Prognostic indicators of outcomes in patients with lung metastases from differentiated thyroid carcinoma during long-term follow-up

Automatic prediction of non-iodine-avid status in lung metastases for radioactive I131 treatment in differentiated thyroid cancer patients

Objectives

The growing incidence of differentiated thyroid cancer (DTC) have been linked to insulin resistance and metabolic syndrome. The imperative need for developing effective diagnostic imaging tools to predict the non-iodine-avid status of lung metastasis (LMs) in differentiated thyroid cancer (DTC) patients is underscored to prevent unnecessary radioactive iodine treatment (RAI).

Methods

Primary cohort consisted 1962 pretreated LMs of 496 consecutive DTC patients with pretreated initially diagnosed LMs who underwent chest CT and subsequent post-treatment radioiodine SPECT. After automatic lesion segmentation by SE V-Net, SE Net deep learning was trained to predict non-iodine-avid status of LMs. External validation cohort contained 123 pretreated LMs of 24 consecutive patients from other two hospitals. Stepwise validation was further performed according to the nodule's largest diameter.

Results

The SE-Net deep learning network yielded area under the receiver operating characteristic curve (AUC) values of 0.879 (95% confidence interval: 0.852-0.906) and 0.713 (95% confidence interval: 0.613-0.813) for internal and external validation. With the LM diameter decreasing from ≥10mm to ≤4mm, the AUCs remained relatively stable, for smallest nodules (≤4mm), the model yielded an AUC of 0.783. Decision curve analysis showed that most patients benefited using deep learning to decide radioactive I131 treatment.

Conclusion

This study presents a noninvasive, less radioactive and fully automatic approach that can facilitate suitable DTC patient selection for RAI therapy of LMs. Further prospective multicenter studies with larger study cohorts and related metabolic factors should address the possibility of comprehensive clinical transformation.

Risk factors for death of follicular thyroid carcinoma: a systematic review and meta-analysis

BACKGROUND

There are conflicting reports on the factors that increase the likelihood of patients dying from follicular thyroid carcinoma (FTC). Therefore, it is critical to identify risk factors of patients with FTC. This study aimed to identify the factors that increase the risk of death of patients with FTC and help clinicians make better treatment and follow-up decisions.

METHODS

A systematic literature review was conducted in PubMed and Web of Science databases for relevant studies published before January 31, 2023. Their reference lists were also analyzed. Two reviewers extracted data and evaluated the quality of eligible studies independently. Studies on patients who had open thyroidectomy procedures with or without neck dissection were included in this review. The RevMan 5.3 software was used to analyze the data.

RESULTS

This meta-analysis included thirteen studies with a total of 2075 patients. The following variables were associated with an increased risk of death in FTC patients: age > 45 years, male, tumor diameter > 4 cm, multifocality, extrathyroidal extension (ETE), widely invasive (WI), cervical lymph node metastasis (CLNM), distant metastases (DM) and non-radical resection tumor. Lobectomy and no radioactive iodine (RAI) treatment was not associated with the death of FTC patients.

CONCLUSION

Clinicians should pay closer attention to the following significant risk factors associated with the death of FTC patients: age (> 45), male, multifocality, tumor diameter > 4 cm, ETE, WI, non-radical resection tumor, CLNM, and DM. Individualized initial treatment and close follow-up are needed FTC patients who have these risk factors.

Analysis of the clinical factors affecting excellent response of Iodine-131 treatment for pulmonary metastases from differentiated thyroid cancer

Background

Iodiene-131 (131I) treatment is the primary therapeutic approach for imaging 131I-avid pulmonary metastases. The response to radioiodine (RAI) treatment is an important prognostic factor in patients with pulmonary metastases from differentiated thyroid cancer (DTC). Patients who achieve an excellent response (ER) to 131I treatment show significantly reduced disease-related mortality. This study aimed to retrospectively analyse the clinical data and therapeutic effects of 131I treatment in patients with DTC and pulmonary metastases and to screen out the clinical factors affecting ER.

