The prognostic value of serum CA-125 measurements was assessed in 54 patients with advanced ovarian adenocarcinoma. All patients received a minimum of two courses of carboplatin as part of the North Thames Cooperative Group trial. With a minimum follow-up of 6 months, 37 patients (69%) have clinical evidence of progressive disease and 28 have died. The absolute prechemotherapy level of CA-125 was of no value in predicting which patients would develop progressive disease. However, the change in CA-125 levels from before chemotherapy to 1 month later, after one course of carboplatin, could be used to divide patients into different prognostic groups. The best discrimination was found by dividing the patients into those who showed a greater than sevenfold decrease in CA-125 levels and those who showed a smaller change. Eight of 14 (58%) patients with a greater than sevenfold decrease in CA-125 levels remain disease-free compared with three of 36 (9%) patients with a lesser fall (P = .0005). The change in CA-125 levels during the first month of chemotherapy may indicate which patients should be offered alternative or symptomatic therapy and which should continue with the currently available toxic chemotherapy.

Summary.-Eleven groups of workers submitted a total of 21 bronchial tumourassociated antigen preparations and 19 antisera for comparative studies. Many of the antisera proved to be polyspecific despite absorption procedures. Most of the antigen preparations contained some material reactive towards a reference antiserum to normal human serum proteins.While it appeared that no participants were studying identical antigen-antibody reactions, several cross-reactivities were identified in the antisera. When immune reactions to CEA, AFP, NCA, ferritin, lactoferrin, human pepsin and gastricsin, and the pregnancy proteins, SP1 and SP3 were excluded by use of reference antisera and electroimmunoprecipitation methods, there remained 5 antigen-antibody reactions defining unique antigens. The clinical usefulness of any of these 5 antigens has yet to be determined.