“Our study shows that the amount of soya needed is not high, and is easily achievable in a typical
Asian diet,” NUH associate professor Koh Woon Puay was quoted as saying. Post-menopausal women, those with a higher body mass index and those who had consumed soya for longer, experienced the greatest reductions in risk, the study found. The results are similar to those of eight other studies conducted on Asians. One in Japan showed an average 12% reduction in breast cancer risk for those who eat the soya bean.

Studies on Caucasian women have been inconclusive, possibly because of the low levels of soya involved, the report said. Koh cautioned against consuming too much soya, which could
lead to conditions such as gout. NUS’ Centre for Molecular Epidemiology is planning a 10-year study
of 12,000 Chinese, Malay and Indian women, with and without breast cancer, to fi nd out how genetic and lifestyle factors interact to determine breast cancer risks.

Women with a very low blood level of vitamin D have a considerably increased breast cancer risk. The effect was found to be strongest in women who were not taking hormones for relief of menopausal symptoms.

A connection between vitamin D level and the risk of developing breast cancer has been implicated for a long time, but its clinical relevance had not yet been proven. Sascha Abbas and colleagues from the working group headed by Dr. Jenny Chang-Claude at the German Cancer Research Centre, collaborating with researchers of the University Hospital in Hamburg Eppendorf, have now obtained
clear results for the first time.

While previous studies had concentrated mainly on nutritional vitamin D, the researchers have now investigated the complete vitamin D status. To this end, they studied 25-hydroxy-vitamin D (25(OH)D) as a marker for both endogenous vitamin D and vitamin D from food intake.

However, the authors note that, in this retrospective study, diagnosis related factors such as chemotherapy or lack of sunlight after prolonged hospital stays might have contributed to low vitamin levels of breast cancer patients.

In addition, the investigators focused on the vitamin D receptor. The gene of this receptor is found in several variants known as polymorphisms. The research team of the DKFZ and Eppendorf Hospitals investigated the effect of four of these polymorphisms on the risk of developing breast cancer.

They found out that carriers of the Taql polymorphism have a slightly increased risk of breast tumours that carry receptors for the female sex hormone estrogen on their surface. No effects on the overall breast cancer risk were found. A possible explanation offered by the authors is that vitamin D can exert its cancer-preventing effect by counteracting the growth- promoting effect of estrogens.

Apart from its cancer-preventing influence with effects on cell growth, cell differentiation and programmed cell death (apoptosis), vitamin D regulates, above all, the calcium metabolism in our body. Foods that are particularly rich in vitamin D include seafi sh (cod liver oil), eggs and dairy products.

However, the largest portion of vitamin D is produced by our own body with the aid of sunlight.

Scientist in the US are developing a screening test for breast cancer that checks a woman’s saliva for evidence of the disease to help find tumors early, when they are most treatable.

In research published recently, the scientists said they identified 49 proteins in saliva that the screening test would track to distinguish healthy women from those with benign breast tumors and those with malignant breast tumors.

Breast cancer triggers a change in the type and amount of proteins in secretions from the salivary glands, said Charles Streckfus, a professor of diagnostic sciences at the University of Texas Dental Branch at Houston.

The proteins are produced by tumour cells and affect cell growth, cell metabolism and cell self-destruction – all of which go awry in cancer, Streckfus said. Streckfus and colleagues tested saliva from 30 women – 10 healthy women, 10 with malignant breast cancer and 10 with benign breast tumours.

The pattern of proteins is different in each of the three groups, the researchers reported
in the journal Cancer Inve stigation. More work needs to be done before a screening test based on these proteins can be made available to the public, Streckfus said.

But US government approval for the test may be sought within five years, he added. Mammography and breast self examination for tumours are leading methods used for early detection of breast cancer. But Streckfus said mammograms – X-rays of the breasts – are too expensive in many developing countries and a cheap, easy-toperform screening test would be valuable.

Streckfus said he envisioned a saliva test as a quick, inexpensive and simple screening method.