Deficient DNA repair capacity linked to breast cancer risk

Deficient DNA repair capacity may increase the risk of breast cancer by as much as threefold, according to a report in the Journal of the National Cancer Institute for January 19th.

‘A lot of studies have looked at the link between DNA repair capacity and lung cancer risk, but few studies have evaluated the association with breast cancer risk,’ senior author Dr. Regina M. Santella, from Columbia University in New York, told Reuters Health.Dr. Santella’s group used various laboratory techniques to compare the DNA repair capacity of lymphoblastoid cell lines obtained from sisters discordant for breast cancer. Data from 158 case patients and 154 controls were included in the analysis.The average percent DNA repair capacity was significantly lower in case patients than in controls, the investigators found.Moreover, as DNA repair capacity diminished, the risk of breast cancer rose. Compared with women in the highest quartile of repair capacity, those in the lowest, next lowest, and next highest quartiles were 2.99-, 2.38-, and 1.23-times more likely, respectively, to have breast cancer.Dr. Santella said these findings could have implications for breast cancer screening. ‘The ultimate goal is to understand an individual’s risk for cancer development so that you can better target screening and prevention efforts.’She noted that the assay used in the present study looked at just one of many DNA repair pathways. ‘At this point, we’re interested in conducting a study using an assay that measures a different DNA repair pathway. Looking at the status of several different pathways may give a better estimate of breast cancer risk.’In a related editorial, Dr. Marianne Berwick, from the University of New Mexico in Albuquerque, and Dr. Paolo Vineis, from Imperial College in London, comment that there is a need for ‘high throughput functional assays’ to assess DNA repair capacity. The ability to measure DNA repair capacity easily and quickly may ultimately lead to the development of ‘interventions to reduce cancer incidence and mortality.'(Source: J Natl Cancer Inst 2005;97:84-85,127-132: Reuters Health: Anthony J. Brown, MD: Oncolink: January 2005.)