“Pink October” and “Blue November” are campaigns to promote awareness for breast and prostate cancer, respectively. In Brazil, as well as in other countries, the population is encouraged to do tests such as the prostate-specific antigen (PSA) for prostate cancer and mammography for breast cancer.
The main idea is screening: to perform tests in healthy persons to detect and to treat diseases before their symptoms appear to increase the chances of cure and even to offer a less aggressive treatment. A good example of cancer screening is for cervical cancer, where incidence of the advanced cases decreased after the Papanicolaou test was introduced (Adegoke et al. 2012). However, studies that assess the efficacy of screening for prostate or breast cancer show that in reality things are more complicated than usually advertised by those campaigns.
In May 2018, the U.S. Preventive Services Task Force (USPSTF) reviewed studies of PSA screening for prostate cancer (Fenton et al. 2018). Only two randomized controlled trials were of sufficient quality to assess impact on mortality. One, called the PLCO,1 did not show differences in mortality. The second trial, called ERSPC,2 showed that screening reduced prostate cancer mortality in men aged fifty-five to sixty-nine. Even in that case, it’s far from simple. In order to avoid one prostate cancer death and three cases of metastatic prostate cancer, 1,000 men aged fifty-five to sixty-nine have to be screened every four years during thirteen years. Of those, twenty-seven men received treatment—prostate surgery and/or radiation therapy. More important, the majority of those who were treated, twenty-four patients, received aggressive treatment with no benefits, only the harms caused by the treatment itself. Regardless of screening, five men died from prostate cancer. See Table 1 for complete estimates.