SEARCH Articles Figures Tables A -Diacetylspermine production and excretion in the urine. DiAcSpm levels begin to increase in cancer cells in the early stages of cancer development. In the kidney, free polyamines and monoacetylpolyamines in the primary urine are reabsorbed in the rentil proximal tubules. DiAcSpm is not reabsorbed and is eventually excreted in the urine [Publishers Imprint]