Materials and methods

The study included a total of 75 patients with exclusively Iodine-131 avid (131I-avid) pulmonary metastases who underwent 131I treatment. Relevant clinical data for these patients were collected. Following treatment, the status of DTC metastatic lesions was categorized as follows: excellent response (ER), biochemical incomplete response (BIR), structural incomplete response (SIR), or indeterminate response (IDR). Gender, age at diagnosis, pathological type, stages (TNM), stimulated thyroglobulin (sTg) value before initial 131I treatment, metastatic nodule size, and type of post-treatment whole body scan (Rx-WBS) were recorded. Mono-factor analysis and binary logistic regression analyses were used to identify the factors that might affect the ER in DTC pulmonary metastases. The receiver operating characteristic (ROC) curve of the sTg value was used to predict the ER of 131I treatment.

Results

All 75 patients with exclusively 131I-avid pulmonary metastases received 131I treatment and underwent follow-up. Out of the 75 patients, 26 achieved ER, resulting in an excellent response rate of 34.7 % (26/75). Among them, 25 (25/26, 96.2 %) achieved an ER after undergoing two rounds of 131I treatment. Binary logistic regression analysis showed that the factors influencing DTC pulmonary metastases excellent response were lower sTg levels [odds ratio (OR) = 0.998, P < 0.001], micronodular metastases (OR = 0.349, P = 0.001) and focal distribution on Rx-WBS imaging (OR = 0.113, P = 0.001). The area under the ROC curve for sTg value predicting ER was 0.876, and the cut-off value was 26.84 ng/mL, with a sensitivity and specificity of 87.9 % and 80.3 %, respectively.

Conclusions

131I treatment is effective for 131I-avid pulmonary metastases of DTC. Some patients who underwent 131I treatment achieved ER. Most patients with ER were obtained after two rounds of 131I treatments. Patients with sTg values before initial 131I treatment lower than 26.84 ng/mL, micronodular metastases, and focal distribution on Rx-WBS imaging were more likely to achieve ER.

Assessment of Pulmonary Metastasis in Differentiated Thyroid Carcinoma: Value of HRCT Correlation with Functional Imaging

Pulmonary metastases in thyroid carcinoma demonstrates varying imaging characteristics and disease biology and the outcome. The valuable complimentary role of high-resolution CT (HRCT) in conjunction with functional imaging such as radioiodine scan has been discussed and illustrated in this review along with the varied clinical and imaging presentations of lung metastases from differentiated thyroid cancer (DTC). A multi-modality patient-specific diagnostic approach and awareness about the atypical presentations helps in early identification as well as effective management of these patients, and especially in certain situations that could need multi-disciplinary management. While HRCT of the lungs as an added tool provides detailed visualization of the lung parenchyma, in the era of hybrid imaging, the routine adoption of SPECT-CT in patients with pulmonary metastases (in diagnostic or post-treatment settings) could provide equivalent or even incremental information from further management viewpoint.

The association between the interval of radioiodine treatment and treatment response, and side effects in patients with lung metastases from differentiated thyroid cancer

Objective

Repeat radioiodine (RAI) treatment has been widely implemented for RAI-avid lung metastases and is clinically effective for lung metastatic differentiated thyroid cancer (DTC). We aim to investigate the association between the interval of RAI treatment and short-term response, and the side effects in patients with lung metastases from DTC and to identify predictors for non-effective response to the next RAI treatment.

Methods

A total of 282 course pairs from 91 patients were established and categorized into two groups by the interval of neighboring RAI treatment (<12 and ≥12 months), and the characteristics and treatment response between the two groups were compared. Multivariate logistic regression was used to identify predictors associated with treatment response. The side effects in the former course and the latter course were compared while taking into account the interval.

Results

No significant difference was found between the two groups in treatment response in the latter course (p > 0.05). In the multivariate analysis, age ≥ 55 years (OR = 7.29, 95% CI = 1.66-33.35, p = 0.008), follicular thyroid cancer (OR = 5.00, 95% CI = 1.23-22.18, p = 0.027), and a second RAI treatment as the former course (OR = 4.77, 95% CI = 1.42-18.61, p = 0.016) were significantly associated with a non-effective response. There was no significant difference in the side effects in the former and latter courses between the two groups (p > 0.05).

Conclusion

The interval of RAI treatment does not affect short-term response and side effects of DTC patients with RAI-avid lung metastases. It was feasible to defer repeat evaluation and treatment with an interval of at least 12 months to obtain an effective response and reduce the risk of side effects.

