By Dr Vishal Rao U S
It’s easy to crunch the numbers on thyroid cancers and assume it is a disease fast on the rise. Statistics across the world are suggestive of an increase in the Incidence in these cancers over the last 3 decades. What is more worrisome is that Over the last few years, however, studies showing there has been a significant increase in the mortality (deaths) in certain groups have caused much debate in the scientific community.
The question is whether or not it is related to detection and radiological studies, or if it is related to an authentic rise in thyroid cancer.”
It is a question that still remains largely unanswered. Evidence from the Surveillance, Epidemiology and End Results database, a registry of cancer cases that is kept by the National Cancer Institute, leaves little question that there are more cases of thyroid cancer today than three decades ago. But the more important question is whether these statistics indicate a true rise in the disease or are simply a result of better diagnostic tools.
Over the last three decades, Ultrasound and fine-needle biopsies have helped diagnose thousands of cases that would never have been found before. In many cases, nodules are discovered by accident during another medical investigation. A study published in Journal of american Medical Association first brought this issue to light in 2006. Researchers concluded that the reported 140 percent increase in thyroid cancer from 1973 to 2002 was simply a result of “increased diagnostic scrutiny.” owing to the increasing use of ultrasound neck.
They argued that a true increase in incidence would be reflected in every stage of the cancer. But the study showed that 87 percent of the increase was from small papillary thyroid cancer tumors — the most common and treatable type of thyroid cancer — that were less than two centimeters in size. Many of these cases, the researchers say, would never have caused any problems. In fact, studies have shown that thyroid cancer is found in nearly 4 percent of all fine-needle aspiration biopsy specimens.
“But there is also going to be a subset of these small tumors that are caught early and would behave more aggressively. Hence while there could be an increased incidence of microscopic thyroid cancers it would be hard to ignore a diagnosis of cancer.”