Thyroid tumour type no longer deemed a cancer: what this means for patients
With the name change, made to counter problem of overdiagnosis, sufferers will no longer face radiotherapy or surgery to remove thyroid gland, saving them money and tears. Other tumours may now be reclassified, doctors hope
A type of thyroid cancer that affects an estimated 45,000 people in the world, including 23,250 people in Asia, has been given a name change and reclassified as benign by an international panel of pathologists and clinicians.
“The reclassification of this thyroid tumour will spare the patients extensive surgery [removal of all the thyroid instead of only one half] and radioactive iodine therapy, as well as the psychological and social impact [e.g. denial of life insurance] of a cancer diagnosis,” says Dr Ronald Ghossein, director of head and neck pathology at Memorial Sloan-Kettering Cancer Centre in New York, and one of two dozen experienced pathologists from seven countries involved in the study.
“Of course, a lot of money will be saved. Avoidance of radioactive iodine therapy alone will save U$5,000 to US$8,000 per patient in the USA.”
More than that, Ghossein and colleagues hope this reclassification may encourage other cancer specialists to downgrade very indolent forms of some common cancers – such as prostate, breast and lung – to benign.
The incidence of thyroid cancer has been rising partly due to early detection of tumours that are indolent or non-progressing, despite the presence of certain cellular abnormalities that are traditionally considered cancerous, explains senior investigator Dr Yuri Nikiforov, professor of pathology at the University of Pittsburgh School of Medicine.
“This phenomenon is known as overdiagnosis,” Nikiforov says. “To my knowledge, this is the first time in the modern era a type of cancer is being reclassified as a non-cancer. I hope that it will set an example for other expert groups to address nomenclature of various cancer types that have indolent behaviour to prevent inappropriate and costly treatment.”
The name change, described in April in JAMA Oncology, is for a type of tumour known as encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), which has increased in incidence by an estimated two- to three-fold over the past 20 to 30 years and makes up 10 to 20 per cent of all thyroid cancers diagnosed in Europe and North America. Ghossein estimates there are about 23,250 such patients in Asia.
To reflect that it is now known to be non-invasive and has a low risk of occurrence, the tumour has been renamed as “non-invasive follicular thyroid neoplasm with papillary-like nuclear features” (NIFTP). There is no known risk factors for this tumour, which usually presents as a lump in the neck without pain, Ghossein says.
Although studies have shown EFVPTC is not dangerous, it is typically treated as aggressively as other types of thyroid cancer. At the recommendation of the US National Cancer Institute, the expert panel independently reviewed 268 tumour samples diagnosed as EFVPTC from 13 institutions. In a group of more than 100 non-invasive EFVPTCs, there were no recurrences or other manifestations of the disease at a median follow-up of 13 years, the panel found.
The new name cites key features to guide pathologists in diagnosis, but omits the word “cancer”, indicating that it need not be treated with radioactive iodine or other aggressive approaches.
“We determined that if NIFTP is carefully diagnosed, the tumour’s recurrence rate is extremely low, likely less than 1 per cent within the first 15 years,” Nikiforov says. “The cost of treating thyroid cancer in 2013 was estimated to exceed US$1.6 billion in the US. Not only does the reclassification eliminate the psychological impact of the diagnosis of ‘cancer,’ it reduces the likelihood of complications of total thyroid removal, and the overall cost of health care.”