Can Prostate Cancer Be Prevented?

Because the exact cause of prostate cancer is not known, at this time it is not possible to prevent most cases of the disease. Many risk factors such as age, race, and family history cannot be controlled.

Current information on prostate cancer risk factors, however, suggests that some cases might be prevented.

Diet

You may be able to reduce your risk of prostate cancer by changing the way you eat.

The American Cancer Society recommends eating a variety of healthful foods, with an emphasis on plant sources, and limiting your intake of red meats, especially high-fat or processed meats. Eat 5 or more servings of fruits and vegetables each day. Bread, cereals, grain products, rice, pasta, and beans are also recommended. These guidelines on nutrition may also lower the risk for some other types of cancer, as well as other health problems.

Tomatoes (raw, cooked, or in tomato products such as sauces or ketchup), pink grapefruit, and watermelon are rich in lycopenes. These vitamin-like substances are antioxidants that help prevent damage to DNA and may help lower prostate cancer risk.

Taking vitamin or mineral supplements may affect your prostate cancer risk, but this is not yet clear. Some studies suggest that taking 50 milligrams (or 400 International Units) of vitamin E daily can lower risk. But other studies have found that vitamin E supplements have no impact on cancer risk and may increase risk for some kinds of heart diseases. Selenium, a mineral, may also lower risk. On the other hand, vitamin A supplements may actually raise prostate cancer risk. Taking any supplements can have risks and benefits. Before starting vitamins or other supplements, you should talk with your doctor.

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) is a large clinical trial designed to find out whether either selenium or vitamin E supplements (or both) can help protect against prostate cancer. The study opened in 2001 and has enrolled more than 32,000 men. The results of the study will probably not be available for several years.

Medications

Some drugs may also help reduce the risk of prostate cancer.

Researchers have been interested in finding out whether a drug called finasteride (Proscar), which is already used to treat benign prostatic hyperplasia (BPH), can reduce prostate cancer risk. Finasteride prevents the body from making a certain potent androgen (male hormone).

The Prostate Cancer Prevention Trial (PCPT) was a study that enrolled more than 18,000 men to learn whether finasteride reduced the risk of prostate cancer. Each man in the study was randomly assigned to take either finasteride or a placebo (sugar pill) each day for 7 years. The men didn’t know which pill they were taking.

At the end of the study, the men taking finasteride were about 25% less likely to have developed prostate cancer than those getting the placebo. But the cancers that did develop in the men taking finasteride looked like they were more likely to grow and spread. The reason for this is not known. Researchers are continuing to watch these men to see if these cancers really do grow and spread more quickly.

The men taking finasteride were more likely to have sexual side effects such as lowered sexual desire and episodes of impotence than those taking placebo. But they were less likely to have urinary problems such as trouble urinating and leaking urine (incontinence).

At this time, it is not clear whether taking finasteride to prevent prostate cancer is a good thing. Men thinking about this should discuss it with their doctors. The results of the PCPT will become clearer over the next few years.

Study: Hair Relaxers Not Linked to Breast Cancer

Study: Hair Relaxers Not Linked to Breast Cancer
Likely Not a Factor in Black-White Breast Cancer Gap
Article patientINFORM

Summary: Using hair relaxers, even over a period of many years, does not appear to raise a woman's risk of breast cancer, according to a large study of African-American women. Researchers were looking at the possibility that exposure to chemicals in these widely used hair-straightening products might explain why young black women have higher rates of breast cancer than young white women do.

Why it's important: When looking at all age groups, breast cancer is more common in white women than in blacks. But African-American women are more likely to develop the disease at a young age (under 40) and are more likely to die from it. Researchers are trying to understand what is behind this difference.

What's already known: Social and economic factors play a role in some of the differences. For instance, African Americans tend to have lower incomes and less health insurance than whites and may therefore be less likely to get regular mammogram screenings that can catch cancer early when it is most treatable. Scientists are searching for more clues to these differences so they can try to lessen their impact.

How this study was done: Because use of hair relaxers is very common among African-American women, especially younger ones, but not common at all among white women, researchers from Boston University and Howard University decided to investigate the possible relation of these products to breast cancer risk specifically in black women. They used data from the Black Women's Health Study, a large, ongoing study of lifestyle and disease involving tens of thousands of African-American women in the US. Since 1995, participants have answered periodic questionnaires about their health and habits like smoking, exercise, and diet.

What was found: The research team had information on the use of hair relaxers for more than 48,000 women in the study. Between 1997 and 2003, 574 of these women developed breast cancer. But the researchers did not find any link to hair relaxer use. Basically, women who had never used hair relaxers were found to have the same risk for breast cancer as those who had used the products for many years (even 20 or more), those who used them multiple times each year (even 7 times or more), those who began using them at a young age (under age 10), or those who had been burned by the products multiple times when using them. The type of product (with lye or without lye) also had no effect on breast cancer risk. The findings are published in the journal Cancer Epidemiology Biomarkers & Prevention.

The bottom line: Because the study was so large, the findings offer strong evidence that hair relaxers are probably not contributing to the breast cancer gap between African-American women and white women, and they are not likely to be a cause for concern among the women who use them.

