Theory and Application of the Serum “acid” Phosphatase Determination in Metastasizing Prostatic Carcinoma; Early Effects Of Castration

Abstract

The authors report on the level of serum "acid" phosphatase in patients with a variety of different diseases. All of 30 normal persons had less than 3 units per 100 cc serum. Of 130 patients with prostate carcinoma and definite or suggestive roent-genographic evidence of metastases 85% showed increases above normal and 15% had normal values. The increase exceeded 1,000 units in 4%. Approximately 89% of 70 cases of prostatic carcinoma without roentgenographic evidence of skeletal metastases gave values less than 3 units; in the remaining 11% the values were between 3 and 5 units. All 85 cases with diseases of the prostate gland other than carcinoma presented normal values. Of a control group of 570 patients with non-prostatic disease, which included neoplasia other than prostate carcinoma and non-neoplastic diseases of bone, 90% had normal serum "acid" phosphatase levels. Of 96 cases of Paget''s disease 21% and of 9 cases of hyperparathyroidism 33% had values higher than 3 units. Castration in 31 patients with metastasizing prostatic carcinoma and serum "acid" phosphatase levels ranging from 5.20 to 4.2 units per 100 cc resulted in an early precipitous fall in serum "acid" phosphatase (often temporarily arrested about the third week by a slight, transient secondary rise, to be followed by a prolonged decline) until after 2 or 3 months an equilibrium was reached. The effect of castration on the serum "alkaline" phosphatase was more variable. After a latent period (of no significant change, or erratic fluctuation or downward trend) a marked increase in serum "alkaline" phosphatase usually developed, most often about the 2d or 3d wk., followed by a gradual decline until equilibrium was reached after many mos. The significance of the detn. of the "acid" phosphatase serum level, particularly in the diagnosis of metastasizing prostatic carcinoma is discussed.