Proton Therapy

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Proton Therapy for Breast Cancer

Thanks to mighty efforts in education, millions of women already know that there’s a one in eight chance that they will be diagnosed with breast cancer at some point in their lives. What every woman should know is that breast cancer can be a highly curable disease if detected and treated early. Close to 300,000 women are diagnosed with this disease every year in the U.S. 

If you choose treatment at Seattle Cancer Care Alliance (SCCA) for breast cancer, you’ll be receiving care from some of the world’s leading and most experienced breast cancer surgeons, medical oncologists, radiation oncologists, breast radiologists, and pathologists. 

SCCA’s specialists offer the latest and most effective therapies for breast cancer. Among them are chemotherapy regimens that are easier to tolerate, surgical procedures that are less invasive, biological therapies that target cancer cells, and radiation treatment that can be calibrated to minimize exposure to healthy tissue, including Calypso breath-hold technology—and proton therapy. Learn more information about breast cancer treatment at SCCA.

Breaking New Ground in Treatment for Locally Advanced Breast Cancers

As a precisely targeted form of radiation, proton therapy enables radiation oncologists to deliver radiation dosages sufficient to destroy cancer cells, while minimizing exposure to healthy tissue. This technology is most commonly recommended to reduce the likelihood of secondary tumors (cancers that result from radiation treatment), and to avoid damage to patients’ critical organs. In the case of breast cancer, the most vulnerable organs are the heart, lungs, and opposite breast.

Although proton therapy has been in clinical use in the U.S. since the 1970s, its use in treating breast cancer has been, until very recently, limited to one treatment facility in the U.S.—and focused solely on partial breast radiation for early stage breast cancers.  

SCCA radiation oncologists are breaking new ground in investigating the benefits of using protons in treating locally advanced breast cancers. The advantage with protons in treating these cancers is that it can enable radiation oncologists to deliver adequately high radiation doses to cancer targets such as the chest wall and lymph nodes—while sparing surrounding healthy organs .

SCCA is engaged in a multi-institutional trial that is exploring the effectiveness of proton therapy in treating stage III breast cancers. There are several eligibility requirements for this trial; if you are interested in participating, please talk with our radiation oncologists to learn more. Our Patient Guide to Clinical Studies is also a useful resource.

Proton Therapy in Accelerated Partial Breast Irradiation

Currently, SCCA radiation oncologists are also planning to open a clinical trial to investigate the use of proton therapy in accelerated partial breast irradiation (APBI). APBI is a safe option for a select group of women with early stage breast cancer. It is a condensed course of treatment to the part of the breast where the tumor was removed; the objective is to contain the radiation to the tumor cavity.

SCCA is participating in a national study that has already enrolled more than 4,000 women. This study is comparing standard external beam radiation therapy with APBI. We offer enrollment to all patients who are eligible.

If APBI is an appropriate option based on the stage and other unique features of your cancer, it can offer certain advantages. Partial breast irradiation can further spare surrounding tissues from radiation exposure. It is delivered twice a day for a total of five days. For women who have received radiation to the chest for another cancer, this may be an option to lower the chance of side effects.

Proton therapy is one of several techniques that are available to deliver APBI. It can be also delivered on a linear accelerator or through devices that are placed in the breast itself. Which technique is most appropriate depends on several factors that your radiation oncologist can discuss with you.

There are many eligibility requirements for APBI. If you are interested in this option, please talk with our radiation oncologists. Again, our Patient Guide to Clinical Studies is a useful resource.

The “Promise” of Proton Therapy for Breast Cancer 

In the words of SCCA radiation oncologist L. Christine Fang, MD, who specializes in treating breast and gynecologic cancers: “Weighing the risks and benefits of radiation treatment for cancer is a judgment call that radiation oncologists have to make every day. Treating cancer is our primary objective, but a very close second is making sure that we protect everything else around it.”

At SCCA, we are committed to addressing the need for definitive studies on proton therapy for breast cancer. We see promise in this therapy in treating breast cancer, both in its ability to deliver adequate doses to cancer targets, and its ability to spare healthy tissue. Our goal is to help discover and define how we can make the most effective use of proton therapy to advance treatment outcomes for women with this disease.