Propensity score matching analysis of the prognosis for the rare oxyphilic subtype of thyroid cancer (Hurthle cell carcinoma)

Comparison of prognosis between oncocytic thyroid carcinoma and follicular thyroid carcinoma: a population-based propensity score matching analysis

BACKGROUND

Oncocytic thyroid carcinoma (OTC) is a rare subtype of thyroid cancer known for its distinctive morphology and high likelihood of recurrence, setting it apart from follicular thyroid carcinoma (FTC). Despite this, there is limited research comparing the clinicopathological characteristics and outcomes of OTC and FTC.

METHODS

We retrospectively searched through the Surveillance, Epidemiology, and End-Results (SEER) database (2004-2015) for histologically diagnosed OTC and FTC patients. Kaplan-Meier analysis, propensity score matching (PSM), univariate Cox proportional risk regression model, and subgroup analysis were employed to investigate the prognostic effect of clinicopathological features and treatment regimens on survival outcomes of OTC and FTC patients.

RESULTS

2329 OTC patients and 5679 FTC patients were included in the study. OTC patients were prone to older age, white race, lymph node metastasis, distal metastasis, extension and multiple primary tumors compared with FTC patients. After using a 1:1 PSM matching ratio, there were no significant differences in demographic and clinicopathological characteristics between the matched groups. Further Cox regression analysis showed that OTC patients had lower overall survival (OS) and cancer-specific survival (CSS) in contrast with FTC patients. Subgroup survival analysis suggested that the OTC patients were related to lower OS in subgroups including those over 55 years old, male sex, white ethnicity, extrathyroidal extension, single primary tumor, surgery and without chemotherapy compared with the FTC patients in these subgroups. In addition, the OTC patients were connected with lower CSS in subgroups including male sex, white ethnicity, married status, tumor size is less than 20 mm or more than 40 mm, N0 stage, localized stage, single primary tumor, surgery, radiotherapy, and without chemotherapy compared with the FTC patients in these subgroups. Meanwhile, the OTC patients had lower CSS compared to FTC patients regardless of age and extrathyroidal extension.

CONCLUSIONS

The results suggested that OTC patients have unique clinical features and poorer prognoses compared to FTC patients. Surgical resection and radioactive iodine therapy are recommended for OTC patients and FTC patients. It is worth noting that the prognosis of OTC relies largely on the selection of treatment strategies. Therefore, our results highlighted the clinical significance of the early distinguishment and the correct choice of treatment in OTC patients.

Radioactive iodine therapy improves overall survival outcome in oncocytic carcinoma of the thyroid by reducing death risks from noncancer causes: A competing risk analysis of 4641 patients

BACKGROUND

Oncocytic carcinoma of the thyroid (OCA) is an independent type of thyroid cancer. Radioactive iodine (RAI) therapy was frequently administered to OCA patients, but its contribution to improving survival is indefinite.

METHODS

4641 OCA patients from 2000 to 2018 were identified from the Surveillance, Epidemiology, and End Results (SEER) database. Cox proportional hazard regression and competing risk analysis were applied.

RESULTS

Tumor size, SEER stage, primary surgery, and neck dissection were prognostic factors for cancer-specific survival. The results of competing risk analysis demonstrated that age over 55 years dramatically increased non-OCA death risks. Treatments that improve non-OCA survival (including total thyroidectomy, RAI therapy, and systemic therapy) should be recommended in OCA patients older than 55 years of age. Neck lymphadenectomy should not be recommended for OCA, since the metastatic lymph node ratio was low (about 3%).

CONCLUSIONS

RAI therapy can improve survival in OCA by reducing noncancer death risks.

Radioactive Iodine Therapy Does not Improve Cancer-specific Survival in Hürthle Cell Carcinoma of the Thyroid

CONTEXT

It is unclear whether radioactive iodine (RAI) therapy could improve cancer-specific survival (CSS) in patients with Hürthle cell carcinoma (HCC) of the thyroid.

OBJECTIVE

To investigate the effect of RAI on CSS in HCC patients.

METHODS

HCC patients who underwent total thyroidectomy (TT) were identified from the Surveillance, Epidemiology, and End Results (SEER) database between 2000 and 2018. The Kaplan-Meier method and the Cox proportional hazards regression model were used to evaluate CSS. Propensity score-matched (PSM) analyses were performed to control the influence of potential confounders.

