Doctors employ new breast cancer treatments

UNDATED (WJRT) -- (04/08/10) -- Two medical breakthroughs are helping doctors track down and kill breast cancer.

HealthFirst reporter Leslie Toldo show us how this new technology gets the job done.

Nearly 200,000 women will learn they have breast cancer this year. Even with all of the strides that have been made, nearly a quarter of those women will die - all the more reason to improve the way breast cancer can be caught and destroyed.

Pamela Peterburs thought she had her life mapped out until her path abruptly changed. "It did not show up on a monthly mammogram, and to me that underscores how valuable it is doing your self breast exams."

Dr. Anne Wallace from Moores UCSD Cancer Center is making sure the cancer didn't spread to the lymph nodes, the first place cancer may go. "You can take a picture and actually see where the lymph node is."

Doctors are using a new molecule called lymphoseek to find the right lymph nodes to test. It lights up the area to help doctors see the nodes that need to biopsied for possible cancer. "Taking all those out, which is standard, can lead to more arm swelling, pain and difficulty with healing and long-term range of motion."

It's also been an uphill battle for Eileen Kastura. "I did last year 20 weeks of chemo, went through radiation and three surgeries."

She was diagnosed with triple negative breast cancer. "Much more aggressive, much more resistant to chemo and outcomes are not as good," said Dr. Dana Zakalik from Beaumont Hospital

Kastura is using a new type of drug called parp inhibitors. It blocks a cancer cell's ability to repair its own DNA.

"By blocking that enzyme, the cell dies off. It can't repair itself," Zakalik said.

In one study, a parp inhibitor improved survival by 60 percent when added to a chemo routine. In stage-four cancer patients like Kastura, tumors shrank by 48 percent.

"The fact that it prolongs survival is huge because for a drug to prolong survival means that it's making a big impact on the biology of the cancer," explained Zakalik.

"I'm still a mom of two girls and still working two days a week and stay busy," said Kastura.

"I feel great. I really do. I feel healthy," Peterburs said.

Parp inhibitors are also being tested on ovarian and prostate cancers.

BREAST CANCER BACKGROUND: Nearly 200,000 women were estimated to be diagnosed with breast cancer last year, according to the American Cancer Society. More than 40,000 women died from the disease. Although the incidence of breast cancer has increased over the past 30 years, deaths attributed to the disease have lowered thanks to advancements in treatment.

LYMPHOSEEK: In breast cancer, lymph node status is a strong predictor of outcome and influences the course of treatment since lymph nodes are the first place breast cancer travels in the body. Lymphoseek is a radioactive tracing and mapping agent used to target cancerous cells during lymph-node biopsies. The radioactive portion of the molecule lights up the area and allows doctors to see the lymph nodes that are most likely good candidates for a biopsy. Results of phase III trials of Lymphoseek showed 93 of 97 cancerous nodes detected by traditional dyes were also detected by Lymphoseek.

PARP INHIBITORS: Triple negative breast cancer is an especially hard-to-treat form of cancer that accounts for up to 20 percent of all breast cancers. This type of disease is more resistant to chemotherapy and tends to recur more frequently and more quickly than other, more common types of breast cancer. A new class of compounds under investigation is helping women battle the disease more effectively. "PARP inhibitors are medications that block an enzyme that's in the cell call PARP," Dana Zakalik, director of the Cancer Genetics Program at Beaumont Hospital in Royal Oak, Mich., told Ivanhoe. "PARP is over expressed in triple negative breast cancers. By blocking that enzyme, the cell dies off, and it can't repair itself because that enzyme is key to a DNA repair pathway that is present in triple negative breast cancers. So by blocking that protein, that enzyme, the cell cannot repair itself, and then it dies."

Doctors hope treatment with PARP inhibitors, more specifically, an inhibitor called BSI 201, will prolong survival for patients with triple negative breast cancer long enough to try other treatments. A phase II study of the drug found 62 percent of 116 patients who received BSI 201 along with chemotherapy experienced clinical benefit compared to 22 percent who were treated with chemotherapy alone. Tumors shrank in 48 percent of women treated with the PARP inhibitor, while tumors shrank in 16 percent of patients on chemotherapy only. Survival for patients on BSI 201 was a median of 9.2 months, and 5.7 months for patients on chemotherapy alone.