Purpose
Studies suggest lowering the threshold of the prostate specific antigen test in obese men due to the hemodilution effect but prostate specific antigen may be affected by prostate volume and insulin resistance, which also increase with obesity. Thus, we examined the combined effect of these factors on prostate specific antigen.
Materials and Methods
We analyzed 3,461 Korean men 30 to 80 years old with prostate volume data available who underwent routine evaluation. We examined the effect of plasma volume, homeostatic model assessment index, prostate volume and body mass index on prostate specific antigen, and prostate specific antigen mass and mass ratio (total circulating prostate specific antigen protein per prostate volume) by the trend test and/or ANOVA after adjusting for age and/or prostate volume.
Results
Body mass index had positive associations with plasma volume, the homeostatic model assessment index and prostate volume (p for trend <0.01). Prostate specific antigen had a positive association with prostate volume and a negative association with plasma volume (p for trend <0.01) but not with homeostatic model assessment index. The adjusted R2 of prostate volume vs prostate specific antigen was greater than for plasma volume vs prostate specific antigen while for body mass index vs prostate volume it was less than for body mass index vs plasma volume (0.0892, 0.0235, 0.1346 and 0.3360, respectively). Prostate specific antigen mass was not associated with plasma volume or body mass index but it was still associated with prostate volume after adjusting for plasma volume or body mass index (p for trend <0.01). Mean prostate specific antigen mass ratio did not change significantly across body mass index, plasma volume or prostate volume quartiles in men older than 55 years.
Conclusions
It is not logical to lower the prostate specific antigen threshold based on only the hemodilution effect since body mass index related prostate volume enlargement can increase prostate specific antigen in obese men. Another tool is needed and prostate specific antigen mass ratio may be an option.
Volume 184, Issue 2, Pages 488-493 (August 2010)
prostate Specific Antigen Mass Ratio Potential as a Prostate Cancer Screening Tool
Ho-Chun Choi, Jin-Ho Park, Be-Long Cho, Ki-Young Son, Hyuk-Tae Kwon
Showing posts with label BMI. Show all posts
Showing posts with label BMI. Show all posts
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Body Mass Index and Prostate-Specific Antigen Failure Following Brachytherapy for Localized Prostate Cancer.
PURPOSE:
Increasing body mass index (BMI) is associated with prostate-specific antigen (PSA) failure after radical prostatectomy and external beam radiation therapy (EBRT). We investigated whether BMI is associated with PSA failure in men treated with brachytherapy for clinically localized prostate cancer.
PATIENTS AND METHODS:
Retrospective analyses were conducted on 374 patients undergoing brachytherapy for stage T1c-T2cNXM0 prostate cancer from 1996-2001. Forty-nine patients (13%) received supplemental EBRT and 131 (35%) received androgen deprivation therapy (ADT). Height and weight data were available for 353 (94%). Cox regression analyses were performed to evaluate the relationship between body mass index (BMI) and PSA failure (nadir + 2 ng/ml definition). Covariates included age, race, preimplantation prostate-specific antigen (PSA), Gleason score, T category, percent of prescription dose to 90% of the prostate, use of supplemental EBRT, and ADT.
RESULTS:
Median age, PSA, and BMI were 66 years (range, 42-80 years), 5.7 ng/ml (range, 0.4-22.6 ng/ml), and 27.1 kg/m(2) (range, 18.2-53.6 kg/m(2)), respectively. After a median follow-up of 6.0 years (range, 3.0-10.2 years), there were 76 PSA recurrences. The BMI was not associated with PSA failure. Six-year PSA failure rates were 30.2% for men with BMI less than 25 kg/m(2), 19.5% for BMI of 25 or greater to less than 30 kg/m(2), and 14.4% for BMI of 30 kg/m(2) or greater (p = 0.19). Results were similar when BMI was analyzed as a continuous variable, using alternative definitions of PSA failure, and excluding patients treated with EBRT and/or ADT. In multivariate analyses, only baseline PSA was significantly associated with shorter time to PSA failure (adjusted hazard ratio, 1.12; 95% confidence interval, 1.05-1.20; p = 0.0006).
CONCLUSIONS:
Unlike after surgery or EBRT, body mass index (BMI) is not associated with prostate-specific antigen (PSA) failure in men treated with brachytherapy for prostate cancer. This raises the possibility that brachytherapy may be a preferred treatment strategy in obese patients.
Increasing body mass index (BMI) is associated with prostate-specific antigen (PSA) failure after radical prostatectomy and external beam radiation therapy (EBRT). We investigated whether BMI is associated with PSA failure in men treated with brachytherapy for clinically localized prostate cancer.
PATIENTS AND METHODS:
Retrospective analyses were conducted on 374 patients undergoing brachytherapy for stage T1c-T2cNXM0 prostate cancer from 1996-2001. Forty-nine patients (13%) received supplemental EBRT and 131 (35%) received androgen deprivation therapy (ADT). Height and weight data were available for 353 (94%). Cox regression analyses were performed to evaluate the relationship between body mass index (BMI) and PSA failure (nadir + 2 ng/ml definition). Covariates included age, race, preimplantation prostate-specific antigen (PSA), Gleason score, T category, percent of prescription dose to 90% of the prostate, use of supplemental EBRT, and ADT.
RESULTS:
Median age, PSA, and BMI were 66 years (range, 42-80 years), 5.7 ng/ml (range, 0.4-22.6 ng/ml), and 27.1 kg/m(2) (range, 18.2-53.6 kg/m(2)), respectively. After a median follow-up of 6.0 years (range, 3.0-10.2 years), there were 76 PSA recurrences. The BMI was not associated with PSA failure. Six-year PSA failure rates were 30.2% for men with BMI less than 25 kg/m(2), 19.5% for BMI of 25 or greater to less than 30 kg/m(2), and 14.4% for BMI of 30 kg/m(2) or greater (p = 0.19). Results were similar when BMI was analyzed as a continuous variable, using alternative definitions of PSA failure, and excluding patients treated with EBRT and/or ADT. In multivariate analyses, only baseline PSA was significantly associated with shorter time to PSA failure (adjusted hazard ratio, 1.12; 95% confidence interval, 1.05-1.20; p = 0.0006).
CONCLUSIONS:
Unlike after surgery or EBRT, body mass index (BMI) is not associated with prostate-specific antigen (PSA) failure in men treated with brachytherapy for prostate cancer. This raises the possibility that brachytherapy may be a preferred treatment strategy in obese patients.
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