One in three women with breast cancer detected by a mammogram is treated unnecessarily, because screening tests found tumors that are so slow-growing that they’re essentially harmless, according to a Danish study published in the Annals of Internal Medicine, which has renewed debate over the value of early detection. The study raises the uncomfortable possibility that some women who believe their lives were saved by mammograms were actually harmed by cancer screenings that led to surgery, radiation and even chemotherapy that they didn’t need, said Dr. Otis Brawley, chief medical officer of the American Cancer Society, who wrote an accompanying editorial but was not involved in the study.

China’s C-section rate lower than thought

China, which has long been criticized for soaring C-section rates, actually has rates lower than previously reported, although they are still quite high, according to a large new study done jointly by Chinese and American scientists. Public health alarms were raised in 2010 when the World Health Organization reported that 46 percent of Chinese babies were delivered by Caesarean rather than vaginal birth. The new study in JAMA found the real rate to be about 35 percent. C-sections are medically necessary to save the life of the child or the mother in only 10 to 15 percent of all births, according to the WHO.

Hearing loss linked to type of anemia

Iron deficiency anemia may be linked to hearing loss, new research has found. Researchers studied 305,339 men and women ages 21 to 90, of whom 4,807 had hearing loss and 2,274 had iron deficiency anemia. Hearing loss was more prevalent among women in the sample, and after adjusting for sex, the researchers found the risk for hearing loss was nearly 2½ times as high in those with anemia. The risk for sensorineural hearing loss, the type linked to problems in the nerves of the inner ear, was 82 percent higher in those deficient in iron. The study is in JAMA Otolaryngology — Head & Neck Surgery. Although the reason for the association remains unknown, animal studies suggest that iron deficiency may reduce blood flow to the inner ear, affecting the cochlear ganglion, the group of nerve cells that transmit sound to the brain.

News services