Background: It is well recognized that tumor volume correlates with pathological stage, histological grade and progression in prostate cancer. We analyzed the tumor volume and the percent of gland involvement with tumor (%TV/PV) to determine if either or both of these morphometric factors would be good predictors of pathological stage.
Methods: The pathological reviews were retrospectively performed on the basis of the 22 step sectioned prostate specimens removed by radical retropublic prostatectomy for clinical T1c-T2-T3 prostate cancer. The percent of gland involvement with tumor was calculated using the following formula [100 x (tumor volume cc/prostate volume cc)]. When the patients had organ confined disease (OCD) or specimen confined disease (SCD) they were defined as surgically cured patients, whereas the patients with positive surgical margin, seminal vesicle involvement or positive lymph node were defined as not surgically cured patients.
Results: The likelihood of OCD was 25% in patients with clinical T1c-T2 disease. No patients with clinical T3 had OCD. Patients with SCD was not observed. The mean tumor volume was 1.3 cc in the surgically cured patients and 6.2 cc in the not surgically cured patients. The tumor volume correlated with pathological stage (r = 0.607, p = 0.0054). The mean %TV/PV was 3.23% in the surgically cured patients and 18.2% in the not surgically cured patients. The %TV/PV also correlated with pathological stage (r = 0.543, p = 0.0129). Both the tumor volume and the %TV/PV in surgically cured patients were less than those in the not surgically cured patients. A correlation between tumor grade and both the tumor volume and the %TV/PV were not observed.
Conclusion: The tumor volume and the %TV/PV correlated well with the final pathological stage. Multiple regression analysis showed that the tumor volume was the best predictor of pthological stage.