Cancer Prevention Study

Cancer Prevention Study I

The Cancer Prevention Study I (CPS-I) is a prospective mortality study of approximately 1 million adult men and women enrolled between October 1, 1959 and February 15, 1960 and followed up through September 1972. Participants were recruited into the study in twenty-five states by approximately 68,000 volunteers for the American Cancer Society. Enrollment was by families (i.e., households). All family members age 30 and over were recruited if at least one participating household member was 45 years or older. At the time of enrollment, each participant completed a four-page baseline questionnaire providing information on height, weight, demographic characteristics, personal and family history of cancer and other diseases, menstrual and reproductive history (women), occupation, diet, alcohol and tobacco use, and physical activity. Supplemental questionnaires were mailed to participants in 1961, 1963, 1965, and 1972, inquiring about cancer and changes in smoking habits. These additional questionnaires were used only to confirm vital status. The participants' vital status was determined annually (in October) from 1960 through 1965, and again in 1971 and 1972, through personal inquiries by the volunteers. At each of these eight follow-ups, the volunteers were asked whether their enrollees were alive or dead and the date and place of all deaths. Death certificates were obtained from State Health departments.

Cancer Prevention Study II

CPS II Baseline Cohort

The Cancer Prevention Study II (CPS-II) is a prospective cohort study funded and conducted by the American Cancer Society (ACS). The goal of the study is to examine the impact of environmental and lifestyle factors on cancer etiology in a large group of American men and women. To achieve this goal, approximately 1.2 million men and women were enrolled in 1982 with the help of 77,000 ACS volunteers in 50 states, the District of Columbia, and Puerto Rico. Many of the participants were friends, neighbors, family members, or acquaintances of the volunteers. Study participants (known as the CPS-II Baseline Cohort) completed an initial study questionnaire in 1982 that obtained information on a range of lifestyle factors such as diet, use of alcohol and tobacco, occupation, medical history, and family cancer history. These data have been examined extensively in relation to cancer mortality. Vital status of study participants is updated biennially through computerized linkage with the National Death Index. Cause of death has been documented for over 98% of all deaths that have occurred. Mortality follow-up of the CPS-II Baseline Cohort is complete through 2002 and is expected to continue for many years. Over 385,000 deaths have occurred in this cohort from 1982 to 2002.

CPS II Nutrition Cohort

In 1992, a new questionnaire was mailed to a subgroup of the CPS-II Baseline Cohort to obtain detailed information on diet, to update other lifestyle factors, and to conduct prospective cancer incidence followup in addition to mortality followup. This subgroup was chosen among baseline cohort members, aged 50-74, who resided in 21 states with population-based state cancer registries (California, Connecticut, Florida, Georgia, Illinois, Iowa, Louisiana, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Mexico, New Jersey, New York, North Carolina, Pennsylvania, Utah, Virginia, Washington, and Wisconsin). Known as the CPS-II Nutrition Cohort, this subgroup of 184,194 men and women received additional mailed questionnaires in 1997, 1999, 2001 and 2003 to update exposure information and to obtain self-reported cancer diagnoses. With permission from study participants, self-reported cancer diagnoses are verified by medical record review. Computerized linkage with state cancer registries is used to supplement self-reported information on cancer incidence. Future questionnaires are planned on a biennial basis.

CPS II Biospecimen Repository

In 1998, the CPS-II Lifelink Cohort was initiated to obtain blood samples from 40,000 surviving members of the CPS-II Nutrition Cohort residing in urban and suburban areas. These bloods are being stored in liquid nitrogen for future epidemiologic investigations, including the role of nutritional, hormonal, and genetic factors in the development of cancer and other disease. Blood collection was coordinated by ACS staff and volunteers and performed by hospital staff at community hospitals (approximately 312 hospitals in 20 states, recruited mainly from American College of Surgeons (ACOS) Commission on Cancer approved programs). Collection of blood samples for LifeLink was completed in June, 2001. A total of 39,371 Nutrition Cohort members gave a single blood sample. In January 2001, researchers began collecting buccal (cheek) cell samples as a source of DNA from CPS-II Nutrition Cohort members who were unable or unwilling to donate a blood sample. Using a mailed collection kit, samples were obtained from 70,000 participants and are currently being stored in liquid nitrogen for future epidemiologic investigations.

drug temsirolimus for advanced renal cell carcinoma, a form of kidney cancer

The US Food and Drug Administration has approved the drug temsirolimus for advanced renal cell carcinoma, a form of kidney cancer. The announcement coincides with the publication this week of a study showing the drug helps people with this late-stage disease live longer.

Temsirolimus, made by Wyeth, will be sold under the name Torisel. It is one of 3 drugs recently approved for kidney cancer but the only one so far that has been shown to improve survival. Studies thus far have shown that Nexavar (sorafenib, made by Bayer Healthcare and Onyx Pharmaceuticals) delays the time it takes for the cancer to start growing again, while Sutent (sunitinib, made by Pfizer Oncology) also delays tumor growth and shrinks tumors.

