Micronuclei frequency in peripheral blood lymphocytes of thyroid cancer patients after radioiodine therapy and its relationship with metastasis

Effect of radioactive iodine therapy on hematological parameters in patients with thyroid cancer: systematic review and meta-analysis

Background

Patients with thyroid cancer (TC) are commonly treated with radioactive iodine therapy (RIA) to prevent neoplastic transformation and the re-emergence of cancer cells. However, it has major side effects on blood cells. However, the degree of change in hematological parameters reported varies across studies. Therefore, the aim of this review was to assesses the mean differences in hematological parameters after RAI therapy.

Methods

The relevant articles for this review were identified through extensive searches of databases and the Google search engine. The identified articles were subsequently selected using predetermined eligibility criteria. All relevant information from the screened articles was extracted. The pooled standardized mean differences (SMDs) of the parameters were assessed via a random effects model. The heterogeneity was determined by I2 statistics test. Funnel plots and Egger's test were utilized to assess publication bias.

Results

A total of 17 studies including 4,112 and 3,766 study participants before and after RAI therapy, respectively, were included. The pooled SMDs of the total leucocyte count (TLC) (*109/L) at one, three, six and 12 months and the last follow-up period were 2.39, 2.46, 5.84, 3.19, and 0.53, respectively. Changes in the TLC after one, three and six months of therapy were statistically significant. In terms of the absolute neutrophil count (ANC; *109/L) and absolute lymphocyte count (ALC; *109/L), the pooled SMDs at the last follow-up period were 6.32 and 7.37, respectively. In addition, statistically significant changes in the platelet count (PLT; *109/L) were observed at one, three, six and 12 months and at the last follow-up, with pooled SMDs of 7.01, 0.22, 2.63, 6.61, and 8.76, respectively. Furthermore, statistically significant changes in red blood cells (RBCs; *1012/L) and hemoglobin (Hgb; g/dl) were detected after three and six months of therapy, with pooled SMDs of -1.088 and 2.4, respectively.

Conclusion

According to the current systematic review and meta-analysis, radioiodine therapy had a significant effect on hematological parameters. Thus, early screening and correction of hematological toxicity may be helpful for improving quality of life in thyroid cancer patients receiving radioiodine therapy.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42024586449.

Shortened telomere length in peripheral blood leukocytes is associated with cumulative radioactive iodine doses in patients with differentiated thyroid carcinoma

BACKGROUND

Telomere length is associated with cancer risk and cancer aggressiveness. Radioactive iodine (RAI) therapy for thyroid cancer has raised concerns for second primary malignancy (SPM) in patients with high cumulative doses. The association between RAI dose and peripheral blood leukocyte telomere length was examined.

METHODS

A total of 425 patients were included who underwent total thyroidectomy and were followed up for at least 1 year with or without RAI treatment. The relative telomere length (RTL) of the patients was assessed via a quantitative polymerase chain reaction amplification method. RAI doses were divided into five groups on the basis of cumulative dose, and a comparison was made among these groups.

RESULTS

The number of patients with RAI treatment was 287 (67.5%), and the cumulative RAI dose was 3.33 GBq (range, 1.11-131.35 GBq). The mean RTL was significantly shorter in the highest RAI group (>22.2 GBq) compared to both the no-RAI and lower dose groups. The association between RAI dose and RTL was positive in the lower RAI group (1.1-3.7 GBq) and negative in the highest RAI group in both univariate and multivariate analyses. We observed 59 (13.9%) SPMs and 20 (4.7%) mortalities, and RTL did not show a significant risk effect for all-cause, thyroid cancer-specific, or SPM-specific mortality.

CONCLUSIONS

In patients with thyroid cancer who underwent total thyroidectomy, peripheral blood leukocyte telomere length exhibited a significant association with cumulative RAI dose higher than 22.2 GBq. These results suggest the possibility of telomere length shortening in patients who undergo high-dose RAI treatment.

