McClatchy Newspapers
BALTIMORE – At 36, Tamera Bittinger wasn’t even old enough for a mammogram. And when she found a lump in her breast last year, her doctor dismissed it.
She barely had time for her concern to abate, however, because the lump quickly grew large and painful, and she returned for another exam. After a biopsy, the mother of two was told she had stage-three “triple negative” breast cancer, an aggressive form of the disease that disproportionally strikes younger women and African-Americans, and is impervious to the newest treatments.
“Initially, even my gynecologist blew me off because I was so young,” she said. “It was cancer, and it was an aggressive kind. … I had never heard of it.”
Up to about 20 percent of women diagnosed with breast cancer have the “triple negative” type, yet many people don’t know about it. Researchers and doctors, meanwhile, have been somewhat stymied by it.
This cancer can spread more quickly, recur earlier and be harder to treat because no one really knows how it grows. The very characteristic that defines it – a lack of three markers that usually contribute to the growth of cancer cells – means that doctors don’t have the targets used to treat other kinds of breast cancer.
That leaves fewer options for treatment.
“We’re stuck with chemo,” said Dr. Saranya Chumsri, Bittinger’s doctor at the University of Maryland Marlene and Stewart Greenbaum Cancer Center, about the drugs in the arsenal. “Once the cancer has spread, we keep giving the patients chemo drugs, but eventually we run out of drugs for them.”
Promising new therapies, however, are in development. They attack the cancer in different ways: depriving it of blood, breaking down the cancer cell DNA or interrupting the cancer cells’ effort to rebuild.
There are 14 clinical trials around the nation aimed specifically at testing triple negative breast cancer treatments, according to the National Institutes of Health’s database of trials. Patients at centers at the University of Maryland, Johns Hopkins University and Franklin Square Hospital Center are participating in some of them. There also are other studies in the Baltimore area that include triple negative patients.
Developing drugs for this type of cancer means understanding it. Breast cancer is considered triple negative when three specific markers are not present: The tumor cells do not have receptors for the hormones estrogen and progesterone, or for the protein human epidermal growth factor (HER2).
These receptors and proteins typically contribute to the growth of cancers and can occur in any combination. The receptors receive signals from hormones to grow, and the proteins grow at an abnormal rate. But they also serve as targets for new drugs on the market, including Herceptin, which is boosting survival rates in women with the HER2 type of cancer.
When a patient is negative for all three, there are no special targets for treatment. That leaves only the old standbys of surgery, radiation and chemotherapy drugs for triple negative patients, and doctors say that isn’t enough for some women, particularly when the cancer has spread to other organs.
A 2007 study published in the journal Cancer of women with all stages of breast cancer found that 77 percent of triple-negative patients survived at least five years, compared with 93 percent of women with other types of breast cancer.
As with all cancers, statistics are worse for those whose cancer has spread – to the lung, liver or brain. The median survival for a triple negative patient with metastasized cancer is about 13 to 14 months. Median survival for those with other types of breast cancer is two to three years, according to Dr. Katherine H. Rak Tkaczuk, professor of medicine and director of the Maryland cancer center’s breast evaluation and treatment program.
The center has about 1,000 breast cancer patients, with about 200 new cases coming in a year. Up to 30 percent are triple negative breast cancer. Many are younger and African-American, though researchers do not know why.
The Maryland center is participating in two studies, one specifically aimed at triple negative patients. One more is planned.
One drug being tested at Maryland and a few other hospitals – ABT-888 – is for those with more advanced cancer. In previous trials, this family of drugs has been shown to extend life for patients with breast, prostate and ovarian cancers and has garnered enthusiasm among researchers.
The drug works by inhibiting poly (ADP-ribose) polymerase, or PARP, enzymes needed for cancer cells to repair themselves after they have been damaged by chemotherapy or genetic defect. The cells then die, Tkaczuk said.
Another nationwide study in which breast cancer patients at Maryland are participating is for Avastin, which has sparked some controversy because it has not been shown to extend life for those with advanced breast cancer and has serious side effects. The drug, which may no longer be used on those kinds of patients, works by blocking blood vessel production in cancerous tumors. Cancer cells need the oxygenated blood to survive.
This study, however, is for early-stage cancer patients such as Bittinger. For a year and a half, Bittinger, who lives in Barton in western Maryland, came to the university center three weeks a month to participate in the trial. She had hoped she’d get both the normal standard of care and the trial drug, which she did. She finished about two months ago.
After a cocktail of chemotherapy drugs and Avastin, surgery, radiation and another course of chemo drugs and Avastin, her scans show no cancer. She once had a tumor approximately 6-9 centimeters that shrank to less than a half a millimeter before it was surgically removed.
“The tumor shrank pretty dramatically,” Bittinger said. “A local doctor I had seen said if she’d not examined me beforehand herself she’d not have known there was ever anything there.”