For decades, people always believe cancer screening saves lives, but a study published in JAMA last week expressed concerns about the harm caused on patients who undergo breast and prostate cancer screening.
Dr Laura Esserman and colleagues who carried out the study found that screening often finds harmless or non-life-threatening tumors that could have gone unnoticed, this has led to huge increase in cancer diagnosis and unnecessary and aggressive treatment for patients while the most lethal, fast-growing cancers are often missed.
They reported 40% increase in breast cancer diagnosis but only 10% decline in late stage cancers. The rate of breast cancer overdiagnosis is as high as 1 in 3 for non-invasive cancers. Similarly, diagnosis in prostate cancer rocketed with the PSA test introduced in the 1980s, but most men with high PSA level turn out not to have cancer. Patients diagnosed with these cancers are often aggressivley and overtreated with radiation and surgery leading to long term harm.
The authors pointed out that the dilemma for breast and prostate cancer is that it is difficult to distingush dangerous cancers from harmless ones and the idea that some cancers are not dangerous and might go away on their own is not always accepted.
Although routine screening has identified more early stage cancers, it has not led to a corresponding reduction in mortality rate in breast and prostate cancer. The study concluded that "screening has value but we need to undertsand what it can and cannot do......., less screening is not necessarily a bad thing" and urged clinicians to rethink the use of breast and prostate cancer screening.
The American Cancer Society (ACS), as a result of the findings of this study, has acknowledged that the benefits of early screening has been overstated.
Source: "Rethinking screening for breast cancer and prostate cancer" JAMA. 2009;302(15): 1685-1692. (f/t via Athens)
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