RESULTS

A total of 2279 patients were identified. RAI treatment was not significantly associated with improved CSS in overall or PSM cohort. Subgroup analyses indicated similar results, even in patients with aggressive features such as age 55 years or older, tumor size greater than 40 mm, distant disease in SEER staging, extrathyroidal extension, and lymph node metastases (all P > .05).

CONCLUSION

RAI has no statistically significant influence on the CSS in HCC patients. This information may aid in decision-making for RAI therapy in these patients.

Prognostic factors and survival analysis of Hurthle cell carcinoma: A population-based study

BACKGROUND

Hurthle cell carcinoma is a rare type of differentiated thyroid cancer and historically associated with a worse prognosis. The aim of this study was to define the demographic and socioeconomic factors, tumor characteristics, and surgical treatment status associated with Hurthle cell carcinoma survival using the most recent population-level data.

METHODS

The Surveillance, Epidemiology, and End Results database was queried for adult patients (>18 years of age) diagnosed with Hurthle cell carcinoma from 2000 to 2018. The demographic factors, socioeconomic factors, tumor characteristics, and extent of surgery data were collected as potential predictors. The outcomes of interest were 10-year overall and disease-specific survival, which were estimated using the Kaplan-Maier method. The associations between the potential predictors and survival were evaluated using the Cox proportional hazard model.

RESULTS

In total, 4,643 patients with Hurthle cell carcinoma were identified using the Surveillance, Epidemiology, and End Results database. The cohort was predominately White, had a mean age of 57.7 (±15.6), 69% female sex, and median follow-up was 90 months. The 10-year overall survival and Hurthle cell carcinoma-specific survival were 78.1% (95% confidence interval: 76.7%-79.5%) and 91.8% (95% confidence interval: 90.9%-92.9%), respectively. Younger age <55 years, female sex, White race, Hispanic ethnicity, higher household income, and lower tumor grade and stage were significantly associated with increased survival (P < .01). In the multivariate Cox proportional hazard model, all variables except race and ethnicity remained significantly associated with overall survival. Although patients who underwent thyroid surgery had improved survival compared to no surgery, the extent of surgery did not have any effect on their overall or disease-specific survival.

CONCLUSION

This study highlighted the aggressive nature of Hurthle cell carcinoma and the effect of socioeconomic factors, such as household income, which may play a role in Hurthle cell carcinoma survivorship. Research is needed to understand the interplay of these factors and their role in predicting patient outcomes.

Avidity and Outcomes of Radioiodine Therapy for Distant Metastasis of Distinct Types of Differentiated Thyroid Cancer

CONTEXT

The recommendations for radioactive-iodine treatment (RAIT) in metastatic differentiated thyroid cancer (DTC) are mostly based in the experience with papillary histotype and do not consider the differences within the distinct types of DTC, in terms of RAIT uptake and response.

OBJECTIVE

This work aims to investigate the association between histology and RAIT avidity and response, and to evaluate whether histotype was an independent prognostic factor in progression-free survival (PFS) and disease-specific survival (DSS) after RAIT for distant metastatic disease.

METHODS

A retrospective analysis was conducted of all DTC patients who underwent RAIT for distant metastatic disease, from 2001 to 2018, at a thyroid cancer referral center. We included 126 patients: 42 (33.3%) classical variant papillary thyroid cancer (cvPTC), 45 (35.7%) follicular variant PTC (fvPTC), 17 (13.5%) follicular thyroid cancer (FTC) and 22 (17.5%) Hürthle cell carcinoma. Main outcome measures included RAIT avidity and response.

RESULTS

RAIT avidity was independently associated with histology (P < .001) and stimulated thyroglobulin (Tg) at first RAIT for distant lesions (P = .007). Avidity was lowest in HCC (13.6%), intermediate in cvPTC (21.4%), and highest in fvPTC (75.6%) and FTC (76.5%). Regarding RAIT response, HCC and FTC were not different; both showed significantly more often progression after RAIT than fvPTC and cvPTC. Histology influenced PFS (P = .014), but tumor type was not a significant prognostic factor in DSS. Instead, age at diagnosis, resection status, and stimulated Tg at the first RAIT were significantly associated with DSS.

CONCLUSION

DTC histotype influenced RAIT avidity and PFS. It is crucial to better detect the metastatic patients that may benefit the most from RAIT.

