Investigating the risk of thyroid disorders in survivors of Hodgkin lymphoma.

This study investigated the risk of developing a range of thyroid disorders in both childhood and adult-treated female survivors of Hodgkin lymphoma (HL). The data showed that the risk of developing thyroid disorders increased significantly over time in both childhood and adult-treated survivors of HL.

Hodgkin lymphoma (HL) is a cancer that starts in white blood cells called lymphocytes. These are a part of the body’s immune system. Patients with HL are commonly treated with chemoradiation therapy (CRT). CRT is a combination of chemotherapy and radiation.

Hypothyroidism may develop following chemoradiation therapy. Hypothyroidism means that the thyroid does not produce enough thyroid hormone. As a result, the patient may feel tired, depressed, or gain weight. Patients who underwent radiation therapy to the head and neck region are also at a higher risk of developing thyroid cancer. Most of the studies on thyroid outcomes after HL treatment focuses on patients treated in childhood and not in adulthood. However, there are very few studies investigating the risk of developing thyroid disorders in both childhood and adult-treated survivors of HL.

This study involved 237 female survivors of HL. 43.6% of the patients received CRT, 8% of the patients received chemotherapy (CT) only, and 68.8% received radiotherapy (RT) only. The average follow-up time was 40 years.

Overall, 33.8% of patients developed thyroid disorders. 30% of these patients developed hypothyroidism and 6.8% of the patients developed thyroid nodules (unusual growth of thyroid cells in the thyroid gland). After 40 years, the risk of developing a thyroid disorder increased to 42.9% of the patients.

Patients treated with RT alone were 6.8 times more likely to develop a thyroid disorder than patients treated with CT alone. The risk of developing a thyroid disorder was higher in patients treated with increasing doses of RT above the diaphragm (the muscle that separates the lungs and heart from the organs in the abdomen).

There was no significant association between the risk of developing a thyroid disorder and any CT agent or the number of CT cycles.

Risks of developing thyroid disease (more than 40%) were similar in patients treated at childhood or at adulthood. Risks of thyroid disease after RT above the diaphragm were similar between adult and childhood-treated patients.

This study concluded that the risk of developing thyroid disorders increased consistently over time in both childhood and adult-treated patients of HL. Hypothyroidism was the most common disorder and radiotherapy significantly increased the risk of developing a thyroid disorder in a dose-dependent manner.

This study looked back in time at medical records. The sample size was very small. It only involved patients treated at a single institution in the United Kingdom.