Second primary malignancies in thyroid cancer patients

Abstract

The late health effects associated with radioiodine ( 131 I) given as treatment for thyroid cancer are difficult to assess since the number of thyroid cancer patients treated at each centre is limited. The risk of second primary malignancies (SPMs) was evaluated in a European cohort of thyroid cancer patients. A common database was obtained by pooling the 2-year survivors of the three major Swedish, Italian, and French cohorts of papillary and follicular thyroid cancer patients. A time-dependent analysis using external comparison was performed. The study concerned 6841 thyroid cancer patients, diagnosed during the period 1934 -1995, at a mean age of 44 years. In all, 17% were treated with external radiotherapy and 62% received 131 I. In total, 576 patients were diagnosed with a SPM. Compared to the general population of each of the three countries, an overall significantly increased risk of SPM of 27% (95% CI: 15 -40) was seen in the European cohort. An increased risk of both solid tumours and leukaemias was found with increasing cumulative activity of 131 I administered, with an excess absolute risk of 14.4 solid cancers and of 0.8 leukaemias per GBq of 131 I and 10 5 person-years of follow-up. A relationship was found between 131 I administration and occurrence of bone and soft tissue, colorectal, and salivary gland cancers. These results strongly highlight the necessity to delineate the indications of 131 I treatment in thyroid cancer patients in order to restrict its use to patients in whom clinical benefits are expected.

Management Guidelines for Patients with Thyroid Nodules and Differentiated Thyroid Cancer: The American Thyroid Association Guidelines Taskforce

“…If radioiodine is being considered, prior external beam radiotherapy and concomitant glucocorticoid therapy are strongly recommended to minimize the effects of a potential TSH-induced increase in tumor size and the subsequent inflammatory effects of the radioiodine (261)-Recommendation C Management of complications of radioiodine therapy. While radioiodine appears to be a reasonably safe therapy, it is associated with a cumulative dose-related low risk of early and late onset complications such as salivary gland damage, nasolacrimal duct obstruction (268), and secondary malignancies (267). Therefore, it is important to ensure that the benefits of repeated radioiodine therapy outweigh the potential risks.…”

“…Surgical correction should be considered for nasolacrimal outflow obstruction, which often presents as excessive tearing (epiphora) but also predisposes to infectionRecommendation B Second malignancies and leukemia from radioiodine therapy. Long-term follow-up studies demonstrate a very low risk of secondary malignancies (bone and soft tissue malignancies, colorectal cancer, salivary tumors, and leukemia) in long-term survivors (267). The risk of secondary malignancies is dose-related (267).…”

“…Long-term follow-up studies demonstrate a very low risk of secondary malignancies (bone and soft tissue malignancies, colorectal cancer, salivary tumors, and leukemia) in long-term survivors (267). The risk of secondary malignancies is dose-related (267). There appears to be an increased risk of breast cancer in women with thyroid cancer (270).…”

Multiple Metachronous Malignancies, One Patient with Three Primary Malignancies

“…In the same study, several other cancer sites showed significantly increased risks in both directions, including salivary glands, prostate, breast, kidney, scrotum, brain and leukemia. A relationship between the total dose of I 131 and SPT has been reported for solid cancers and leukemias [5]. Verkooijen et al differ to suggest that this phenomenon occurs only due to genetic predisposition and environmental factors, as at least half of breast cancers occur before the treatment with I 131 for thyroid cancer [6].…”

Why radioiodine remnant ablation is right for most patients with differentiated thyroid carcinoma

“…In a series of articles in the 1950s by Seidlin, the father of radioiodine treatment for thyroid carcinoma, and coworkers [31][32][33] it was well documented that there is an excess risk of leukaemia after treatment with high cumulative activities of radioiodine [34,35], correlating with the administered total radioiodine activity [36]. In practice this means that this excess risk only materializes in patients with metastatic disease after repeated (high-activity) treatments.…”