A clinical trial on diagnostic scoring system of choriocarcinoma and invasive mole in Vietnam.

Objectives: The aim was to discriminate preoperatively invasive mole (IM) and choriocarcinoma (CC) in patients with gestational trophoblastic neoplasm (GTN) for early and satisfactory treatment in Vietnam.

Methods: In 1990, 122 patients with GTN treated at TUDU Hospital were retrospectively analysed to make a differential diagnosis between CC and IM by using the JSOG scoring system and these results were later compared with postoperative histopathological findings. Furthermore, to raise the predictive diagnostic value for CC, the authors modified the JSOG system and devised a scoring system of TUDU hospital which results were compared with that of the JSOG ones. From the end of 1990 to March 1993, in 151 patients with GTN who underwent surgery, preoperative and postoperative diagnoses of CC and IM were prospectively compared using the JSOG and the modified scoring system. The comparative data were statistically analysed using the t-test, chi 2 test and Fisher test. The sensitivity, specificity, and the positive and negative predictive value, and false positive and false negative were calculated and compared. RESULTS RETROSPECTIVE STUDY: In making a predictive diagnosis of 122 patients with findings of trophoblastic tumors, the authors found some differences in possibility of CC of the following subfactors: latent period, primary lesion, pulmonary metastases, metastases except pulmonary metastases and hCG rerise. So, a modified scoring system of TUDU hospital was devised.

Prospective study: Of 151 Vietnamese patients with GTN using the JSOG scoring system and the modified system, a diagnostic probability in 108 cases predicted choriocarcinoma by JSOG scoring system was 61%, while that of invasive mole in 43 cases was 62.8%. Accordingly, the false positive rate for invasive mole of 64 cases predicted choriocarcinoma was 38.9%. According to the modified scoring system, of 75 patients predicted choriocarcinoma, 69 patients were histologically confirmed choriocarcinoma. Therefore, the diagnostic specificity was high (94.20%) and the false positive rate was low (5.3%), while of 76 patients predicted invasive mole, 13 patients were histologically diagnosed as choriocarcinoma. Accordingly, the false negative rate was low (13.1%).

Conclusion: The modified JSOG scoring system is of more diagnostic value in the preoperative differentiation between CC and IM in Vietnam.