Objective: To determine the value of serial 6-monthly transrectal ultrasonography (TRUS) in a cohort of men with localized prostate cancer who consented to a programme of watchful waiting with selective delayed intervention.
Patients and methods: Since November 1995, 180 men were accrued into an ongoing prospective study of watchful waiting with selective delayed intervention; 174 patients enrolled before 31 December 1999 comprised the cohort for the present study. The prospectively collected clinical data, including the TRUS reports, were reviewed systematically. Twenty-eight men met the arbitrarily predefined criteria of disease progression and required definitive treatment. The TRUS findings were scored as being consistent with the clinical scenario (i.e. clinical, biochemical or histological progression) if they reported a new or enlarging hypoechoic peripheral zone lesion, or a > or = 30% increase in overall prostate volume at the time of progression. In 136 men who had undergone two or more serial TRUS examinations the relationships between the rate of change of prostate-specific antigen (PSA) and changes in both gland volume and the number of hypoechoic lesions were also examined.
Results: The group of 28 men who progressed to require radical intervention underwent 83 TRUS examinations (median number per patient, three). Two men underwent TRUS only once at baseline because of progression within 6 months. Of these 28 men, only seven had changes on TRUS that were regarded as being consistent with progression; all seven consisted of the growth of an existing nodule or the appearance of a new nodule. In only one case was this accompanied by an increase of > or = 30% in gland volume. In the 136 men who underwent two or more serial TRUS examinations (median three, maximum nine), there was no correlation between the rate of change of PSA and changes in either gland volume or the number of peripheral zone hypoechoic lesions.
Conclusion: The use of serial TRUS in men with known but untreated prostate cancer is of limited value as a determinant of disease progression.