Long-term outcomes and prognostic factors of patients with lung metastases from differentiated thyroid cancer after radioiodine therapy in Japan

Long-term survival in patients with differentiated thyroid cancer (DTC) and lung metastasis remains unexplored in Japan. This study aimed to investigate the long-term survival and prognostic factors of radioiodine therapy (RIT) in a University Hospital setting. This retrospective study included 62 patients with lung metastases from DTC who received RIT between March 2005 and December 2016. According to the ¹³¹I whole-body scan and chest computed tomography results, lung metastases were classified as ¹³¹I-avid or non-¹³¹I-avid, and miliary, micronodular, or macronodular metastases. The 5- and 10-year overall survival (OS) rates from the initial RIT were calculated by the Kaplan-Meier method, and a proportional hazard fit analysis was performed to determine prognostic factors. With a median follow-up of 7.9 years, the 5- and 10-year OS rates from the initial RIT were 93% and 72%, respectively. Univariable and multivariable analyses of patient subgroups revealed that macronodular lung metastases (defined as nodules >1 cm), older age at initial RIT, and high thyroglobulin values (>400 ng/mL) at initial RIT predicted low OS. The 5- and 10-year OS rates of DTC patients with lung metastases were similar to those in previous Japanese reports, which included a smaller sample size compared with ours. Patients with ≤1 cm lung metastases, aged ≤55 years, and a thyroglobulin level of ≤400 ng/mL at the initial RIT had favorable outcomes.

Radioactive Iodine-Refractory Pulmonary Metastases of Papillary Thyroid Cancer in Children, Adolescents, and Young Adults

CONTEXT

Few studies have explored radioactive iodine-refractory (RAIR) disease in children, adolescents, and young adults with papillary thyroid cancer (CAYA-PTC).

OBJECTIVE

This study systematically investigated the clinicopathologic characteristics and prognosis of CAYA-PTC with RAIR disease.

METHODS

Sixty-five patients with PTC aged ≤20 years were enrolled in this study, and all patients were confirmed to have pulmonary metastases. Clinicopathologic profiles were compared between the radioactive iodine-avid (RAIA) and RAIR groups. Univariate and multivariate regression analyses were performed to identify risk factors for RAIR status and progressive disease (PD). Gene alterations were detected in 17 patients.

RESULTS

Overall, 20 patients were included in the RAIR group, accounting for 30.8% (20/65) of all patients. No significant difference in pathologic characteristics was observed between patients aged <15 years and patients aged 15-20 years, but younger patients were more likely to develop RAIR disease (hazard ratio [HR] 3.500, 95% CI 1.134-10.803, P = .023). RET fusions were the most common genetic alterations in CAYA-PTC, but an association with RAIR disease was not detected (P = .210). RAIR disease (HR 10.008, 95% CI 2.427-41.268, P = .001) was identified as an independent predictor of PD. The Kaplan-Meier curve revealed a lower progression-free survival (PFS) and disease-specific survival (DSS) rate in the RAIR group than in the RAIA group (P < .001 and P = .039). Likewise, RAIR disease was a risk factor for unfavorable PFS in patients aged <15 years (P < .001).

CONCLUSION

RAIR disease occurs in one-third of CAYA-PTC with pulmonary metastases. Younger patients (aged < 15 years) are more susceptible to RAIR status, which leads to unfavorable PFS and DSS.

Survival prognostic factors for differentiated thyroid cancer patients with pulmonary metastases: A systematic review and meta-analysis

Background

The prognostic factors for differentiated thyroid cancer (DTC) patients with pulmonary metastases (PM) remain scantly identified and analyzed. Therefore, this systematic review and meta-analysis were performed to identify and summarize the prognostic factors in adult DTC patients with PM to help distinguish patients with different prognoses and inform the rational treatment regimens.

Method

We performed a comprehensive search of the relevant studies published in the Cochrane Library, PubMed, Scopus, Embase, Wanfang database, VIP database, China National Knowledge Infrastructure, and Google Scholar from their inception until February 2021. The pooled hazard ratios (HR) for overall survival and/or progression-free survival (PFS) with 95% confidence intervals were applied to evaluate and identify the potential prognostic factors. Pooled OS at different time points were also calculated for the available data. A random-effects model was used in the meta-analysis.

