Thyroid Cancer Overtreated, Qatari Study Finds
In the last few decades, the number of thyroid cancer diagnoses has risen sharply. Since the 1970s, cases of the disease have more than doubled worldwide, and it is now the form of cancer with the fastest-growing number of new cases. New research by a scientist at Qatar University has shown this is due to better detection techniques, not unhealthy modern lifestyles.
“We don’t have a sensible approach to dealing with the diagnosis of thyroid cancer,” Dr. Suhail Doi, one of the authors of the study, said. “It’s costing billions of dollars.”
“In some countries there is a 15-fold increase in detection and yet survival rates haven’t increased,” he said.
That, Doi said, is because in many cases the cancer would likely not grow or become aggressive enough to kill or harm a patient, yet the tumor is removed and treated anyway. Doi argues it’s time for that to change.
“With certain cases of thyroid cancer, you’ll probably die of something else,” he said.
In their study, Doi and his colleagues looked at the records of thousands of post-mortem exams over the last 60 years of patients who didn’t die of thyroid cancer. The records showed there had been no change in incidence rates of small tumors or lesions on thyroids—it’s just they weren’t previously diagnosed while the patient was alive.
“So it means these tumors are being detected because of technology,” Doi explained, “and the patients are then subjected to surveillance for the rest of their lives, [and given] hormone replacement and surgery for absolutely no reason because it has no effect on survival.”
Instead, it would be better practice to just keep an eye on the lesion and then take action only if it should grow, Doi said.
“We should leave these patients alone and only intervene if necessary.”
It’s hard to estimate how many people in the Middle East and North Africa suffer from thyroid cancer, but Doi says it is likely to be somewhere between five and 15 people per thousand. “No doubt, there are many thousands or millions of Arabs who are affected by this,” he says.
Dr. Mohammed Bashir, a thyroid specialist at the Hamad Medical Corporation in Doha, agrees with Doi to an extent but still takes a somewhat cautionary approach with his patients.
“The improvement and availability of detection has improved a lot so we’re picking it up more than we have in the past,” he said. “Maybe we’re overdoing it, but we still don’t have a strong tool to tell us how the lesions will behave in the future.”
He adds that treatment for thyroid cancer has already been toned down in recent years. “We are backing off from aggressive treatments, but we’ll still take precautionary steps,” he said. “We used to give everyone radiology and surgery. Now we don’t always take out the entire thyroid, and the radiology isn’t as heavy because the survival rates at lower doses are also good.”
For this study, Doi and his colleagues relied on data from Australian autopsies. It would have been impossible to reach reliable conclusions if they had wanted to only use data from Arab countries. That’s because families are often reluctant to allow autopsies on the bodies of deceased family members, usually because of the religious requirement in Muslim practice to inter the body without delay after death.
Islamic guidelines on the matter of autopsies vary among legal scholars, but in general the practice is approved because of the scientific and medical benefits it provides. The laws of individual countries also vary.
“It’s extremely difficult. Culturally here, people just don’t accept post-mortem studies on the deceased,” Bashir said. “And the government won’t overturn the family’s decision unless the death was caused by a crime.”
While Bashar believes it’s understandable and important to respect individuals’ wishes and cultures, he also believes it creates a lost opportunity for research. “We’re missing out on a lot of potential studies because researchers don’t have access to a source of data here like they do in other countries,” he said.
He added that until attitudes change or the political will changes, Arab researchers who need this sort of data will always have to look to abroad for help. “It’s a problem, but there’s no momentum to try and change it right now,” he said.