The impact of radioactive iodine treatment on survival among papillary thyroid cancer patients according to the 7th and 8th editions of the AJCC/TNM staging system: a SEER-based study

Impact of Radioactive Iodine Treatment on Long-Term Relative Survival in Patients with Papillary and Follicular Thyroid Cancer: A SEER-Based Study Covering Histologic Subtypes and Recurrence Risk Categories

For patients with differentiated thyroid cancer (DTC), that is, papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC), the American Thyroid Association and European Thyroid Association generally recommend radioactive iodine (RAI) therapy after surgery only for high-risk patients. For intermediate-risk patients, RAI therapy is recommended only as a should-be-considered option. For low-risk patients, RAI therapy is not routinely recommended. Other countries, such as Germany, are more in favor of using RAI. Thus, RAI therapy remains a matter of controversial debate, because prospective long-term data on survival are scarce. Methods: We retrospectively compared long-term relative survival in DTC cohorts treated with and without RAI. From the Surveillance, Epidemiology, and End Results Program database, 101,087 patients harboring DTC were identified between 2000 and 2020. Patient cohorts were subdivided based on histology (classical PTC, aggressive variants of PTC, FTC, and minimally invasive FTC). These cohorts were stratified into the following categories: very low risk, low risk, intermediate risk, and high risk. Relative survival was determined for each subgroup. Statistics included a z-test specifically developed for comparison of relative survival, testing the long-term effect of RAI therapy (3, 5, and 10 y). Results: The relative survival rate is higher or tends to be higher in most subgroups undergoing RAI therapy than in subgroups not undergoing RAI therapy. Even for low-risk minimally invasive FTC, the 10-y relative survival rate tends to be higher by 2.0% (P = 0.055). For larger tumor size or lymph node involvement in classical PTC, a 10-y relative survival benefit of 1.3%-2.0% (P = 0.045) in the RAI subgroup prevails. In high-risk DTC, benefits in relative survival of up to 30.9% (P < 0.05) were observed. Relative survival is not negatively affected in any RAI subgroup. Conclusion: In patients with DTC, depending on histology subtype, a benefit in relative survival prevails in low-, intermediate-, and high-risk subgroups that underwent RAI therapy compared with patients who did not undergo RAI therapy. Even in low-risk minimally invasive FTC, a clear trend toward higher survival rates is observed. For PTC, a survival benefit prevails in the presence of lymph node involvement, larger tumor size, or distant metastasis.

Comparative analysis through propensity score matching in thyroid cancer: unveiling the impact of multiple malignancies

BACKGROUND

The incidence of thyroid cancer is on the rise worldwide, with childhood exposure to radiation being the sole acknowledged catalyst for its emergence. Nonetheless, numerous other factors that may pose risks are awaiting thorough examination and validation. This retrospective study aims to explore the malignancies linked to thyroid cancer and contrast the survival rates of those afflicted with a solitary tumor versus those with multiple primary neoplasms (MPN).

METHODS

This retrospective study examined data from King Hussein Cancer Center (KHCC), Jordan. Among 563 patients diagnosed with thyroid cancer, 30 patients had thyroid malignancy as part of MPN. For a 1:3 propensity score-matched analysis, 90 patients with only a primary thyroid malignancy were also enrolled.

RESULTS

Hematologic and breast malignancies were among the most frequent observed cancers alongside thyroid neoplasm. Patients who had MPN were diagnosed at older age, had higher body mass index and presented with higher thyroglobulin antibody levels (p < 0.05 for each). Additionally, MPN patient displayed a stronger family history for cancers (p= 0.002). A median follow-up duration of 135 months unveiled that MPN patients faced a worse 5-year survival compared to their counterparts with a singular neoplasm (87% vs 100% respectively; p < 0.01). However, no distinction emerged in the 5-year event-free survival between these two groups.

CONCLUSION

MPN correlates with a significantly altered survival outcome of thyroid cancer patients. The diagnosis of thyroid carcinoma at an older age, accompanied by elevated initial thyroglobulin antibody levels and a notable familial predisposition, may raise concerns about the potential occurrence of synchronous or metachronous tumors.

Outcomes and Trends of Treatments in High-Risk Differentiated Thyroid Cancer

OBJECTIVES

To analyze the variant-specific survival benefits and usage patterns of standardized treatment combinations of surgery (S), radioactive iodine ablation (RAI), and thyroid-stimulating hormone suppression therapy (THST) for high-risk differentiated thyroid cancer.

STUDY DESIGN

Retrospective cohort study.

SETTING

National Cancer Database.

METHODS

The 2004-2017 National Cancer Database was queried for patients receiving definitive surgery for high-risk papillary, follicular, or Hurthle cell thyroid cancer. Cox proportional hazards and Kaplan-Meier analyses assessed for treatment-associated survival.

