Coexisting Papillary and Anaplastic Thyroid Cancer: Elucidating the Spectrum of Aggressive Behavior.

BACKGROUND: Anaplastic thyroid carcinoma (ATC) is a rare and lethal form of thyroid cancer. Overall prognosis is unclear when it arises focally in a background of papillary thyroid cancer (PTC). Clinicopathologic features and outcomes of tumors with coexisting PTC and ATC histologies (co-PTC/ATC) were categorized. METHODS: The National Cancer Database was queried for histologic codes denoting PTC, ATC, and co-PTC/ATC, defined as Grade 4 PTC, diagnosed from 2004 to 2017. Clinicopathologic features, OS, and treatment outcomes were analyzed by histologic type. RESULTS: A total of 386,862 PTC, 763 co-PTC/ATC, and 3,880 ATC patients were identified. Patients with co-PTC/ATC had clinicopathologic features in-between those of PTC and ATC, including rates of tumor size >4 cm, extrathyroidal extension, and distant metastases. On multivariable Cox proportional hazards modeling, age >55 years, Charlson-Deyo score ≥2, positive lymph nodes, lymphovascular invasion, distant metastases, and positive surgical margins were associated with worse OS, whereas radioactive iodine (RAI) and external beam radiation therapy (EBRT) were associated with improved OS, irrespective of margin status. OS was worse for co-PTC/ATC than for PTC but better than for ATC and differed based on the presence or absence of "aggressive" tumor features, including lymph node positivity, lymphovascular invasion, distant metastases, and positive surgical margins. CONCLUSIONS: Survival of patients with co-PTC/ATC is dependent on the presence of aggressive clinicopathologic features and lies within a spectrum between that of PTC and ATC. Adjuvant RAI and EBRT treatment may be beneficial, even after R0 resection.

Proposed Risk Stratification and Patterns of Radioactive Iodine Therapy in Malignant Struma Ovarii.

Introduction: Malignant struma ovarii (MSO) is a rare thyroid cancer arising within an ovarian teratoma. While surgical excision of the primary tumor is widely accepted as standard of care, recommendations for adjuvant treatment of MSO-whether or not to administer radioactive iodine (RAI)-are based largely on case reports and remain debated. In this study, we aimed to propose a risk stratification and analyze RAI utilization patterns in MSO cases. Methods: The National Cancer Database (NCDB) was queried for patients with MSO between 2004 and 2016. Demographic, oncological, and clinicopathologic data were compared between groups using Fisher's exact test. Kaplan-Meier curves were used to estimate overall survival (OS), and variables associated with OS were assessed via univariate Cox regression. We adapted the 2015 American Thyroid Association risk guidelines for MSO patients. We stratified patients into low-, intermediate-, and high-risk groups using metastasis, extraovarian extension, lymphovascular invasion, lymph node status, surgical margins, tumor size, and grade. Risk stratification, demographic, oncological, and clinicopathologic data were compared between the groups receiving and not receiving RAI therapy. We then queried the Surveillance, Epidemiology, and End Results (SEER) 18 registry for patients with MSO between 2000 and 2018 to confirm our risk stratification analysis. Results: In the NCDB analysis, a total of 158 patients were identified, and 19 received RAI. RAI therapy was associated with distant metastasis (p = 0.005) and lymph node status (p = 0.012). Twenty-one NCDB patients were stratified as high risk, and 30% of high-risk patients received RAI. High-risk stratification was associated with decreased OS via univariate Cox regression (hazard ratio = 4.0 [95% confidence interval 1.11-14.26], p = 0.034). In our subsequent analysis using the SEER registry, there were 95 MSO patients, and 18 received RAI. Again, the majority of high-risk patients did not receive RAI, with only 41% of high-risk patients receiving RAI. Conclusions: MSO is a rare malignancy with apparently variable and inconsistent patterns of postoperative RAI administration. The risk stratification described here provides a framework to identify patients potentially at risk for mortality, and utilization of RAI in this group should be studied further.

Insurance type is associated with appropriate use of surgical and adjuvant care for differentiated thyroid carcinoma.

BACKGROUND: We aimed to characterize the association between differentiated thyroid cancer (DTC) patient insurance status and appropriateness of therapy (AOT) regarding extent of thyroidectomy and radioactive iodine (RAI) treatment. METHODS: The National Cancer Database was queried for DTC patients diagnosed between 2010 and 2016. Adjusted odds ratios (AOR) for AOT, as defined by the American Thyroid Association guidelines, and hazard ratios (HR) for overall survival (OS) were calculated. A difference-in-differences (DD) analysis examined the association of Medicaid expansion with outcomes for low-income patients aged <65. RESULTS: A total of 224,500 patients were included. Medicaid and uninsured patients were at increased risk of undergoing inappropriate therapy, including inappropriate lobectomy (Medicaid 1.36, 95% confidence interval [CI]: 1.21-1.54; uninsured 1.30, 95% CI: 1.05-1.60), and under-treatment with RAI (Medicaid 1.20, 95% CI: 1.14-1.26; uninsured 1.44, 95% CI: 1.33-1.55). Inappropriate lobectomy (HR 2.0, 95% CI: 1.7-2.3, P < .001) and under-treatment with RAI (HR 2.3, 95% CI: 2.2-2.5, P < .001) were independently associated with decreased survival, while appropriate surgical resection (HR 0.3, 95% CI: 0.3-0.3, P < .001) was associated with improved odds of survival; the model controlled for all relevant clinico-pathologic variables. No difference in AOT was observed in Medicaid expansion versus non-expansion states with respect to surgery or adjuvant RAI therapy. CONCLUSION: Medicaid and uninsured patients are at significantly increased odds of receiving inappropriate treatment for DTC; both groups are at a survival disadvantage compared with Medicare and those privately insured.

Association of medicaid expansion of the Affordable Care Act with the stage at diagnosis and treatment of papillary thyroid cancer: A difference-in-differences analysis.

BACKGROUND: The Affordable Care Act's (ACA) Medicaid expansion has increased insurance coverage and improved various cancer outcomes. Its impact in papillary thyroid cancer (PTC) remains unclear. METHODS: Non-elderly patients (40-64 years-old) with PTC living in low-income areas either in a 2014 expansion, or a non-expansion state were identified from the National Cancer Database between 2010 and 2016. Insurance coverage, stage at diagnosis, and RAI administration were analyzed using a difference-in-differences analysis. RESULTS: 10,644 patients were included. Compared with non-expansion states, the percentage of uninsured patients (adjusted-DD -2.6% [95%-CI -4.3to-0.8%],p = 0.004) and patients with private insurance decreased, and those with Medicaid coverage increased (adjusted-DD 9.7% [95%-CI 6.9-12.5%],p < 0.001) in expansion states after ACA implementation. The percentage of patients with pT1 did not differ between expansion and non-expansion states; neither did the use of RAI. CONCLUSIONS: Medicaid expansion has resulted in a smaller uninsured population in PTC patients, but without earlier disease presentation nor change in RAI treatment.