FIGO Stage IV and Age Over 55 Years as Prognostic Predicators in Patients With Metastatic Malignant Struma Ovarii

Abstract

Introduction: Metastatic malignant struma ovarii (MSO) is an extremely rare disease that lacks treatment consensus and accurate prognosis. The objective of this study was to present the clinical, pathological, and treatment characteristics of metastatic MSO, while also investigate the overall survival (OS) rate and factors affecting prognosis in this population. Materials and Methods: A total of 79 cases of metastatic MSO were reviewed, including four cases of metastatic MSO from our hospital and 75 cases selected from the literature. Logistic regression was used to identify potential factors affecting disease free survival (DFS). The Kaplan-Meier method and log-rank test were used to determine OS; further Cox regression was used to evaluate factors affecting OS. Results: The mean age of all the patients at diagnosis was 43.8 years. The most common metastatic sites were peritoneum, bone, liver, omentum and lung in descending order. Only two patients (2.6%) coexisted with local primary thyroid cancer. Follicular carcinoma (41.8%) as the most prevalent subtype, followed by papillary carcinoma, follicular variant of papillary carcinoma, and mixed follicular-papillary carcinoma. 36.7% of the patients received conservative surgery, 43.0% of them underwent aggressive surgery, and 15.2% of them did not receive any surgery. 74.7% of patients who received adjuvant therapy underwent radioiodine therapy (RAI). Logistics regression revealed that FIGO stage IV was the only prognostic factor in predicting DFS (P = 0.002; Odds Ratio [OR] 5.333; 95% confidence interval [CI]: 1.839-15.471). Only seven deaths occurred. The OS rates at 5, 10, 15 years were 89.3, 82.4, 65.9%, respectively. Multivariate analysis showed age over 55 years (P = 0.006; OR 9.362; 95%CI: 1.895-46.246) was the only risk factor for OS. Conclusion: Patients with metastatic MSO have an excellent disease-specific OS rate, FIGO stage IV and age over 55 years were two factors affecting disease prognosis. Conservative surgery with residual ablation by RAI after total thyroidectomy should be preferred since the benefits of aggressive surgery are uncertain.

Metastatic Malignant Struma Ovarii and Graves’ Disease: A Rare Occurrence

“…Despite different management strategies, a recent study showed that patients with malignant SO have excellent disease-specific survival rates, whether or not metastases occurred. 8 This was in agreement with previous reports of 89% to 94.3% 10-year survival rates for patients with malignant SO. 17 , 18 …”

“…In a case series and literature review of metastatic malignant SO, Li et al 8 reported that 24% to 50% initially presented with a benign SO, and the time interval ranged from 2 months to 26 years. This adds to the challenge of a timely diagnosis and reinforced the need for regular follow-up even in benign SO.…”

Malignant Struma Ovarii with Concurrent Thyroid Cancer: Outcomes during and after Pregnancy

“…There are some factors that have been associated with increased risk of aggressive behavior in malignant SO such as struma size greater than 5 cm, presence of more than 50% of proliferating tissue within a teratoma, extra-ovarian spread, adherence to adjacent organs, ascites, age over 55 years, and FIGO (International Federation of Gynecology and Obstetrics) stage IV of ovarian cancer [2,4,14]. The first 2 were present in our case.…”

Survival Outcomes and Prognostic Predictors in Patients With Malignant Struma Ovarii

“…Although their study included patients with and without metastasis, they did not evaluate risk factors for overall survival (OS). Our previous study found a similar OS rate in patients with MSO (confined to the ovary) and metastatic MSO ( 10 , 11 ). We found that age ≥55 years was a strong risk factor for OS in patients with metastatic MSO but did not find any statistically significant predictive factor for OS in patients with MSO confined to the ovary.…”