• Polymerase chain reaction is a technique that can produce millions of copies of a single DNA molecule with great precision in a short period of time. The method is automated and can be applied in routine clinical setting. The procedure is being continually refined and modified to meet specific need.

• Cells of the immune system can be engineered to secrete certain toxins that are tagged to home-in on to specific cancer cells because of the presence of a unique surface molecule. These toxin-secreting cells accumulate in the tumor and locally secrete toxins to kill the tumor cells, thus reducing systemic toxicity.

• Men with low level of blood testosterone may have prostate cancer that cannot be detected by standard digital rectal examination or prostate-specific antigen measurements; in these individuals these tests may show normal values falsely. In such cases additional prostate biopsy is prudent if testosterone therapy is contemplated since this hormone is known to stimulate prostate cancer.

• Monoclonal antibody CD3, commonly used as an immune suppressant for organ transplant patients is known to stimulate immune system in much smaller dose. In a clinical trial scientists injected extremely small doses of anti-CD3, just once a month, to patients with brain tumors that failed to respond to standard treatment. A few patients experienced compete and partial remission. If further studies confirm anti-CD3 could be a promising new treatment for patients with primary brain tumors.

• Extensive infection with human papillomavirus that is associated with cervical cancer causes alteration in the production of immune system modulators called cytokines. Cytokine testing, therefore, could be used to determine prognosis or to decide whether cytokine-based therapy is indicated.

• Impaired wound healing in postsurgical and immobilized patients can reduce their quality of life. This is a very common problem. These patients carry a high risk of infection that could become complicated and ultimately fatal. Recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF), when applied topically, is reported to have healing effect on wounds of various origin.

• Animal and laboratory experiments suggest that treatment of chronic myelogenic leukemia with a combination of the conventional anticancer drug cyclophosphamide and polymers designed to inactivate a specific mutated gene may be more effective than either treatment alone.

• A newly synthesized vitamin D5 compound designated 1alpha(OH)D5, unlike the natural active metabolite of vitamin D3, strongly inhibited the development of precancerous lesions in animal breast organ culture media, but did not raise the calcium level in the blood serum to toxic threshold. This compound, the first of its kind, may prove useful in cancer prevention.

• In December 1996 the US Food and Drug Administration (FDA) approved the first in vitro diagnostic kit utilizing Fluorescence in situ Hybridization (FISH) technology to identify abnormal chromosome numbers in leukemia patients. This Chromosome Enumeration Probe (CEP) developed by the Illinois-based Vysis Inc. interacts with the chromosome's centromere and highlights the area with a bright orange signal that can be visualized under a special microscope, allowing the cytogeneticists to easily count the number of chromosome copies.

• At present, there are no tumor markers which fulfill the strict criteria for perfection: to be demonstrable only in tumor hosts and absent in patients with non-malignant disease. If we abandon this all or nothing attitude, there is at least one optimal marker combination available for the most frequent solid carcinomas. New markers (in order to determine their sensitivity and specificity as well as their improved diagnostic power over the currently available tests) require rigorous comparisons. This is the case with telomerase, an enzyme present in almost all primary human tumors investigated which shows promise as biomarker for early stage cancers. Hard data must ultimately carry the day.

• Normal housekeeping in a healthy, multicellular organism depends on the ability of its cells to reproduce and self-destruct. Cellular suicide is optimally programmed to remove superfluous or disordered cells. Too much or too little suicide may contribute to malignant growth: tumor cells neglect to sacrifice themselves on cue. Preceding genetic damage fails to trigger apoptosis, an intricate machinery which requires a precise, well-balanced interplay between onco- and suppressor genes. One player of increasingly recognized importance is p21, one of the cell cycle regulatory proteins, designated as "mitotic inhibitor."

• Among the discussions in the conference was the need for agents to modulate drug resistance in elderly patients with blood cell cancers. The gene R-1 that codes for p-glycoprotein (Pgp) is shown to cause treatment failure in acute myeloid leukemia (AML) as well as multiple myeloma (MM) patients. The refractory patients responded well when a R-modulator PSC-833 that inhibits Pgp was added to standard chemotherapy regimen.

• The National Cancer Institute (NCI) is launching a large national study to answer the most controversial question in women's health: What should women and their physicians do about the mild abnormalities that often show up on Pap test? Most abnormalities on Pap tests are the result of human papillomavirus (HPV) infection, but all types do not cause cancer. The trial is designed to determine whether HPV testing can help predict which women are at high risk of developing cancer and need to undergo colonoscopy and biopsy. At present, many physicians recommend immediate colonoscopy and biopsy for mild abnormalities.

Glossary

• A glossary of unfamiliar words and jargons in Cancer Watch, February 1997.