Previously we showed that in cases of stage A prostatic cancer, if the tumor involved 5 per cent or less of the tissue and was not high grade (stage A1), only 2 per cent of the tumors progressed at 4 years. The current study investigated a larger group of 94 men with stage A1 disease and extended followup. While 26 men (mean age 75 years) died of other causes less than 4 years after diagnosis, of the 50 men who remained at risk 8 years or longer from the time of diagnosis 8 (16 per cent) had progression of disease. The intervals from diagnosis to progression ranged from 3.5 to 8 years, with 6 of the 8 patients dying of the cancer. Neither volume nor grade predicted progression, since of the 8 tumors that progressed 4 involved less than 1 per cent of the tissue and 6 were low grade. Based on these findings we conclude that stage A1 tumors progress at longer intervals from diagnosis and at lower frequency than stage A2 tumors. However, patients with stage A1 disease are not entirely free of risk of progression, and because 16 per cent of the men in this study who were at risk 8 years or longer experienced progression this factor must be recognized in the management of young men with stage A1 tumors.
Epstein et al. (1986) studied this question.