Thyroid cancer treatment may be overly aggressive

Thyroid cancers that are clinically insignificant - and may never cause serious disease - may be treated too aggressively in some patients, according to the author of the 2006 Hayes Martin Lecture, published in the Archives of Otolaryngology-Head and Neck Surgery.

Physicians need to be more selective in how aggressively they evaluate patients who have low-risk thyroid cancer in the earliest stages and stable thyroglobulin levels, Dr. Keith S. Heller told Reuters Health. Elevated or rising levels of thyroglobulin, a protein produced in the thyroid gland, may indicate the presence of thyroid cancer. However, elevated thyroglobulin is also caused by many benign conditions.

Heller from New York University School of Medicine, New York, contends that several of the American Thyroid Association guidelines for the treatment of patients with thyroid nodules or stage 1 thyroid cancer may lead to overly aggressive treatment. In particular, the use of sonography, and how much of a thyroglobulin elevation requires further evaluation, need to be reconsidered.

After reviewing some of the articles that led to these guidelines, Heller asserts: “All of these studies, guidelines, and recommendations lack data that prove that the presence of these minimally involved lymph nodes in any way affects the patient’s prognosis.” There is also no evidence that the removal or treatment of these lymph nodes improves patients’ survival.

“I find these guidelines very troubling for those reasons.”

In Heller’s personal experience with 360 patients younger than 45 years at the time of initial treatment for differentiated thyroid cancer, 99 percent are still alive. Three died from causes unrelated to thyroid cancer and only one died of thyroid cancer.

Similarly, among 449 of his older patients with previously untreated differentiated thyroid cancer, 91 percent are alive, and of the 40 patients who died, only 8 died of thyroid cancer.

“My objection is not that the guidelines are wrong, but that they need to be clearer in using risk stratification to determine which patients need to be the subject of which guidelines,” Heller said.

“In many ways the ability to detect microscopic metastatic thyroid cancer creates a dilemma similar to that faced by urologists when an elevated PSA leads to the detection of microscopic prostate cancer,” he pointed out. “Clearly, not all of these need to be treated.”

He concludes: “We have embarked on a quixotic quest to rid our patients of microscopic and probably clinically unimportant thyroid cancer. We need to refocus our efforts, not to detect more occult disease, but to identify and cure those few patients whose disease is likely to shorten their lives.”

SOURCE: Archives of Otolaryngology-Head and Neck Surgery, July 2007.

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