Radiation Exposure Linked to Aggressive Thyroid Cancers

Thyroid cancer patients who've previously been exposed to radiation have more aggressive disease and worse outcomes than other patients, a new study finds.

Researchers at Mount Sinai Hospital in Toronto studied 125 thyroid cancer patients who'd been exposed to radiation -- for example, in the workplace, through environmental exposure, or for treatment of acne or other benign conditions -- at least three years before they had surgery for their thyroid cancer.

The average age of the patients at time of radiation exposure was 19.4 years, and their thyroid cancers were diagnosed an average of 28.7 years later. The patients were followed for an average of 10.6 years after diagnosis. During that time, 16 percent suffered a recurrence of thyroid cancer, and 9 percent had cancer that spread to other areas of the body (distant metastases). At the final follow-up, 86 percent were alive and cancer-free, 4 percent were alive with recurrent thyroid cancer, 4 percent were alive with distant metastases, 4 percent had died of their cancer, and 2 percent had died of unrelated causes.

The researchers compared these patients to a group of 574 thyroid cancer patients who hadn't previously been exposed to radiation and found that the radiation-exposed patients were more likely to:

• Undergo total or near-total removal of the thyroid -- 83 percent vs. 38 percent.
• Require additional surgery -- 23 percent vs. 2 percent.
• Have stage IV disease -- 16 percent vs. 5 percent.
• Have distant metastases -- 9 percent vs. 2 percent.
• To have thyroid cancer at follow-up -- 8 percent vs. 3 percent.
• To have died of the disease -- 4 percent vs. 1.5 percent.

Dr. Raewyn M. Seaberg and colleagues said their findings show "that patients who have been exposed to radiation have more aggressive disease and worse clinical outcomes than other patients with thyroid cancer and, therefore, may require more aggressive treatment."

The study was published in the April issue of the Archives of Otolaryngology -Head & Neck Surgery.

STUDY: Thyroid and Parathyroid Surgical Outcomes In Pregnant Women

Thyroid and parathyroid surgery outcomes may be worse in pregnant women. Pregnant women appear to have worse clinical and economic outcomes after thyroid and parathyroid surgery compared with women who are not pregnant, according to a report in the May issue of Archives of Surgery, one of the JAMA/Archives journals.

Thyroid and parathyroid surgery are used to treat cancer and other conditions. The incidence of thyroid cancer has increased by almost 250 percent over the last 30 years, increasing from 3.6 to 8.7 cases per 100,000 persons, according to background information in the article. The rate is almost double in pregnant women, with 14.4 cases per 100,000 persons. "Hyperthyroidism [overactive thyroid] has been reported in 0.1 percent to 0.4 percent of pregnancies. Inadequately treated hyperthyroidism during pregnancy poses significant risks to both mother and fetus," the authors write. "Outcomes after thyroid and parathyroid procedures during pregnancy have not been well characterized in the surgical literature."

SreyRam Kuy, M.D., of Yale University School of Medicine, New Haven, Conn., and United States Department of Veterans Affairs, Washington, and colleagues compared clinical and economic outcomes of thyroid and parathyroid surgery performed on 201 pregnant women (average age 29) and a group of 31,155 age-matched, non-pregnant women from 1999 to 2005. Fetal, maternal and surgical complications as well as in-hospital death, length of stay and hospital costs were measured.

Of the 201 pregnant women, 165 underwent thyroid procedures and 36 underwent parathyroid procedures. "Compared with non-pregnant women, pregnant patients had a higher rate of endocrine [relating to glands that secrete hormones](15.9 percent vs. 8.1 percent) and general complications (11.4 percent vs. 3.6 percent), longer unadjusted lengths of stay (two days vs. one day) and higher unadjusted hospital costs ($6,873 vs. $5,963)," the authors write. "The fetal and maternal complication rates were 5.5 percent and 4.5 percent, respectively," Additionally, pregnant patients had higher surgical complications than non-pregnant patients for benign (27 percent vs. 14 percent) and malignant (21 percent vs. 8 percent) thyroid diseases while undergoing thyroidectomy (the surgical removal of part or all of the thyroid gland).

"Differences between pregnant and non-pregnant women in complication rates were most pronounced by diagnosis, race and hospital size," the authors note. When compared to non-pregnant women of the same race, white pregnant patients had double the complication rate (21 percent vs. 10 percent), black pregnant patients had nearly five times the complication rate (48 percent vs. 10 percent) and Hispanic pregnant patients had an almost three-fold higher complication rate (30 percent vs. 12 percent).

"These data suggest that thyroid and parathyroid surgery during pregnancy should be approached with caution and careful deliberation about whether the risks are outweighed by the benefits," the authors conclude. "Surgeon volume is an important predictor of outcomes, so pregnant women undergoing thyroid and parathyroid procedures should be directed to high-volume surgeons whenever possible. Disparities in outcomes based on race and insurance must be overcome. Optimizing maternal and fetal outcomes requires the collaboration of surgeons, endocrinologists, obstetricians, neonatologists, anesthesiologists, insurers and policy makers."

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SJCCF Thy-NET Editor's Note: The study was supported by the Robert Wood Johnson Foundation and the United States Department of Veterans Affairs. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc. Available pre-embargo to the media at http://www.jamamedia.org/ (Arch Surg. 2009;144[5]:399-406.)

For More Information Contact: Helen Dodson
Email:  helen.dodson@yale.edu
Telephone: 203-436-3984
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