For breast cancer patients, Penn researchers are comparing costly proton therapy with standard radiation

Heather Klebon was weeding in her garden at her Delaware beach house when she felt a painful lump in her left breast on a summer afternoon in 2019.

She would soon learn she had breast cancer. “My whole world stopped,” Klebon recalled.

After surgery to remove her left breast and lymph nodes, followed by three months of IV-infused chemotherapy, her doctor at Penn Medicine prescribed radiation treatment to eradicate lurking cancer cells.

She had two treatment options: proton beam radiation or traditional (X-ray) radiation. Both work well to treat cancer. But, it’s still not clear which is more advantageous for breast cancer patients.

Klebon, 59, wants to help answer that question. She’s among the participants in the largest clinical trial to date comparing outcomes among patients with advanced, but still curable, breast cancer. At stake is the health of millions of breast cancer patients and, potentially, billions in health-care costs.

» READ MORE: Penn Medicine is going all in on proton therapy, a costly treatment that is unproven for most common cancers

Penn’s Justin Bekelman, a radiation oncologist, is the lead investigator of the trial, which aims to enroll 1,278 patients from more than 20 proton therapy centers nationwide, including Penn.

The trial is still recruiting participants who will be randomly selected to receive either proton therapy or standard radiation. Such randomized clinical trials are the gold standard of research.

The results could influence whether private insurers expand coverage of proton radiation therapy, which often costs twice as much as standard radiation, for breast cancer patients.

The study seeks to answer three central questions in the debate over proton therapy vs. traditional radiation: Which has fewer side effects? Which is better at keeping the cancer from coming back? And, since radiation can cause heart damage in breast cancer patients, which leads to fewer heart problems later in life?

“This study is so important,” Bekelman said, “because it’s going to give patients a sense, over time, which of these treatments are better and for whom?”

The $12 million breast cancer study, called RadComp, is largely funded with federal dollars. In addition to breast cancer, at least five other taxpayer-funded, randomized clinical trials are underway, comparing proton therapy to standard radiation for treating cancers of the lung, prostate, liver, esophagus, and brain.

Back in 2020, Klebon’s doctor asked if she’d like to be put in a “lottery” for a study that if selected, she would be placed randomly in either a pool of patients treated with proton beam therapy or conventional radiation.

Klebon said she had no preference, though she characterized her placement in the proton pool as akin to winning a lottery.

“I get this opportunity to have this wonderful radiation that’s pretty cutting edge,” Klebon said.

Aside from cost, the main difference between standard radiation and proton beam therapy is the latter enters the body and then stops at the tumor, so it’s less likely to deliver so-called “scatter” radiation to organs and tissues on the other side of the tumor.

» READ MORE: What to know about proton therapy, the costly and controversial cancer radiation treatment

So far, comparative research has been limited, with mixed results for either treatment.

Five days a week for five weeks, Klebon’s husband drove her back and forth from their home in Newark, Del., to Penn’s Roberts Proton Therapy Center in University City for radiation sessions.

Klebon completed the radiation in late May 2020 and so far, the cancer has not come back, she said.

“Who wants to be the guinea pig when you’re already so sick and going through so much? I get that. But I did. I wanted to be the guinea pig,” she said. “It’s only research until you try.”

Private insurers typically do not cover proton therapy for the most common adult cancers, including prostate and breast disease, citing expense and unproven benefits. Medicare, the government health insurance program for people 65 and up, generally covers proton treatment.

Klebon, who works out of her home buying and selling antiques, could participate in the study because her insurer at the time had a deal with Penn. Three regional companies — Independence Blue Cross, Horizon Blue Cross Blue Shield of New Jersey, and Aetna — have agreements with Penn to cover proton beam therapy at the same rate as traditional radiation for its breast cancer patients participating in research.

Once enrollment is complete, Bekelman said researchers hope to have information on early side effects about a year later. In three to five years, the study aims to publish on breast cancer recurrence outcomes. It will take a decade or more to publish findings on major heart problems later in life, Bekelman said.

“Clinical research is a really important part of American medicine,” Bekelman said. “This is going to be a definitive trial. We’ll have answers … We just have to be patient.”