Retrospective Evaluation of Cytogenetic Effects Induced by Internal Radioiodine Exposure: A 27-Year Follow-Up Study

Radioiodine (131I) is widely used in the treatment of hyperthyroidism and as an effective ablative therapy for differentiated thyroid cancer. Radioiodine (131I) constitutes 90% of the currently used therapies in the field of nuclear medicine. Here, we report the cytogenetic findings of a long-term follow-up study of 27 years on a male patient who received two rounds of radioiodine treatment within a span of 26 months between 1992 and 1994 for his papillary thyroid cancer. A comprehensive cytogenetic follow-up study utilizing cytokinesis blocked micronucleus assay, dicentric chromosome assay, genome wide translocations and inversions was initiated on this patient since the first administration of radioiodine in 1992. Frequencies of micronuclei (0.006/cell) and dicentric chromosomes (0.008/cell) detected in the current study were grossly similar to that reported earlier in 2019. The mFISH analysis detected chromosome aberrations in 8.6% of the cells in the form of both unbalanced and balanced translocations. Additionally, a clonal translocation involving chromosomes 14p; 15q was observed in 2 of the 500 cells analyzed. Out of the 500 cells examined, one cell showed a complex translocation (involving chromosomes 9, 10, and 16) besides 5 other chromosome rearrangements. Collectively, our study indicates that the past radioiodine exposure results in long-lasting chromosome damage and that the persistence of translocations can be useful for both retrospective biodosimetry and for monitoring chromosome instability in the lymphocytes of radioiodine exposed individuals.

Clinical Applications of Biological Dosimetry in Patients Exposed to Low Dose Radiation Due to Radiological, Imaging or Nuclear Medicine Procedures

Radiation dosimetric biomarkers have found applications beyond radiation protection area and now are actively introduced into clinical practice. Cytogenetic assays appeared to be a valuable tool for individualized quantifying radiation effects in patients, with high capability for assessing genotoxicity of various medical exposure modalities and providing meaningful radiation dose estimates for prognoses of radiation-related cancer risk. This review summarized current data on the use of biological dosimetry methods in patients undergoing various medical irradiations to low doses. The highlighted topics include basic aspects of biological dosimetry and its limitations in the range of low radiation doses, and main patterns of in vivo induction of radiation biomarkers in clinical exposure scenarios, occurring in X-ray diagnostics, computed tomography, interventional radiology, low dose radiotherapy, and nuclear medicine (internally administered ¹³¹I and other radiopharmaceuticals). Additionally, several specific issues, examined by biodosimetry techniques, are analysed, such as contrast media effect, radiation response in pediatric patients, impact of magnetic resonance imaging, evaluation of radioprotectors, detection of patients' abnormal intrinsic radiosensitivity and dose estimation in persons involved in medical radiation incidents. A prognosis of possible directions for further improvements in this area includes the automation of cytogenetic analysis, introduction of molecular biodosimeters and development of multiparametric biodosimetry platforms. A potential approach to the advanced biodosimetry of internal exposure and/or low dose external irradiation is suggested; this can be a multiparametric platform based on the combination of the γ-H2AX foci, dicentric, and translocation assays, each applied in the optimum postexposure time range, with the amalgamation of the dose estimates. The study revealed the necessity of further research, which might clarify medical radiation safety concerns for patients via using stringent biodosimetry methodology.

A review on genotoxicity in connection to infertility and cancer

Genotoxicity has been identified as the main cause of infertility and a variety of cancers. The mechanisms affect the structure, quality of the information or the segregation of DNA and are not inherently correlated with mutagenicity. The concept of genotoxicity, the chemical classes that cause genetic damage and the associated mechanisms of action are discussed here. Hazardous effects of pharmaceuticals, cosmetics, agrochemicals, industrial compounds, food additives, natural toxins and nanomaterials are, in large part, identified by genotoxicity and mutagenicity tests. These are critical and early steps in industrial and regulatory health assessment. Though several in vitro experiments are commonly used and approval by regulatory agencies for commercial licensing of drugs, their accuracy in human predictions for genotoxic and mutagenic effects is frequently questioned. Treatment of real and functional genetic toxicity problems depends in detail on the knowledge of mechanisms of DNA damage in the molecular, subcellular, cellular and tissue or organ system levels. Current strategies for risk assessment of human health need revisions to achieve robust and reliable results for optimizing their effectiveness. Additionally, computerized methods, neo-biomarkers leveraging '-omics' approaches, all of which can provide a convincing genotoxicity evaluation to reduce infertility and cancer risk.

