Whether women should perform breast self-examination (BSE) monthly or not has been a controversial topic. In 2003, the Cochrane Review published their analysis on the beneficial effect of screening by BSE and its impact on breast cancer death rate. The study, based on two large population-based studies conducted in Russia and Shanghai, concluded that BSE was not efficacious in reducing breast cancer death rate. The study suggested that BSE caused more harm since it identified a greater number of benign lesions and led to an increased number of biopsies being performed. Consequently several organizations have backed away from recommending self BSE while others have continued. The review was updated in 2008 and since no new studies were available since 2003, the review came to the same conclusion.

At the recent 10^th Annual Meeting of the American Society of Breast Surgeons, a study from Duke University found BSE to be accurate and efficacious in detecting breast cancer in high-risk women. The study involved 147 women at high risk of developing breast cancer. The women had mammography, MRI and BSE training at study entry. Thereafter, they performed BSE every 6 months and mammography and MRI screening every 12 months. At 3 year follow-up, the proportion of patients detected with breast cancer by BSE, mammography and MRI was about the same.

The controversy about whether BSE is useful or not will continue. One of the criticisms leveled at the Russian and Shanghai studies on BSE was the low compliance in the study population. BSE may cause false positives in a proportion of women but no test in medicine is free of false positive results. For example, mammography has a false positive rate of about 11%. False positive results will lead to further intervention, including surgery.

To be able to perform a proper BSE, one has to be taught. Some women will find it relatively easy to pick up the skills, but others might find it difficult or shudder at the thought of finding something wrong in the breasts. For the latter group of women, BSE is probably not going to work and they are better off going to their doctor for regular breast examination. For those who are adept at BSE, BSE could be viewed as a means of becoming more familiar with their bodies. It should not be viewed as a substitute to their visits to the doctor for the recommended screening programme; it should be seen as an adjunct.

Folate deficiency during pregnancy leads to neonates being born with neural tube defects. This knowledge led to the introduction of folic-acid fortification of wheat flour in the United States in 1996 and in Canada in 1997. This became mandatory in both countries in 1998. The government of Chile introduced a mandatory programme of folic-acid fortification of wheat flour in 2000 to reduce the incidence of neural tube defects in newborns. Indeed, this has been achieved with stunning results but a recent report from Chile showed that the rate of colorectal cancer in Chile has increased since 2000.  

Researchers from the University of Chile analyzed hospital discharge data for two 4-year periods – before folic-acid fortification (1992 – 1996) and after fortification (2001 – 2004). They found a significant increase in the number of cases of colon cancer in the second period. Among people aged 45 – 64 years, the increase in the rate ratio was 2.6 times while the increase was 2.9 times in people aged 65 – 79 years. While some would argue that the increased rate of obesity (from 19.7% in 1997 to 22% in 2003) in the population may have contributed to the increased rate of colorectal cancer, the lack of consistent patterns of change in other diseases such as cardiovascular diseases would argue against this (Eur J Gastroenterol Hepatol 2009; 21: 436 – 439).

Indeed, similar findings were published by researchers from the Tufts University in Boston 2 years earlier (Cancer Epidemiol Biomarkers Prev 2007; 16: 1325 – 1329). The authors noted that both United States and Canada experienced an abrupt reversal of the downward trend in the colorectal cancer (CRC) incidence seen in the preceding decade. The absolute rate of CRC in the United States began to rise in 1996 and peaked in 1998 and in Canada it rose in 1998 and peaked in 2000. The rates have continued to exceed the pre-1996 / 1997 trends by 4 – 6 additional cases per 100,000 individuals. While this observation did not prove a causal link, it was worrying.

