Myungchan Park

Asan Medical Center, Sŏul, Seoul, South Korea

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Publications (3)5.26 Total impact

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    ABSTRACT: To determine whether the prevalence of prostate cancer is associated with a decrease in bone mineral density (BMD) compared to a healthy control group and to identify the factors associated with osteoporosis in patients diagnosed with prostate cancer before the initiation of any kind of treatment. A retrospective study was conducted in 582 patients with prostate cancer and 2536 healthy men. Confounding variables affecting BMD, including age, serum testosterone, body mass index (BMI), diabetes mellitus, hypertension, and smoking were matched in the 2 study groups using propensity score analysis. The propensity score model included 6 variables, and matching by propensity score yielded 502 patients in the prostate cancer group matched to 502 men in the healthy control group. On the basis of the lowest T-score available, a high prevalence of osteoporosis was found in the prostate cancer group (P = .0001). Prostate cancer was the factor correlating significantly with osteoporosis before propensity score matching (odds ratio [OR] 2.96, P <.001) and after propensity score matching (OR 3.22, P <.001). By multivariate analysis, conducted to assess the significance of each variable affecting the development of osteoporosis in patients with prostate cancer, bone metastasis was found to be an independent predictor of osteoporosis (OR 3.45, P = .002), along with BMI (continuous, OR 0.75, P <.001). After controlling for variables affecting BMD, prostate cancer was a risk factor for osteoporosis. Measurement of BMD is a logical first step in the clinical strategy to avoid or minimize potential bone-related complications in men with prostate cancer, especially if they have bone metastasis and a slender stature.
    Urology 10/2013; 83(2). DOI:10.1016/j.urology.2013.08.045 · 2.13 Impact Factor
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    ABSTRACT: OBJECTIVE To determine whether repeat prostate biopsies are associated with more favourable prognoses compared with diagnosis at initial biopsy in patients who undergo radical prostatectomy for prostate cancer and to determine if this association is affected by the number of cores taken at initial biopsy. PATIENTS AND METHODS We reviewed 1147 patients with prostate cancer from 1991 to 2008. Patients were stratified into two groups by the number of biopsies before diagnosis (initial biopsy vs repeat biopsy: at least two biopsies). The effects of several variables on pathological outcomes and biochemical recurrence-free and systemic progression-free survivals were assessed. RESULTS Of the 1147 patients, 1064 (92.8%) were diagnosed with cancer at first biopsy and 83 (7.2%) at repeat biopsy. Compared with patients diagnosed at initial biopsy, those diagnosed at repeat biopsies were more likely to have a lower clinical stage (cT1c: 79.5% vs 55.5%, P < 0.001) and organ-confined tumours (78.3% vs 61.3%, P = 0.003), but there was no significant difference in initial biopsy core number (8.3 vs 8.7, P = 0.373). Five-year biochemical recurrence-free and progression-free survival rates did not show significant differences between the two groups (88.8% vs 82.2%, P = 0.078; 100.0% vs 96.5%, P = 0.105, respectively), and these results were not affected by the number of cores taken at initial biopsy. CONCLUSIONS Although prostate cancer diagnosed after repeat biopsies was related to better pathological outcomes after radical prostatectomy, the number of previous biopsies did not predict disease recurrence. Moreover, the number of cores taken at initial biopsy did not affect these associations.
    BJU International 09/2011; 109(10):1474-9. DOI:10.1111/j.1464-410X.2011.10442.x · 3.13 Impact Factor
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    ABSTRACT: The prognosis of patients with malignant pheochromocytoma is poor, but the predictive factors are not well understood. We aimed to identify the clinical characteristics predictive of malignancy after initial surgical removal in patients with pheochromocytoma. We retrospectively reviewed the records of 152 patients diagnosed with pheochromocytoma, including 5 (3.3%) with metastasis at the time of the initial surgical excision and 12 (7.9%) who developed metastasis during follow-up. To determine the factors predictive of malignancy, we compared clinical, radiographical, and urinary chemical findings between patients with benign and malignant disease. Mean follow-up was 41.5 months (range, 0.9-298 months) after surgery. Malignant tumors were significantly larger than benign tumors (11.1±4.0 cm vs. 6.2±3.4 cm, p<0.001), and postoperative persistence of arterial hypertension was more frequent after removal of malignant than benign tumors (p=0.001). Among the 147 patients without metastatic disease at diagnosis, those who developed metastasis had significantly lower concentrations of urinary catecholamine metabolites per unit of tumor, including vanillylmandelic acid (1.2 vs. 3.7 mg/day/cm, p=0.049), epinephrine (4.5 vs. 168.9 µg/day/cm, p=0.008), and norepinephrine (13.1 vs. 121.8 mg/day/cm, p<0.001). The overall 5-year metastasis-free survival rate was 84.4% and was significantly higher in patients with smaller tumors (≤5.5 vs. >5.5 cm; 90.6% vs. 81.2%, p=0.025) and higher 24-hour secretion of vanillylmandelic acid (>2.1 vs. ≤2.1 mg/day/cm; 94.9% vs. 70.9%, p=0.019). Large tumor size (>5.5 cm) and minimally elevated 24-hour urinary vanillylmandelic acid (≤2.1 mg/day/cm) were significantly associated with a higher probability of a malignant pheochromocytoma portending a lower metastasis-free survival and mandating more rigorous follow-up after surgery.
    Korean journal of urology 04/2011; 52(4):241-6. DOI:10.4111/kju.2011.52.4.241

Publication Stats

20 Citations
5.26 Total Impact Points


  • 2013
    • Asan Medical Center
      • Department of Urology
      Sŏul, Seoul, South Korea
  • 2011
    • University of Ulsan
      Urusan, Ulsan, South Korea
    • Ulsan University Hospital
      Urusan, Ulsan, South Korea