SAN FRANCISCODrug therapies aimed at reducing or eradicating intraepithelial neoplasia (IEN) could reduce the burden of IEN and the incidence of malignancies, according to the American Association for Cancer Research (AACR) Task Force on the Treatment and Prevention of Intraepithelial Neoplasia. Three of the co-chairs of this Task Force reviewed key recommendations at a news briefing at the 93rd Annual Meeting of the AACR.The IEN Task Force recommended the initiation of clinical trials to evaluate the usefulness of treating IEN only in high-risk populations. Individuals with, for example, severe Barrett’s esophagus, high-grade prostatic intraepithelial neoplasia, and women with abnormal breast cells who have been previously treated for breast cancer or who have a family history of breast cancer would be considered to be at high risk.
"The earlier you intervene, the more likely it is that you’ll have a good result. As cancer becomes invasive, it becomes increasingly resistant to treatment," noted Gary Kelloff, MD, a senior scientist in the National Cancer Institute’s Division of Cancer Treatment and Diagnosis.
Therapeutic Interventions Limited
Therapeutic interventions for IEN are limited, however. With only a few exceptions, IEN is currently treated with surgery, with its attendant risks and limitations. "Surgery gets only one focal lesion at a time, and often you have many lesions present, such as a damaged epithelium that has been insulted with cigarette smoke for 20 years," Dr. Kelloff said.
Disfigurement is another disadvantage associated with certain surgeries, such as mastectomies. Drug therapies for treating IEN would not have these disadvantages. Currently, however, there are only about five drugs on the market for treating intraepithelial neoplasia. "Why do we have so few?" asked Joyce O’Shaughnessy, co-director of breast cancer research, Baylor-Sammons Cancer Center, US Oncology, Dallas. "It’s because it takes over a decade, $50 to $100 million, and many thousands of patients to do a clinical trial to prove the effectiveness of a cancer prevention drug if you have to wait for the cancers to develop."
The major finding of the Task Force, she said, is that "we don’t have to wait for cancer to occur to prove that a drug is beneficial."