Can Cancer be Prevented with a Pill?

 

Dr. Scott M. Lippman checks chemoprevention study participant Maria Torres' glands, as Dr. Anita Sabichi looks on.

 

 

For more than four years, Maria Torres has begun each morning by brushing her teeth and taking a chemotherapy pill.

 

She doesn't have cancer, but volunteers for an ongoing chemoprevention study because breast and ovarian cancer run in her family and she wants to help find a way to prevent the disease.

 

"I'm doing this because I have four daughters and four granddaughters. If we can learn more about these cancers, maybe they won't have to face these cancers or even worry about having them," the 59-year-old Torres says of her involvement in the five-year study.

 

Her mother and sister died of ovarian cancer, and two cousins died of breast cancer.

 

Torres has been participating in the Breast Cancer Prevention Trial, a nationwide chemoprevention study designed to determine the effectiveness of a particular chemoprevention drug for people at high risk of developing the disease. The trial is one of several major ongoing studies, including lung, colon, bladder, and head and neck, in clinical chemoprevention research.

 

The trials are geared to identify effective and non-toxic compounds which can be used to prevent various cancers in people assessed to be at increased risk for developing cancer due to age, personal or family history, and other factors.

 

According to Dr. Anita Sabichi, assistant professor of clinical cancer prevention, low-dose chemoprevention drugs that have no noticeable side effects are used so participants in the study may continue with normal daily activities.

 

Says Torres, "This therapy hasn't affected me in any adverse way. I can go about my life as usual."

 

Through studies, researchers are looking for the lowest effective dose of chemoprevention agents for healthy people like Torres who are at high risk. This is in contrast to higher doses of relatively toxic chemotherapy drugs that are usually required for someone battling cancer, says Dr. Scott M. Lippman, chairman of the Department of Clinical Cancer Prevention, and holder of the Margaret and Ben Love Professorship in Clinical Cancer Care in honor of Dr. Charles A. LeMaistre.

 

Cancer generally takes a long time to develop and afflicts a fairly small percentage of people, even those at higher-than-average risk. Therefore, it can require 10 or more years and thousands of subjects to determine whether a chemopreventive agent can prevent cancer, which is the major goal of these definitive chemoprevention trials, Dr. Sabichi says.

 

According to Dr. Sabichi, intensive efforts are under way to reduce the length and patient population required by these trials. Deemed translational chemoprevention, "the research initiatives incorporate analyses of various biological markers into clinical studies to help determine the biological effects of a particular chemopreventive therapy."

 

In these studies, blood, urine or tissue samples collected from patients are analyzed to determine whether there is any indication that the drug is having an effect. "By using these biologic markers, we can attempt to identify the most effective prevention agents in a shorter period of time and with fewer people than is necessary for definitive chemoprevention trials," Dr. Sabichi says.

 

Translational chemoprevention studies in a number of sites, including head and neck, lung, colon, cervix, bladder, prostate, breast and skin, are currently under way through collaborative efforts between several clinical and basic science groups within the institution and through cooperative group trials.

 

"In the future, individuals may be able to use effective chemopreventive measures, but that goal will require substantial amounts of additional funding and dedicated research efforts," says Dr. David Menter, assistant professor of clinical cancer prevention.

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