Among the highlights in the July 1998 Cancer Watch issue are: Deletion of Chromosome 3, An Early Event in Cervical Cancer, Angiogenesis Blockers, A Premature Elation, New High-Tech Procedure Simultaneously Screens for Different Tumor Markers, Insulin-Like Growth Factor-I and Risk of Breast Cancer, Meeting Report: American Society of Clinical Oncology, "Designer" Estrogens Prevent Breast Cancer, Timing of Mammography May be Important, Biochemotherapy in Malignant Melanoma, DNA, The Master Molecule: A Molecular Approach to Cure Triplet Repeat Diseases by Ribozyme Engineering, Management of Cancer Pain in Elderly Patients, Why Hormone Therapy for Prostate Cancer Eventually Fails, Transmission of Tumors by Transplantation, Antioxidants in Colorectal Cancer, Widespread Misconceptions About Leading Cancer Killer, Anti-ras Therapy with Potent, Specific Inhibitors and Folates in Cancer, New Roles?

• Deletion of Chromosome 3, An Early Event in Cervical Cancer
• Angiogenesis Blockers, A Premature Elation
• New High-Tech Procedure Simultaneously Screens for Different Tumor Markers
• Insulin-Like Growth Factor-I and Risk of Breast Cancer

• Prostate screening can save lives is the report from a controversial randomized trial from Canada. But all clinicians are not convinced. Some believe that every man, with or without symptons, should be screened. A new class of compounds, known as antisense, has come of age. These novel anti-cancer agent works at the genetic level to interrupt the synthesis of cancer-causing proteins. These agents can interfere specifically with signals that stimulate cell growth.

• The two "designer" estrogens, raloxifene and tamoxifen, may prevent breast cancer rather than merely delay it. The specially engineered hormones cut the risk of breast cancer by up to two-thirds in large clinical trials.

• Owing to high breast density screening mammography is not very effective in younger women. Increased density interferes with sensitivity and specificity of mammography. A smaller proportion of women is found to have extremely dense breast during the first half of the menstrual cycle. Therefore scheduling mammography during the first half of the cycle may improve the quality of screening among the premenopausal women.

• A pilot trial among patients with malignant melanoma confirms antitumor activity for a modified M.D. Anderson biochemotherapy regimen and finds it to be feasible for an outpatient cooperative group setting.

• Several neurological disorders are associated with the presence of persistent repetitions of triplet sequences such as GCC, CAG and CTG in the human genome. A potential therapeutic approach based on trans-splicing by group I intron ribozymes to repair the mutations is described.

• Cancer pain can be treated adequately employing the various drugs and administration modalities standardized by the World Health Organization; but because of poor physician and caregiver training, and the lack of proper pain assessment information, most cancer patients especially the elderly and women, are not adequately treated.

• Some antiandrogen drugs, commonly used for prostate cancer treatment can stimulate the cancer cells to grow.

• Ideally cancer patients should not be considered as organ donors. However, because of acute shortage in organs for transplatations, certain exceptions are being made. Primary brain tumors rarely spread outside the brain and these patients are allowed to donate organs. Risk for cancer transmission through organs donated by brain cancer patients should be investigated further.

• Although the majority of life forms, as we know them today and to which we belong, are irreversibly dependent on oxygen, this "fountain of life" also carries irrevocably the end of all individual life. Only recently has the intricate interplay between redox status, cell proliferation and ultimately, apoptosis become better understood. But, while our level of information is beguilingly increasing and once again, various vitamins and similar substances return (through another door, this time) into the limelight, all this new acquired knowledge is not of much practical use. Yet.

• In recent years public awareness of deadly diseases, especially cancer, has increased due to programs by healthcare systems and wide dissemination of information through popular press. However, it seems that a major fraction of the population may not be getting all the information. Most people including a large number of women believe that breast cancer is the major cause of cancer death in women when it is the lung cancer that causes more cancer death in women.

• Mutated versions of ras genes are found in various human cancers, which makes them a logical target for specific drug design. The critical step that activates the Ras precursor protein is farnesylation, catalyzed by a housekeeping enzyme named farnesyl-protein transferase (FPTase). Inhibitors of FPTase block the growth of ras-transformed tumor cells in colony forming assays; this may be a promising approach in the restoration of normal differentiation and apoptosis.

• The role of vitamins in cancer is undecided at best and dubious at worst. As it is so often the case in malignant growth, nothing can nor should be generalized; there are so many reports of good and bad vitamin effects (some with dangerous credibility) that we tend to accept some selectively. Since we are now entering an ominous period of increasing scientific illiteracy, supported by media hype, the average cancer patient tends to cling to rays of hope, often fragile and false. Folates may be an exception; they have been recognized as an important factor in cancer for a long time. For those who need to dust off a few cobwebs from long forgotten memories: folic acid belongs to a large family of related compounds; it is in fact pteroylglutamic acid, stored as pteroylheptaglutamic acid ( a conjugate), with dihydropteroylglutamic acid as intermediate. The active form is tetrahydrofolic acid and 5-formyltetrahydropteroylglutamic acid (also: folinic acid, leucovorin or citrovorum factor) which is a notorious carrier of one-carbon units. The folate antagonist, 4-aminopteroylglutamic acid (aminopterin ) is a potent inhibitor of cell division and plays a recognized role in cancer chemotherapy. Much more recent is the inclusion of folates into highly toxic chemotherapeutic protocols as a protector of hemopoiesis.

Glossary

• A glossary of unfamiliar words and jargons in Cancer Watch, July 1998.