Evaluation of the physical and biological dosimetry methods in iodine-131-treated patients

The aim of the study was to compare physical and biological dosimetry methods in iodine-131 (I-131)-receiving patients. The present study comprised of 47 patients (mean age: 47.9 ± 15.8 years), treated with I-131. Group I consisted of 17 patients with hyperthyroidism and mean administered activity of this group was 432.9 ± 111 MBq. There were 15 follow-up patients of differentiated thyroid cancer (DTC) in Group II with mean administered activity of 185 ± 22.2 MBq, who were administered scanning dose of I-131. Group III comprised of 15 patients with DTC, ablated with high-dose of I-131, and this group's mean administered activity was 4347.5 ± 695.6 MBq. The whole-body absorbed doses were calculated in all patients both with the Medical Internal Radiation Dosimetry (MIRD) method using MIRDOSE3 software and cytokinesis-block micronucleus (MN) assay-based MN analysis and were compared. The whole-body absorbed dose, calculated by MIRD method, showed very good correlation with the administered I-131 activity (r = 0.89, P < 0.001), but it was moderate in the MN method (r = 0.52, P < 0.01). Absorbed dose estimations with MIRD method were 49.2 ± 20.8 mGy in Group I, 6.5 ± 1.6 mGy in Group II, and 154.3 ± 47.8 mGy in Group III; the differences were statistically significant (P < 0.001), as expected. Pre- and posttreatment MN frequencies differed significantly in all groups (P < 0.05). The whole-body absorbed doses, based on MN method, were 68.2 ± 17.5, 46.0 ± 11.4, and 90.5 ± 26.9 mGy in Groups I–III, respectively. The difference was significant between Group II and Group III (P < 0.01). The mean absorbed dose was 74.6 ± 27.9 mGy with MN versus 68.0 ± 67.1 mGy in MIRD method (P = 0.087) in the entire study population and the correlation was moderate (r = 0.73, P < 0.001). The whole-body absorbed doses, estimated by MN method, showed moderate correlation with administered radioiodine activities in low radioiodine doses and had significantly different and fluctuating values as compared to MIRD method in patients treated with I-131.

Lymphocyte function following radioiodine therapy in patients with thyroid carcinoma

Aim: Since the nuclear disaster in Fukushima has raised great concern about the danger of radioactivity, we here addressed the question if the therapeutic use of iodine 131, the most frequently applied radionuclide, was harmful to immune function in patients. It was our aim to define for the first time in a clinical setting how radioiodine therapy alters anti-microbial immune responses. Patients, methods: In 21 patients with thyroid carcinoma anti-microbial lymphocyte responses were assessed by lymphocyte transformation test and ELISpot – measuring lymphocyte proliferation and on a single cell level production of pro- and anti-inflammatory cytokines (interferon-γ and interleukin- 10) – prior to therapy, at day 1 and day 7 post therapy. Results: Proliferative lymphocyte responses and interferon-γ production after in vitro stimulation with microbial antigens were significantly (p < 0.05) increased at day 1 vs. pre therapy, and returned to pre therapy levels at day 7. On the contrary, at day 1 interleukin-10 production was significantly (p < 0.05) reduced. Thus, we observed a short-term increase in pro-inflammatory immune responses. However, T lymphocyte responses were in the range of healthy controls at all three time points. Conclusion: Thyroid carcinoma patients receiving radioiodine therapy do not display any sign of immunosuppression.

In vivo evaluation of the genotoxic effects of gonadotropins on rat reticulocytes

BACKGROUND

Gonadotropins, as ovulation-inducing drugs, have been used widely to treat infertility. An epidemiologic correlation between infertility therapy and ovarian cancer development has been reported. However, the effect of gonadotropins in the formation of reproductive tract cancers is controversial.

OBJECTIVE

The aim of the study was to determine the in vivo genotoxic effects of gonadotropins on rat reticulocytes.

