Serum lactic dehydrogenase and primary carcinoma of the ovary.

Serum lactic dehydrogenase (LDH) was evaluated in 51 patients with primary carcinoma of the ovary. An increased activity of this enzyme was found in 69% of the patients. The mean +/- SD activity of LDH correlated significantly with stage of disease: 200 +/- 73 U/l in stages 1 and 2, 295 +/- 107 U/l in stages 3A and 3B, and 362 +/- 91 U/l in stages 3C and 4. Moreover, LDH activity correlated significantly with the histological type of the tumor: 170 +/- 57 U/l in mucinous, 300 +/- 107 U/l in serous, 330 +/- 106 U/l in endometroid, and 352 +/- 98 U/l in undifferentiated carcinoma. Normal activity of LDH was observed in 86% of patients in stages 1 and 2, but in only 21% of patients in stages 3 and 4. Serum LDH activity was not found to be a good predictor of late prognosis of the disease, and it did not correlate with the surgical findings on second-look laparotomy. In addition, LDH activity did not correlate with the surgical debulking effort. However, after completion of cytoreductive surgery and adjuvant therapy, LDH did correlate with the course of the disease. It is concluded that LDH may have a role in the evaluation of a patient with carcinoma of the ovary or with a pelvic mass.