RESULTS

Of 21,076 cases, 18,214 underwent survival analysis with a mean ± SD age of 50.6 ± 17.1 years (71.3% female). When compared with surgery alone, S + RAI was associated with reduced mortality in papillary (hazard ratio [HR], 0.574; P < .001) and follicular (HR, 0.489; P = .004) thyroid cancer. S + RAI + THST was associated with reduced mortality in papillary (HR, 0.514; P < .001), follicular (HR, 0.602; P = .016), and Hurthle cell (HR, 0.504; P = .021) thyroid cancer. In papillary thyroid cancer, S + RAI (91.3%), S + THST (89.2%), and S + RAI + THST (92.7%) were associated with higher 5-year overall survival rates than surgery (85.4%, all P < .001). Papillary thyroid cancer treatments involving THST were associated with higher 5-year overall survival rates than corresponding regimens without THST (all P < .001). In follicular thyroid cancer, S + RAI (73.9%) and S + RAI + THST (78.7%) were associated with higher 5-year overall survival rates than surgery (65.6%, all P < .05). In Hurthle cell thyroid cancer, S + RAI (66.5%) and S + RAI + THST (73.4%) were associated with higher 5-year overall survival rates than surgery (53.7%, all P < .05). On linear regression, THST usage increased by 77.5% (R² = 0.944, P < .001), while RAI usage declined by 11.3% (R² = 0.320, P = .035).

CONCLUSIONS

High-risk differentiated thyroid cancer exhibited varying susceptibilities to different treatment combinations depending on histology, with greatest responses to regimens that included RAI. Physician practices have trended toward decreased RAI and increased THST usage.

Age increased the cancer-specific mortality risk of thyroid cancer with lung metastasis

OBJECTIVE

To investigate the relationship between age and cancer-specific mortality in thyroid cancer (TC) with lung-metastasis.

PATIENTS AND METHODS

A total of 1418 patients with initial distant metastases from Surveillance, Epidemiology, and End Results databases were investigated. Patients with a median follow-up time of 8 months (interquartile range [IQR]: 2-27] and a median age of 66 years (IQR: 55-76) were divided into five groups by age and the association between age and TC-specific mortality was analysed.

RESULTS

The TC-specific mortality rates were 32.78% (118/360), 46.71% (156/334), 53.93% (199/369), 58.96% (158/268) and 82.76% (72/87) in patients aged ≤55 years, >55 but ≤65 years, >65 but ≤75 years, >75 but ≤85 years and >85 years. Kaplan-Meier curves showed that TC-specific mortality rate was associated with increased age (p < .001). Compared with patients ≤55 years, patients aged >55 but ≤65 years, >65 but ≤75 years, >75 but ≤85 years and >85 years had significantly higher hazard ratios (HRs) of 1.69 (1.26-2.26), 1.97 (1.47-2.64), 2.18 (1.59-2.99) and 3.24 (2.08-5.06) after adjustments for sex, tumour size and radiation therapy (all p < .001). In TC with initial lung-metastasis, compared with patients ≤55 years, patients aged >55 but ≤65 years, >65 but ≤75 years, >75 but ≤85 years and >85 years had significantly higher adjusted HRs of 1.68 (1.20-2.36; p = .003), 2.18 (1.57-3.02), 2.16 (1.51-3.08) and 2.91 (1.79-4.75; p < .001). Similar results were obtained in papillary TC.

CONCLUSIONS

The TC-specific mortality was increased with age in TC patients with initial lung-metastasis, indicating that further risk stratification based on age was necessary for TC over 55 years with lung-metastasis. Individual treatment strategies maybe recommended for such patients.

Establishment and validation of a nomogram model for predicting the survival probability of differentiated thyroid carcinoma patients: a comparison with the eighth edition AJCC cancer staging system

PURPOSE

This study aimed to develop a clinically predictive nomogram model to predict the survival probability of differentiated thyroid carcinoma patients and compare the value of this model with that of the eighth edition AJCC cancer staging system.

METHODS

We selected 59,876 differentiated thyroid carcinoma patients diagnosed between 2004 and 2015 from the SEER database and separated those patients into a training set (70%) and a validation set (30%) randomly. We used Cox regression analysis to build the nomogram model (model 1) and the eighth edition AJCC cancer staging model (model 2). Then we compared the predictive accuracy, discrimination, and clinical usage of both models by calculating AUC (Area under the curve), C-index, as well as analyzing DCA (Decision Curve Analysis) performance respectively.

RESULTS

AUCs of all predicted time points (12-month, 36-month, 60-month, and 120-month) of model 1 were 0.933, 0.913, 0.879, and 0.868 for the training set; 0.933, 0.926, 0.916, and 0.894 for the validation set. As for model 2, data were 0.938, 0.906, 0.866, and 0.847 for the training set; 0.924, 0.925, 0.912, and 0.867 for the validation set. C-indices of model 1 were higher than those of model 2 (0.923 vs. 0.918 for the training set, 0.938 vs. 0.930 for the validation set). DCA comparison showed that the net benefit of model 1 was bigger when comparing with that of model 2.

CONCLUSIONS

Model 1 provided with both better predictive accuracy and clinical usage compared with those of model 2 and might be able to predict the survival probability of differentiated thyroid carcinoma patients visually and accurately with a higher net benefit.