PSA screening: The USPSTF got it right

In his book, How We Do Harm: A Doctor Breaks Ranks About Being Sick in America, Otis Brawley¹ writes, “I believe that a man should know what we know, what we don’t know, and what we believe about prostate cancer. I have been concerned that many patients and physicians have confused what is believed with what is known.” I agree.

Common sense is what we believe. Does common sense trump science? Did the US Preventive Services Task Force (USPSTF) get it wrong? I don’t think so.

The USPSTF bases its recommendations on an explicit assessment of the science that informs us of the benefits and harms of a preventive service, and a judgment about the magnitude of net benefit.

So what do we know about the benefits of prostate cancer screening? When attempting to answer the question of whether an intervention is beneficial, there is a hierarchy of evidence, from most likely to be wrong to most likely to be right. Relying on our personal stories is the former; relying on well-conducted randomized trials is the latter.

We do an enormous disservice to our patients if we pretend that this is just a blood test. Men will get biopsies and there will be complications.In the multicenter Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial² conducted in the United States, there was a nonsignificant increase in prostate-cancer mortality in the screening group, while the European Randomized Study of Screening for Prostate Cancer (ERSPC)³ trial showed a statistically significant absolute reduction of 0.10 prostate-cancer deaths per 1000 person-years after a median follow-up of 11 years. In the ERSPC trial, all-cause mortality was 19.1% in the screened group and 19.3% in the control group, a difference that was not significant. What we know is that after 10 years, even with aggressive treatment of 80% to 90% of screen-detected cancers, very few, if any, men will have lived longer because they were screened.

What don’t we know about the benefits? We don’t know whether following screened and nonscreened men for 15 or 20 years or longer will demonstrate a larger difference in mortality. Competing causes of mortality make it progressively less likely that men who are screened will actually live longer. The average age of death from prostate cancer is 80 years, and 70% of all deaths occur after age 75.⁴ Contrast those statistics to breast cancer, for which the average age of death is 68 years and 63% of all deaths occur before age 75.⁵

What do we believe about the benefits? Some certainly believe the trials must be wrong; common sense tells us that early detection and treatment must provide more benefit than what the evidence has shown. Common sense tells us that the decline in prostate cancer mortality over the past 2 decades must be due to screening, although the ERSPC results clearly show that neither the magnitude nor the timing of the decline can be attributed to screening.

What do we know—and not know—about the harms?

We know that much of the suffering from prostate cancer is a consequence of the diagnosis and management of the disease, rather than the disease itself. Complications of both diagnosis and treatment of prostate cancer are frequent and serious.⁶ We also know that many screen-detected cancers would never become apparent in a man’s lifetime without screening.

We don’t know the precise magnitude of overdiagnosis, although all estimates suggest it is substantial. In the ERSPC trial, 9.6% of the screened group received a prostate cancer diagnosis, vs 6.0% of the control group—a 60% increase in the rate of diagnosis. The recently published long-term results from the Prostate Cancer Prevention Trial⁷ are enlightening. Finasteride reduced the incidence of screen-detected cancers by 30%, with no impact on all-cause mortality at 18 years. If those screen-detected cancers had been a significant threat to health, then after 18 years we would have expected some mortality benefit from finasteride.

What do we believe about the harms of screening?
We believe that by being more conservative about who gets treated, we shift the balance of benefits and harms of screening. There is no question that reducing the burden of overdiagnosis and overtreatment would provide a welcome reduction in the harms. But can we do it?⁸

In the United States 90% of men found to have prostate cancer are treated (including about 75% of men with low-risk cancers).⁶ And although we hope to be able to reduce harms without changing benefits, we do not know what impact more conservative management of screen-detected cancers would have on the already small effect of screening on prostate cancer mortality.

So what is the balance of benefit and harms? Should we make that judgment on what we know, or on what we believe?

