The Problem with Cancer Screening
Cancer testing is a large part of a doctor’s business. We have been told that if we find cancer early, and cut it out, burn it with radiation, or poison it with chemotherapy, we can make a bigger difference.
While there is a lot of debate over this issue, we still continue to try to detect cancer early – or before it even starts. I’m going to focus on the most common cancer screening tools, the ones you’ve all heard about, and that you were told you should do – or else! These include:
- PSA testing
- PAP smears
I started studying cancer screening over ten years ago when I had a patient with an inexplicable case of cancer. Because there were many cases in her family, Cecilia was always afraid of getting cancer and did all she could to prevent it by eating all organic and exercising regularly. She even got all her cancer screening tests, PAP smears, annual mammograms and a colonoscopy at age 50.
One day, she came in to see me with a lump in her left breast. It was large, a couple of centimeters, and not tender. I looked at the mammogram report done only a few months before and it was negative for any signs of malignancy. I reassured her that it was probably a cyst, but we would send her for an ultrasound to be sure. A biopsy was done, it was cancer and, in spite of all the treatments, she died just over a year later.
Since I had known Cecilia for years and knew she was diligent in her health care, I was shaken by her death. I wondered how we could have missed such a large tumor. How could the mammogram have missed it only months before? I asked the radiologist to review it, and he found no evidence of any mass in that exact location at that time. So, I started doing some real research on the test itself, and was shocked by what I found! Not only were mammograms questionable, but most of the cancer screening tests did more harm than good!
A mammogram is an x-ray, and x-rays don’t distinguish the difference between normal tissue and cancer. Instead, the radiologist looks for tiny calcium deposits that indicate there is some inflammation in the tissue. The problem is that calcium deposits happen with any kind of inflammation, and are not specific to cancer. Thus, many women who don’t have cancer are told they do, and the aggressive real cancers are missed; like in Cecilia, because they don’t form calcium deposits.[i] The newer mammograms are better able to distinguish tissues with less radiation, however the problems with screening persist.
The primary problem with mammograms is that they don’t decrease mortality, at all. In the long-term studies, including the Canadian study[ii] and the Oslo study (noted above) after 25 years and 14 years, respectively, the incidence of mortality from breast cancer remained the same – in spite of finding more cancer.
The Canadian Study showed that 22% of the women who were treated for cancer didn’t even have cancer! Or, they would not have died from it if they did.
The eight major long-term studies have been reviewed extensively. The most detailed study of all of them, the 2011 Cochrane Review[iii], said:
“Screening is likely to reduce breast cancer mortality. As the effect was lowest in the adequately randomized trials, a reasonable estimate is a 15% reduction corresponding to an absolute risk reduction of 0.05%. Screening led to 30% over-diagnosis and overtreatment, or an absolute risk increase of 0.5%. It is thus not clear whether screening [mammography] does more good than harm.”
In short: The risk (0.5%) is greater than the benefit (0.05%) by TEN TIMES! In other words, you are ten times more likely to end up with treatment for a cancer you didn’t have, than to prolong your life span by finding and treating a tumor earlier.
What do I do to screen for breast cancer?
Other screening tests for breast cancer have similar problems… and that is finding something that gets treatment, but would not have become life-threatening if left alone. One of my patients wanted MRI screening tests because she was afraid of the radiation (there is about a 1/5000 risk) from a mammogram, and didn’t want her breasts pinched in the machine. A mass was found, and biopsy showed it was an Interductal Carcinoma In-Situ, and she was told she needed surgical removal, radiation, and chemotherapy. She opted-out of treatment, and she is still fine – with her mass that continues to grow – twelve years later. She would have been considered a “cure” if she had been treated.
Whether you use MRI, ultrasound, mammogram, or thermogram, you must consider what you will do once you find a bump! Do you wait? Do you treat aggressively? Unfortunately, we have more questions than answers. Judging by the numbers in the Cochrane study above, I might opt out of screening for this one. Instead, I would do my best to prevent breast cancer from forming in the first place: [am4show guest_error=’noaccess’]
- Breast feed the baby
- Vitamin D3 – 50,000 IU per week
- Iodine – 6.25mg per week
- Selenium – 200mcg per week
- Low-inflammation diet (no sugar) high in nutrients
You enter the GI doctors’ office, having been up all night with diarrhea to clean out your bowels. They give you sedation to ease the pain. You climb into the upside-down chair and hear gloves snap as the doctor inserts a long scope into…
OK. Is this good? It’s not comfortable, but is it worth the pain? Let’s look at the risks and benefits.
The biggest risk of colonoscopy are related to perforation – or puncturing a hole – in the colon. Other risks are bleeding, Dysbiosis (bad bacteria growing back), and inflammation. A hole in the wall of the colon allows stool to get into the abdomen, causing infection, and sometimes death. These happen most often in the elderly, and those who are disabled. It happens between 2 in a thousand and 5 in a hundred, depending on the study and the one who performs the procedure.[iv]
The risk of death from colonoscopy is not small: 1/3,000 to 1/30,000 depending on the study and circumstances.[v] risk of death from colon cancer in the United States is around 1/10,000.[vi] Thus, the risk of complications from colonoscopy is on the same level as the risk of death from the cancer.
