Mayo announces $200 million expansion of proton cancer therapy center

Mayo Clinic is spending $200 million to expand its proton beam therapy center, which is overwhelmed by patient demand despite criticisms at the time of its construction that it would be a costly and inefficient form of cancer care.

Patients are filling up every slot at Mayo's six-year-old center, which uses a particle accelerator to direct focused beams of proton radiation that target tumors and minimize damage to surrounding tissues. The center operates four treatment rooms from 7 a.m. to 11 p.m. each weekday and makes rare midnight or weekend runs for patients with urgent needs.

Clinicians are having to delay treatment for some patients or send them to other centers across the country to make sure that the most urgent cases are prioritized, said Dr. Nadia Laack, chairwoman of radiation oncology at Mayo Clinic in Rochester. "It's very hard for our staff to have to tell patients that the bar is getting higher and higher for the medical need because the machine is full."

The expansion will add two more treatment rooms and step up Mayo's investment in a technology that gradually is expanding into treatment of more types of cancer. Insurance coverage early on was granted only for certain types of cancers, such as those of the head and neck that demanded precise radiation, but proton therapy is gaining acceptance and coverage for more common cancers of the breast, prostate and other organs.

The capital expense of the accelerator does raise the cost at first, but Laack said proton therapy requires fewer sessions for cancer patients than other forms of radiation and can lower cost over time.

"For our prostate patients, it used to be 40 treatments," she said. "It's now five treatments — one eighth of the length of time."

Proton therapy is one of a growing number of options for cancer care, often following tumor removal surgeries to prevent regrowth. Photon radiation has been around longer and is becoming more precise through technological advances as well.

Chemotherapy can be used to chemically eliminate cancer cells, and new immunotherapies coax an immune system response to fight off aggressive cancers.

Mayo's approach has been to charge the same rate for cancer radiotherapy, regardless of the type used, so the health system absorbs the extra expense when opting for proton beam therapy, Laack said. The health system has participated in 300 studies in the past few years assessing proton therapy's use for different cancers.

"We feel like we've made a compelling case that this is the right thing to do," Laack said.

Treatment prioritization right now varies by the type and location of tumor. For example, a patient with breast cancer might receive earlier access to proton therapy if a tumor is on her left breast and closer to the heart.

At the time the Mayo facility opened in 2015, the U.S. was seeing a downsizing in proton beam facilities as some early centers shut down and others fell into bankruptcy.

Since then, the number of U.S. centers has increased from single digits to nearly 40.

Improved technology has allowed for the construction of smaller accelerators and single-room treatment centers that can operate in smaller hospitals. Mayo opted for an expansion adjacent to its existing center in Rochester to give patients a single check-in site.

When it opens in late 2025, the expansion will allow Mayo to treat another 900 patients each year and add another 117 jobs.

Cancer incidence rates are expected to climb in Minnesota in the coming years along with the gradual aging of its population.

Jeremy Olson • 612-673-7744