Controversies in prostate cancer screening. Analogies to the early lung cancer screening debate
M. M. Collins and M. J. Barry
General Medicine Division, Medical Services, Massachusetts General Hospital, Boston 02114, USA.
The current debate regarding early detection and aggressive treatment of
prostate cancer is fueled by the absence of controlled studies defining the
risks and benefits of prostate cancer screening, and by the lack of
adequately powered trials demonstrating the benefit of curative treatment
for early-stage prostate cancer. Pending the results of clinical trials in
10 to 15 years, advocates of early detection of prostate cancer with
digital rectal examination and prostate-specific antigen have compared
prostate cancer screening with the effective strategy of breast cancer
screening, implying that prostate cancer screening should similarly reduce
cancer mortality. They have also cited the high burden of disease, the
acceptable operating characteristics of digital rectal examination and
prostate-specific antigen, a stage shift among cases detected by screening,
and the theoretical curability of early-stage disease as sufficient reasons
to proceed with screening. These arguments, however, are reminiscent of
earlier arguments in favor of lung cancer screening with chest x-ray
examination and sputum cytology, a practice ultimately proven ineffective
in clinical trials. We reviewed published articles on lung and prostate
cancer screening and identified many parallels. While prostate cancer
screening may one day prove effective, analogies between the current
prostate cancer screening controversy and the older lung cancer screening
debate should inject some caution regarding widespread dissemination of
prostate cancer screening without experimental evidence that such screening
does more good than harm.