Results

The review and meta-analysis included 21 studies comprising 2722 DTC patients with PM. The prognostic factors for poor OS were: age over 40 years (HR=7.21, 95% confidence interval [CI] 1.52-34.10, P=0.01, N=788), age over 45 years (HR=2.18, 95% CI 1.26-3.77, P<0.01, N=601), male gender (HR=1.01, 95% CI 1.01-1.19, P=0.03, N=1396), follicular subtype of thyroid cancer (HR=1.63, 95% CI 1.36-1.96, P<0.01, N=2110), iodine non-avidity (HR=3.10, 95% CI 1.79-5.37, P<0.01, N=646), and metastases to other organs (HR=3.18, 95% CI 2.43-4.16, P<0.01, N=1713). Factors associated with poor PFS included age over 45 years (HR=3.85, 95% CI 1.29-11.47, P<0.01, N=306), male gender (HR=1.36, 95% CI 1.06-1.75, P=0.02, N=546), iodine non-avidity (HR=2.93, 95% CI 2.18-3.95, P<0.01, N=395), pulmonary metastatic nodule size over 10mm (HR=2.56, 95% CI 2.02-3.24, P<0.01, N=513), and extra-thyroidal invasion (HR=2.05, 95% CI 1.15-3.67, P=0.02, N=271). The pooled 1, 3, 5, 10, 15, and 20-years OS were 95.24%, 88.46%, 78.36%, 64.86%, 56.57%, and 51.03%, respectively.

Conclusions

This review and meta-analysis identified the prognostic factors of DTC patients with PM. Notably, FTC, metastases to other organs, and iodine non-avidity were particularly associated with poor prognosis. The identified prognostic factors will help guide the clinical management of DTC patients with PM.

Systematic review registration

https://inplasy.com/inplasy-2022-2-0026/, identifier (INPLASY202220026).

Impact of Lung Metastasis versus Metastasis of Bone, Brain, or Liver on Overall Survival and Thyroid Cancer-Specific Survival of Thyroid Cancer Patients: A Population-Based Study

We investigate the impact of lung metastasis versus metastasis of bone, brain, or liver on overall survival (OS) and thyroid cancer-specific survival (TCSS) in patients with thyroid cancer (TC). Therefore, de-identified SEER 18 registry data of primary TC patients diagnosed between 2010 and 2016 were analyzed. The primary outcome was the prognosis of TC patients with lung metastasis compared with other sites. The secondary outcomes included the prognosis comparison between patients with and without surgery and between single and multiple metastasis sites. Isolated lung metastasis was associated with worse OS and TCSS than bone metastasis (both p < 0.05) and was associated with worse OS than liver metastasis (p = 0.0467). Surgery performed either for the primary or distant site was associated with better OS and TCSS in patients with metastasis of lung or bone (p < 0.05). Isolated lung metastasis was related to better OS and TCSS than lung−liver, lung−brain, and lung−other multiple metastases. The multivariable analysis revealed that age < 55 years, surgery to the primary site, and to the distant site(s) were associated with better outcomes, while T4 and Tx were associated with worse outcomes. Nevertheless, it revealed that the other race (i.e., any race other than white, black, or unknown) and male gender were associated with better TCSS only (p < 0.05). Isolated lung metastasis is associated with a worse prognosis in TC patients compared with bone or liver metastasis. Surgery performed either for the primary or distant site(s) is associated with better survival outcomes in TC patients with metastasis of lung or bone.

Long-term outcomes and prognostic factors in papillary thyroid microcarcinoma patients with distant metastases

PURPOSES

Distant metastasis from papillary thyroid microcarcinoma (PTMC) is extremely rare and the long-term outcomes and independent prognostic factors remain unclear. The present study aimed to investigate clinicopathological characteristics and evaluate the long-term outcomes and prognostic factors of PTMC patients with distant metastases (DM) who underwent surgery and radioactive iodine (¹³¹I) treatment.

METHODS

We retrospectively reviewed the medical records of 13,441 patients with thyroid cancer (including 1697 cases with PTMC) who underwent ¹³¹I treatment at our institution between January 2008 and December 2019. PTMC patients with distant metastases with sufficient clinical follow-up data were enrolled in this cohort study. The overall survival (OS) and progression-free survival (PFS) were analyzed by the Kaplan-Meier method and the prognostic factors were assessed by Cox proportional hazards.

