Serum granulocyte macrophage colony stimulating factor (GM-CSF) in gestational trophoblastic diseases.

GM-CSF was assayed by a solid phase enzyme immunoassay in sera of 42 cases of vesicular mole, 24 cases of choriocarcinoma and 23 cases of normal pregnant women at their first trimester (controls). Diagnosis of gestational trophoblastic disease (GTD) was based on histopathologic examination of biopsy specimens obtained by endometrial curettage in cases of choriocarcinoma and molar tissue in patients with vesicular mole. Serum concentration of chorionic gonadotrophin beta subunit (hCG beta) was determined by I125 solid phase radioimmunoassay before and after treatment at weekly intervals for 3 months and then monthly for one year. According to pathologic diagnosis and serial serum hCG beta assays, cases of GTD were subdivided into remission and progressive tumour groups. Results demonstrated that serum GM-CSF levels in cases of vesicular mole as well as remission cases of choriocarcinoma were not significantly different from those of controls. On the other hand, progressive tumour cases of choriocarcinoma which later showed an abnormal hCG beta regression curve had significantly elevated serum GM-CSF level, where the mean fold rise amounted to 2.55 of the mean control value. Moreover, the incidence of abnormally elevated serum GM-CSF in these cases was 80%. It seems that this rise reflects a possible mechanism of immune surveillance. These results indicate that serum GM-CSF assay may be considered as a valuable prognostic biomarker in cases of malignant trophoblastic tumours where the assay is clinically useful in identifying high risk choriocarcinoma cases, thus justifying the installation of early specific treatment as well as intensive follow up care.