[Skip to Content]
[Skip to Content Landing]
June 26, 1981

Unpredictable Fluctuations in Serum Acid Phosphatase Activity in Prostatic Cancer

Author Affiliations

From the Department of Medicine, Duke Comprehensive Cancer Center (Drs Brenckman and Lastinger) and the Clinical Chemistry Laboratory (Dr Sedor), Duke University Medical Center, Durham, NC.

JAMA. 1981;245(24):2501-2504. doi:10.1001/jama.1981.03310490019016

Repeated determinations of the elevated serum acid phosphatase activities in five patients with advanced prostatic cancer were found to be highly variable during 24 to 48 hours of observation. Samples collected every three hours had fluctuations of 44% to 97% around the 24- to 48-hour mean values. These fluctuations appeared to be random, had no apparent circadian rhythm, and were unrelated to concurrent medications or activity. These spontaneous variations indicate the need for caution when using serial serum acid phosphatase determinations as an indicator of the response of prostate cancer to therapy. Elevated serum alkaline phosphatase activities did not show these extreme fluctuations.

(JAMA 1981;245:2501-2504)