Thyroid Cancer Rates Still Alarming

By Raam Wong, Albuquerque Journal Staff Writer
ALBUQUERQUE — Thyroid cancer rates remain significantly higher among women in Los Alamos County than the rest of the state, according to newly released data about a phenomenon that has long stumped researchers.

"The rate is high," said Charles Wiggins, director of the New Mexico Tumor Registry at the University of New Mexico. "Why it is I can't tell you."

A 1996 state Health Department epidemiology study could not explain why Los Alamos County residents developed thyroid cancer at a rate four times higher than the rest of the state between 1988 through 1995.

Since then, the rate among non-Hispanic white males in Los Alamos County has been falling and today is actually below the statewide average. But the rate among Anglo women remains a concern: 66 cases per 100,000 residents between 2001 and 2005, compared to an average of 21 cases for all other counties. In real numbers, that's 22 cases among the population of non-Hispanic white women in Los Alamos County.

Numbers like that warrant further analysis, according to public health officials. The state Health Department plans to do a "descriptive epidemiology" analysis in hopes of identifying patterns in the disease, according to spokeswoman Deborah Busemeyer.

A high rate of cancer in a particular region inevitably raises concerns that environmental hazards — such as nuclear weapons work at Los Alamos National Laboratory — may be a factor.

But health experts caution against drawing conclusions from the data without further study. The 1996 study couldn't explain the cause of the high rate and found no conclusive evidence that radiation from LANL was to blame. The high rate was likely to have multiple causes, the report concluded.

Rates of thyroid cancer — a relatively rare but generally curable disease — have been increasing nationally for years. And the reason may have less to do with environmental exposures than advances in detection methods.

That may help explain why rates in Los Alamos remain high. Experts suspect the highly educated, affluent population in Los Alamos has better-than-average access to medical care.

Wiggins said he would like to begin taking a closer look at the characteristics of the patients, particularly at what stage the cancer was detected. If the disease was diagnosed early in a number of cases, it could signal that the medical community is proactive in looking for the cancer, which could help explain the high rate, he said.

LANL epidemiologist Laurie Wiggs said in a statement that the thyroid cancer rate remains a mystery.

"To date, we've not discovered any evidence for an occupational or job-related situation at the laboratory that would explain the high cancer rate," Wiggs said. "We would agree that a new, comprehensive study of this phenomenon would be very helpful — not just for lab employees, but for all residents of Los Alamos County."

Thyroid cancer is more commonly found in women than men, and epidemiologists estimate that thyroid cancer induced by radiation exposure may not be diagnosed for 20 to 40 years. Other possible risk factors for the disease include family history of thyroid cancer, breast cancer and obesity.

Los Alamos County's thyroid cancer rate for non-Hispanic white men dropped from nearly 15 cases per 100,000 residents in the mid 1990s to 3.11 between per 100,000 since 2001. That's below the 7.83 rate in all other New Mexico counties.