Outsmarting breast cancer
06/14/2014 10:41 AM
08/08/2014 10:24 AM
Over the past few decades, changes in the treatment of breast cancer amount to a revolution in patient care. And it’s not over yet.
There was a time when the standard approach was a radical mastectomy, which involved removal of not just the breast, but all the lymph nodes in the armpit and underlying muscles in the chest wall. This approach has been replaced by less extensive surgery that, through decades of clinical trials, has proved to be equally effective at treating patients, as well as safer and less disfiguring. J. Dirk Iglehart, director of the Susan F. Smith Center for Women’s Cancers at Dana-Farber Cancer Institute in Boston, estimated that he now performs a tenth of the number of mastectomies than when he entered the field in the 1970s.
Currently, most women with early stage breast cancer have a lumpectomy; only the tumor and a small margin of surrounding normal tissue are removed, along with a few lymph nodes. Patients then receive localized radiation therapy and often drug therapy to head off a recurrence.
Even though this approach is less aggressive, breast cancer death rates have dropped steadily since 1990, a combined result of earlier diagnosis and medical therapies developed largely through a major national investment in cancer research, according to Clifford A. Hudis, chief of breast cancer medicine service at Memorial Sloan-Kettering Cancer Center in New York.
“Treatment today is getting much more individualized,” Hudis said. Depending on the molecular nature of a woman’s tumor, postoperative hormonal or other drug treatments are routinely prescribed to prevent or delay a recurrence of disease.
Still, with nearly 40,000 breast cancer deaths annually in this country, more needs to be done.
Instead of waiting for cancer to recur in certain high-risk patients, scientists are now developing techniques to outsmart the cancer cell’s aggressive tactics by prompting the patient’s immune system to execute a continuous attack that keeps the disease at bay indefinitely.
Another nonsurgical approach under study involves destroying the tumor by freezing it with an ice probe, but leaving it in place so that the immune system can be trained to attack it, Hudis said. The patient then would be given an immune stimulant to help overcome the molecular obstacles that had kept the immune system from recognizing the cancer as foreign tissue.
When tumors are more advanced at diagnosis, it is already sometimes possible to minimize the extent of surgery without compromising a woman’s chances of disease-free survival.
“The size of the tumor and presence of positive nodes may not matter as much as we thought,” said Deborah M. Axelrod, a surgeon who directs breast cancer programs at the center. “It’s not even true that if the cancer is metastatic, it’s curtains.”
Tests are being developed to help doctors predict an individual patient’s response to various therapies, Axelrod said.
Patients now are encouraged to become well informed about their disease and possible therapies and to participate in treatment decisions.
“There’s no right or wrong decision, as long as patients are well informed and choose what is best for them,” said Jennifer K. Litton, a surgical oncologist at M.D. Anderson Cancer Center in Houston. “The old days of paternalistic medicine are gone.”
Knowing that the effectiveness of treatment is reduced once breast cancer has metastasized – that is, spread to other regions of the body – researchers are now testing creative ways to prevent such recurrences. One, a vaccine called NeuVax, is in the final stage of multinational clinical tests under the direction of Elizabeth A. Mittendorf, a surgical oncologist at M.D. Anderson.
The vaccine is made from a peptide, a small piece of a cancer protein, that is combined with an immune stimulant. Early results suggest that the vaccine can reduce the risk of recurrence by 50 percent among breast cancer patients whose tumors produce low levels of the protein HER2, a marker for more aggressive breast cancer.
Without the vaccine, such patients have a 20 percent chance of a recurrence, Mittendorf said. Rather than waiting to see if a patient’s cancer comes back, doctors give the vaccine at the time of initial treatment, when few if any cancer cells are present, she explained.