For breast, lung, and other cancers, chemotherapy has long been considered the "dogma" for treatment—but now, a growing number of cancer patients are being spared the grueling treatment in favor of other approaches, Gina Kolata reports for the New York Times.
Chemotherapy isn't necessary for all patients
At the time of her breast cancer diagnosis, Seema Doshi, a dermatologist in private practice in the Boston suburb of Franklin, thought she would have to undergo chemotherapy—but she was wrong.
According to Gabriel Hortobagyi, a breast cancer specialist at MD Anderson Cancer Center in Houston, chemotherapy has been "the rule, the dogma" for treating many forms of cancer for decades. However, data from various sources suggest that treatment method isn't necessary for all cancer patients.
There are now genetic tests that can assess the potential benefit of chemotherapy —and several new and burgeoning treatment options for those whom chemotherapy isn't likely to be successful. In addition, there is a growing willingness among cancer doctors to scale back the number of drugs involved and the duration of treatment, even when chemotherapy is necessary.
About 20 years ago, Robert Vonderheide, a lung cancer specialist who heads the University of Pennsylvania's Abramson Cancer Center, said that the discussion was, "Do you give patients two different types of chemotherapy or three?"
"Now we are walking in to see even patients with advanced lung cancer and telling them, 'No chemo,'" Vonderheide said.
As a result of these shifts in care, thousands are spared from chemotherapy each year, Kolata writes, as well as its accompanying hair loss, nausea, fatigue, and potential to cause permanent damage to the heart and nerves in the hands and feet.
Changing the course of treatment
According to Kolata, one field that has seen a dramatic shift in care is breast cancer. Thirty years ago, the National Cancer Institute issued aggressive breast cancer treatment guidelines, under which some 95% of patients underwent chemotherapy.
But since then, new targeted treatments have emerged, Kolata writes. One of the first Herceptin, a targeted drug which was approved as an initial treatment for roughly 30% of patients who had a particular protein on their tumors' surfaces, Kolata writes. Herceptin initially was given along with chemotherapy, and it reduced the chance of a recurrence by half—and the risk of dying from breast cancer by a third, "almost regardless of how much and what type of chemotherapy was used," Hortobagyi said.
Over time, additional research indicated that Herceptin and another targeted drug could provide a substantial benefit even when given without any chemotherapy, Hortobagyi said—findings that ultimately enabled providers to "star[t] to break the dogma" that chemotherapy was essential.
Today, there are at least 14 new targeted breast cancer drugs on the market—three were approved within the last year—and dozens more are in clinical trials, along with hundreds in initial development.
Another technological development that has helped provider limit the use of chemotherapy is genetic sequencing. In recent years, the cost of genetic sequencing has come down while the speed at which it can be conducted has accelerated, enabling providers to test whether a patient's tumor would respond to various targeted drugs. Similarly, genetic tests that looked at proteins on cancer cells accurately predicted who would benefit from chemotherapy and who would not.
As doctors' uptake of these alternative approaches increased, chemotherapy use appeared to decrease, Kolata writes. According to Kolata, a study of nearly 3,000 women treated from 2013 to 2015 found that chemotherapy use in early-stage breast cancer declined from 26% to 14% over the study time period. For those with evidence of cancer in their lymph nodes, the use of chemotherapy declined from 81% to 64%.
More recently, data compiled but not yet published by Jeanne Mandelblatt, a professor of medicine and oncology at Georgetown University, and her colleagues, found that the percentage of study participants—including 572 women 60 years or older—who received chemotherapy declined from 35% in 2012 to 19% by the end of 2019.
In addition to avoiding chemotherapy, many patients have also seen improved outcomes, Kolata reports. For example, the median survival for women with metastatic breast cancer who are eligible for Herceptin increased from 20 months in the early 1990s to about 57 months now—and further improvements are expected as new drugs become available.
For women with tumors that are fed by estrogen, the median survival rate has increased from around 24 months in the 1970s to almost 64 months today. According to Hortobagyi, some patients are in remission 10 or even 15 years after their initial treatment.
Another success story for lung cancer treatment
A similar trajectory has occurred in the field of lung cancer, Kolata writes. About 25 years ago, nearly all patients with advanced lung cancer could expect to receive chemotherapy, and most tumors continued to grow and spread. Roy Herbst, a professor and oncologist at the Yale School of Medicine, said fewer than half of his advanced lung cancer patients survived more than a year, and just 5% to 10% survived five years.
However, in 2010, targeted drugs for lung cancer patients began to emerge. There are currently more than nine such drugs available, and about 25% of lung cancer patients are eligible for treatment with these therapies alone, Kolata writes. And while these drugs eventually stop working for most patients—at which point many start chemotherapy—they've contributed to increased survival rates: Nowadays, the five-year survival rate for advanced lung cancer patients is nearly 30%.
And about five years ago, immunotherapy—which uses drugs to help the immune system attack cancer—was developed to treat lung cancer with and without chemotherapy. Immunotherapy is given for two years, and it almost doubles life expectancy, according to Charu Aggarwal, a lung cancer specialist at the University of Pennsylvania. (Kolata, New York Times, 9/28)