Diurnal VarIatIon of Urinary “hCG $ Subunit Core Fragment ” Production Evaluated in Patients wfth

Urinary metabolites of the (3 subunit of human chorionic gonadotropin (hCG(3), particularly the fragment known as (3-core, are potential tumor markers for gynecological can-cers (1-6). We have found that an increased concentration (tg’L) of (3-core in early-morning urine samples is rela-tively common in gynecological cancers, but the sensitivity (36%) and specificity (90%) of such measurements are low (7). Most clinical studies have reported /3-core concentra-tions in early-morning or random urine specimens without correction for urine volume or concentration (1-7). For many urinary solutes, however, including proteins, ex-pressing the concentration as a ratio to the urinary creat-inine concentration is less variable and may better reflect the true urine output than does concentration per unit volume (8-11)