Cleveland on ‘front lines’ of breast cancer treatment

CLEVELAND, Ohio — Marianne Alciati, the head of research science for Susan G. Komen for the Cure, visited Cleveland last week to see what local researchers are doing to fight breast cancer. Komen has a history of sustained commitment to funding breast cancer research.

Dr. Joseph Barr of the Ireland Cancer Center at University Hospitals is investigating a vaccine that could help breast cancer patients with triple negative cancer to boost their immune system and avoid recurrence.

Breast cancer mortality rates have been declining since 1990, by more than 2 percent per year. These reductions have been credited for saving 50,000 lives from breast cancer. Researchers now understand that breast cancer is not one disease; there are distinct subtypes that are characterized by their biology. And we now have treatments that target those biologic differences.

Between 70 percent and 75 percent of all breast cancers are a subtype called “estrogen receptor positive.” Much like a key inserted into a lock, estrogen unlocks the growth signals in these cancer cells.

Hormone-based therapies, like Tamoxifen, block the estrogen receptor and can be effective, not only in treatment but in shrinking tumors before surgery and providing information about treatment response. Between 15 percent and 20 percent of cancers are “HER2 positive,” and a drug called Herceptin inhibits the growth-signaling of HER 2 receptors on the surface of cancer cells.

Advances will not only add therapeutic options but will allow doctors to better select which patients are most likely to benefit. For example, an enzyme is critical in Tamoxifen metabolism, but some patients don’t have this enzyme. The enzyme function is an inherited trait and could become a tool to optimize breast cancer therapy.

A new class of treatments that is exciting is called PARP — poly (ADP-Ribose) polymerase — inhibitors, an enzyme involved in DNA repair. Resistance to chemotherapy can occur when tumor cells become efficient at repairing the therapy-induced DNA damage that kills cancer cells.

This drug inhibits or blocks the ability of tumor cells to repair chemotherapy-induced damage, so the therapy can continue to work. PARP inhibitors also may be able to directly cause cancer cells to die.

2009 WKYC-TV