Maximum tumor diameter could predict recurrence after radical prostatectomy
MedWire News: The maximum diameter of the primary tumor removed at radical prostatectomy (RP) could be used to predict the likelihood of biochemical disease recurrence (BCR) in men with small tumors, report Japanese researchers.
Their analysis showed that maximum tumor diameter (MTD) was independently associated with BCR, and that men with a diameter above 20 mm were significantly more at risk for BCR than those with an MTD of 20 mm or below.
"Prediction of BCR after prostatectomy is imperative in counseling with patients on adjuvant therapy and prognosis," explain Hiroshi Fukuhara and colleagues from the University of Japan in Tokyo.
"Considering the simplicity in measurement, MTD would be a clinically useful indicator for BCR," they add, in the journal Prostate Cancer and Prostatic Diseases.
The team evaluated the prognostic value of MTD measurements for BCR in 364 prostate cancer patients who were all treated with RP for clinically localized disease. The cohort was followed-up with prostate-specific antigen (PSA) testing every 1-6 months for a mean 33 months.
The median MTD, defined as the largest diameter of the largest tumor, was 15 mm, and BCR, considered to be two sequential PSA levels of above 0.2 ng/ml after RP at least 1 month apart, occurred in 66 men.
Fukuhara et al found that BCR was significantly associated with MTD measurements, with BCR rates rising from 10.7% among men with a MTD of 0.9-10.0 mm, to 29.4% among men with a measurement of 21.0-30.0 mm.
They observed that pre-operative PSA levels (<10 vs ≥10 ng/ml or above), pathological stage (pT2 vs T3a and above), and Gleason score (≤6 vs ≥7) were all significantly associated with MTD.
Having a larger MTD (>20 mm vs ≤20 mm) was a significant independent predictor of BCR after univariate analysis, as was advanced pathological stage (pT3b or T4), a higher Gleason score (≥8), and positive surgical margin status. These results were confirmed by multivariate analysis.
However, when MTD was analyzed as a continuous variable, the significant association was lost.
"These findings may indicate that MTD is more significant a factor in a cohort with smaller tumor size, suggesting the utility in contemporary series of early detected prostate cancer," the team concludes.
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By Sarah Guy