New statewide statistics on breast cancer show a drop in reported incidence and mortality rates for non-Hispanic white women in Marin between 2006 and 2010, the county health department announced last week. Although the mortality rate for the group dipped just below the state average in recent years, the incidence rate remains 10 percent higher than the state average and 20 percent higher than the national average. Marin’s high incidence rates have stoked fears in the coastal county, where from 1990 to 2010, non-Hispanic white women suffered higher mortality rates than their Hispanic or Asian/Pacific Islander counterparts, according to the county. (The rate for blacks was not calculated because there were fewer than 15 deaths in that time period, according to the county.) But Peter Byrne, an investigative journalist and critic of breast cancer data, says the incidence rates for breast cancer are essentially meaningless. Because Marin is especially affluent, women seek mammograms more often, he says, leading to false positives. But these are never scrubbed from the collected data, Mr. Byrne says. “They [also] end up identifying a lot of cancers in situ that really shouldn’t be treated [because they would never metastasize],” he told the Light. Furthermore, he said, the focus on white women is misguided, since it is black women statewide who experience higher mortality rates from breast cancer. According to 2009 data collected by the National Cancer Institute, the mortality rate from breast cancer per 100,000 women in California was 16.4 for Hispanics, 23.2 for whites and 33.5 for blacks.