Page 45 - TD-1-2

Tumor Discovery Benefits and harms of screening breast cancer

First, we must differentiate a diagnostic and/or displays all three elements of arrogance. First, preventive
detection procedure from a screening procedure, as well as medicine is “aggressive” in that asymptomatic individuals
preventive medicine from anticipatory medicine (primary are often solicited and instructed on what they have to do to
prevention). stay healthy; second, preventive medicine is “presumptuous”
In screening, the individuals included in the process in that it assumes that its prescriptions always did more good
are asymptomatic and have no medical history nor have than harm; third, preventive medicine is “despotic” in that it
that they undergone any examination before screening; lashes out at anyone who dissents from its recommendations.
otherwise, it would be considered a diagnostic procedure. Considering the complications arising from
overdiagnosis, and especially with overtreatment, Sackett
Regardless of the sensitivity and specificity of each
screening procedure, not all of them present the same argues that the pledge we must make when we solicit
and exhort individuals to accept preventive interventions
degree of inconvenience (damage and harm resulting from should be that they will be better off by adopting these
doing something). In some cases of screening, such as measures. Consequently, the assumption that justifies
those for breast, colon, and prostate cancer, they are based the aggressive assertiveness with which we go after naïve
on imaging test and/or endoscopy, in which risks may arise healthy individuals must be based on the highest level
due to diagnostic errors and subsequent actions. There are of evidence. We must be certain that our preventive
other screenings, such as the screening for atheromatous maneuvering does, in fact, do more good than harm.
cardiovascular disease, in which the procedure is totally
predictive since it is not based on images, but rather the A number of studies have demonstrated that the main
scores obtained through risk adjustment systems that tool of overdiagnosis, universal screening, is expensive,
make long-term predictions (up to 10 years), which might ineffective, and even dangerous. Therefore, every individual
eventually lead to potentially harmful and unnecessary should be informed of the risks, inconveniences, and dangers
pharmacological treatments. of each proposed test other than its possible benefits.
In 1975, Sackett published a paper in The Lancet on However, it seems that apart from these uncertain
[1]
the discussions and debates between the different roles of benefits, political and/or economic cost-effectiveness are
screening, case finding, diagnosis, and epidemiological some of the advantages of screening, which are enhanced
surveys in disease detection. According to Sackett, when both objectives coincide.
discussions would improve when participants define the These premises serve as the foundation for our analysis
different purposes and characteristics of each procedure, of a screening that is widely accepted.
recognize the ideological and intentional differences
between the defenders and the critics, and value the 2. Breast cancer screening
quantitative and qualitative differences for decision-making In a review of five Swedish trials, published in The Lancet
in front of the individual patient or before the community.
[3]
in 1993 , it was found that screening reduced breast
While the advocates of screening, generally for cancer mortality by 29% (however, as we shall discover
irreproachable reasons, have claimed that with the existing later, this was not the case). Despite this, the review has
evidence and given the current rate of disability and premature also addressed the need to consider other factors, both
death, mass screening programs should be imposed for beneficial and harmful ones, in addition to mortality,
the detection of citizens with risk factors; methodologists before recommending universal screening. Needless to say,
have insisted that screening, like any other unproven health that 29% of successes were, in principle, highly appealing,
practice, could do more harm than good, and should meet thus concealing other recommendations.
scientific and ethical criteria before being implemented.
In reality, this reduction in mortality is equivalent to
Sackett revealed the differences between the advice saving one woman in every 1000 screened over 10 years.
directed at an individual patient and that directed at The benefit of detection is therefore very small. Translating
a community. A higher level of evidence of efficacy is it into standard language, according to the study, in that
required to recommend treatment at the community level, 10-year period, four women out of 1000 died from breast
especially when patients are solicited through screening. cancer, while only three died among those screened.
A community cannot be treated as a patient and vice versa. Therefore, the absolute reduction in mortality for breast

Years later, in 2002, Sackett’s displeasure toward the cancer was only 0.1% (1 in 1000) after 10 years. This 0.1%,
application of this type of medicine became more evident . using relative risk reduction (RRR), became the 29% cited.
[2]
Sackett claimed that preventive medicine (referring to primary Moreover, those figures were “inflated.” Later, reviews
prevention, or as its critics call it, anticipatory medicine) have found that the reduction in mortality was in fact

Volume 1 Issue 2 (2022) 2 https://doi.org/10.36922/td.v1i2.228