ORLANDO, Fla.—Maximum tumor diameter (MTD) is a significant predictor of prostate cancer (PCa) outcomes following salvage radiation treatment, researchers reported at the annual Genitourinary Cancers Symposium.
They concluded that MDT should be used in clinical decision making in this patient population as well as in future clinical risk assessment tools.
The study, presented by Skyler B. Johnson, BS, a fourth-year medical student at the University of Michigan in East Lansing, included 173 PCa patients who received salvage radiation therapy following a rising post-radical prostatectomy PSA. The median follow-up was 76.5 months and the median MTD 18 mm. An analysis showed that an MTD of 14 mm was the most prognostic cut-point. An MTD greater than 14 mm was associated with a 1.8-fold, fourfold, and eightfold increased risk of biochemical failure, metastasis, and prostate cancer-specific mortality (PCSM), respectively. Each 10 mm increase in MTD was associated with a 1.7-fold, twofold, and 1.6-fold increased risk of metastasis, PCSM, and overall death, respectively.