Cancer treatment once followed a simple philosophy: More is better.

But decades of research have turned that approach on its head, giving clinicians the world over the tools to treat cancer more precisely — and, in some cases, less aggressively.

Today, oncologists are increasingly tailoring treatment plans to individual patients, using advances in understanding the relationship between genetics and the disease, targeted therapies and other approaches to determine when less treatment can be just as effective.

The goal is to spare patients the debilitating side effects without compromising their chances of survival.

“The mainstream idea of cancer treatment (was) always go big, right? Have the biggest operation, have the biggest chemotherapy, have the biggest radiation therapy, if necessary,” said Dr. Emilia Diego, co-director of the UPMC Hillman Cancer Center/UPMC Magee-Womens Hospital Breast Cancer Program. “For us as cancer doctors at this point in time, that mantra has shifted so much over on the other end of the spectrum — where, because there’s so much known about cancer (now), the mantra is not about going with the biggest treatment. It’s actually about going with the most effective treatment for that person, and we’re trying to individualize care at every situation possible.”

Whether it’s research indicating that some patients with Stage 3 colon cancer can receive chemotherapy for a shorter duration or studies showing that certain patients with early hormone receptor-­positive breast cancer can avoid the debilitating treatment altogether, understanding the differences among cancer types has been key to furthering the overall approach of de-escalation, said Diego and Dr. Charles Geyer, division chief of medical oncology at Pitt.

“The thing that really started to move us toward de-escalation was the research that started to identify subtypes of breast cancer,” Geyer said. “Not all breast cancer is the same.”

In the case of HER2+ breast cancer, for instance, in 2018, chemotherapy was found to be totally ineffective in about 70% of cases in one of the more high-profile developments.

But the idea of de-escalation can be as simple as opting for a lumpectomy as opposed to a full mastectomy when applicable, or opting for a therapy before surgery to shrink a tumor and reduce the amount of tissue removed. And it can be as nuanced as creating a genomic profile to ascertain risk level and determine which therapeutic options might work best.

There are many other avenues: precise radiation therapy that delivers high doses to tumors while limiting exposure to healthy tissues; immune checkpoint inhibitors that remove the immune system’s “off” switch to better fight cancers now being administered in lesser amounts over less time; or trials testing whether the breast cancer drug tamoxifen might be just as effective while lessening or eliminating side effects.

The American Cancer Society projects that more than 2 million people in the U.S. will be diagnosed with various types of cancer in 2026. But for the most part, they won’t have to seek out specific doctors who adhere to the ethos of de-escalating treatment — individualized treatment is increasingly standard practice.

.

“I think we have become so good as doctors who manage breast cancer as a team. Breast cancer treatment, just like many other cancers, is a team sport. You can’t have just one doctor because it’s not just about surgery alone, or medicines alone, or radiation alone,” Diego said. “But it’s about working together as a team to optimize all the treatment options.”

And it all represents a distinct shift in approach from a cancer-treatment arms race that Geyer said first began in the 1970s. In that era, Pittsburgher Dr. Bernard Fisher revealed, among other breakthroughs, that cancer is a systemic disease rather than something emanating outward from a tumor.

“Ever since then, what we have been doing is adding to the idea that if a single drug works a little bit, maybe three drugs will work better than one drug,” Geyer said. “Dr. (Gianni) Bonadonna from Milan (Italy) published a study that showed combination chemotherapy is better than single-agent. And from that point forward, we’ve been looking at adding on treatments, sort of incremental improvements.

“With each thing we do, we push the cure rates up. So after 50 years of escalation, (it’s about) do we have the tools to let us be smarter and de-escalate a little bit?”