I just finished my January 2016 Top Holistic Health Reads. I also made some exciting announcements regarding my upcoming book release, a free three-part webinar series, and a bonus blog, “The Impact of Epigenetics on Health and Behavior.” You can gain access to all of this here.
There was a huge and impactful article released in January that deserves an honorable mention here. The study, published in the British Medical Journal entitled, “Why cancer screening has never been shown to “save lives”–and what we can do about it,”caused an uproar of debate among all health communities. Science Daily reported:
Cancer screening has never been shown to “save lives” as advocates claim, argue experts in The BMJ. This assertion rests on reductions in disease specific mortality rather than overall mortality, say Vinay Prasad, Assistant Professor at Oregon Health and Science University and colleagues. They argue that overall mortality should be the benchmark against which screening is judged and call for higher standards of evidence for cancer screening.
There are two chief reasons why cancer screening might reduce disease specific mortality without significantly reducing overall mortality, write the authors.
Firstly, studies may be underpowered to detect a small overall mortality benefit. Secondly, disease specific mortality reductions may be offset by deaths due to the downstream effects of screening.
Such “off-target deaths” are particularly likely among screening tests associated with false positive results (abnormal results that turn out to be normal) and overdiagnosis of harmless cancers that may never have caused symptoms, they explain.
Many experts argue that these false positive rates cause unnecessary psychological harms; whereas, others say that even one life saved is worth the rates of overdiagnosis.
According to the authors of the BMJ article:
Consideration of harms becomes more important in the absence of clear overall mortality benefit. Empirical analyses show that primary screening studies pay little attention to the harms of screening–of 57 studies only 7% quantified overdiagnosis and just 4% reported the rate of false positive results.35 When researchers do examine the harms of screening the results are typically sobering.
False positive results on breast cancer screening have been associated with psychosocial distress as great as a breast cancer diagnosis 6 months after the event.36 False positive results affect over 60% of women undergoing screening mammography for a decade or more,37 and 12-13% of all men who have undergone three or four screening rounds with PSA.38 In the NLST 39.1% of people had at least one positive test result, of which 96.4% were false positives.
Overdiagnosis affected 18% of people diagnosed with lung cancer on low dose CT in the NLST,39 and researchers have found that as many as one in three diagnoses of invasive breast cancer (or one in two for invasive cancer and carcinoma in situ) by mammography constitute overdiagnosis.40 These numbers are broadly equivalent to those found with most major screening tests.41
Recently, in the Natural Path, I discussed the latest updates of mammography recommendations from JAMA and the conflicting evidence of the benefits of screening. For example, in 2010, the New England Journal of Medicine analyzed data from 40,075 women and concluded, “The availability of screening mammography was associated with a reduction in the rate of death from breast cancer, but the screening itself accounted for only about a third of the total reduction.” Furthermore, the British Medical Journal (2014) stated, “Annual mammography in women aged 40-59 does not reduce mortality from breast cancer beyond that of physical examination or usual care when adjuvant therapy for breast cancer is freely available. Overall, 22% (106/484) of screen detected invasive breast cancers were over-diagnosed, representing one over-diagnosed breast cancer for every 424 women who received mammography screening in the trial.”
Interesting, two new studies also came out in January with conflicting information. One, in the Annals of Internal Medicine supported biennial screening and concluded, “Biennial screening for breast cancer is efficient for average-risk populations. Decisions about starting ages and intervals will depend on population characteristics and the decision makers’ weight given to the harms and benefits of screening.”
In the second study, according to Health Day, the authors found evidence that supported annual screening in the elderly. This study, “analyzed Medicare data from 1995 to 2009 on more than 4,800 black women and more than 59,000 white women, all of whom were aged 69 or older. Among women aged 75 to 84, those who had annual mammograms were less likely to die from breast cancer over a 10-year period than those who had irregular or no mammograms.”The issue with this study could be confounded by this select population.
To Screen or Not to Screen?
That is a good question! What makes a definitive conclusion on screening is most of the studies have limitations and are based on assumptions of populations. This makes decisions elusive. Most studies also do not take into account biochemical individuality and lifestyle.
I think we need to remember that screening is NOT prevention. Unless we change how we treat our bodies with lifestyle, stress modulation, diet, healthy relationships, and proper rest, we will continue to turn on unfavorable epigenetic switches, including metabolic links to cancer. (This is why I love epigenetics.)
We need to remember that a healthy lifestyle is the best prevention. Screening options and discussing the benefits of harms verses benefits should be made by you and your physician. For example, a woman a family history of cancer and who has poor lifestyle choices may benefit from screening. However, a healthy woman who is modulating her breast cancer risk factors, has no family history, and carries genetic variances that make her sensitive to stress or radiation, may not.
I think a 2014 article in JAMA said it best:
To maximize the benefit of mammography screening, decisions should be individualized based on patients’ risk profiles and preferences. Risk models and decision aids are useful tools, but more research is needed to optimize these and to further quantify overdiagnosis. Research should also explore other breast cancer screening strategies.
BMJ. Cancer screening has never been shown to ‘save lives,’ argue experts. Science Daily. January 12, 2016.
Vinay Prasad, Jeanne Lenzer, David H Newman.Why cancer screening has never been shown to “save lives”–and what we can do about it. BMJ. 2016; h6080 DOI: 10.1136/bmj.h6080
Gerd Gigerenzer. Full disclosure about cancer screening. BMJ. 2016; h6967 DOI: 10.1136/bmj.h6967
Bleyer A, Welch HG. Effect of three decades of screening mammography on breast-cancer incidence. N Engl J Med.2012;367:1998-2005.
Pace LE, Keating NL. A systematic assessment of benefits and risks to guide breast cancer screening decisions. JAMA.2014;311:1327-35
Keating N, Pace LE. New Guidelines for Breast Cancer Screening in US Women JAMA. 2015;314(15):1599-1614. doi:10.1001/jama.2015.12783
Ji S. Cancer Screening Has Never Saved Lives, BMJ Study Concludes. Green Med Info. January 12, 2016. http://www.greenmedinfo.com/blog/cancer-screening-has-never-saved-lives-bmj-study-concludes-1
See references at: The Natural Path. Naturopathic Perspective on New Breast Cancer Screening Recommendations. October 22, 2015. http://thenatpath.com/natural-news/naturopathic-perspective-on-new-breast-cancer-screening-recommendations/
Mandelblatt JS, Stout NK, Schechter CB, van den Broek JJ, Miglioretti DL, Krapcho M, et al. Collaborative Modeling of the Benefits and Harms Associated With Different U.S. Breast Cancer Screening Strategies. Ann Intern Med. [Epub ahead of print 12 January 2016] doi:10.7326/M15-1536
Preidt R. Regular Mammograms Worthwhile for Elderly Women. Health Day. January 7, 2016.