“Overdiagnosis is the detection of pseudodisease—screening-detected abnormalities that meet the pathologic definition of cancer but will never progress to cause symptoms,” researchers wrote. “The consequence of overdiagnosis is overtreatment—surgery, chemotherapy, or radiation—that provides the patient no benefits, but only adverse effects.”
In an accompanying editorial, Dr. H. Gilbert Welch, professor of medicine at Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, N.H., wrote that patients understand the benefits and harms associated with treatments, but not necessarily with screening.
“Our patients have been taught to think differently about screening,” Welch wrote. “There are no harms. It's always good to know. It is just about gathering information. Of course you want it. It is a brain-dead decision.”
He added that the truth “is more nuanced,” and more study needs to be done as there is “plenty of uncertainty” about the magnitude of the harms and benefits cancer screening.
Of those surveyed, 36% reported undergoing two screenings, 27.1% reported having three or more, 19.9% reported one and 17% indicated they didn't have any. Eighty percent said they would like to be told of potential harms before screening, according to the report. Mammography was the most common screening reported by women. Colonoscopy and prostate-specific antigen, or PSA, were the most reported by men.
“Most individuals desired information about screening harms, which was not given, and attested that this knowledge would matter to them,” researchers concluded. “Our results should prompt medical educators to improve the quality of teaching about screening and encourage medical journal editors to enforce clear reporting about overtreatment when publishing results on the effectiveness of cancer screening.”
Follow Andis Robeznieks on Twitter: @MHARobeznieks