation, protons are the most precise in targeting the tumor, reducing exposure to radiation to healthy parts of the body,” says Dr. Ramesh Rengan, medical director at SCCA Proton Therapy Center. “Therefore protons are the least likely among types of external radiation to put the patient at risk for secondary malignancies.”

Secondary malignancies within the original radiation field most commonly appear 10 years or more after treatment, so childhood cancer patients are most at risk for developing these tumors, as they generally have decades of life ahead of them. In addition, their growing bodies are more sensitive to radiation. Because it can decrease this risk, proton therapy is the preferred form of radiation for many childhood cancer patients.

As with all cancer treatments, it is important that patients know all the associated risks, so they can make an informed decision about their treatment plans. For more information, visit www.sccaprotontherapy.com.