Serum enzyme changes during chemotherapy for ovarian cancer

Serum lactate dehydrogenase (LD), gamma-glutamyl transferase (gamma GT) and alkaline phosphatase (ALP) activities have been measured in 105 patients with ovarian cancer for periods of up to 4 years. The extent of the disease was assessed at laporotomy according to the FIGO classification. Chemotherapy was started one week after surgery, at which time 25% of patients had elevated LD, 29% elevated gamma GT and 21% elevated ALP. Of 51 patients who went into complete remission, 4% still showed elevated LD, 25% elevated gamma GT and 12% elevated ALP. Reactivation of tumour growth was apparent in 32 patients; there was a significant increase in the serum LD, gamma GT and ALP activities when remission and recurrence were first detected in 65%, 50% and 35% of patients respectively. With 14 patients, there was an unexplained increase in the activity of one or more of the enzymes 1-6 months prior to recurrence being detected; these changes may predict that chemotherapy is losing effect. During long-term remission, serum LD was increased in patients suffering from urinary tract infection or bladder dysfunction.