Serial urinary cyclic guanosine monophosphate measurements in the assessment of response to treatment in epithelial ovarian cancer.

Serial measurements of urinary cyclic guanosine monophosphate (cGMP) were performed in 47 patients with epithelial ovarian cancer. In 30 patients, the pre-chemotherapy cGMP level was above the range for normal controls (marker positive); the remainder were within the normal range. Marker positive patients demonstrated a 96% correlation of disease regression with a fall in marker level and a 75% correlation of disease progression with a rise in marker level. The corresponding correlations in the marker negative group were 41% and 39%. Marker positive patients also demonstrated a rise in marker before clinical recognition of disease progression in six of 11 instances whereas only one of nine instances in marker negative patients showed such a rise. Patients with evidence of static disease had normal and stable marker levels.