Scientists are looking to telomerase for answers

"Advances in genetics, of course, underlie many recent breakthroughs in our understanding of cancer and new ways of detecting and treating the disease," Dr. Willis said. "Cancer research is particularly exciting – and challenging – at this point in history. Whole new sets of tools are being developed for investigating cancer, and with these new tools comes the need for great care and responsibility in their use."

Among these tools are drugs to inhibit angiogenesis, the formation of blood vessels. Harvard/Boston Children’s Hospital researcher Judah Folkman, MD, proposed in 1971 the concept of starving tumors of their blood supply via anti-angiogenesis and later discovered the first angiogenesis inhibitor molecule. Therapy with cancer drugs known to have anti-angiogenic properties has led to elimination of cancer in laboratory mice and to dramatic tumor regression in some patients. Dr. Folkman received his first angiogenesis grant from the ACS.

Clinical studies are now underway to more carefully evaluate the role of  anti-angiogenesis in preventing and treating cancer. Cancer researchers will continue to share their discoveries with heart disease researchers, who actually promote angiogenesis to nourish damaged heart muscle with a fresh blood supply.

Vaccines as Cancer Treatment

Vaccinations against polio, measles, and other infectious diseases were among the most compelling medical breakthroughs of the 20th century, and vaccines used as treatment for many types of cancer may well make news in this early part of the 21st century, Dr. Willis said.

ACS Clinical Research Professor Ronald Levy, MD, of Stanford University, and others are using a vaccine-like treatment to help patients with B-cell lymphoma and multiple myeloma. In 1999, investigators reported on promising vaccines for treating men with prostate cancer. "The vaccines are used as therapy, tailor-made individually to each person's tumor, to induce the patient's immune system to destroy the tumor," Dr. Willis said. In addition, a number of researchers are studying preventive vaccine strategies to counter exposure to infectious agents such as the human papillomavirus associated with cervical cancer and H pylori, a bacterium linked to stomach cancer.

Scientists are looking at the tumor suppressor gene known as p53 and the protein it produces as keys to "programming" the death of cancer cells.  Cellular suicide or apoptosis is part of a cell’s normal life cycle, but when the process goes wrong, the result can be unchecked cell growth and tumor formation.  Scientists such as Waun Ki Hong, MD, of M.D. Anderson Cancer Center at the University of Texas, Houston, are evaluating ways to restore normal p53 function through gene therapy. Dr. Hong is an ACS clinical research professor.

Scientists Look to Telomerase

In addition, the enzyme telomerase continues to be of great interest to cancer researchers. Telomeres are bits of DNA attached to the ends of chromosomes by telomerase. Unless telomeres are replaced by telomerase, chromosomes get shorter and lose information each time the cell divides. Non-cancerous cells die when they loses too much crucial information, but an overabundance of telomerase can keep cancer cells dividing indefinitely.

ACS Research Professor Robert Weinberg, PhD, of the Whitehead Institute for Biomedical Research, Cambridge, Mass., used this accumulating knowledge about telomerase and apoptosis to create for the first time, human cancer cells in the laboratory. Scientists are searching for an anti-telomerase drug.

This greater understanding of what specific genetic steps move a cell from normal to cancer is demystifying the cancer process and is pointing to even more hopeful areas of research, Dr. Willis said. The entire human genetic material, or genome, will be sequenced within a few years. Already, scientists are using DNA microchips to discover new cancer-related genes.

Eventually, it will be possible to screen a person's DNA at birth and predict what diseases he or she is likely to get, what environmental exposures they should avoid, what prevention strategies they should adopt, and what treatments are likely to be successful when they do become ill, according to Dr. Willis. This may cause ethical problems in relation to things like insurance and job discrimination.

"And, of course, the greatest advance of the next century will be something that no one has yet predicted, or even imagined," Dr. Willis concluded.