Therapy-related acute myeloid leukemia following radioactive iodine treatment for thyroid cancer

Radioactive Iodine-Induced Chronic Myeloid Leukemia in a Patient With Graves' Disease: A Case Report

Therapy-related leukemia is an increasing concern in hematology. One of these substances that showed to increase the incidence of leukemia is radioactive iodine (RAI). We report here a case of radioactive iodine-induced chronic myeloid leukemia (CML) in a patient with Graves' disease, although most cases in the literature were for thyroid cancer. Also, our patient received a very low dose, which is unique compared to previous case reports in the literature.

Acute Myeloid Leukemia following Radioactive Iodine Therapy for Metastatic Follicular Carcinoma of the Thyroid

Radioactive iodine (RAI) therapy is widely used and has an important role in the management of hyperthyroidism and thyroid malignancies. The development of acute or chronic leukemia is a very rare complication of RAI therapy. We report a case of metastatic Follicular thyroid cancer (FTC) who underwent total thyroidectomy followed by treatment with a cumulative dose of 1600 mCi of RAI (for 4 years) and by palliative radiotherapy for L4 spinal metastasis, later on, developed acute myeloid leukemia. Thus, all patients with thyroid carcinoma treated with RAI should undergo periodic hematological examinations irrespective of RAI dose.

Acute Myeloid Leukemia after Low-Dose Radioiodine Therapy for Papillary Thyroid Carcinoma

Papillary thyroid carcinoma is the most common primary thyroid cancer. Most frequently treated with surgical resection, some cases require radioactive iodine (RAI) therapy. Studies have suggested that there is an increase in second primary malignancy after RAI therapy amongst thyroid cancer survivors including acute myeloid leukemia (AML) as an infrequent cancer related to RAI therapy; it has a higher relative risk ratio in patients on higher doses of radiation exposure. We would like to report a 30-year-old lady who was diagnosed with papillary thyroid carcinoma. She underwent total thyroidectomy and received a low-dose RAI ¹³¹I therapy at a dose of 150 mCi, after which she developed therapy-related AML. Here we would like to highlight the association of AML with low-dose RAI as an infrequent cause of a second primary tumor compared to high doses.

Crystal engineering of coordination-polymer-based iodine adsorbents using a π-electron-rich polycarboxylate aryl ether ligand

This work revealed that the synergy of microporous channels and convergent arrangements of halogen bonding and charge-transfer interaction sites within coordination polymers facilitated the iodine adsorption process.

Myeloid malignancies after treatment for solid tumours

The cure rate for several solid tumour malignancies including breast cancers, head and neck cancers, bone cancers, and sarcoma has improved remarkably with the advent of neoadjuvant and adjuvant therapies. Unfortunately, exposure to chemotherapy or radiation as a part of these treatments exposes patients to the risk of subsequent myeloid malignancies. Therapy related myeloid malignancies have certain characteristic findings. They typically arise within 10 years of treatment exposure, they are seen in younger patients, and the greatest risk is in patients who receive therapy with alkylating agents or topoisomerase II inhibitors. Solid tumours whose therapies utilize these agents at higher doses, namely bone/soft tissue cancers, testicular cancer, anal cancer, and brain tumours, appear to be the groups at highest risk for T-MN. Beyond these patients, emerging populations diagnosed with T-MN include prior platinum exposure, and patients requiring G-CSF support with chemotherapy.

Radioactive Iodine-Related Clonal Hematopoiesis in Thyroid Cancer Is Common and Associated With Decreased Survival

CONTEXT

Radioactive iodine (RAI) has been epidemiologically associated with the development of hematologic malignancies. Clonal hematopoiesis (CH) is a precursor clonal state that confers increased risk of leukemia and occurs at an elevated rate in patients with thyroid cancer relative to other solid tumors.

OBJECTIVE

We explore if the high prevalence of CH may be a result of RAI exposure and whether CH may be a surrogate in the association between RAI and leukemia.

DESIGN

CH, CH-potential driver (CH-PD), and overall survival were evaluated in 279 patients with advanced thyroid carcinoma.

RESULTS

The prevalence of CH in patients with thyroid cancer was 37%, and that of CH-PD was 5.2%. Age was the strongest predictor of CH and CH-PD. For every year increase in age, there was a 5% and 13% increase in the odds of CH and CH-PD, respectively. RAI dose was significantly associated with CH and CH-PD, even after adjustment for age, external beam radiation therapy, and chemotherapy. For every 10 mCi increase in the dose of RAI administered, there was a 2% and 4% increase in the odds of CH and CH-PD, respectively. Patients with CH-PD previously exposed to RAI had a significantly poorer survival, even when stratified by age (heart rate = 3.75, 95% CI = 1.23 to 11.5, P = 0.02).

CONCLUSIONS

RAI was associated with a high prevalence of CH, and CH is a precursor state of hematologic malignancies. The implications of this study may favor identification of CH in patients where the risks might outweigh the benefits of receiving RAI therapy for thyroid cancer.

Risk of Hematologic Malignancies After Radioiodine Treatment of Well-Differentiated Thyroid Cancer

Purpose To investigate the risk and outcomes of second hematologic malignancies (SHMs) in a population-based cohort of patients with well-differentiated thyroid cancer (WDTC) treated or not with radioactive iodine (RAI). Methods Patients with WDTC were identified from SEER registries. Competing risk regression analysis was performed to calculate the risks of SHMs that occurred after WDTC treatment and outcomes after SHM development were assessed. Results Of 148,215 patients with WDTC, 53% received surgery alone and 47% received RAI. In total, 783 patients developed an SHM after a median interval of 6.5 years (interquartile range, 3.3 to 11.2 years) from WDTC diagnosis. In multivariable analysis, compared with those undergoing thyroidectomy alone, RAI treatment was associated with an increased early risk of developing acute myeloid leukemia (AML; hazard ratio, 1.79; 95% CI, 1.13 to 2.82; P = .01) and chronic myeloid leukemia (CML; hazard ratio, 3.44; 95% CI, 1.87 to 6.36; P < .001). This increased risk of AML and CML after RAI treatment was seen even in low-risk and intermediate-risk WDTC tumors. Occurrence of AML but not CML in patients with WDTC was associated with shorter median overall survival compared with matched controls (8.0 years v 31.0 years; P = .001). In addition, AML developing after RAI trended toward inferior survival compared with matched controls with de novo AML (median overall survival, 1.2 years v 2.9 years; P = .06). Conclusion Patients with WDTC treated with RAI had an increased early risk of developing AML and CML but no other hematologic malignancies. AML that arises after RAI treatment has a poor prognosis. RAI use in patients with WDTC should be limited to patients with high-risk disease features, and patients with WDTC treated with adjuvant RAI should be monitored for myeloid malignancies as part of cancer surveillance.