METHODS

In this prospective, randomized, controlled study, rats were randomly assigned to 1 of 5 groups. The calculated rat doses of 0.65 human menopausal gonadotropin (hMG), 0.95 hMG, 0.65 follitropin beta (FB), 0.95 FB, or normal saline (control group) were injected, respectively. These calculated rat doses (U/g) are based on average human gonadotropin doses of 150 and 225 IU/d for a 70-kg woman given in 2-mL saline (the control group received 2 mL of saline). Injections were administered once per day for 5 days, followed by 5 days of rest. Each treatment was repeated for 6 estrus cycles in the rats for a total of 12 estrus cycles. Six months after the last day of the 12(th) cycle, the rats were euthanized. Bone marrow tissues were removed, and pluripotent reticulocyte cells with micronuclei, nuclear buds, and binuclear abnormalities were analyzed using an in situ micronuclei assay under light microscopy. The proportion of micronucleated cells, cells with anaphase bridge, nuclear buds, and other nuclear abnormalities were measured.

RESULTS

The number of cells with nuclear buds and binuclear abnormalities in the hMG 225 and FB 225 groups was significantly higher (P < 0.05) than that from the hMG 150, FB 150, and control groups in the cytogenetic analysis of bone marrow stem cells. An increased rate of genotoxicity in all gonadotropin groups versus that of placebo was found.

CONCLUSION

In rats, the micronucleus genotoxicity assay suggests a dose-dependent gonadotropin effect on genomic instability in bone marrow stem cells in vivo.

Radioprotective effect of the Barbados Cherry (Malpighia glabra L.) against radiopharmaceutical iodine-131 in Wistar rats in vivo

Background

The increasing consumption of fruits and vegetables has contributed to the improvement of populational health, due in part, to the abundance of antioxidants in these foods. Antioxidants reduce the level of oxidative damage to DNA caused by free radicals and ionizing radiation, including the radioisotope iodine-131 (131I). This isotope is used for the diagnosis and treatment of thyroid injuries, such as hyperthyroidism and cancer.

Methods

This study aimed to evaluate the radioprotective and cytotoxic activity of acute and subchronic treatments with Barbados Cherry (BC) (Malpighia glabra L.) fruit juice (5 mg), which is rich in potent antioxidants such as vitamin C, phenols, carotenoids, anthocyanins and yellow flavonoids and its activity against the mutagenic activity of the therapeutic dose of 25 μCi of radioiodine for hyperthyroidism. The test system used was the bone marrow cells of Wistar rats (Rattus norvegicus) that were treated in vivo by gavage.

Results

BC showed radioprotective activity in acute treatments, which is most likely due to the joint action of its antioxidant components. In subchronic treatments, the continuous treatment presented an effective radioprotective activity, which was significantly different from treatment with the radiopharmaceutical only. Treatment with BC prior to (PRE) and simultaneous with (SIM) ionizing radiation decreased the number of induced chromosomal alterations, while post-treatment produced no protective effect. In addition, BC exhibited no cytotoxic activity.

Conclusions

These data serve as evidence that BC can be used as a preventive health measure to improve public health quality by countering the action of inevitable exposure to mutagens, such as 131I.

Correlation between micronuclei frequency in peripheral blood lymphocytes and retention of 131-I in thyroid cancer patients

Differentiated thyroid cancers (DTCs) derive from thyroid follicular cells and include papillary and follicular cancers. In patients with DTCs, the initial treatment includes thyroidectomy and radioactive iodine (131-I) therapy. The objective of this study was to examine whether the intensity of DNA damage in peripheral blood lymphocytes (PBLs) of DTC patients depends on the amount of 131-I retained in the selected regions of interest (thyroid and abdominal region) as well as in the whole-body 72 hours after therapy. In addition, the possible influence of other factors that may affect micronuclei (MN) frequency, such as age, gender, smoking habits, and histological type of tumour was analyzed. The study population consisted of 22 DTC patients and 20 healthy donors. Data on the distribution of 131-I were obtained from the whole-body scans. MN frequency and cytokinesis-block proliferation index (CBPI) were measured using cytokinesis-block micronucleus assay. 131-I therapy significantly increased the MN frequency (19.50±6.90 vs. 27.10±19.50 MN) and significantly decreased the CBPI (1.52±0.20 vs. 1.38±0.17) in patients' lymphocytes. There was a clear correlation between the increased MN frequency and 131-I accumulation in the thyroid region in patients without metastases. The MN values did not differ in relation to the factors that could affect MN, such as age, gender, smoking habits, and histological type of tumour. In conclusion, the MN frequency in PBLs of DTC patients without metastases depends on the accumulation of 131-I in the thyroid region and does not depend on the other factors examined.

