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Treating a cancer that was never going to cause trouble. It is the harm that overdiagnosis causes: the diagnosis itself does not leak urine or end erections, the operation does. Published estimates of how much prostate cancer is overdiagnosed range from under 2 percent to two thirds, and the range is a fact about the methods, not about the disease.
Overdiagnosis is finding a cancer that would never have caused symptoms or death; overtreatment is what turns that into an injury. The distinction matters because only one of the two can be fixed once the test has been done. An overdiagnosed cancer managed by active surveillance costs anxiety and appointments; the same cancer taken to radical prostatectomy or radical radiotherapy costs the continence and sexual function of a man who was never at risk from it.
The range, and why it is a range. Loeb and Etzioni reviewed the primary data across epidemiological, clinical and autopsy studies and found overdiagnosis estimates from 1.7 percent to 67 percent. Four incompatible methods sit behind that spread: lead-time modelling, which gave 23 to 42 percent of screen-detected cancers in the United States calibration and 66 percent in the Rotterdam one (Draisma); excess incidence against a pre-screening baseline, which is how Welch and Albertsen counted an additional 1,305,600 United States diagnoses and 1,004,800 definitive treatments between 1986 and 2005, and concluded that more than 20 men were diagnosed for each man who experienced the presumed benefit; counting low-grade minimal tumours in prostatectomy specimens, which gives 1.7 to 46.8 percent; and autopsy series, which find prostate cancer in 18.5 to 38.5 percent of men who died of something else. Each method answers a different question, each depends on the background incidence of the population it was measured in, and none of them is wrong. A single overdiagnosis percentage quoted without its method and its population is not a meaningful figure.
The harm side is better measured than the numerator. The 2018 United States task force statement puts it in units a man can weigh: screening men aged 55 to 69 may prevent about 1.3 prostate cancer deaths and about 3 cases of metastatic disease per 1,000 men screened over about 13 years, while about 1 in 5 men who have radical prostatectomy develop long-term urinary incontinence and 2 in 3 experience long-term erectile dysfunction. Those harms fall only on the men who are treated, which is why the size of the overtreatment problem depends on how many screen-detected cancers are managed conservatively, and why the rise of active surveillance, magnetic resonance imaging triage before biopsy and risk-banded guidelines (NICE NG131 offers active surveillance first in Cambridge Prognostic Group 1) changes the answer without changing the test.
Showing the technology this term belongs to: Active surveillance.
The clearest evidence that radical treatment of localised prostate cancer saves lives when the cancer was found clinically rather than by a blood test, and the clearest single statement of what grade does: a Gleason score above 7 carried ten times the risk of death of a score of 6 or lower in the same trial.
The current shape of the screening question in the United States, and the best short statement of the trade-off in numbers a man can weigh. The three-to-one ratio between metastatic cases prevented and deaths prevented is also the argument for using metastatic presentation, not mortality, to judge a screening programme sooner.
The trial that made observation a defensible choice for low-risk prostate cancer found by a blood test, and that supplied the number a man needs when weighing surgery: the progression it prevents is mostly progression on a scan or a blood test, and the harms it causes are felt every day.
The honest state of the overdiagnosis question. Prostate cancer is common in the prostates of men who die of something else, screening finds a proportion of it, and how much of that is harm depends on what is done next. The fix is not a better estimate but fewer treatments for the cancers that do not need them.
The clearest case in cancer screening of a national body acting on the harms rather than the headline. Whether it was right is still argued: testing and localised-stage diagnosis fell, and the long-term effect on metastatic presentation and mortality is the subject of the studies that followed.
The reference for anyone quoting an overdiagnosis figure in prostate cancer. The honest statement is a range with its definition and its population attached, and the paper is the reason this page does not print one number.
The number that anchors the overdiagnosis argument in prostate cancer: over a million American men treated for a cancer that, for most of them, was never going to surface. It is the reason active surveillance exists as a formal pathway and the reason magnetic resonance imaging was brought in front of the biopsy.
Shares Lead time, and lead-time bias, Number needed to screen (and number needed to diagnose), PSA and MRI-first prostate cancer screening, Overdiagnosis and the tags gu, prostate-glossary.
Shares PSA and MRI-first prostate cancer screening, Gleason score / Grade Group, Localised prostate cancer, intermediate risk, Localised prostate cancer, very low and low risk and the tags gu, prostate-glossary.
Shares PSA and MRI-first prostate cancer screening, Overdiagnosis, Gleason score / Grade Group, Localised prostate cancer, intermediate risk and the tags gu, prostate-glossary.
Shares Gleason score / Grade Group, Localised prostate cancer, intermediate risk, Localised prostate cancer, very low and low risk, Prostate cancer and the tags gu, prostate-glossary.
Shares USPSTF 2018: screening for prostate cancer, recommendation statement (grade C at 55 to 69, grade D at 70 and over), Judge a prostate screening programme on metastatic presentation, not on incidence or mortality, The hardest cancers are found late, Prostate cancer and the tags gu, prostate-glossary.
Shares Quality of life, Toxicity and quality of life are undervalued, Prostate cancer and the tags gu, prostate-glossary.
Shares Quality of life, Toxicity and quality of life are undervalued, Prostate cancer and the tags gu, prostate-glossary.
Shares Gleason score / Grade Group, Prostate cancer and the tags gu, prostate-glossary.