Science trumps common sense. For every 1000 men screened, at most, one will avoid a prostate cancer death at 10 years. But 30 to 40 will have erectile dysfunction, urinary incontinence, or both due to treatment, 2 men will experience a serious cardiovascular event, one will have a venous thromboembolic event, and one in 3000 screened will die from complications of surgical treatment.⁶

The USPSTF concluded that the benefits of PSA screening do not outweigh the harms, but acknowledged that shared decision making is still appropriate when a physician feels obliged to offer the test or a patient requests it.

What does shared decision making look like? Just offering screening and answering any questions is not good enough. We do an enormous disservice to our patients if we pretend that this is just a blood test and that we can decide later what to do with the information. Men will get biopsies and there will be complications. Cancer will be detected, and men will be treated, many unnecessarily.

Routine screening for prostate cancer in the absence of a truly formed decision is unacceptable.We need to tell our patients that the likelihood of avoiding a prostate cancer death over 10 years as a result of regular PSA screening is at most very small, and that many more men will suffer the harms of unnecessary treatment than will benefit. A few will die prematurely as a result of the complications of treating a screen-detected cancer.

If, with this knowledge, a patient places a higher value on the possibility of avoiding a prostate cancer death than he does on the known harms of diagnosis and treatment, he can still decide to be screened. He has made an informed decision. However, routine screening for prostate cancer in the absence of a truly informed decision is unacceptable.

In his book, How We Do Harm: A Doctor Breaks Ranks About Being Sick in America, Otis Brawley¹ writes, “I believe that a man should know what we know, what we don’t know, and what we believe about prostate cancer. I have been concerned that many patients and physicians have confused what is believed with what is known.” I agree.

Common sense is what we believe. Does common sense trump science? Did the US Preventive Services Task Force (USPSTF) get it wrong? I don’t think so.

The USPSTF bases its recommendations on an explicit assessment of the science that informs us of the benefits and harms of a preventive service, and a judgment about the magnitude of net benefit.

So what do we know about the benefits of prostate cancer screening? When attempting to answer the question of whether an intervention is beneficial, there is a hierarchy of evidence, from most likely to be wrong to most likely to be right. Relying on our personal stories is the former; relying on well-conducted randomized trials is the latter.

We do an enormous disservice to our patients if we pretend that this is just a blood test. Men will get biopsies and there will be complications.In the multicenter Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial² conducted in the United States, there was a nonsignificant increase in prostate-cancer mortality in the screening group, while the European Randomized Study of Screening for Prostate Cancer (ERSPC)³ trial showed a statistically significant absolute reduction of 0.10 prostate-cancer deaths per 1000 person-years after a median follow-up of 11 years. In the ERSPC trial, all-cause mortality was 19.1% in the screened group and 19.3% in the control group, a difference that was not significant. What we know is that after 10 years, even with aggressive treatment of 80% to 90% of screen-detected cancers, very few, if any, men will have lived longer because they were screened.

What don’t we know about the benefits? We don’t know whether following screened and nonscreened men for 15 or 20 years or longer will demonstrate a larger difference in mortality. Competing causes of mortality make it progressively less likely that men who are screened will actually live longer. The average age of death from prostate cancer is 80 years, and 70% of all deaths occur after age 75.⁴ Contrast those statistics to breast cancer, for which the average age of death is 68 years and 63% of all deaths occur before age 75.⁵

What do we believe about the benefits? Some certainly believe the trials must be wrong; common sense tells us that early detection and treatment must provide more benefit than what the evidence has shown. Common sense tells us that the decline in prostate cancer mortality over the past 2 decades must be due to screening, although the ERSPC results clearly show that neither the magnitude nor the timing of the decline can be attributed to screening.

What do we know—and not know—about the harms?

We know that much of the suffering from prostate cancer is a consequence of the diagnosis and management of the disease, rather than the disease itself. Complications of both diagnosis and treatment of prostate cancer are frequent and serious.⁶ We also know that many screen-detected cancers would never become apparent in a man’s lifetime without screening.

