Social - May 2003

New drugs take varied approaches

Published May 2, 2003

By JEREMY ASHTON, LTN Staff Writer

In the 10 years since he finished his fellowship, Dr. Dean Butler has seen some remarkable advances in cancer treatment.

The progress is even more impressive considering how many different types of cancer exist.

“The challenge with cancer is it’s not one disease,” said Butler, an oncologist with Piedmont Oncology Associates in Charlotte. “Biologically, it’s hundreds of different diseases.”

Each year, new treatments are approved that attack cancer — which occurs when cells in a part of the body grow uncontrollably — in many different ways.

Gleevec, a pill developed with the help of a grant from the American Cancer Society, is one of the most promising.

The pill, Butler said, has “absolutely been a godsend” for patients with chronic myelogeous leukemia, a slow-progressing cancer that creates an excess of abnormal white blood cells.

In the past, the only treatments for CML were chemotherapy or a bone marrow transplant, both of which could leave patients in a weakened state. Gleevec, however, specifically attacks the cancer cells without most of the side effects of the other treatments.

“It’s almost like on ‘Star Trek,’” Butler said. “It works against a specific protein on the cell wall that CML patients have, and it pretty much leaves the rest of the tissues of the body alone.”

Tamoxifen, a drug commonly prescribed for breast cancer, uses a different method.

Certain types of breast cancer are dependent on estrogen receptors, specialized proteins that stimulate cancer cells to grow in the presence of the hormone estrogen. Tamoxifen works by binding to those receptors and locking out estrogen.

A relatively new class of drugs, aromatase inhibitors, has been developed that, according to Butler, treats post-menopausal women better than tamoxifen.

Rather than blocking estrogen from the receptors, these drugs solve the problem by lowering the amount of estrogen the body produces.

Oxaliplatin, a chemotherapy drug approved in the past year, is designed for metastatic colon cancer patients. While it is not curing them, the drug is improving their response rate to treatment.

Rituxan is a recently developed drug that takes an innovative approach to treating non-Hodgkin’s lymphoma, another blood-related cancer.

It is the first anti-cancer treatment that makes use of monoclonal antibodies, substances that bind to a specific protein. In this case, the antibodies attach to the CD20 protein in cancer cells, targeting them for the body’s immune system to destroy.

Unlike chemotherapy and some other treatments, monoclonal antibodies focus specifically on the cancer cells, making them a hot area of research, Butler said.

“What we’re going to see is evolving toward treatments that are better able to focus on the cancer cells and minimize the impact,” he said.

The strides that are being made in cancer research aren’t just focused on curing the diseases.

A common side effect of chemotherapy is a temporary reduction in white blood cells, which protect the body from infection.

A new treatment, however, has been developed in which natural substances called growth factors are injected into a patient, stimulating the body to quickly make more white blood cells.

Aside from reducing the likelihood of infection after chemotherapy, the treatment has positive implications for breast cancer patients, Butler said.

Since patients don’t have to wait as long for their white blood cell counts to recover, oncologists can administer chemotherapy on a more frequent basis. Butler said initial studies of this approach have shown a decrease in the recurrence of breast cancer because the cancer cells have less time to reproduce.

Oncologists are also using growth factors to increase the production of red blood cells, the body’s oxygen-carrying cells.

A low red blood cell count leaves patients severely fatigued, another common symptom of chemotherapy.

Butler said another new medication is set to be released in a couple of weeks that will help control nausea and vomiting, two more side effects of chemotherapy.

“We’re not only hoping to improve survival, but we’re hoping to have a positive impact on patient’s quality of life and minimize side effects,” Butler said.

© 2001 Lincoln Times-News  

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