[Predictive model for prostate cancer in patients with biopsy indication]

Area of Science:

• Urology
• Oncology
• Medical Statistics

Background:

• Prostate carcinoma diagnosis relies on various factors, including age, digital rectal examination (DRE), and prostate-specific antigen (PSA) levels.
• Transrectal biopsy is often indicated based on these factors, but precise probability assessment remains crucial for patient management.

Purpose of the Study:

• To determine the probability of developing prostate carcinoma using age, DRE, and PSA levels after a transrectal biopsy has been indicated.
• To provide enhanced information for physicians and patients regarding prostate cancer risk assessment.

Main Methods:

• A retrospective study involving 633 transrectal biopsies.
• Data collected included patient age, DRE findings, PSA level, and histology.
• Logistic regression analysis was performed using SPSS software.

Main Results:

• Digital rectal examination demonstrated the highest discriminatory value (odds ratio 5.9).
• The developed mathematical model achieved 57% sensitivity and 84% specificity.
• Post-test probability increased from 36% to 70%, with a positive predictive value of 67%.

Conclusions:

• A mathematical model can individually determine the probability of prostatic carcinoma.
• This model provides more precise probability estimates than criteria for biopsy alone.
• Digital rectal examination is the most significant predictive parameter for prostate cancer, surpassing PSA and age individually.