We don’t know the precise magnitude of overdiagnosis, although all estimates suggest it is substantial. In the ERSPC trial, 9.6% of the screened group received a prostate cancer diagnosis, vs 6.0% of the control group—a 60% increase in the rate of diagnosis. The recently published long-term results from the Prostate Cancer Prevention Trial⁷ are enlightening. Finasteride reduced the incidence of screen-detected cancers by 30%, with no impact on all-cause mortality at 18 years. If those screen-detected cancers had been a significant threat to health, then after 18 years we would have expected some mortality benefit from finasteride.

What do we believe about the harms of screening?
We believe that by being more conservative about who gets treated, we shift the balance of benefits and harms of screening. There is no question that reducing the burden of overdiagnosis and overtreatment would provide a welcome reduction in the harms. But can we do it?⁸

In the United States 90% of men found to have prostate cancer are treated (including about 75% of men with low-risk cancers).⁶ And although we hope to be able to reduce harms without changing benefits, we do not know what impact more conservative management of screen-detected cancers would have on the already small effect of screening on prostate cancer mortality.

So what is the balance of benefit and harms? Should we make that judgment on what we know, or on what we believe?

Science trumps common sense. For every 1000 men screened, at most, one will avoid a prostate cancer death at 10 years. But 30 to 40 will have erectile dysfunction, urinary incontinence, or both due to treatment, 2 men will experience a serious cardiovascular event, one will have a venous thromboembolic event, and one in 3000 screened will die from complications of surgical treatment.⁶

The USPSTF concluded that the benefits of PSA screening do not outweigh the harms, but acknowledged that shared decision making is still appropriate when a physician feels obliged to offer the test or a patient requests it.

What does shared decision making look like? Just offering screening and answering any questions is not good enough. We do an enormous disservice to our patients if we pretend that this is just a blood test and that we can decide later what to do with the information. Men will get biopsies and there will be complications. Cancer will be detected, and men will be treated, many unnecessarily.

Routine screening for prostate cancer in the absence of a truly formed decision is unacceptable.We need to tell our patients that the likelihood of avoiding a prostate cancer death over 10 years as a result of regular PSA screening is at most very small, and that many more men will suffer the harms of unnecessary treatment than will benefit. A few will die prematurely as a result of the complications of treating a screen-detected cancer.

If, with this knowledge, a patient places a higher value on the possibility of avoiding a prostate cancer death than he does on the known harms of diagnosis and treatment, he can still decide to be screened. He has made an informed decision. However, routine screening for prostate cancer in the absence of a truly informed decision is unacceptable.

In his book, How We Do Harm: A Doctor Breaks Ranks About Being Sick in America, Otis Brawley¹ writes, “I believe that a man should know what we know, what we don’t know, and what we believe about prostate cancer. I have been concerned that many patients and physicians have confused what is believed with what is known.” I agree.

Common sense is what we believe. Does common sense trump science? Did the US Preventive Services Task Force (USPSTF) get it wrong? I don’t think so.

The USPSTF bases its recommendations on an explicit assessment of the science that informs us of the benefits and harms of a preventive service, and a judgment about the magnitude of net benefit.

So what do we know about the benefits of prostate cancer screening? When attempting to answer the question of whether an intervention is beneficial, there is a hierarchy of evidence, from most likely to be wrong to most likely to be right. Relying on our personal stories is the former; relying on well-conducted randomized trials is the latter.

We do an enormous disservice to our patients if we pretend that this is just a blood test. Men will get biopsies and there will be complications.In the multicenter Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial² conducted in the United States, there was a nonsignificant increase in prostate-cancer mortality in the screening group, while the European Randomized Study of Screening for Prostate Cancer (ERSPC)³ trial showed a statistically significant absolute reduction of 0.10 prostate-cancer deaths per 1000 person-years after a median follow-up of 11 years. In the ERSPC trial, all-cause mortality was 19.1% in the screened group and 19.3% in the control group, a difference that was not significant. What we know is that after 10 years, even with aggressive treatment of 80% to 90% of screen-detected cancers, very few, if any, men will have lived longer because they were screened.

