Yukio Tomaru

Effect of castration monotherapy on the levels of adrenal androgens in cancerous prostatic tissues.

The mechanism accounting for the development of castration-resistant prostate cancer (CRPC) remains unclear. Studies in CRPC tissues suggest that, after androgen deprivation therapy (ADT), the adrenal androgens may be an important source of testosterone (T) and 5-alpha dihydrotestosterone (DHT) in CRPC tissues. To clarify the role of adrenal androgens in the prostatic tissues (prostatic tissue adrenal androgens) during ADT, we developed a high sensitive and specific quantification method for the levels of androgens in prostatic tissue using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human prostatic tissues were purified using mixed-mode reversed-phase, strong anion exchange Oasis cartridges (Oasis MAX). Analysis of steroids was performed using LC-MS/MS after picolinic acid derivatization. The validation tests showed that our method of quantitative analysis was precise and sensitive enough for the quantification of dehydroepiandrosterone (DHEA), androstenedione, androstenediol, T, and DHT in the prostatic tissue. The levels of adrenal androgens in prostate cancer tissues after ADT were similar to those in untreated PCa. Especially, DHEA was the most existing androgen precursor in PCa tissues after ADT. The levels of DHEA were high in PCa tissues, irrespective of ADT. We assumed that DHEA played a significant role in the synthesis of T and DHT in PCa tissues after ADT.

New quantification method for estradiol in the prostatic tissues of benign prostatic hyperplasia using liquid chromatography–tandem mass spectrometry

Estrogen is suspected to play a role in the pathogenesis of benign prostatic hyperplasia (BPH) and prostate cancer. To clarify the role of estradiol (E2) in the prostatic tissues (prostatic tissue E2) during the development of prostatic disorders, we developed a new sensitive and specific quantification method for prostatic tissue E2 using liquid chromatography-tandem mass spectrometry (LC-MS/MS). For the solid-phase extraction, E2 was purified by anion-exchange through an Oasis MAX cartridge. In addition, after the formation of 3-pentaflurobenzyl-17beta-pyridinium-estradiol derivative (E2-PFBPY), E2-PFBPY was purified by cation-exchange through an Oasis WCX cartridge. These processes in the LC-MS/MS method improved the specificity and sensitivity for prostatic tissue E2 measurement, compared to the radioimmunoassay (RIA) method. The validation tests showed that intra-day and inter-day precisions were both within +/-15% (except for 15.5% of the inter-day precision of the lowest concentration), with the accuracy ranging from 88 to 110%. The quantification limit of this assay was 0.15pg/tube in our method, which was 80-fold more sensitive than that of the RIA method. With the use of our present method, the median E2 levels in the prostatic tissues in patients with BPH (n=20, median age: 71 years) were 12.0pg/g tissue (95% confidence interval=9.1-22.6pg/g tissue). Furthermore, the E2 levels increased significantly with aging. These results showed that our present method would be useful for elucidating the role of prostatic tissue E2 in the development of prostatic disorders with a small amount of tissue samples.

Significance of a new stratification of alkaline phosphatase and extent of disease in patients with prostate carcinoma with bone metastasis.

Bone is the most frequent site of metastatic prostate cancer and the prognosis of patients with bone metastasis is poor. The authors have investigated a semiquanti‐tative system to evaluate bone metastatic lesions in terms of cancer‐specific survival. Based on the extension of disease (EOD) grade proposed by Soloway and associates, a new EOD grading system obtained from bone scintig‐raphy alone and EOD score obtained from bone scintig‐raphy and alkaline phosphatase was studied in 164 patients with prostate cancer with metastatic bone involvement. In terms of a cancer‐specific survival and prostate cancer death, both the new EOD grade and the EOD score were apparently superior to eight other items studied (age, medical score, gait disturbance, histologic grade, erythrocyte sedimentation rate, prostatic acid phosphatase, and alkaline phosphatase). Multivariate analysis revealed that the EOD score was better than the new EOD grade. This improvement was due to the elimination of false‐positive or nonactive metastatic bone lesions on bone scintigraphy through the alkaline phosphatase evaluation.

The Significance of Erythrocyte Sedimentation Rate as a Prognostic Factor for Patients with Prostate Cancer: Gunma Urological Oncology Study Group Investigation

The Gunma Urological Oncology Study Group has performed a multivariate statistical analysis of prognostic factors based on 353 patients with prostate cancer diagnosed between 1974 and 1984. This paper discusses the prognostic significance of erythrocyte sedimentation rate (ESR) in these patients with prostate cancer. Based on three ranges (<20, >20‐ <50, >50 mm/h) of ESR, a significant difference of survival rates among the patients was found by means of univariate analysis. ESR apparently includes components which represent anemia or infection. Hemoglobin, frequently used as a prognostic factor, was compared with ESR by means of multivariate analysis, and ESR was found to be a more useful prognostic factor than hemoglobin. Moreover ESR showed the highest partial coefficient value among the items studied (clinical stage, pathological differentiation, age, acid phosphatase, gait disturbance). It seems that ESR includes not only anemia and infection components but also provides a clue to the degree of bone metastasis or the degree of prostate cancer progression.