Introduction/Background Gestational Throphoblastic Neoplasia (GTN) is a malignant lesion originating from the villous and extra villous trophoblast of the placenta. Main treatment is chemotherapy, only few cases need hysterectomy. The effectivity of hysterectomy in decreasing in serum Beta HCG in gestational trophoblastic neoplasia (GTN) is analyzed in this study

Methodology A Cross sectional study of 12 patients with GTN who underwent hysterectomy since 2015 until 2021 at Dr. Soetomo General Academic Hospital in Surabaya – Indonesia was done. The level of serum Beta HCG was measured pre and post hysterectomy. The collected datas were analyzed with Wilcoxon test then continue with Pearson correlation test. Bivariate analysis between characteristics and hCG level tested with chi-square.

Results Twelve cases were analyzed, consisted of choriocarcinoma (7/12), Placental Site Trophoblastic Tumor (2/12), invasive mole (2/12), and hydatidiform mole (1/12). The average patient’s age was 37 years old. The highest pre-operative hCG level was 378.909 mIU/mL. The highest post-operative beta hCG level was 136.710 mIU/mL. The Average decrease of serum beta HCG was 72.317,34 mIU/mL. Post-operative hCG levels were found to be normal (<5 mIU/mL) only in four cases (33.33%). There was significant difference of hCG level between pre and post hysterectomy (p=0,002) with strong correlation (r=0,773). Clinical characteristic that correlated with normal Beta hCG level after hysterectomy was WHO score (p=0,007). Age, parity, history of miscarriage, last child age, histopathology type, and surgery type were not correlated with normal hCG level after hysterectomy.

Conclusion Hysterectomy was a procedure that can effectively decrease serum Beta HCG level in GTN patients. WHO risk score also correlated with the post-hysterectomy level of serum Beta HCG.