Thyroid Function and Cancer Survival

Glioblastoma patients with low T3 were likely to have poor prognosis following surgery

(RxWiki News) How cancer starts and grows is really a maze of biological wonder. So many things are involved. Now, researchers believe that the thyroid plays a role in the outlook of brain cancer patients.

A new study has found that glioblastoma (the most common form of brain cancer) patients with low functioning thyroids do not do as well as patients with normal thyroid function.

Managing thyroid function may be appropriate for brain cancer patients, according to the researchers.

"Having severe headaches? Call a doctor."

The thyroid helps direct a lot of the body’s functions. Everything from breathing, heart rate and metabolism are influenced by this gland. So having normal thyroid function is important.

The thyroid also produces hormones, two of which are very important – triiodothyronine (T3) and thyroxine (T4). T3 is the more active thyroid hormone.  

Researchers at the Lithuanian University of Health Sciences, the University of North Carolina at Chapel Hill (UNC) and Brigham & Women's Hospital at Harvard University collaborated on a study to see if T3 levels impacted the outcomes of brain cancer patients. Adomas Bunevicius, MD, PhD, at UNC led the study.

Earlier studies have linked low T3 levels with poorer outcomes for patients with other diseases, including heart disease.

To study whether low T3 levels predicted the outlook for glioblastoma patients, researchers performed thyroid function tests before and after surgery. Surgery is commonly used to treat brain tumors.

The researchers also wanted to know if there was a link between low T3 levels and depression and anxiety.

A total of 90 patients participated in this small study. The median age of participants was 55.

T3 levels were measured the morning before the surgery and the morning after surgery. Low thyroid syndrome was defined as a free T3 level of 3.1 picomoles per liter (pmol/L) or lower.

Depression and anxiety were also measured before and after the surgery. 

Here’s what the study revealed:

  • Low T3 levels were seen in 38 percent of patients before surgery and 54 percent of patients after surgery.
  • Patients with low T3 syndrome were five times more likely to have poor outcomes compared to patients with normal T3 levels.
  • Depression and anxiety scores were higher before surgery than after.

“Low T3 syndrome is a strong independent predictor of unfavorable clinical outcomes and depressive symptoms, and its diagnosis and preoperative management should be considered in patients undergoing neurosurgery for the treatment of brain tumors,” the authors concluded.

Findings from the study were published March 12 in the Journal of Neurosurgery. This research was funded by a grant from the Research Council of Lithuania. The authors reported no conflicts of interest.

Review Date: 
March 12, 2013