It sounds counterintuitive: Researchers found rates of the most common type of thyroid cancer had tripled since the 1970s, but they weren't particularly alarmed. That's because they say the problem is rooted in the way we diagnose the disease rather than the cancer itself. In essence, technology is allowing us to find tiny tumors that may never even go on to cause symptoms, let alone death. The study ... found that despite the threefold increase from 1975 to 2009 in this particular form of thyroid cancer, mortality rates have remained unchanged. Add papillary thyroid cancer to the list of cancers that more and more researchers believe may [be] overdiagnosed because of overzealous screenings and advanced technologies. Other studies have suggested this problem may include such conditions as slow-growing prostate cancer and precancerous ductal carcinoma in situ, or DCIS, of the breast. The concern among the researchers is that treatment of these diseases may cause more patient harm than the disease itself. In the last few years, the tide has turned. People are recognizing overdiagnosis more and more," said Dr. Louise Davies, the thyroid cancer study's author. The disease in the thyroid ... is often detected incidentally, meaning that it's discovered during a scan for something else or picked up during a routine exam. "The cancers that are picked up incidentally are not causing symptoms and are small. Those are the ones that are probably not going to be a problem," said Davies. "The risk of death from thyroid cancer is very, very small ... but it's not zero."