Tumor markers for ovarian cancer. A comparative immunohistochemical and immunocytochemical study of two commercial monoclonal antibodies (OV632 and OC125).

A comparative immunohistologic and immunocytologic study was performed to assess the immunoreactivity of the monoclonal antibodies OC125 and OV632, both directed at antigens present on epithelial ovarian tumors. OC125 reacted with 53 of 59 ovarian carcinomas, 20 of 20 uterine carcinomas, and 25 of 111 nongynecologic tumors (including 20 of 38 breast carcinomas). OV632 was demonstrated in 47 of 59 ovarian carcinomas, 11 of 20 uterine carcinomas, and only 7 of 111 nongynecologic tumors. With OV632 no reactivity was found in carcinomas of the breast or the gastrointestinal tract. Cytologic preparations of malignant effusions of patients with ovarian cancer showed reactivity with OC125 in 32 of 35 cases, and OV632 with positivity in 34 of 35 cases. Mesothelial cells in reactive effusions were OC125 positive in 16 of 20 cases but never showed positivity with OV632. The authors conclude that for histopathology a combination of OC125 and OV632 offers high sensitivity (0.86) and specificity (0.89) for ovarian cancer. For cytology, OV632 is the most specific tumor marker available.