Concordance of DNA content between prostatic intraepithelial neoplasia and concomitant invasive carcinoma: Evidence that prostatic intraepithelial neoplasia is a precursor of invasive prostatic carcinoma

It has been postulated that prostatic intraepithelial neoplasia (PIN) is a precursor lesion to invasive carcinoma in the prostate, yet there has been little direct evidence for this relationship. Therefore, we studied the DNA content of the epithelial cells in PIN lesions with accompanying invasive carcinoma in seven cases. DNA content of nuclei in Feulgen-stained tissue sections was performed using the CAS200 System (Cell Analysis Systems Inc, Elmhurst, Ill), with normal and hyperplastic glands serving as controls for diploid DNA content. In four cases, the cells of both lesions (PIN and invasive carcinoma) contained only diploid DNA; in one case, an additional aneuploid tumor stem line was present only in the invasive component; and in two cases, both PIN and carcinoma cells contained aneuploid cells having similar DNA content. The concordance of DNA content between PIN and invasive carcinoma in these cases provides evidence that PIN is a precursor lesion for invasive carcinoma.