Efficacy of radioiodine therapy for treating 20 patients with pulmonary metastases from differentiated thyroid cancer and a meta-analysis of the current literature

Abstract

BackgroundRadioiodine therapy (RAI) after total or near-total thyroidectomy is a recommended treatment for patients with pulmonary metastasis from differentiated thyroid cancer (DTC). However, the total effective rate of iodine-131 therapy remains controversial. This study aimed to determine the efficacy of RAI for treating patients with pulmonary metastasis from DTC, and to identify independent predictors of its efficacy.MethodsWe conducted a retrospective study to evaluate 20 patients with pulmonary metastasis from DTC who underwent RAI at our center at first and performed a meta-analysis to evaluate relevant literature regarding the overall efficacy of RAI and subgroup-specific efficacies subsequently.ResultsThe efficacy rate at our center was 40%, and no significant differences were observed according to sex, age, pathological type, metastasis state, or interval between the initial RAI and final surgery. The meta-analysis revealed that the pooled overall efficacy rate was 58%, and significant differences were observed when we compared pulmonary metastasis versus pulmonary and other distant metastasis, age of < 40 years versus age of ≥ 40 years, papillary thyroid cancer versus follicular thyroid cancer and male patients versus female patients.ConclusionsThese results suggest that RAI is an effective treatment for patients with pulmonary metastasis from DTC after surgical treatment. The efficacy of RAI was significantly predicted by the presence of papillary thyroid cancer, age of < 40 years, the absence of non-lung distant metastasis and female patients.

Association of the Cumulative Dose of Radioactive Iodine Therapy With Overall Survival in Patients With Differentiated Thyroid Cancer and Pulmonary Metastases

“…Our research suggested that the risk of death for patients with DTC and PM increased sharply along with increasing age until 40 years of age, whereas the trend was moderate for patients aged >40 years. This non-linear pattern supported studies that had taken 40 years as a cutoff point for prognosis prediction (7, 38). The poor prognosis in patients aged >40 years could be attributed to a relatively longer disease duration, higher prevalence of advanced disease, poor curative effect of iodine treatment, a decline in the immune system, and a more aggressive variant of TC (16, 39).…”

“…A poor prognosis in elder patients with DTC is regarded as common sense by pathologists and clinicians, and recent studies have suggested that age should be treated as a spectrum rather than a specific cutoff point (35). For patients with DTC and PM, the optimal cutoff points for age varied from 40 to 60 years (17, 36–38), but no study has taken age as a continuous variable. Our research suggested that the risk of death for patients with DTC and PM increased sharply along with increasing age until 40 years of age, whereas the trend was moderate for patients aged >40 years.…”

Radioactive Iodine Therapy in Patients With Thyroid Carcinoma With Distant Metastases: A SEER-Based Study

“…The demographic characteristics included age at diagnosis (45 years and >45 years) and sex (male and female). The patient characteristics included grade (well-differentiated, moderately differentiated, poorly differentiated, undifferentiated, and unknown), histology (according to the International Classification of Diseases for Oncology, Third Edition, codes 8050/3, 8052/3, 8130/ 3, 8260/3, 8341/3, 8342/3, 8343/3, 8344/3, 8347/3, 8408/3, 8450/3, 8452/3, 8460/3, and 8507/3 were defined as papillary histology; code 8340/3 was defined as papillary with follicular variant histology; codes 8345/3, 8346/3, 8347/3, and 8510/3 were defined as follicular histology; and codes 8020/3 and 8805/3 were defined as undifferentiated histology), lymphatic metastases (LMs; absent, present), tumor size (10,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40), >40 mm), EE (absent, present), and DMs (absent, present). Based on surgical treatments, patients were categorized as receiving total thyroidectomy (surgery of primary site variable values of 50), receiving other surgery (surgery of primary site variable values of 10-40), refusing surgery (surgery of primary site variable values of 00), and unknown (surgery of primary site variable values of 80-99).…”

Micronuclei Formation upon Radioiodine Therapy for Well-Differentiated Thyroid Cancer: The Influence of DNA Repair Genes Variants

“…Moreover, considering that activating RAS mutations are commonly observed in FTC but not in PTC [53,58,59], the association between increased RAS expression and decreased frequency of IR-induced MN reported by Miller et al [60] is coherent with our own observation of lower 131 I-induced BNMN frequency in FTC, supporting the idea that this histotype is less sensitive to the DNA damaging effects of IR than PTC. Such hypothesis (i.e., higher sensitivity to IR in PTC) is further reinforced by a recent observation, through meta-analysis, of increased efficacy of RAI therapy in PTC patients, compared to FTC [61] but more studies are needed for a solid conclusion to be drawn.…”