RESULTS

Thirty-three PTMC patients with DM were enrolled in this study. The median follow-up was 75 months (range: 5-151 months). The 5-year and 10-year OS rates were 96.97 and 81.41%, respectively, and the 5-year and 10-year PFS rates were 90.46 and 69.68%, respectively. Multivariate analysis showed that male sex (P = 0.005), radioactive iodine refractory PTMC (P = 0.033), and symptomatic DM (P = 0.022) were significantly associated with worse 10-year PFS in PTMC patients with DM. No independent predictor related to poor 10-year OS was found in the present study.

CONCLUSIONS

The prognosis of PTMC patients becomes worse after the development of DM. Male sex, radioactive iodine refractory PTMC, and symptomatic DM were identified as independent factors associated with PFS.

Risk stratification in differentiated thyroid cancer with RAI-avid lung metastases

OBJECTIVE

Radioactive iodine (RAI) therapy is effective for differentiated thyroid cancer (DTC) patients with lung metastasis. However, some patients have a poor prognosis despite the RAI accumulation. The utility of inflammatory biomarkers, including neutrophil-to-lymphocyte ratio (NLR), has been reported as a prognostic factor for many carcinomas. This study aimed to investigate the risk factors related to DTC patient survival with RAI-avid lung metastasis and to attempt risk stratification.

DESIGN AND METHODS

This retrospective study included 123 patients with RAI-accumulating lung metastatic DTC. The cause-specific survival (CSS) rate from the time of detection of lung metastasis was tested using the Kaplan-Meier log-rank test, and the multivariate analysis was calculated using the Cox proportional hazards model. NLR was retrospectively calculated using the blood sample collected before initial RAI treatment. The NLR cutoff value was 2.6 on the ROC curve.

RESULTS

Age ≥ 55 years at the time of operative treatment, follicular carcinoma, lung metastasis tumor ≥ 10 mm in diameter, age ≥ 55 years at the time of detection of lung metastasis, age ≥ 55 years at the time of RAI treatment, and NLR ≥ 2.6 at the initial RAI treatment were predictive of decreased CSS. Multivariate analysis identified that the independent prognostic factors were lung metastatic tumor ≥ 10 mm in diameter and NLR ≥ 2.6. Patients in the high-risk group with both factors had significantly lower CSS rates than those in the low- and intermediate-risk groups with one or none of these factors.

CONCLUSIONS

The high-risk group patients had significantly poorer survival, and these patients could be considered as future candidates for tyrosine kinase inhibitor therapy.

BRAF and TERT promoter mutations: clinical application in thyroid cancer

Given the long-term survival of most patients with thyroid cancer, it is very important to distinguish patients who need aggressive treatment from those who do not. Conventional clinicopathological prognostic parameters could not completely predict the final outcome of each patient. Recently, molecular marker-based risk stratification of thyroid cancer has been proposed to better estimate the cancer risk. Although BRAF mutation has drawn much attention based on its high prevalence, its association with recurrence or mortality is not clear. Recently, telomerase reverse transcriptase (TERT) promoter mutation has been identified in thyroid cancer. It increases telomerase activity, which allows cancer cells to immortalize. It was found in 10 to 20% of differentiated thyroid carcinoma and 40% of dedifferentiated thyroid carcinoma. It is highly prevalent in old age, large tumor, aggressive histology, advanced stages, and distant metastasis. It is associated with increased recurrence and mortality. Concomitant BRAF and TERT promoter mutations worsen the survival rate. Inclusion of TERT promoter mutation analysis with conventional clinicopathological evaluation can lead to better prognostication and management for individual patients.

Metastatic propagation of thyroid cancer; organ tropism and major modulators

Thyroid cancer, as the most prevalent endocrine malignancy, comprises nearly 1% of all cancers in the world. The metastatic propagation of thyroid cancer is under the control of a number of modulating processes and factors such as signaling pathways and their components, cell division regulators, metabolic reprogramming factors, extracellular matrix remodelers, epithelial to mesenchymal transition modulators, epigenetic mechanisms, hypoxia and cytokines. Identifying the exact molecular mechanisms of these dysregulated processes could help to discover the key targets for therapeutic purposes and utilizing them as diagnostic, prognostic and predictors of the clinical course of patients. In this review article, we describe different aspects of thyroid cancer metastasis by focusing on defective genes and pathways involved in its metastatic spread.

