Monthly Archives: February 2014

Story Created: Feb 26, 2014 at 12:27 AM ECT

Story Updated: Feb 26, 2014 at 12:27 AM ECT

INFECTIONS In addition to HPV infections discussed last week, there are other infections that can increase the risk of cancers. Hepatitis B and C viruses increases the risks of liver cancers. Human T-Cell Leukemia Virus -(HTLV-1)-Increases the risk of leukemia and lymphoma. Human Immunodeficiency virus (HIV)-increases the risk of lymphoma, and a rare cancer called Kaposi Sarcoma. Epstein Barr Virus (E.B. virus) is linked to increased risk of lymphoma. Human Herpes Virus is a risk factor for Kaposi Sarcoma Helicobacter Pylori-a is bacteria that causes stomach ulcers and is thought to increase the risk of stomach cancers and lymphomas.

ALCOHOL There are clear patterns that have emerged between alcohol consumption and certain types of cancer such as head and neck cancers, oesophageal, liver, breast and colon cancers. People who consume 50 or more grammes of alcohol per day have a two or three times greater risk of developing cancer than non drinkers. When alcohol is metabolised, it forms a compound known as Acetaldehyde which is toxic and a possible human carcinogen which damages human DNA. Alcohol also generates reactive oxygen species which damages the DNA, in addition, alcohol impairs the bodys ability to break down and absorb a variety of nutrients that may be associated with cancer risks. Alcohol also increases blood levels of oestrogen, a sex hormone linked to risk of breast cancers.

FOODS AND CHEMICALS Chemicals can be found in certain foods such as potato chips, French fries and other food products which are produced by high temperature cooking. One example is Asparagine which is an amino acid, a building block of proteins found in many vegetables and foods, such as potatoes. When heated to high temperatures, Asparagine, can form Acrylamide -a possible human carcinogen which can cause oral, pharynx, larynx, breast and ovarian cancers. Heterocyclic amines (HCA) and Polycyclic aromatic hydrocarbons (PAH) have also been found to be cancer causing. These are produced when muscle meat, including beef, pork or poultry, is cooked at very high temperature. HCA and PAH can cause mutations or changes in DNA that may increase cancer risks. Artificial sweeteners: These are substances that are used instead of sucrose (table sugar) to sweeten food and beverages. They include; saccharin, aspartame, sucralose, neotame and cyclamate. Many of these chemicals are thought to be carcinogenic as they have been found to cause cancers in animal studies. Agricultural products: Researches have shown that people exposed to certain products may have an increased risk of developing one or more types of cancer. Farmers, farm workers and family members may be exposed to substances such as pesticides, herbicides, engine exhausts, solvents, dusts, animal viruses, fertilisers, fuels and certain microbes that may increase cancer risks. Chemicals such as Formaldehyde, a colorless, flammable, strong smelling chemical used in building materials and house hold products,is also carcinogenic especially in cases of long term exposures. It is used in pressed woods, particle boards, plywoods, fibre boards, glues and adhesives, and is also found in fungicides, germicides, disinfectants and in preservatives in mortuaries. People who have certain jobs like painters, construction workers and those in chemical industries have increased risk of certain cancers especially when exposed to chemicals such as Asbestos, benzene, cadmium, nickel and vinyl chloride.

RADIATION Ionising radiation can cause cell damage that leads to cancers. X rays medically used for diagnostic investigations can increase cancer risk, even though the risk is low. Radiation therapy used to treat certain cancers can also increase the risk of some other cancers. Its not uncommon to meet a patient who requests an X-ray even when it is not necessary. The fact is that x-rays are a diagnostic tool, not a treatment, and they are not always beneficial. Unnecessary demand and frequent exposure to them may not be a wise idea. Ultra Violet (UV) radiation from the sun is another risk factor. Our UV index is generally high each time you see the weather news. These rays cause the early aging of the skin and skin changes that can lead to skin cancers, especially in caucasians, albinos and people with low melanin (skin pigmentations).

HAIR DYES More than 5,000 different chemicals are used in hair dye products, some of which are reported to be carcinogenic. Over the years, some studies have found an increased risk of bladder cancers in hairdressers and barbers. Some studies also linked the personal use of hair dyes with increased risks of certain cancers of the blood and bone marrow. However some of these studies need further research to make definitive conclusions but given the widespread use of hair dye products, even a small increase in risk may have a considerable public health impact.

SMOKING The role of smoking in the development of many forms of cancers is well documented. Each cigarette consists of over 400 carcinogenic materials that causes DNA damage and increased cancer risks as well as other diseases.

AGEING Cancer risk increases as you grow older, with most cancers occuring in people during their fifties or sixties. However many other cancers do develop before then, and there are some forms of cancers that afflict children.

FAMILY HISTORY Certain cancers develop because of changes or mutations in genes and risk factors can trigger some of these changes. Several cases of the same cancer types in a family are linked to inherited gene changes. If you think you are at risk, talk to your doctor and get checked. Contact Dr Maxwell on 3631807/7575411.

More:
Tidal wave of cancers Part 2

U.S. medical advisers are considering whether there is scientific justification for allowing human studies of a controversial procedure known as "three-parent in vitro fertilization (IVF)," a technique supporters say could prevent horrific genetic defects but that critics believe could lead to designer babies.

During two days of public hearings starting on Tuesday, scientists were scheduled to present their research to outside advisers to the U.S. Food and Drug Administration. The agency will decide whether safety concerns raised by three-parent IVF are minimal enough to allow clinical trials to begin.

The committee is focusing only on the science, and at the end of Tuesday's hearing some committee members expressed concern that animal research cannot yet show that human studies would be safe for women and any children born via the three-parent technique.

Several panelists felt "there was probably not enough data in animals . . . to move on to human trials without answering a few additional questions" about safety, said committee chairman Dr. Evan Snyder of the Sanford/Burnham Medical Research Institute in La Jolla, California, in summarizing their views at the end of Tuesday's session.

Although the panel has not been asked to consider legal or ethical issues, members of the public focused on those. Speakers warned the panel that use of three-parent IVF "could alter the human species," represented "an unprecedented level of experimentation on non-consenting human subjects" (meaning any children born via the technique), and "could open the door to genetically modified children" who would be "manufactured products."

In the three-parent procedure, one man would donate sperm and all its DNA for in-vitro fertilization. The would-be biological mother would contribute the egg and most of its DNA. But if the mother carries harmful genetic mutations in cellular structures called mitochondria, scientists would remove her unhealthy mitochondria and substitute those of a second woman so the baby would not inherit a potentially devastating "mitochondrial disease."

Allowing such procedures "would produce genetically modified human beings," Marcy Darnovsky, executive director of the Berkeley, California-based Center for Genetics and Society, a non-profit that focuses on genetic and reproductive technologies, told the committee.

If the FDA allows clinical trials, she warned, it would introduce "a regime of high-tech consumer eugenics" and represent "the first time a government body had okayed genetic changes for humans and their descendants."

Although the FDA committee is considering only scientific issues, such as whether animal research can show mitochondrial manipulation is safe or not, the agency said it is prepared to go beyond that.

"We have heard the concerns expressed at the advisory committee meeting, and will take the information back to consider whether we need to facilitate a public discussion and, if so, how best to do this," spokeswoman Jen Rodriguez told Reuters.

Read this article:
FDA weighs evidence on producing '3-parent' embryos