Collaboration among experts in bioengineering, gene therapy and chemotherapy is expected to help tame cancer, Alzheimer's and other diseases within the next 25 years, scientists say.

While scientists have been talking for decades about hope for a cure for cancer, expectations for progress on this and other diseases are now based on reality, said Dr. David G. Nathan, professor emeritus at Dana-Farber Cancer Institute.

"The combinations of mathematicians, of physicians, of physicists and engineers are going to move these fields, and that's what's happening. You're now starting to see serious teamwork," said Nathan, co-author of an editorial in Wednesday's Journal of the American Medical Association.

The journal includes several essays dealing with medical advancements expected in the next 25 years.

Advances in bioengineering are helping scientists develop drugs that target specific components which help cancer cells thrive.

Nathan noted in an interview that an experimental drug called STI571 has shown great promise in treating chronic myelogenous leukemia, a cancer of the white blood cells that affects about 4,400 Americans yearly, mostly adults.

The drug targets an abnormal enzyme that causes white blood cells to grow uncontrollably, and also is being tested in certain gastrointestinal tumors.

In one recent study, cancer in all 31 leukemia patients who got the drug went into complete remission.

The drug "is a new paradigm for targeted cancer drug development," Drs. David Livingston and Ramesh Shivdasani, of Dana-Farber, wrote in JAMA. Both doctors are consultants to Novartis Pharmaceuticals, which makes the drug.

Cancers of the lung, breast and colon, which typically result in extensive cell damage almost as soon as microscopic abnormalities emerge, will likely prove to be more challenging to treat, Nathan said.