Micronucleus frequency among Iraqi thyroid disorder patients

Micronucleus (MN) assay has been extensively used in detection of DNA damage, instability in cancer, and genetic disorders. In the current study, MN, binucleated cells, and nuclear division index (NDI) were investigated in Iraqi patients with thyroid disorders. The results indicated significantly (p < 0.05) increased binucleated cells with micronucleus (BNMN) frequencies in thyroid cancer group (37.58 ± 3.07) versus other thyroid disorder groups (6.60 ± 1.29, 14.90 ± 1.69, 15.56 ± 1.76). On the other hand, the frequency of micronucleus per 1,000 and the NDI were significantly (p < 0.05) decreased in hypothyroidism (MN 1.55 ± 0.36) (NDI 0.009 ± 0.001) versus other thyroid disorder groups (MN: 6.05 ± 0.97, 6.09 ± 0.53, 5.34 ± 0.56) (NDI: 0.049 ± 0.003, 0.032 ± 0.002, 0.025 ± 0.002), with no difference versus healthy group (0.0 ± 0.0). The number of BNMN and MN are parallel to the severity of thyroid disorders which were 6.60 ± 1.29, 14.90 ± 1.69, 15.56 ± 1.76, and 37.58 ± 3.07 for hypothyroidism, thyroid toxic goiter, thyroid nontoxic goiter, and thyroid cancer, respectively. The number of BNMN and MN are parallel to the severity of thyroid disorders which were 6.60 ± 1.29, 14.90 ± 1.69, 15.56 ± 1.76, and 37.58 ± 3.07 for hypothyroidism, thyroid toxic goiter, thyroid nontoxic goiter, and thyroid cancer, respectively. The results also indicate that there were no significant differences among age and sex groups as related with BNMN formation within each thyroid disorder groups and healthy control group.

The effect of Ginkgo biloba extract on genotoxic damage in patients with differentiated thyroid carcinoma receiving thyroid remnant ablation with iodine-131

BACKGROUND

Radioiodine ((131)I) therapy is usually performed in patients with differentiated thyroid cancer (DTC). Although (131)I is generally considered safe, genotoxic damage has been demonstrated both in vivo and in vitro. The aim of the current study was to evaluate the effect of Ginkgo biloba extract (GBE) on the time-course of appearance, after (131)I therapy for DTC, of plasma factors with chromosome-damaging properties (so-called "clastogenic" factors [CFs]) and of micronuclei (MN) in lymphocytes.

METHODS

Twenty-three patients (median age 42 years, range 18-73) with DTC receiving (131)I activity (3.7 GBq) for thyroid remnant ablation were randomly assigned to receive GBE (120 mg/day for one month; n=10) or placebo (n=13) in a double-blind manner. Blood samples were taken at various intervals (from baseline to 90 days) after (131)I therapy. The frequency of MN in blood lymphocytes was determined, and CFs were assayed in plasma by a method that used MN increase in lymphocytes from an healthy donor as the endpoint of the assay.

RESULTS

MN in blood lymphocytes increased significantly after (131)I treatment in the placebo group, peaking at the 7th day (p=0.002) and slowly declining thereafter. In contrast, in similarly treated patients who were also treated with GBE both before and after (131)I treatment, a significant increase of blood lymphocyte MN level was not observed. In addition, only the placebo group showed a significant, progressive increase in CFs activity. This peaked at the 14th day (p=0.003 vs. baseline) and was still noted for the last plasma sample. The differences in the change in lymphocyte MN and CFs activity between the placebo and GBE-treated groups were significant (p<0.01 and p<0.05, respectively). Thyroid function tests, including serum thyroglobulin (Tg) and anti-Tg antibody levels, were never significantly different.

CONCLUSIONS

GBE may protect from possible oxidative and genotoxic damage associated with (131)I treatment in patients requiring (131)I therapy for thyroid cancer, without affecting the clinical outcome. Further studies with larger cohorts of patients are needed to confirm this report and verify the beneficial effect of GBE in patients requiring (131)I therapy, particularly for those in whom repeated treatments and high activities of (131)I are required.

