Testes para a detecção de câncer da próstata têm eficiência questionada

Acaba de ser publicado pela revista "Archives of Internal Medicine" o artigo "The Effectiveness of Screening for Prostate Cancer - A Nested Case-Control Study ", de autoria de Concato e outros autores, realizado em 10 "Veterans Affairs medical centers" em New England (EUA) e englobando 1.002 pacientes. Destes, 501 tinham diagnóstico de câncer da próstata. O estudo não encontrou benefício para os pacientes em terem realizado triagem para câncer da próstata nem por meio de PSA nem por meio de toque retal na redução da mortalidade. A amostragem é pequena e aguarda-se a conclusão de um estudo multicêntrico que deverá ser concluído em 2.009. Por enquanto recomenda-se que os pacientes sejam informados quanto às limitações dos procedimentos de triagem para câncer da próstata para uma decisão conjunta com seu médico quanto a se submeter ou não a estes exames.
Veja o "Abstract" do trabalho abaixo:
"The Effectiveness of Screening for Prostate Cancer - A Nested Case-Control Study
John Concato, MD, MPH; Carolyn K. Wells, MPH; Ralph I. Horwitz, MD; David Penson, MD; Graeme Fincke, MD; Dan R. Berlowitz, MD, MPH; Gregory Froehlich, MD; Dawna Blake, MD; Martyn A. Vickers, MD; Gerald A. Gehr, MD; Nabil H. Raheb, MD; Gail Sullivan, MD, MPH; Peter Peduzzi, PhD
Arch Intern Med. 2006;166:38-43.
Background Screening for prostate cancer is done commonly in clinical practice, using prostate-specific antigen (PSA) tests or digital rectal examination (DRE). Evidence is lacking, however, to confirm a survival benefit among screened patients. We evaluated the effectiveness of PSA, with or without DRE, in reducing mortality.
Methods We conducted a multicenter nested case-control study at 10 Veterans Affairs medical centers in New England. Among 71 661 patients receiving ambulatory care between 1989 and 1990, 501 case patients were identified as men who were diagnosed as having adenocarcinoma of the prostate from 1991 through 1995 and who died sometime between 1991 and 1999. Control patients were men who were alive at the time the corresponding case patient had died, matched (1:1 ratio) for age and Veterans Affairs facility. The exposure variable (determined blind to case-control status) was whether PSA testing or DRE was performed for screening prior to the diagnosis of prostate cancer among case patients, with the same time interval for control patients. The association of screening and overall or cause-specific (prostate cancer) mortality was adjusted for race and comorbidity.
Results A benefit of screening was not found in our primary analysis assessing PSA screening and all-cause mortality (adjusted odds ratio, 1.08; 95% confidence interval, 0.71-1.64; P = .72), nor in a secondary analysis of PSA and/or DRE screening and cause-specific mortality (adjusted odds ratio, 1.13; 95% confidence interval, 0.63-2.06; P = .68).
Conclusions These results do not suggest that screening with PSA or DRE is effective in reducing mortality. Recommendations for obtaining "verbal informed consent" from men regarding such screening should continue."