Survival Outcomes and Prognostic Predictors in Patients With Malignant Struma Ovarii

Background: Malignant struma ovarii (MSO) is an extremely rare ovarian malignant tumor and there is limited data on the survival outcomes and prognostic predictors of MSO. The objectives of this study were to investigate the disease-free survival (DFS), overall survival (OS), and disease-specific survival (DSS) rates of patients with MSO, and also evaluate the prognostic factors in this population.Methods: A retrospective study was conducted and 194 cases of MSO were selected. DFS was assessed by the logistic regression, OS by the Kaplan–Meier method, and DSS was evaluated by the Cox regression.Results: The median age of these patients was 46.0 years; 142 cases (73.2%) were confined to the ovary and 52 cases (26.8%) had extraovarian metastasis at the initial diagnosis of MSO. During the follow-up, 75.3% of these patients showed no evidence of disease and 18.0% were alive with disease. Only 13 deaths occurred, with 10 attributed to MSO. The 5, 10, and 15-year OS rates were 91.4, 87.7, and 83.5%, respectively. The 5, 10, and 15-year DSS rates were 93.8, 90.0, and 85.7%, respectively. Logistic regression revealed that International Federation of Gynecology and Obstetrics (FIGO) stage IV was the only risk factor for DFS [p < 0.001; odds ratio (OR) 7.328; 95% CI 3.103–16.885, FIGO stage IV vs. stage I; p = 0.021; OR 4.750, 95% CI 1.264–17.856, FIGO stage IV vs. stage II-III]. The multivariate Cox regression analysis showed that poor differentiation was the only risk factor for both OS (p = 0.005, OR 6.406; 95% CI 1.730–23.717) and DSS (p = 0.001, OR 9.664; 95% CI 2.409–38.760), while age ≥45 years was the prognostic predictor for OS (p = 0.038, OR 4.959; 95% CI 1.093–22.508).Conclusion: Survival outcomes were excellent in patients with MSO, irrespective of the treatment strategy, FIGO stage IV, age ≥45 years, and poor differentiation of tumors were the independent risk factors.

Clinical characteristics and survival outcomes of malignant struma ovarii confined to the ovary

Background Malignant struma ovarii (MSO) is a unique type of ovarian malignancy that data on the survival outcome is limited and management strategy remains controversial due to its extreme rarity. Methods To investigate the clinical characteristics and treatment options in patients with MSO confined to the ovary, while also evaluating the recurrent-free survival (RFS) and overall survival (OS) rate in this population, a retrospective study was conducted. One hundred twenty-five cases of MSO confined to the ovary were enrolled and their clinical characteristics, treatment strategies, and results of follow-up were analyzed. OS and RFS were assessed by Kaplan-Meier analyses and Cox regression models. Results The most common pathological subtype in this cohort was papillary carcinoma (44.8%). Other reported subtypes, in order of prevalence, were follicular variant of papillary carcinoma, follicular carcinoma, and mixed follicular-papillary carcinoma. Surgical treatment options varied in this cohort that 8.0% of the patients received ovarian cystectomy, 33.6% underwent unilateral salpingo-oophorectomy (USO), 5.6% received bilateral salpingo-oophorectomy (BSO), 21.6% received total abdominal hysterectomy with BSO (TAH/BSO), and 17.6% were treated with debulking surgery; 20.0% of them received radioiodine therapy (RAI). Twenty-seven patients experienced recurrence with a median RFS of 14.0 years (95% confidence interval [CI], 9.5–18.5). The 5-year and 10-year recurrent rate were 27.1, 35.2%, respectively. Eight patients died during follow-up, with five attributed to MSO; the 5-year, 10-year, and 20-year OS rate was 95.3, 88.7 and 88.7%, respectively. However, the univariate and multivariate Cox regression showed no potential risk factor for RFS and OS. Conclusion Patients with MSO confined to the ovary had an excellent survival outcome, despite varied treatment strategies, and the recurrent rate was relatively high. We recommend USO as the preferred surgical option in this population since more aggressive surgery does not improve outcomes and the benefits of RAI are uncertain.

The Clinical and Pathological Characteristics of Malignant Struma Ovarii: An Analysis of 144 Published Patients

The objective of this study is to summarize the clinical and pathologic characteristics of malignant struma ovarii to facilitate the early diagnosis and treatment of this disease. All 144 patients were females from 27 countries. The mean age of the patients at diagnosis was 42.6 years. Overall, 35.71% of the patients underwent unilateral oophorectomy, 58.57% of the patients underwent bilateral oophorectomy, 5.72% of the patients were not ovariectomized, and 38.57% of the patients received radioactive iodine treatment with an average dose of 158.22 mCI each time. “Impure” types accounted for 70.19% of the cases, while pure types accounted for 29.81% of the cases. Among these cases, papillary thyroid carcinoma accounted for 50.00%, follicular thyroid carcinoma accounted for 26.47%, follicular variant of papillary thyroid carcinoma accounted for 18.63%, papillary and follicular mixed thyroid carcinoma accounted for 2.94%, anaplastic carcinoma accounted for 0.98%, and medullary carcinoma accounted for 0.98%. In total, 21 patients (51.22%) had elevated CA125. More than half of the patients (51.94%) had metastasis outside the ovary. The most common metastatic site was the pelvic cavity. The misdiagnosis rate was 17.27%. Mortality was related to metastasis and the cancer type. Gene mutations were found in the NRAS, KRAS, BRAF, and KIT genes and were similar to those in thyroid carcinoma, but some patients (37.5%) did not exhibit any gene mutations. Regardless of the treatment received, the survival rate is high. Treatment could initially include ovariectomy; however, in cases with metastasis and iodine uptake of the metastatic tumor, thyroidectomy, radioactive iodine therapy, and thyroid hormone inhibiting therapy are indicated.