On my homepage blog, I discussed some updates
in cancer screening and presented several theories with a potential to unite
conventional and integrative cancer treatments. It was a pretty big task! The
blog was a result ov a hodgepodge of studies that I came across when I was
evaluating metanalysis in the International
Journal of Epidemiology that
concluded:
Among
currently available screening tests for diseases where death is a common
outcome, reductions in disease-specific mortality are uncommon and reductions
in all-cause mortality are very rare or non-existent. (Systematic
review of meta-analyses and randomized trials.2015 DOI: 10.1093/ije/dyu140)
The goal of my blogs is to provide my readers
with empowering information that allows them to make the best personal decisions.
This blog is meant to make you contemplate your awareness of the benefit and
harm when deciding on any intervention.
Overestimation &
Underestimation
A 2012 study was done to assess participants’
estimates of the benefits of screening for breast and bowel cancer and
medication to prevent hip fractures and cardiovascular disease. The study was
based on questionnaires from three general practitioners who sent it to 5,000 of
their patients aged 50 to 70 years undergoing the intervention. This occurred over
a period of 10 years undergoing the intervention. The results were based on 354
returned questionnaires and indicated that patients overestimated the benefits
of all four interventions.
Although this study contained sampling
biases, the results were reported as follows:
Participants
overestimated the degree of benefit conferred by all interventions: 90% of
participants overestimated the effect of breast cancer screening, 94%
overestimated the effect of bowel cancer screening, 82% overestimated the
effect of hip fracture preventive medication, and 69% overestimated the effect
of preventive medication for cardiovascular disease. Estimates of minimum
acceptable benefit were more conservative, but other than for cardiovascular
disease mortality prevention, most respondents indicated a minimum benefit greater
than these interventions achieve. A lower level of education was associated
with higher estimates of minimum acceptable benefit for all interventions.
CONCLUSION Patients overestimated the risk reduction
achieved with 4 examples of screening and preventive medications. A lower level
of education was associated with higher minimum benefit to justify intervention
use. This tendency to overestimate benefits may affect patients’ decisions to
use such interventions, and practitioners should be aware of this tendency when
discussing these interventions with patients.(1)
A more comprehensive review was reported in JAMA Internal Medicine. According
to Medscape:
In a
systematic review of studies assessing patients’ expectations of the benefits
and harms of any treatment, screening, or diagnostic test, the majority of the
participants overestimated intervention benefit and underestimated harm, a
finding that has implications related to the “ever increasing” uptake of
medical interventions and rising costs, report Tammy C. Hoffman, PhD, and Chris
Del Mar, MD, FRACGP, from the Centre for Research in Evidence-Based Practice,
Faculty of Health Sciences and Medicine, Bond University, Queensland,
Australia. (2)
The study’s results were based on a
comprehensive search of 4 databases, cited reference searches, and two
independent researchers evaluating the quality of the studies and authors’
estimates. 36 articles from 35 studies involving 27,323 patients were
evaluated. The authors concluded the following:
The majority
of participants overestimated intervention benefit and underestimated harm.
Clinicians should discuss accurate and balanced information about intervention
benefits and harms with patients, providing the opportunity to develop
realistic expectations and make informed decisions. (3)
Healthy Behaviors Can Decrease Cancer
Risk
A recent study in the Journal of Clinical Nutrition evaluated
whether adherence to the American Cancer Society (ACS) cancer prevention
guidelines is associated with reduction in cancer incidence, cancer mortality,
and total mortality.
The trial was based on data from the NIH-AARP
Diet and Health Study, a prospective cohort study of a total of 476,396
eligible adults aged 50-71 years at recruitment in 1995-1996. Participants were
followed for a median of 10.5 years for cancer incidence, 12.6 years for cancer
mortality, and 13.6 years for total mortality. The authors used a 5-level score
of measuring adherence to ACS guidelines including baseline body mass index,
physical activity, alcohol intake, and several aspects of diet. They also accounted
for smoking.
Conclusions: In both men and women, adherence to the ACS
guidelines was associated with reductions in all-cancer incidence and the
incidence of cancer at specific sites, as well as with reductions in cancer
mortality and total mortality. These data suggest that, after accounting for
cigarette smoking, adherence to a set of healthy behaviors may have
considerable health benefits. (4)
The key here is to consider that certain
interventions may produce some side effects. Interestingly, concepts such as
bioactive compounds and lifestyle preventions can be potent therapies prior to
our need to reach for a medication or other intervention.
References:
(1) Patients’ expectations of screening and
preventive treatments. Ann Fam Med.
2012;10:495-502. http://www.annfammed.org/content/10/6/495.full
(2) Philips, D. Patients Misestimate
Benefits, Harms of Medical Interventions. Medscape Medical News. December 26,
2014
(3) Patients’ Expectations of the Benefits
and Harms of Treatments, Screening, and Tests A Systematic Review. JAMA Intern Med. Published online
December 22, 2014. doi:10.1001/jamainternmed.2014.6016
(4) Adherence to cancer prevention guidelines
and cancer incidence, cancer mortality, and total mortality: a prospective
cohort study. Am J of Clinical Nutrition. January
7, 2015. doi: 10.3945/?ajcn.114.094854