June 5, 2009 -- A variation in a gene already associated with breast cancer risk is also linked with especially unpleasant underarm body odor and wet ear wax, according to a team of Japanese scientists.
The discovery is not meant to make women with either condition anxious, says Toshi Ishikawa, PhD, professor of biomolecular engineering at the Tokyo Institute of Technology and the senior author of the study. Rather, he says, "we do strongly hope that our study will provide a new tool for better prediction of breast cancer risk" by using a new method of finding the variation developed by his team.
Having wet ear wax or excessively smelly armpits does not mean a woman is destined to get breast cancer, Ishikawa says. "To be clear, I should strongly mention that the [specific gene variation found to link body odor, wet ear wax, and breast cancer risk] is one factor that increases breast cancer risk," Ishikawa says. "And it might have to work in tandem with something else -- such as environmental factors and mutations of tumor suppressor genes such as BRCA1, BRCA2, p53, and so on."
Ishikawa's team extracted DNA from blood samples provided by 124 volunteers at Nagasaki University in Japan.
They studied a gene called ABCC11, discovered by them and others in 2001. Variations in the gene have been found to be associated with increased breast cancer risk. These variations, called SNPs ("snips") or single nucleotide polymorphisms, occur when a single nucleotide or molecule in an individual's genome sequence changes. SNPs are common in the population.
In this study, Ishikawa monitored the activities of a protein created by the ABCC11 gene, finding a distinct link between the ABCC11 gene and having extremely smelly underarm odor and wet, sticky earwax.
Then they figured out the cellular mechanisms that control wet ear wax, excessively bad underarm odor, and breast cancer risk.
They developed a rapid method of typing this SNP in the DNA sequence associated with the higher risk for the three conditions. It can be done in 30 minutes.
The study is published in The FASEB Journal.
Armpits, Ear Wax, and Breast Cancer
Women shouldn't get anxious about the research, says Christy Russell, MD, associate professor of medicine at the University of Southern California, Los Angeles, who reviewed the study for WebMD. "At this point the research is very early and women should not be concerned about body odor or earwax as a clue that they may have a higher risk of breast cancer."
"Having ear wax and body odor are normal physical processes that all women go through," she says.
To put the research in perspective, she says, the researchers are looking for common gene abnormalities in glands that secrete mucus, sweat, or wax that may be linked with breast cancer risk.
The researchers managed to figure out the exact cellular level mechanisms which lead to all three conditions, says Gerald Weissmann, MD, editor-in-chief of The FASEB Journal and research professor of medicine and director of the Biotechnology Study Center at New York University.
"I think this is a groundbreaking study which combines human genetics, human anthropology, and first-rate molecular and cell biology," he says. The development of the rapid SNP typing method, he says, promises to help predict who might be at higher risk for serious conditions such as cancer by looking at "trivial observations such as smelly armpits and wet ear wax."