In the new study, published in this week's issue of the New England Journal of Medicine, people who took Torisel lived an average of about 11 months, compared to about 7 months for those treated with interferon, a standard therapy for late-stage kidney cancer. In addition, those on Torisel went more than 5 months before their disease began to get worse, compared to about 3 months for people on interferon.

Torisel is given by infusion into a vein. The most common side effects include rash, fatigue, mouth sores, nausea, swelling, and loss of appetite. The drug can also raise blood sugar, cholesterol, and triglyceride levels, and lower blood counts.

Torisel is a targeted drug that blocks growth signals and blood vessel formation in tumors. It is being studied as a treatment for several other types of cancer, including mantle cell lymphoma, solid tumors, brain tumors, melanoma, and ovarian cancer.

Torisel should be available to patients in July 2007, according to Wyeth.
(as said by cancer.org)

What are the causes of colon cancer?

Doctors are certain that colorectal cancer is not contagious (a person cannot catch the disease from a cancer patient). Some people are more likely to develop colorectal cancer than others. Factors that increase a person's risk of colorectal cancer include high fat intake, a family history of colorectal cancer and polyps, the presence of polyps in the large intestine, and chronic ulcerative colitis.

Diet and colon cancer

Diets high in fat are believed to predispose humans to colorectal cancer. In countries with high colorectal cancer rates, the fat intake by the population is much higher than in countries with low cancer rates. It is believed that the breakdown products of fat metabolism lead to the formation of cancer-causing chemicals (carcinogens). Diets high in vegetables and high-fiber foods such as whole-grain breads and cereals may rid the bowel of these carcinogens and help reduce the risk of cancer.

Colon polyps and colon cancer

Doctors believe that most colon cancers develop in colon polyps. Therefore, removing benign colon polyps can prevent colorectal cancer. Colon polyps develop when chromosome damage occurs in cells of the inner lining of the colon. Chromosomes contain genetic information inherited from each parent. Normally, healthy chromosomes control the growth of cells in an orderly manner. When chromosomes are damaged, cell growth becomes uncontrolled, resulting in masses of extra tissue (polyps). Colon polyps are initially benign. Over years, benign colon polyps can acquire additional chromosome damage to become cancerous.

Ulcerative colitis and colon cancer

Chronic ulcerative colitis causes inflammation of the inner lining of the colon. For further information, please read the Ulcerative Colitis article. The risk of colon cancer is much higher than average for patients with chronic ulcerative colitis of long duration. The risk of colon cancer increases significantly after 10 years of colitis.

Genetics and colon cancer

A person's genetic background is an important factor in colon cancer risk. Among first-degree relatives of colon cancer patients, the lifetime risk of developing colon cancer is eighteen percent (a threefold increase over the general population in the United States).

Even though family history of colon cancer is an important risk factor, majority (80%) of colon cancers occur sporadically in patients with no family history of colon cancer. Approximately 20% of cancers are associated with a family history of colon cancer. And 5 % of colon cancers are due to hereditary colon cancer syndromes. Hereditary colon caner syndromes are disorders where affected family members have inherited cancer causing genetic defects from one or both of the parents.

Chromosomes contain genetic information, and chromosome damages cause genetic defects that lead to the formation of colon polyps and later colon cancer. In sporadic polyps and cancers (polyps and cancers that develop in the absence of family history), the chromosome damages are acquired (develop in a cell during adult life). The damaged chromosomes can only be found in the polyps and the cancers that develop from that cell. But in hereditary colon cancer syndromes, the chromosome defects are inherited at birth and are present in every cell in the body. Patients who have inherited the hereditary colon cancer syndrome genes are at risk of developing large number of colon polyps, usually at young ages, and are at very high risk of developing colon cancer early in life, and also are at risk of developing cancers in other organs.

FAP (familial adenomatous polyposis) is a hereditary colon cancer syndrome where the affected family members will develop countless numbers (hundreds, sometimes thousands) of colon polyps starting during the teens. Unless the condition is detected and treated (treatment involves removal of the colon) early, a person affected by familial polyposis syndrome is almost sure to develop colon cancer from these polyps. Cancers usually develop in the 40’s. These patients are also at risk of developing other cancers such as cancers in the thyroid gland, stomach, and the ampulla (the part where the bile ducts drain into the duodenum just beyond the stomach).

AFAP (attenuated familial adenomatous polyposis) is a milder version of FAP. Affected members develop less than 100 colon polyps. Nevertheless they are still at very high risk of developing colon cancers at young ages. They are also at risk of having gastric polyps and duodenal polyps.

HNPCC (hereditary nonpolyposis colon cancer) is a hereditary colon cancer syndrome where affected family members can develop colon polyps and cancers, usually in the right colon, at early ages of 30’s to 40’s. Certain HNPCC patients are also at risk of developing uterine cancer, stomach cancer, ovarian cancer, and cancers of the ureters (the tubes that connect the kidneys to the bladder), and the biliary tract (the ducts that drain bile from the liver to the intestines).

MYH polyposis syndrome is a recently discovered hereditary colon cancer syndrome. Affected members typically develop 10-100 polyps occurring at around 40 years of age, and are at high risk of developing colon cancer.

(thanks medicinenet.com)