Clinical impact of follicular oncocytic (Hürthle cell) carcinoma in comparison with corresponding classical follicular thyroid carcinoma

PURPOSE

There are controversial debates if patients with Hürthle cell carcinoma, also known as oxyphilic or oncocytic cell follicular thyroid carcinoma, have a poorer outcome. In this study, we systematically evaluated the clinical outcome in a large patient cohort following thyroidectomy and initial I-131 radioactive iodine therapy (RIT).

METHODS

We retrospectively evaluated a total of 378 patients with diagnosed oncocytic follicular Hürthle cell carcinoma (OFTC) (N = 126) or with classical follicular thyroid carcinoma (FTC) (N = 252). Patients received thyroidectomy and complementary I-131 RIT. Clinical data regarding basic demographic characteristics, tumor grade, persistent disease and recurrence during follow-up, and disease-free, disease-specific, and overall survival were collected during follow-up of 6.9 years (interquartile range 3.7; 11.7 years). Univariate and multivariate analyses were used to identify factors associated with disease-related and overall survival.

RESULTS

Before and after matching for risk factors, recurrence was significantly more frequently diagnosed in OFTC patients during follow-up (17% vs. 8%; p value 0.037). Likewise, OFTC patients presented with a reduced mean disease-free survival of 17.9 years (95% CI 16.0-19.8) vs. 20.1 years (95% CI 19.0-21.1) in FTC patients (p value 0.027). Multivariate analysis revealed OFTC (HR 0.502; 95% CI 0.309-0.816) as the only independent prognostic factor for disease-free survival. Distant metastases of OFTC patients were significantly less iodine-avid (p value 0.014). Mean disease-specific and overall survival did not differ significantly (p value 0.671 and 0.687) during follow-up of median 6.9 years (3.7; 11.7 years).

CONCLUSIONS

Our study suggests that recurrence is more often seen in OFTC patients. OFTC patients have a poorer prognosis for disease-free survival. Thus, OFTC and FTC behave differently and should be categorized separately. However, patients suffering from OFTC present with the same overall and disease-specific survival at the end of follow-up indifferent to FTC patients after initial RIT.

Long-term outcome of rare oncocytic papillary (Hürthle cell) thyroid carcinoma following (adjuvant) initial radioiodine therapy

PURPOSE

Oncocytic (Hürthle cell) papillary thyroid carcinoma (OPTC) is a rare variant of the papillary thyroid carcinoma (PTC) which comprises approximately 1 to 11 % of PTC cases. Its clinical course and prognosis have not been comprehensively documented and the clinical outcome remains a controversial issue. Therefore, we investigated the long-term prognosis after thyroidectomy and (adjuvant) initial radioactive iodine therapy (RIT) of OPTC compared to PTC.

METHODS

A total of 563 patients (47 with OPTC and 516 with PTC) with a median follow-up of 9.9 (0.3; 23.5) years were studied. All patients underwent thyroidectomy followed by (adjuvant) initial RIT. Data on the patients' demographics, pathology, laboratory findings, imaging studies, treatment, and follow-up including recurrence, and disease-specific survival were collected. Cox's multivariate regression model was used to identify independent prognostic factors for survival.

RESULTS

OPTC patients were significantly older (55.2 ± 12.3 years) than PTC patients (50.3 ± 13.5) at the time of initial diagnosis (p value 0.016). Initial tumor size was larger in the OPTC group (2.8 ± 1.8 cm for OPTC patients, 1.5 ± 1.2 cm for PTC patients, p value < 0.001). Before matching, OPTC patients presented more often with evidence of disease at the last visit of follow-up (p value 0.046). However, this difference was not observed anymore after matching for risk factors (p value 0.637). Disease-specific survival did not differ significantly. Age (HR, 1.183; 95% CI, 1.097-1.276) was identified as an independent prognostic factor for disease-specific survival. OPTC patients predominantly showed a recurrence of distant metastasis within a shorter time despite being not statistically significant.

CONCLUSION

At initial diagnosis, OPTC shows significant differences in terms of age and initial tumor size compared to PTC. Patients suffering from OPTC present with the same clinical long-term outcome indifferent to PTC after (adjuvant) initial RIT after matching.

