OVERDIAGNOSIS Making People Sick in the Pursuit of Health · OVERDIAGNOSIS: Making People Sick in...
6
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health H. Gilbert Welch MD, MPH A Fundamental Medical Paradigm: The best way to keep people healthy is to find and treat disease early. Underlying assumption: Without intervention, early forms of cancer invariably progress to advanced cancer. Inconsistent observations: Whenever we look for early cancer, we find a lot more people have cancer than we would ever expect to go on to develop advanced cancer. (i.e. not all early cancers progress to become advanced cancer) Implications: 1. Early diagnosis leads us to label too many people as having cancer. Those not destined to develop symptoms or death from their cancer are overdiagnosed. 2. Because we don't know who is overdiagnosed and who is not, we treat everybody. Thus some are treated who can't benefit from treatment (because their "cancer" would never bother them) and can only be harmed. Disclaimers 1. Not saying that advanced cancer is not a bad disease – it is. 2. Not saying you should never be screened for cancer. Instead trying to be clear there are two-sides to the issue. While some may be helped, others are hurt. DNA damage Failure to repair Atypical cell Carcinoma in situ Invasive cancer Cancer death Deterministic model DNA damage Failure to repair Atypical cell Carcinoma in situ Invasive cancer Cancer death Stochastic model STOP STOP STOP STOP STOP
Transcript of OVERDIAGNOSIS Making People Sick in the Pursuit of Health · OVERDIAGNOSIS: Making People Sick in...
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health H. Gilbert Welch MD, MPH
A Fundamental Medical Paradigm:
The best way to keep people healthy is to find and treat disease early.
Underlying assumption: Without intervention, early forms of cancer invariably progress to advanced cancer.
Inconsistent observations: Whenever we look for early cancer, we find a lot more people have cancer than we would ever expect to go on to develop advanced cancer. (i.e. not all early cancers progress to become advanced cancer)
Implications: 1. Early diagnosis leads us to label too many people as having cancer. Those not destined to develop symptoms or death from their cancer are overdiagnosed. 2. Because we don't know who is overdiagnosed and who is not, we treat everybody. Thus some are treated who can't benefit from treatment (because their "cancer" would never bother them) and can only be harmed.
Disclaimers 1. Not saying that advanced cancer is not a bad disease – it is. 2. Not saying you should never be screened for cancer. Instead trying to be clear there are two-sides to the issue. While some may be helped, others are hurt.
DNAdamage
Failureto repair
Atypicalcell
Carcinomain situ
Invasivecancer
Cancerdeath
Deterministic model
DNAdamage
Failureto repair
Atypicalcell
Carcinomain situ
Invasivecancer
Cancerdeath
Stochastic modelSTOP
STOP
STOP
STOP
STOP
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health - 2
There is a vast reservoir of cancer...
Figure 1 - PROSTATE CANCER RESERVOIR IN MEN DYING FROM AN ACCIDENTAL DEATH
...so as we look harder we always find more
Figure 2 - HOW INCREASING THE NUMBER OF BIOPSIES (LOOKING HARDER) FINDS MORE PROSTATE CANCER
0%
10%
20%
30%
40%
50%
60%
70%
80%
20-29 30-39 40-49 50-59 60-69 70-79
Age Group
Proportion foundto have
prostate cancer
0% 10% 20% 30% 40%
6 biopsies
11 biopsies
Look Hard
Look Harder
6 biopsies
12 biopsies
6 biopsies
13 biopsies
18 normal biopsies
32-38 biopsies
% of men found to have prostate cancer
0%
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health - 3
Look Harder, Find More
How many lakes in the State of Utah?
Continental US View = 1
Utah View = 3
High Uinta View = 39+
(in one section)
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health - 4
National Data: Prostate Cancer
Better safe than sorry?
Risks of surgery: loss of sexual function, difficulty urinating or being able to control urine
Risks of radiation: painful defecation due to radiation proctitis
0
25
50
75
100
125
150
175
200
225
1975 1980 1985 1990 1995 2000 2005
New prostatecancer diagnoses(per 100,000 men)
TURP era PSA era
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health - 5
National Data: Thyroid Cancer, Melanoma & Breast Cancer
Thyroid Cancer more neck exams more ultrasounds
Better safe than sorry?
Risks of surgery - hoarseness, trouble swallowing, calcium imbalance Must take life-long replacement medication.
Melanoma more skin exams more biopsies
Better safe than sorry? Risks of surgery - generally minor, occasionally requires flaps & grafts Anxiety associated with life-long surveillance
Breast Cancer more mammography
Better safe than sorry? Disfiguring surgery often combined with ≈30 radiation treatment and/or chemotherapy (with attendant nausea, fatigue, and hair loss)
...and all these diagnoses can affect the ability to obtain health insurance
0
25
50
75
100
125
150
175
1975 1980 1985 1990 1995 2000 2005
New diagnoses
Deaths
New breast
cancer diagnoses
and deaths(per 100,000 women)
0
5
10
15
20
1975 1980 1985 1990 1995 2000 2005
New diagnoses
Deaths
New melanoma
diagnoses
and deaths(per 100,000 people)
0
2
4
6
8
10
1975 1980 1985 1990 1995 2000 2005
New diagnoses
Deaths
New thyroid
cancer diagnoses
and deaths(per 100,000 people)
OVERDIAGNOSIS: Making People Sick in the Pursuit of Health - 6
Appendix Cancer screening is only one aspect of the
"early detection" dogma There are other ways we turn people into patients
We are also screening more for conditions other than cancer (coronary artery disease, carotid stenosis, abdominal aortic aneurysm, peripheral vascular disease, etc.) and whenever we look harder, we find more. We have "changed the rules" to expand the number of Americans said to have various conditions. Like what constitutes a normal cholesterol...
...and have done the same for diabetes, high blood pressure and osteoporosis.
Finally, there's the whole issue of genetic testing for chronic diseases. We all harbor genetic variants that will show us to be at "increased risk" for some disease or other. If we continue to blindly follow this dogma, we all could be turned into patients. But is this really the road to better health?
0%
10%
20%
30%
40%
40 80 120 160 200 240 280 320 360 400
Cholesterol level (mg/dl)
Proportion of
US adultpopulation
New patients
Old patients
