Milkman et al.

Purpose-For select men with low-risk prostate cancer, active surveillance (AS) is more often being considered a management strategy. In a multicenter retrospective study we evaluated the actuarial rates and predictors of remaining on AS, incidence of cancer progression, and pathologic findings of delayed radical prostatectomy.Methods-A cohort of 262 men from four institutions met the following inclusion criteria: age ≤75, PSA ≤10 ng/ml, clinical stage T1-T2a, biopsy Gleason sum ≤6, ≤3 positive cores at diagnostic biopsy, a repeat biopsy before AS, and no treatment for six months following the repeat biopsy. AS started on the date of the second biopsy. Actuarial rates of remaining on AS were calculated and univariate Cox regression used to assess predictors of discontinuing AS.Results-With a median follow-up of 29 months 43 patients ultimately received active treatment. The two and five-year probabilities of remaining on AS were 91% and 75%, respectively. Patients with cancer on the second biopsy (HR=2.23; 95% CI: 1.23-4.06; p=0.007) and a higher number of cancerous cores from the two biopsies combined (p=0.002) were more likely to undergo treatment. Age, PSA, clinical stage, prostate volume, and number of total biopsy cores sampled were not predictive of outcome. One patient developed skeletal metastases 38 months after starting AS. Of the 43 patients undergoing delayed treatment, 41 (95%) are without disease progression at a median of 23 months following treatment.Conclusions-With a median follow-up of 29 months, AS for select patients appears to be safe and associated with a low risk of systemic progression. Cancer at restaging biopsy and a higher total number of cancerous cores are associated with a lower likelihood of remaining on AS. A restaging biopsy should be strongly considered to finalize eligibility for AS.

No abstract

Forty wether lambs were used in a 2 x 4 factorial arrangement to determine the response of animal performance, muscle growth, proteinase activity, and meat tenderness to beta-adrenergic agonist (BAA) supplementation. Lambs were fed a finishing diet with or without 4 ppm of L644,969 and slaughtered after 0, 2, 4, and 6 wk of treatment. The ADG was higher (P < .05) in the treated than in the control lambs after 2 wk and returned to control levels thereafter. Semitendinosus weight and calpastatin activity were higher and mu-calpain activity was lower in the treated than in the control lambs after 2, 4, and 6 wk. Cathepsin B activity was higher (P < .01) and cystatin-like activity was lower (P < .05) after 2 wk in treated than in control lambs but returned to control levels thereafter. Longissimus protein:DNA was higher after 4 (P < .05) and 6 (P < .01) wk in the treated lambs than in the controls. The concentration of RNA and RNA:DNA ratio were higher (P < .01) in the longissimus and semitendinosus muscles in the treated lambs after 2 wk and remained higher throughout the study. Semitendinosus protein and RNA content were higher after 2, 4, and 6 wk and DNA content was higher after 2 and 6 wk in the treated than in the control lambs. Longissimus shear-force values were higher (P < .001) in the treated than in the control lambs at all slaughter end points. These data indicate a rapid alteration of muscle growth, activity of the calpain-calpastatin system, and meat tenderness during BAA treatment.(ABSTRACT TRUNCATED AT 250 WORDS)