Among the highlights in the November 1998 Cancer Watch issue are: H pylori Linked to Gastric Cancer, Postoperative Radiation Prevents Brain Cancer Recurrence, Relapse Rate is Higher for Younger Breast Cancer Patients with Breast-Conserving Surgery, Risk of Thyroid Cancer and Exposure to Radioactive Iodine, Adverse Effect of Herbal Extract on Prostate Cancer, General View on Alternative Medicine, Cigarette Smoking On the Rise Among College Students, PPAR, a Nuclear Receptor, and Colorectal Cancer, High-Tech Molecular Staging of Melanoma, Loss of Imprinting and Risk of Colorectal Cancer, Ultrasonography to Evaluate Endometrial Cancer, Inhibition of Enzyme Improves Leukemia Treatment, Overweight and Breast Cancer, Virus Therapy for Cancer, Prostate Cancer Susceptibility Gene on X Chromosomeand Research in Basic Science to Find Cure and Prevention for Cancer.

• H pylori Linked to Gastric Cancer
• Postoperative Radiation Prevents Brain Cancer Recurrence
• Relapse Rate is Higher for Younger Breast Cancer Patients with Breast-Conserving Surgery
• Risk of Thyroid Cancer and Exposure to Radioactive Iodine
• Adverse Effect of Herbal Extract on Prostate Cancer
• General View on Alternative Medicine

• During the last three decades cigarette smoking has decreased immensely and so has the rate of smoking-related deaths. However, this habit is still very popular among adolescent and young adults. Nearly all smoking starts at early age and if unchecked it will be reflected in the increasing number of adult smokers. Though adolescence smoking prevalence is tracked regularly, very little is known about this habit among college students. The present study indicates that a large number of college students are starting to smoke regularly and trying to stop. Effort should be extended to this group to reduce smoking.

• Most biological activities are regulated by molecules that bind to a specific target molecule known as receptor for its function. Once bound they can stimulate specific function acting as an agonist or suppress it as an antagonist. A class of nuclear receptors, peroxisome proliferator-activated receptor (PPAR) participate, being stimulated by agonists, in regulation of a variety of key functions such as differentiation, and metabolism. These receptors have medical relevance and are target for drug development. Troglitazone, a synthetic ligand that binds to PPARg is found to be effective in the treatment of type II diabetes and is being investigated in colon cancer treatment because this receptor is expressed in most colon cancer. In the mouse model of the human genetic disease familial adenomatous polyposis coli (FAP) the synthetic drug seems to increase the number of tumors; however, in colon cancer cell line and in transplanted tumors in mice the drug appears to reverse the events that lead to cancer and produces smaller tumors in treated mice.

• Melanoma is an aggressive disease and prognosis depends upon staging. Once the disease spreads to the lymph node, survival rate decreases drastically. Therefore sensitive techniques are needed to detect cancer cells in the node which may be missed by routine histological analysis. Detection of mRNA by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) can measure submicroscopic melanoma metastases.

• Genetic imprinting is a natural phenomenon in gametogenesis which ensures that when the expression of any gene is silenced, it is silenced either in the maternal or in the paternal allele. Therefore mutation of functioning pair of the imprinted gene will result in the loss of that gene function. Conversely, if the imprinted gene regains its function (loss of imprinting) the gene will overexpress. Depending upon the gene involved, both the above situations, can cause disease including cancer. Loss of imprinting of the insulin-like growth factor-II gene is found in the normal as well as in the cancerous colonic cells of cancer patients.

• A comparatively noninvasive technique, endovaginal ultrasound, can be used to detect endometrial abnormalities in postmenopausal women with endometrial bleeding who are candidates for biopsy.

• A patient with acute promyelocytic leukemia who developed resistance to all-trans-retinoic acid and other chemotherapeutic agents showed complete clinical and cytogenic remission when phenylbutyrate was included in the treatment regimen. Phenylbutyrate, an aromatic fatty acid, may be restoring the anti-leukemic effect of all-trans-retinoic acid by inhibiting the enzyme histone deacetylase.

• Obesity is being increasingly associated with the incidence of various diseases, in cahoots with diabetes mellitus and hypertension. There are powerful statistics from numerous studies which link overweight to a variety of risk factors, including breast cancer; however, clear statistical significance may have no clinical significance. To blame the effect of the relative proportion of adipose tissue to body size is a simplification which is not helpful in our understanding of disease mechanisms and their causes. Medicine is (or should be) more than the strict application of scientific rules; observation, evidence based experience and clinical epidemiology introduce objective variables which must be taken into account. This is particularly true for evaluating the correlation between obesity and breast cancer.

• The use of virus in cancer therapy mainly involves its employment in transporting therapeutic genes into cells. In such use the virus is inactivated and extreme precautions are taken so that there is no chance of replication of the virus. However, the function of a productive live virus is to kill its host and if a cancer cell type can specifically support the growth of an otherwise harmless virus, eventually it will destroy the cancer cells. Such environment is present in certain type of cancer that overexpress Ras protein needed to maintain reovirus growth. Reovirus infection in human is mild and asymptomatic. In mouse model this virus injected directly into the tumors destroys the tumor mass without infecting the surrounding healthy tissue.

• A new gene site for hereditary prostate cancer has been located on the long arm of chromosome X. Studies among affected families suggest that this gene termed HPCX may account for approximately 16% of hereditary prostate cancer.

• Understanding molecular events in health and disease is essential for developing effective treatment for any disease, especially a disease like cancer which is very complex and dynamic. In the last decade, basic research to unravel the molecular events causing cancer has improved treatment strategies. This has been possible because researchers in diverse disciplines such as computational science, biophysics, chemistry, biochemistry, cell biology, molecular genetics, pharmacology, biochemical pathology, immunology, and oncology exchange their knowledge to enrich the field of cancer research. The National Foundation for Cancer Research has been supporting basic science research since its inception in 1973. During the 25th anniversary of this Foundation, this year, scientists from all over the world were gathered in Washington, DC to share results from some of their recent discoveries.

Glossary

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