What don’t we know about the benefits? We don’t know whether following screened and nonscreened men for 15 or 20 years or longer will demonstrate a larger difference in mortality. Competing causes of mortality make it progressively less likely that men who are screened will actually live longer. The average age of death from prostate cancer is 80 years, and 70% of all deaths occur after age 75.⁴ Contrast those statistics to breast cancer, for which the average age of death is 68 years and 63% of all deaths occur before age 75.⁵

What do we believe about the benefits? Some certainly believe the trials must be wrong; common sense tells us that early detection and treatment must provide more benefit than what the evidence has shown. Common sense tells us that the decline in prostate cancer mortality over the past 2 decades must be due to screening, although the ERSPC results clearly show that neither the magnitude nor the timing of the decline can be attributed to screening.

What do we know—and not know—about the harms?

We know that much of the suffering from prostate cancer is a consequence of the diagnosis and management of the disease, rather than the disease itself. Complications of both diagnosis and treatment of prostate cancer are frequent and serious.⁶ We also know that many screen-detected cancers would never become apparent in a man’s lifetime without screening.

We don’t know the precise magnitude of overdiagnosis, although all estimates suggest it is substantial. In the ERSPC trial, 9.6% of the screened group received a prostate cancer diagnosis, vs 6.0% of the control group—a 60% increase in the rate of diagnosis. The recently published long-term results from the Prostate Cancer Prevention Trial⁷ are enlightening. Finasteride reduced the incidence of screen-detected cancers by 30%, with no impact on all-cause mortality at 18 years. If those screen-detected cancers had been a significant threat to health, then after 18 years we would have expected some mortality benefit from finasteride.

What do we believe about the harms of screening?
We believe that by being more conservative about who gets treated, we shift the balance of benefits and harms of screening. There is no question that reducing the burden of overdiagnosis and overtreatment would provide a welcome reduction in the harms. But can we do it?⁸

In the United States 90% of men found to have prostate cancer are treated (including about 75% of men with low-risk cancers).⁶ And although we hope to be able to reduce harms without changing benefits, we do not know what impact more conservative management of screen-detected cancers would have on the already small effect of screening on prostate cancer mortality.

So what is the balance of benefit and harms? Should we make that judgment on what we know, or on what we believe?

Science trumps common sense. For every 1000 men screened, at most, one will avoid a prostate cancer death at 10 years. But 30 to 40 will have erectile dysfunction, urinary incontinence, or both due to treatment, 2 men will experience a serious cardiovascular event, one will have a venous thromboembolic event, and one in 3000 screened will die from complications of surgical treatment.⁶

The USPSTF concluded that the benefits of PSA screening do not outweigh the harms, but acknowledged that shared decision making is still appropriate when a physician feels obliged to offer the test or a patient requests it.

What does shared decision making look like? Just offering screening and answering any questions is not good enough. We do an enormous disservice to our patients if we pretend that this is just a blood test and that we can decide later what to do with the information. Men will get biopsies and there will be complications. Cancer will be detected, and men will be treated, many unnecessarily.

Routine screening for prostate cancer in the absence of a truly formed decision is unacceptable.We need to tell our patients that the likelihood of avoiding a prostate cancer death over 10 years as a result of regular PSA screening is at most very small, and that many more men will suffer the harms of unnecessary treatment than will benefit. A few will die prematurely as a result of the complications of treating a screen-detected cancer.

If, with this knowledge, a patient places a higher value on the possibility of avoiding a prostate cancer death than he does on the known harms of diagnosis and treatment, he can still decide to be screened. He has made an informed decision. However, routine screening for prostate cancer in the absence of a truly informed decision is unacceptable.