NYTimes.com – Scientists believed for years that some cancer type can vanished without a cure, by itself like kidney cancer and melanomas in rare conditions and under certain circumstances.
Now, researchers say they have found a situation in Norway that has let them ask that question about breast cancer. And their new study, to be published Tuesday in the Archives of Internal Medicine, suggests that even invasive cancers may sometimes go away without treatment and in larger numbers than anyone ever believed.
At the moment, the finding has no practical applications because no one knows whether a detected cancer will disappear or continue to spread or kill.
“Their simplification of a complicated issue is both overreaching and alarming,” said Robert A. Smith, director of breast cancer screening at the American Cancer Society.
But others, including Robert M. Kaplan, the chairman of the department of health services at the School of Public Health at the University of California, Los Angeles, are persuaded by the analysis. The implications are potentially enormous, Dr. Kaplan said.
The study was conducted by Dr. H. Gilbert Welch, a researcher at the VA Outcomes Group in White River Junction, Vt., and Dartmouth Medical School; Dr. Per-Henrik Zahl of the Norwegian Institute of Public Health; and Dr. Jan Maehlen of Ulleval University Hospital in Oslo. It compared two groups of women ages 50 to 64 in two consecutive six-year periods.
