Objective To determine, using a clinical and pathological database, the ann
ual changes in the characteristics of adenocarcinoma of the prostate diagno
sed in consecutive men in Taiwan.
Patients and methods All prostatic adenocarcinomas newly diagnosed between
1991 and 1999 in our institution were analysed, Using logistic regression f
or dichotomous variables, the annual trends were assessed for changes in th
e percentage of Tie disease, incidental carcinoma, clinically localized dis
ease and Gleason grade 4/5 cancers. The annual trends for changes in the pa
thological features of disease in patients treated by radical prostatectomy
were also analysed,
Results The study included 694 patients; the median age at diagnosis increa
sed significantly (P = 0.004) and there was a significant increase in clini
cal Tie disease (relative risk, RR, 1.142, P = 0.022). There were also sign
ificant decreases in incidental carcinomas (RR 0.789, P < 0.001), patients
with a serum prostate-specific antigen (PSA) level of >20 ng/mL (RR 0.848,
P < 0.001) and with Gleason grade 4/5 tumours (RR 0.919, P = 0.005). There
was no significant change in the percentage of clinically localized disease
, Radical prostatectomy was undertaken in 179 men; the annual incidence of
lymph node metastases decreased significantly (P = 0.035) and there was a s
ignificant 19% increase in the RR of having organ-confined disease (pT1-2N0
M0) and a 19% decrease in Gleason grade 4/5 tumours.
Conclusions These results may reflect the annual trends of prostate cancer
in Taiwan in the period for which the PSA assay became available. The incre
asing application of PSA testing was associated with a significant increase
in clinical Tie disease and decrease in incidental carcinoma. There was al
so a significant trend towards less aggressive cancers. Despite the dramati
c increase in the annual detection rate, tumours were not detected at an ea
rlier stage. However, for patients treated with radical prostatectomy, ther
e was a significant change to earlier stage disease and fewer de-differenti
ated cancers.