Premalignancy in Prostate Cancer: Rethinking What we Know.

Area of Science:

• Urologic pathology
• Molecular pathology
• Cancer research

Background:

• High-grade prostatic intraepithelial neoplasia (PIN) is considered the primary precursor to prostate adenocarcinoma.
• However, some lesions diagnosed as high-grade PIN may represent intra-acinar or intraductal spread of invasive carcinoma.
• This overlap is supported by shared genomic alterations (e.g., TMPRSS2-ERG fusion) and molecular phenotypes between high-grade PIN and carcinoma.

Purpose of the Study:

• To address the diagnostic ambiguity between high-grade PIN and invasive prostate cancer spread.
• To highlight the need for molecular pathology to differentiate precursor lesions from intra-acinar/intraductal cancer.
• To improve the interpretation of clinical trials and reduce bias in patient selection.

Main Methods:

• Review of existing epidemiologic, molecular pathologic, and anatomic studies.
• Discussion of the potential for misclassification of high-grade PIN and intraductal carcinoma.
• Emphasis on the necessity for novel molecular approaches for accurate diagnosis.

Main Results:

• Lesions diagnosed as high-grade PIN can mimic intra-acinar or intraductal spread of invasive carcinoma.
• This potential misclassification can confound the interpretation of past clinical trials.
• Molecular markers like TMPRSS2-ERG fusion and PTEN loss show promise in distinguishing these entities.

Conclusions:

• Accurate differentiation of high-grade PIN from invasive cancer spread is crucial for reliable prostate cancer research and clinical trials.
• Novel molecular pathology techniques are essential to resolve diagnostic uncertainties.
• Improved classification of high-grade PIN and intraductal carcinoma will enhance patient stratification and therapeutic strategies.