It’s very hard to interpret the studies on colonoscopy because they are done for so many different reasons. The statistics seem to indicate that there are as many as 50% fewer advanced cancers diagnosed if you get a screening test; however, the death rate doesn’t change very much.[vii]
So, this test has a different problem than the mammogram, it is risky; you can have significant harm or death – this risk must be weighed against the benefits. The benefits of finding cancers is useful if they can be removed and by so doing prevent problems. But, don’t think it will prevent you from dying of this dreaded disease.
I would weigh the risks and benefits. I would not personally do a screening test unless there was some reason to do so, such as blood in the stool, or a family history, or inflammatory bowel disease. I would work on colon cancer prevention instead:
- Eat vegetables every day
- Avoid corn, soy, and canola oil
- Avoid sugar
- Vitamin D3 – 50,000 IU per week
- Selenium – eat a few brazil nuts every week
Last week, my brother went through his second biopsy of the prostate gland. He didn’t want to do it, but the doctor said he must to determine if there is any cancer in there. You see, he had a PSA test, which was elevated, so he was sent to a urologist for further evaluation. The urologist had nothing else to do, so he did a biopsy, which was negative. Now, this requires follow-up, just because someone thought of it. So, my brother repeats the PSA, and it’s still high so he suffers 12 more needles in his prostate (the Spanish Inquisition should have thought of this!).
Medicare quit paying for the PSA screening test because it causes a lot of procedures for no benefit. What was found in multiple studies was essentially the same problem as the mammogram, but on STEROIDS!
So, we’re finding it, radiating it, surgically removing prostates and giving all sorts of poisons, but the overall rate of death remains the same.[viii]
In this case, we even have several studies to indicate that treatment may do more harm than good, as noted in the NIH Consensus Paper on the subject:
“More than half of cancers detected with PSA screening are localized (confined to the prostate), not aggressive at diagnosis, and unlikely to become life-threatening. However, 90 percent of patients receive immediate treatment for prostate cancer, such as surgery or radiation therapy. In many patients, these treatments have substantial short- and long-term side effects without any clinical benefit. Appropriate management of screen-detected, early-stage, low-risk prostate cancer is an important public health issue given the number of men affected and the risk for adverse outcomes, such as diminished sexual function and loss of urinary control.”[ix]
The PSA test is not a bad test as an indicator of prostate inflammation, generally. The problem is that it has become associated with cancer, so if it is high everyone gets overly concerned about that and miss the real problem. If we could instead look at the PSA as an indicator of prostate inflammation only, it might become a useful test.
Primary prevention of prostate cancer includes:
- Low-inflammation diet
- Zinc supplementation
- Lycopene (the red in tomatoes)
- Avoid corn and soy oils
- Eat fish, or fish oil weekly
The Papanicolau (PAP) Smear has much less controversy than the other screening tests. All of the problems surrounding this test revolve around fine-tuning who should have it, when, and how often. There is also an issue of adding on the HPV test for the virus that causes cervical cancer.
Though there has never been a randomized trial to evaluate this test, it has been shown in multiple populations to decrease the incidence of cervical cancer, as well as lowering the death rate.[xi]
Moreover, there is no risk to doing this test, besides the possibility of having an unnecessary procedure if it is wrong. However, unlike the potentially deadly results of the other tests, colposcopy, biopsy, or even a surgical procedure carries little risk to the patient.
The only group that has greater risk from screening is those women under 24 years of age. This is because the incidence of cervical cancer is so low, and because most who get HPV infection will clear it without developing cancer. Thus, PAP smears are not recommended for women under 24.
The interval of screening could be anywhere from annually, for those who have high risk, to every 5 years for those who are at low risk. Generally, women who have had three normal PAP tests and have a monogamous, or no, relationship I recommend every 5 year screening. Those who have had a previous abnormal test and have a high-risk HPV test should be screened every year or two. If there is a question, I recommend getting the HPV test along with it. This virus is necessary, though not sufficient, to cause cervical cancer. The best way to prevent cervical cancer is to have a monogamous relationship with a single individual for life. Click to Tweet.
In short, I don’t recommend cancer screening tests, except the PAP smear. I think primary prevention is the ideal, meaning preventing the cancer before it starts, and secondary prevention, meaning finding a cancer in an early stage to facilitate treatment, is not beneficial in the large majority of cases.
[iii] Gotzsche PC, Nielsen M. Screening for breast cancer with mammography. Cochrane Database Syst Rev. 2011;1:CD001877
[v] Common Questions about Colonoscopy. American Society for Gastrointestinal Endoscopy. Nov. 2005. 13 Oct. 2006 [http://www.askasge.org/pages/procedures/colonoscopy/questions.cfm].