Chest wall metastasis in postoperative thyroid cancer: a case report

Thyroid cancer is common in China. Thyroid adenocarcinoma metastases can be local or distal metastasis. Local metastasis presents as a hard and fixed lymph node in the neck, while distant metastases are found in the lung, skull, vertebrae, and pelvis. However, thyroid follicular carcinomas are mostly observed in hematogenous metastases. The thyroid adenocarcinoma and follicular carcinoma of the thyroid gland are often misdiagnosed. Here, we report the case of a 53-year-old female patient. More than 2 years after her initial diagnosis, her left chest wall was physically examined. The results revealed a progressive enlargement that had a hard quality, poor activity, unclear boundary, pressure pain, and percussion pain. Thyroid follicular cell carcinoma was subsequently diagnosed and treated surgically. The thyroid carcinoma had multiple bone metastases, and the thyroid follicular carcinoma had spread to the chest wall through the blood vessels. Thus, preoperative procedures and follow-up should be strengthened because early pathological thyroid follicular carcinoma and thyroid adenoma can easily be misdiagnosed. Pathologic consultation and follow-ups should be strengthened to prevent misdiagnosis.

Minimal extrathyroidal extension affects the prognosis of differentiated thyroid cancer: Is there a need for change in the AJCC classification system?

Minimal extrathyroidal extension (ETE) is defined as tumor cells extending to the sternothyroid muscle or perithyroidal soft tissue. However, there is controversy regarding whether the magnitude of ETE (minimal or gross) should be considered in assigning a precise TNM stage to patients with thyroid cancer in the seventh/eighth editions of the AJCC system. The present study evaluated Surveillance, Epidemiology, and End Results data from 107,114 patients with differentiated thyroid cancer (2004–2013) to determine whether the magnitude of ETE (thyroid confinement, minimal, or gross) influenced the ability to predict cancer-specific survival (CSS) and overall survival (OS). Patient mortality was evaluated using Cox proportional hazards regression analyses and Kaplan-Meier analyses with log-rank tests. The cancer-specific mortality rates per 1,000 person-years were 1.407 for the thyroid confinement group (95% CI: 1.288–1.536), 5.133 for the minimal ETE group (95% CI: 4.301–6.124), and 29.735 for the gross ETE group (95% CI: 28.147–31.412). Relative to the thyroid confinement group, patients with minimal ETE and gross ETE had significantly poorer CSS and OS in the univariate and multivariate analyses (both P<0.001). After propensity-score matching according to age, sex, and race, we found that thyroid confinement was associated with better CSS and OS rates than minimal ETE (P<0.001) and gross ETE (P<0.001). These results from a population-based cohort provide a reference for precise personalized treatment and management of patients with minimal ETE. Furthermore, it may be prudent to revisit the magnitude of ETE as advocated by the AJCC and currently used for treatment recommendation by the American Thyroid Association.

Factors associated with distant metastasis in pediatric thyroid cancer: evaluation of the SEER database

Objectives Controversies regarding factors associated with distant metastasis in pediatric thyroid cancer remain among the scientific community. The aim of this study was to investigate factors influencing distant metastasis in pediatric thyroid cancer. Methods We reviewed 1376 patients (aged 2 to 18 years) with thyroid cancer treated between 2003 and 2014. Data collected and analyzed included sex, race, age at diagnosis, year of diagnosis, pathological type, number of tumor foci, tumor extension, T-stage, N-stage, surgical procedure and radiation. Univariate and multivariate analyses were conducted to evaluate factors influencing distant metastasis of pediatric thyroid cancer. Results In the univariate analysis, factors influencing distant metastasis of thyroid cancer were age at diagnosis (P < 0.001), N-stage (P < 0.001), number of tumor foci (P = 0.003), tumor extension (P < 0.001) and T-stage (T1 vs T2 (P = 0.803), T3 (P < 0.001) and T4 (P < 0.001)). In multivariate analysis, factors influencing distant metastasis of thyroid cancer were age at diagnosis (P = 0.001), N-stage (P < 0.001) and T-stage (T1 vs T3 (P = 0.036) and T4 (P < 0.001)). Sex, race, year of diagnosis, pathological type, number of tumor foci, tumor extension, surgical procedure and radiation had no significant influence on distant metastasis (all P > 0.05). Furthermore, according to chi-squared test, younger pediatric thyroid cancer patients with higher T- and N-stages are more likely to have distant metastasis. Conclusion Age at diagnosis, T-stage and N-stage influence distant metastasis of thyroid cancer patients aged 2 to 18 years; accordingly, more radical treatments may need to be used for patients with those risk elements.