Clinical outcomes and prognostic factors in patients with no less than three distant organ system metastases from differentiated thyroid carcinoma

OBJECTIVES

For patients with differentiated thyroid carcinoma (DTC), distant metastases are commonly identified in the lungs and bones. However, they are relatively rare in other distant organs, such as the liver, kidneys, or brain. The aim of the current study was to describe the clinical outcomes and evaluate the prognostic factors of patients with no less than three different distant organ system metastases from DTC.

METHODS

This study retrospectively identified 717 patients diagnosed with DTC with distant metastases between January 2005 and December 2017. Patient response to radioactive iodine (RAI) therapy was monitored by changes in serum thyroglobulin levels and imaging changes. Five-year and 10-year overall survival (OS) rates were calculated by the Kaplan-Meier methods and Cox proportional hazards.

RESULTS

Among the 717 participants, 37 (5.16%) patients had no less than three different distant organ system metastases from DTC. Five-year and 10-year OS were 45.9% and 37.8% in patients with three or more distant organ system metastases while 74.5% and 64.9% in individuals with one or two distant organ system metastases, respectively. RAI avidity and RAIR-DTC were main independent prognostic factors influencing the clinical outcomes for both groups of patients. The presence of 3 or more different distant organ system metastases was the only independent prognostic factors for 10-year OS by multivariate analysis.

CONCLUSIONS

Patients with no less than three distant organ system metastases from DTC had poor prognosis. RAI avidity and RAIR-DTC were main factors influencing overall survival for patients with distant metastases from DTC in both groups.

How rapid advances in imaging are defining the future of precision radiation oncology

Imaging has an essential role in the planning and delivery of radiotherapy. Recent advances in imaging have led to the development of advanced radiotherapy techniques—including image-guided radiotherapy, intensity-modulated radiotherapy, stereotactic body radiotherapy and proton beam therapy. The optimal use of imaging might enable higher doses of radiation to be delivered to the tumour, while sparing normal surrounding tissues. In this article, we review how the integration of existing and novel forms of computed tomography, magnetic resonance imaging and positron emission tomography have transformed tumour delineation in the radiotherapy planning process, and how these advances have the potential to allow a more individualised approach to the cancer therapy. Recent data suggest that imaging biomarkers that assess underlying tumour heterogeneity can identify areas within a tumour that are at higher risk of radio-resistance, and therefore potentially allow for biologically focussed dose escalation. The rapidly evolving concept of adaptive radiotherapy, including artificial intelligence, requires imaging during treatment to be used to modify radiotherapy on a daily basis. These advances have the potential to improve clinical outcomes and reduce radiation-related long-term toxicities. We outline how recent technological advances in both imaging and radiotherapy delivery can be combined to shape the future of precision radiation oncology.

The Prognosis of Papillary Thyroid Cancer with Initial Distant Metastasis is Strongly Associated with Extensive Extrathyroidal Extension: A Retrospective Cohort Study

BACKGROUND

Extensive extrathyroidal extension (ETE) has a significant role in the prognosis of papillary thyroid cancer (PTC) without distant metastasis, but its role in PTC with initial distant metastasis has never been studied. This study aimed to evaluate the prognostic significance of extensive ETE regarding disease progression, survival, and remission in PTC patients with initial distant metastasis.

METHODS

This retrospective cohort study included PTC patients with initial distant metastasis who underwent total thyroidectomy with a median follow-up period of 6.7 years. The prognostic significance of extensive ETE was assessed in terms of time to tumor progression (TTP), cancer-specific survival (CSS), and cumulative incidence of remission with all-cause death as the competing event.

RESULTS

The study enrolled 64 patients. Of these patients, 21 (32.8%) had extensive ETE, which was associated with a shorter TTP (adjusted hazard ratio [HR], 4.10; p = 0.015) and a lower CSS rate (p = 0.002, log-rank), particularly for patients 55 years of age or older with stage 4b disease (10-year CSS rate: 33.3% in those with and 92.3% in those without extensive ETE; p = 0.017). Additionally, remission was observed only in patients without extensive ETE (10-year cumulative incidence of remission: 0.0% in those with and 29.3% in those without extensive ETE; p = 0.013).

CONCLUSIONS

Extensive ETE of the primary lesion results in poorer prognoses for PTC patients with initial distant metastasis. The high CSS rate for patients with stage 4b PTC but no extensive ETE indicates that the prognosis of this patient population should be distinguished from that of other stage 4 cases.