In order to gain some information on the association between folate status and the risk of prostate cancers, researchers studied the occurrence of prostate cancer among the participants in the Aspirin / Folate Polyp Prevention Study (J Natl Cancer Inst 2009; 101: 432 – 435). This study is a placebo-controlled randomized trial of aspirin and folic acid supplementation for the chemoprevention of colorectal adenomas conducted between 6/7/1994 and 31/12/2006. These participants were followed for up to 10.8 years. Among the 643 men who were randomly assigned to placebo or folic acid supplementation, the estimated probability of being diagnosed with prostate cancer over a 10-year period was 9.7% in the folic acid group and 3.3% in the placebo group. Aspirin alone had no effect on prostate cancer incidence. Interestingly, in non-multivitamin users, the baseline dietary folate intake and plasma folate level were inversely associated with the risk of prostate cancer. However, this association did not reach statistical significance.

Is natural folate handled differently in our body? Does the folic acid in multivitamin preparations or that used in fortification act differently on our cells? In our quest to build up our body, are we taking too much folic acid as supplements? All these questions are awaiting the definitive answers. For those of us who are not pregnant or suffering from folate deficiency, perhaps we might be better off sticking to natural sources of folate than popping the daily multivitamin pill.

Indeed, natural might be better.

In the United Kingdom, the National Bowel Cancer Screening Programme, which involves 2 yearly faecal occult blood screening, is predicted to reduce the colorectal cancer mortality in those screened by 13-15% over the next 20 years (J Med Screen 2008; 15: 163 – 174). The same researchers from London have now published their analysis predicting that realistic lifestyle modifications involving diet and exercise could prevent more colon cancers than screening. The lifestyle modifications are

·         Consuming < 90 g/day of red and processed meat

·         Consuming ≥ 5 portions /day of fruit and vegetables

·         Exercising ≥ 30 minutes / day on ≥ 5 days / week, at least at moderate intensity (equivalent to brisk walking)

·         Alcohol consumption not exceeding 3 units / day for men and 2 units / day for women (half a pint of beer, a single measure of spirits, a glass of wine or a small glass of sherry or port is equivalent to a unit).

They have estimated that adhering to these lifestyle modifications could lead to a 26% reduction in the number of cases of colorectal cancer in the British population (Eur J Cancer Prev epub, February 20, 2009).

Since this is an estimation based on projection, you might not be convinced that lifestyle changes can have such major impact on your lifetime cancer risks. Consider this then. Researchers from Tokyo University of Science examined the effects of consuming broccoli sprouts on Helicobacter Pylori colonization in the stomach. [The WHO has classified H Pylori as a carcinogen. H. Pylori infection gives rise to gastritis, stomach ulcer and stomach cancer. Eradication of H. Pylori infection with triple therapy leads to resolution of gastritis, stomach ulcers and the prevention of stomach cancer.] The researchers studied 48 people with H. Pylori infection. They were randomized to consume either 70 g / day of broccoli sprouts (containing 420 µmol sulforaphane precursor) for 8 weeks or an equal amount of alfalfa sprouts (Cancer Prev Res 2009; 2: 353 – 360). Alfalfa sprouts are rich in phytochemicals but do not contain sulforaphane. 

All the participants had blood, stool and urine samples taken on days 0, 28, 56 and 112. H. Pylori stool antigen (HpSA), a biomarker of H. Pylori colonization, and serum pepsinogens PGI and II, biomarkers of gastric inflammation, were measured. Urea breath test was used to assess severity of H.Pylori colonization. The HpSA level in the broccoli sprout group was reduced by > 40% while it remained unchanged in the alfalfa group. The serum pepsinogens levels were significantly reduced only in the broccoli sprout group. Two months after stopping broccoli sprouts in the diet, the HpSA and pepsinogens levels returned to baseline.

The study showed that broccoli sprout consumption successfully reduced H. Pylori colonization but does not completely eradicate the pathogen. It is unrealistic to expect any form of dietary chemoprevention to completely eradicate the risk of developing a particular disease or cancer. Just like eating broccoli sprouts, the lifestyle changes suggested above will only help to reduce the risk of developing colon cancer but will not eradicate the risk completely. In order to benefit from them, we have to persevere with these lifestyle changes and maintain the changes or habits over the long term.

The ball is now in your court. You decide.