Relationship of DNA Content to Conventional Prognostic Factors in Clinically Localised Carcinoma of the Prostate

Abstract

Summary— One hundred and nine patients treated by total prostatectomy for apparently localised carcinoma were analysed to investigate the prognostic significance of capsular invasion and penetration, seminal vesicle invasion, lymph node metastases, grade as assessed by the Gleason and MD Anderson Hospital (MDAH) systems and DNA content measured by flow cytometry of nuclear material extracted from paraffin embedded tumour. Comparison of DNA content was made with 36 benign prostates. Mean follow-up/survival was 60.7 months, at which time 21 patients had evidence of recurrence or had died. Only 5 patients had local recurrence. Tumour grade, as assessed by both the Gleason Sum Score and the MDAH system, correlated with anatomical extent and was the most important determinant of time to recurrence. Fifty-nine tumours were diploid, 44 tetraploid and 6 aneuploid. One of 36 benign prostates showed aneuploidy. Ploidy did not correlate with the anatomical extent of the tumour or with grade. Tetraploid tumours recurred earlier than diploid tumours. None of 6 aneuploid tumours have recurred, although only 3 have been followed beyond 5 years. Multivariate analysis showed that after accounting for grade, none of the other variables, including ploidy, contributed any additional significant prognostic information. Although the results must be regarded as preliminary, in view of the small number of patients with recurrence, they suggest that DNA content offers limited prognostic information in clinically localised prostate cancer.