Lung Metastases From Papillary Thyroid Cancer With Persistently Negative Thyroglobulin and Elevated Thyroglobulin Antibody Levels During Radioactive Iodine Treatment and Follow-Up: Long-Term Outcomes and Prognostic Indicators

Background: The lung is the most frequent site of distant metastasis from differentiated thyroid cancer (DTC). However, lung metastasis from papillary thyroid cancer (PTC) with persistently negative thyroglobulin (Tg) and elevated Tg antibody (TgAb) levels is an extremely rare entity, and the prognosis is therefore elusive. We investigated the clinical characteristics, long-term outcomes, and prognostic factors of lung metastases in PTC patients with persistently negative thyroglobulin (Tg) and elevated Tg antibody (TgAb) levels during radioactive iodine (¹³¹I) treatment and follow-up. Methods: We retrospectively reviewed 10,482 patients with DTC who underwent postoperative ¹³¹I treatment from 2007 to 2017 at Shanghai Sixth's People's Hospital. The relationships between progression-free survival (PFS) and several variables were assessed by univariate and multivariate analyses using the Kaplan-Meier method and a Cox proportional hazards model, respectively. Results: Forty-seven patients with PTC were enrolled in this study (4.48‰ of all patients with DTC). The median age at the initial diagnosis of lung metastasis was 39.6 ± 15.4 years, and the patients comprised 14 male and 33 female patients (male: female ratio = 1.00:2.36). Twenty-five patients had ¹³¹I avidity and 22 had non-¹³¹I avidity. At the end of the 5-years follow-up, 12 patients exhibited progressive disease (PD), and 2 patients had died. At the end of the 10-years follow-up, 21 patients showed PD and five patients had died. The 5- and 10-year PFS rates were 74.47 and 53.32%, respectively; the 5- and 10-years overall survival (OS) rates were 95.74 and 89.36%, respectively. The timing of diagnosis of lung metastases, maximal size of lung metastases, and ¹³¹I avidity were significantly associated with the 5-years PFS rate (P = 0.035, P = 0.030, and P<0.001, respectively). Only ¹³¹I avidity was associated with the 10-years PFS rate (P < 0.001). The multivariate analyses also showed that non-¹³¹I avidity were the independent poor prognostic factors for 10-years PFS at the end of follow-up (P < 0.001). Conclusions: Lung metastases from PTC in patients with persistently negative Tg and elevated TgAb levels had an excellent prognosis and survival rate during ¹³¹I treatment and follow-up. The loss of ¹³¹I avidity remained the strongest independent predictor of a poor prognosis and survival in these patients.

Pulmonary metastases in children and adolescents with papillary thyroid cancer in China: prognostic factors and outcomes from treatment with 131I

PURPOSE

Papillary thyroid carcinoma (PTC) with pulmonary metastases is rare in children and adolescents. Unlike adults, limited data are available on children with this disease. Thus, this study evaluated the therapeutic efficacy and prognostic factors of individuals less than 21 years of age with pulmonary metastases from PTC.

METHODS

Seventy-six children and adolescents with pulmonary metastases from PTC treated with ¹³¹I were retrospectively analyzed. Therapeutic efficacy was evaluated by changes in serum thyroglobulin (Tg) and chest computed tomography (CT). Factors predictive of progression-free survival and overall survival were measured by the Kaplan-Meier method.

RESULTS

Among the 76 patients included in this study, 22.4% (17 of 76) were less than 15 years old and 65.8% (50 of 76) were female. Under the evaluation of stimulated serum Tg levels, RAI treatment were effective in 55.9% (38 of 68), stable in 26.5% (18 of 68) and ineffectvie in 17.6% (12 of 68) of patients. Changes on anatomical imaging suggested complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) in 8.5, 62.0, 15.5, and 14.1% of individuals, respectively. Univariate analysis showed that size and tumor doubling time of pulmonary metastases were independent factors affecting therapeutic efficacy. Extra-thyroidal extension, tumor diameter of pulmonary metastases and tumor doubling time were significant independent factors regarding progression-free survival rates, while only tumor doubling time and tumor diameter were significant risk factors associated with overall survival rate.

CONCLUSIONS

Radioactive iodine therapy is an effective treatment for children and adolescents with pulmonary metastases from PTC. Extra-thyroid extension was associated with disease progression while did not show significant influence on overall survival. Tumor doubling time and tumor diameter were the main factors influencing both progression-free survival and overall survival.