Biodosimetry using radiation-induced micronuclei in skin fibroblasts

PURPOSE

We assessed micronuclei in dermal fibroblasts as a local biodosimeter for estimating accidental in vivo radiation exposure.

MATERIALS AND METHODS

Male and female C3H/HeJ and C57Bl6 mice of four age groups (∼11, 36, 60 and 99 weeks) received a single whole body dose of gamma radiation (0-10 Gy) and radiation-induced micronuclei per 1,000 binucleated cells were assessed in skin fibroblasts in their first division after isolation from biopsies taken on days 1 and 7 post irradiation. The method of generalized estimating equations was used for statistical analyses.

RESULTS

Total micronuclei were increased on day 1 in a dose-dependent manner in the range of 1-10 Gy, with no significant attenuation of response between day 1 and day 7 and no significant effect of gender. Between-strain differences were observed with C3H/HeJ mice showing lower background micronuclei and a slightly steeper dose response. Age affected only the background micronuclei (moderate increase with age). The model demonstrated that the assay yields 'unbiased' prediction of the dose between 0 and 7 Gy. Within this dose range, the predicted dose was found to be accurate within ±1.5-2 Gy. When the specificity is set to 95%, the assay can distinguish between unexposed and 2 Gy exposed mice with a sensitivity of around 60%. The sensitivity approached 100% when discriminating between unexposed mice and mice receiving doses equal to or greater than 4 Gy. The percentage of binucleated cells with micronuclei was shown to be useful as a simpler and slightly faster substitute for the total micronuclei count.

CONCLUSION

Micronuclei in dermal fibroblasts isolated up to 1 week after irradiation can be a useful biodosimeter for local dose after accidental radiation exposure.

Mutagenicity of diagnostic and therapeutical doses of radiopharmaceutical iodine-131 in Wistar rats

Iodine-131 ((131)I) is a radioisotope used for the diagnosis and treatment of thyroidal disorders such as hyperthyroidism and cancer. During its decay, (131)I emits beta particles and gamma rays; its physical half-life is 8 days, and it is accumulated preferentially in the thyroid tissue. This study aimed to evaluate the cytotoxicity and mutagenicity of diagnostic and therapeutic doses of (131)I using bone marrow cells of rats treated in vivo in a test system with a single dose by gavage. Concentrations of 5, 25, 50 and 250 μCi in 1 ml of water were used, and after 24 h, the animals were killed. Also, a concentration of 25 μCi/ml of water was used, and the animals were killed after 5 days. The results showed that no concentration of (131)I was cytotoxic and that all concentrations were mutagenic. As a result, there was no statistically significant difference detected by the χ(2) test in the induction of chromosomal aberrations between the different doses. Thus, the present study demonstrated a significant increase in chromosomal aberration in bone marrow cells exposed to (131)I regardless of the dose or the treatment time.

Chromosome aberrations after high-dose 131I and 99mTc-MIBI administration using a micronucleus assay

OBJECTIVE

We evaluated the potential detrimental cytogenetic effects of Tc-methoxyisobutyl isonitrile (MIBI) and I on patients who were exposed to the radiopharmaceutics for cardiac imaging or thyroid cancer therapy, respectively.

METHODS

Mononuclear leukocytes were isolated both before and after radiopharmaceutical administration and subsequently cultured. Micronuclei frequency was then assessed and microscopic evaluation of apoptosis was conducted.

RESULTS

Small statistically insignificant augmentation in the percentage of micronuclei from 10.9+/-3.8 to 11.3+/-2.4% was observed in the Tc-MIBI group. In contrast, I elicited a notable augmentation of micronuclei from 6.3+/-2.2 to 9.6+/-3.1 at 3.7 GBq, and 6+/-1.5 to 9.2+/-2.7 at 5.55 GBq (P<0.05).

CONCLUSION

Our results showed that there were no remarkable alterations either in the micronuclei incidence or in the percentage of apoptotic lymphocytes after in-vivo exposure to radiopharmaceutical imaging, which provides evidence to reduce the growing concern about the safety issue of cardiac imaging with Tc-MIBI, whereas the deleterious effects of I must be considered when it is applied to thyroid cancer treatment.