Top Cancer Killer of Women in Rich Nations Shifts Smoking drives the change By Newser Editors and Wire Services Posted Feb 4, 2015 3:32 PM CST 18 comments Comments In this 2007 file photo, a cigarette burns. According to a report on Wednesday, Feb. 4, 2015, lung cancer has passed breast cancer as the leading cause of cancer deaths for women in rich countries. (Francois Mori) (Newser) – For the first time, lung cancer has passed breast cancer as the leading cause of cancer deaths for women in rich countries. The reason is smoking, which peaked years later for women than it did for men. "We're seeing the deaths now" from lung cancer due to a rise in smoking by women three decades ago, says Lindsey Torre of the American Cancer Society. The society released a report today, based on new numbers from the International Agency for Research on Cancer. Highlights: Globally: There were 14 million new cancer cases and 8 million cancer deaths in 2012, the most recent year available. "Developing countries account for 57% of cancer cases and 65% of cancer deaths," Torre said. Biggest killers: For men, lung cancer has been the leading cause of cancer death globally for decades. In poor countries, breast cancer remains the top cancer killer for women. Colon cancer has grown as a cause of death worldwide. Men vs. women: Prostate and breast are the most commonly diagnosed cancers in men and women, respectively, in rich countries. The outlook: Smoking rates have leveled off or dropped in rich countries. In the US, "we are already seeing lung cancer death rates decline," Torre said. Prevention: Half of all cancers are preventable. Healthy diets and getting enough exercise cut risk. The hepatitis vaccine helps prevent liver cancer; the HPV vaccine lowers the risk of cervical cancer. The biggest factor: Don't smoke. Quitting by middle age can avoid 60% of the risk of dying of lung cancer, Torre said. "It's never too late to quit."