PROLIFERATING CELL NUCLEAR ANTIGEN IN PROSTATIC ADENOCARCINOMA - CORRELATION WITH ESTABLISHED PROGNOSTIC INDICATORS

Objective. The utility of an antibody to proliferating cell nuclear an tigen (PCNA), a growth-specific nuclear protein, was assessed as a pro gnostic variable for prostatic adenocarcinoma. Its expression was corr elated with established prognostic indicators, including tumor grade, stage, prostatic-specific antigen (PSA), and percent of tumor in the g land at excision. Methods. Forty archival needle biopsies containing a minimum of four hundred tumor cells were analyzed. Immunoperoxidase s taining of paraffin sections was performed for PCNA (PC10) after pretr eatment in antigen retrieval solution. A proliferative index (PI) for each case was derived using image analysis with measurement of at leas t four hundred twenty-five nuclei. Results. PI values ranged from 2.4 to 31.3 percent. Mean PI values varied significantly (ANOVA, p = 0.005 ) among cases with dominant Gleason grade (DGG) of 3 (mean PI = 9.3%), 4 (mean PI = 13.7%), and 5 (mean PI = 18.8%). By t test, significant differences were noted for PI in cases with DGG 2 and 3 versus those w ith DGG 4 and 5 (p = 0.0065). PI for cases with DGG 3 versus 5 showed significant difference (p = 0.0017). Tumors of Gleason scores 5 to 7 d iffered significantly from those with scores 8 to 10 (p = 0.0 1 4). A statistical relationship for PI and PSA, clinical stage, and percent t umor at resection could not be established by linear regression. Concl usions. These findings suggest that additional study of the PI, as det ermined by PCNA immunohistochemistry and image analysis, may be warran ted to determine its usefulness as an adjunctive parameter in prostate adenocarcinoma. This technique may be particularly useful in needle b iopsies where limited tumor may render assessment of grade difficult.