Editor's note: CNN conditions expert Dr. Otis Brawley is the chief medical officer of the American Cancer Society, a world-renowned cancer expert and a practicing oncologist. He is also the author of the book "How We Do Harm: A Doctor Breaks Ranks About Being Sick in America."
(CNN) -- Prostate cancer is a significant disease in the U.S. In 2014 alone, the American Cancer Society estimates, 233,000 men will be diagnosed and 29,480 will die of it.
This week, two important studies showing how prostate cancer is treated in the U.S. were published in the journal JAMA Internal Medicine.
The findings should cause those of us who treat prostate cancer and the organizations that advocate for prostate cancer awareness to take notice. These studies found that a large number of American men with prostate cancer get unnecessary and aggressive treatment. In some cases, these treatments are known to be worthless and even harmful.
One study more than 20 years long and involving more than 60,000 men diagnosed with cancer confined to the prostate found that initial treatment with anti-androgen hormonal therapies is common. This study also confirmed previous research showing that this treatment in this population does not prolong survival.
This is a therapy that is appropriate for a small, well-defined group of men with prostate cancer. It is an unnecessary and harmful treatment for the majority of Americans prescribed it. The hormones used cause hot flashes, muscle weakness, osteoporosis and impotence in all who get it. These drugs also raise a man's risk of diabetes, cardiovascular disease and death from cardiovascular disease.
A second study showed that there is significant variation in how physicians treat good-prognosis (low-grade, less aggressive) cancer confined to the prostate. A substantial number get unnecessarily aggressive surgical or radiation therapies. These unnecessary therapies are also associated with significant harms. They can cause urinary and bowel incontinence, sexual impotence and, in some cases, death.
A number of studies in the U.S. and Europe have shown that there is a type of prostate cancer that is localized to the prostate and of good prognosis, meaning it rarely progresses or causes harm if left alone.
All of the organizations that set treatment guidelines based on the scientific evidence recommend that men diagnosed with this type of cancer be carefully observed. These cancers can almost always be effectively treated if found to be progressing. With careful observation, the majority of men will never need treatment and can be spared the burdens of unnecessary therapy.
These low-risk forms of prostate cancer are commonly diagnosed through screening and commonly overtreated in the U.S. Indeed, the massive problem of overtreatment and the resultant large number of harms to the population is part of the reason that a number of respected organizations such as the U.S. Preventive Services Task Force and the American Academy of Family Physicians now recommend against routine prostate cancer screening.
I must note that while the data show that a large number of men receiving these treatments should not be getting them, these therapies are appropriate for a select group of men. It is the physician's responsibility to tailor treatment to the patient and his cancer. These two studies form a long list of patterns of care studies showing that a number of American physicians who treat prostate cancer are not fulfilling this responsibility.
Some will say that physicians are overtreating prostate cancer for profit. Although it is true that most American physicians get paid to treat patients and not to observe them, profit may not be a major motive.
In the case of hormonal prostate cancer therapies, a 2010 study actually demonstrated that their use consistently increased throughout the 1990s. Usage went down dramatically in 2003, when Medicare took much of the profit out of administering the treatment by reducing physician reimbursement for the drugs.
One of the studies published this week shows that there is still tremendous overuse of hormones years after the profit motive was removed.
Some will blame the epidemic of overtreatment on patient demand for aggressive cancer treatment. Patient preference does have a role in overtreatment, but the cooperation of the physician is still necessary to provide the unnecessary treatment.
It is the physician's responsibility to counsel the patient and even teach the patient what approaches are most appropriate. There is evidence that some physicians are able to convince patients to accept less aggressive evidence-based practices.
In one of the studies, author Karen Hoffman and her colleagues noted that younger American physicians were more likely to use observation according to accepted standards, and older doctors were more likely to be associated with more aggressive therapies. I also note that these patterns of overtreatment do not exist in Western Europe.
I believe the major reason for the epidemic of unnecessary therapy in America is that many Americans simply cannot accept that there are cancers that do not need treatment. They have trouble accepting it because of all the messages heard over the years about the evils of cancer and all the devastation that we have seen from the disease. Our emotional prejudice against the disease impairs our ability to approach cancer rationally and understand the diversity within the disease.
In some instances, unnecessary treatment of prostate cancer is curing some men who do not need to be cured, with significant detriment to their quality of life. The large number of "cured" makes aggressive treatment look good when one does not realize that many of the cured did not need to be cured.
For the doctor seeing individual patients and not examining data from large clinical studies, it is difficult to see and accept that our aggressive therapies could be more harmful than more conservative approaches like observation. This, even when the harms of some of these therapies are better proven than the benefits and some have even been proven ineffective. A few of the doctors guilty of overtreatment may not understand the number and quality of the studies showing that there are "good cancers." But most simply cannot accept the truth.
If we physicians claim to practice evidenced-based medicine, we must understand and respect the science and accept its findings. The science is very clear that there is some diagnosed prostate cancer that we can accurately predict as not needing treatment. These tumors are unlikely to progress, cause harm and kill.
The phenomenon of cancers that can be diagnosed but will never progress and cause harm is the end result of dramatic improvements in our diagnostic and imaging technologies.
The technical term for this phenomenon is "overdiagnosis." It has been estimated that overdiagnosis occurs in half of all patients with prostate cancer, perhaps 30% to 40% of those with thyroid cancer, 10% to 30% of breast cancer patients and even some with screen detected lung cancer.
One of the challenges of modern medicine is to develop better abilities to distinguish the cancers that need treatment from those that do not. Ironically, these abilities are relatively well-developed for certain prostate cancers and simply not used in the U.S.
In the paper describing their findings, Hoffman and associates note that some doctors' treatment patterns are more appropriate than others. They suggest that public reporting of physicians' cancer management profiles might enable primary-care physicians and patients to make more informed decisions about selecting physicians to manage prostate cancer.
Such a system is unlikely to be created in the near future and would be cumbersome at best. Aggressive treatment is appropriate in certain cancers, and treatment really does need to be tailored to the individual patient.
I believe the patient needs to be empowered and have good open conversations about their cancer treatment with all their doctors, including their primary-care physician. This conversation should explore all options and discuss the published cancer treatment evidence-based guidelines and how they should apply. A second opinion from other physicians is always appropriate.