Non-ASTRO-related news update: Thursday, September 25

Additional, non-ASTRO-related news today  includes the following:

  • Screening, treatment, and mortality in Medicare-eligible populations
  • Genetic variants and relationships to clinical and pathological variables
  • The application of MRI in prostate cancer management
  • Predictors of aggressive biochemical recurrence after radical prostatectomy>

Before the availability of the PSA test, the Seattle-Puget Sound and Connecticut Surveillance, Epidemiology and End Results (SEER) areas had similar prostate cancer mortality rates. Early in the PSA era (1987-1990), men in the Seattle area were screened and treated more intensively for prostate cancer than men in Connecticut. It was previously reported that in the male Medicare population of these two areas, more intensive screening and treatment early in the PSA era did not lower prostate cancer mortality through 11 years. This publication by Lu-Yao et al. extends follow-up to 15 years. Male Medicare beneficiaries aged 65-79 from the Seattle (N = 94,900) and Connecticut (N = 120,621) SEER areas were followed from 1987-2001. The authors analyzed rates of prostate cancer screening; treatment with radical prostatectomy, external beam radiotherapy, and androgen deprivation therapy; and prostate cancer-specific mortality. The study shows that 15-year cumulative incidences of radical prostatectomy and radiotherapy through 2001 were 2.84 and 6.02 percent, respectively, for Seattle cohort members, compared to 0.56 and 5.07% percent for Connecticut cohort members. The cumulative incidence of androgen deprivation therapy from 1991-2001 was 4.78 percent for Seattle compared to 6.13 percent for Connecticut. The adjusted rate ratio of prostate cancer mortality through 2001 was 1.02 in Seattle versus Connecticut. They conclude that, among men aged 65 or older, more intensive prostate cancer screening early in the PSA era and more intensive treatment, particularly with radical prostatectomy, over 15 years of follow-up were not associated with lower prostate cancer-specific mortality.

Fifteen independent genetic variants have been implicated in prostate cancer risk by recent genome-wide association studies. However, according to a report by Xu et al., there was no association between risk for these genetic variants and the clinical and pathological vaiables (such as biopsy Gleason score, pathologic Gleason score, pathologic stage, age at diagnosis, or serum PSA level) in a series of 1,563 patients undergoing radical prostatectomy.

Mazaheri et al. have reviewed the application of magnetic resonance imaging (MRI) in the evaluation and management of of prostate cancer. They state that the main applications of MRI are: (1) to guide targeted biopsy when prostate cancer is clinically suspected and previous ultrasound-guided biopsy results are negative; (2) to localize and stage prostate cancer and provide a roadmap for treatment planning; and (3) to detect residual or locally recurrent cancer after treatment. Other MR techniques such as proton MR spectroscopic imaging (MRSI), diffusion-weighted imaging (DWI), and contrast-enhanced MRI (CE-MRI) complement conventional MR imaging by providing metabolic and functional information that can improve the accuracy of prostate cancer detection and characterization. In everyday clinical practice, and to account for patient comfort, MR imaging studies are limited to 1 h. To obtain consistently high-quality images, a well-designed protocol is necessary. Routine MR imaging can be supplemented by other MR techniques such as MRSI, DWI or CE-MRI depending on the expertise available and the clinical questions that need to be answered.

Elevated levels of preoperative PSA, pathological Gleason sums of 8-10 or 7, the presence of extraprostatic extension (ECE) and/or positive surgical margins (PSMs), and seminal vesicle invasion (SVI) are well known predictors of risk for biochemical recurrence following prostate cancer surgery. Teeter et al. have now published data suggesting that the same factors can be used to predict risk for aggressive disease recurrence associated with a short PSA doubling time of ≤ 9 months post-surgery, based on data from 856 men included the Shared Equal Access Regional Cancer Hospital (SEARCH) database.

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