Screening of non-smoking women in Taiwan associated with lung cancer overdiagnosis

A brand new examine based mostly on knowledge from a nationwide most cancers registry in Taiwan discovered proof that lung most cancers screening could also be resulting in overdiagnosis on the inhabitants degree. Low-dose computed tomography (LDCT) has been promoted in Taiwan to folks, particularly younger ladies, who shouldn’t have a historical past of smoking. Investigators from Brigham and Girls’s Hospital and collaborators at Taipei Medical College have discovered that over the past 15 years there was a 6-fold enhance in early-stage most cancers diagnoses amongst ladies, however there was no change in incidence of late-stage lung most cancers or dying from lung most cancers, suggesting that screening is resulting in overdiagnosis. Outcomes are revealed in JAMA Inner Drugs.

“Promotions for lung most cancers screening in Taiwan function photos of younger ladies and dramatic language encouraging folks to ‘keep away from the tragedy of sudden dying from terminal lung most cancers,’” mentioned senior creator H. Gilbert Welch, MD, MPH, of the Brigham’s Middle for Surgical procedure and Public Well being. “These campaigns conflate the chance of prognosis and the chance of dying. However what we discover is that whereas elevated screening has led to elevated early-stage prognosis amongst younger ladies, it has not led to a lower in late-stage most cancers or dying. This implies that screening isn’t main to raised outcomes — it’s resulting in overdiagnosis.”

The US Preventive Service Job Power recommends lung most cancers screening just for people who’ve smoked a median of 1 pack of cigarettes per day for 20 years and are between the ages of fifty and 80. However in different nations, together with Taiwan, lung most cancers screening for nonsmokers has turn into widespread, regardless that it’s not lined by Taiwan’s nationwide medical insurance program. Smoking prevalence amongst ladies in Taiwan is low — the speed has been lower than 5 p.c since 1980. Hospitals in Taiwan started to advertise screening providers within the mid-2000s, across the similar time that the variety of CT scanners elevated dramatically. Well being care professionals and a few celebrities have publicly known as for screening to be lined by the nationwide insurance coverage program.

Welch and colleagues examined knowledge from the Taiwan Nationwide Most cancers Registry, evaluating charges of early-stage and late-stage lung most cancers diagnoses. They discovered {that a} complete of 57,898 ladies have been identified with lung most cancers, out of roughly 12 million ladies in Taiwan. From 2004 to 2018, the incidence of early-stage lung most cancers (levels 0-1) elevated 6-fold, from 2.3 to 14.4 instances per 100,000 folks. However the incidence of late-stage lung most cancers (levels 2-4) was unchanged. The workforce estimated that someplace between 7,000 and 12,000 Taiwanese ladies have been overdiagnosed with lung most cancers.

Lung most cancers mortality was steady, reducing simply barely from 17 to 16 deaths per 100,000 folks. The five-year survival fee jumped dramatically — a discovering that’s not stunning when overdiagnosis is at play, in accordance with the researchers.

The Taiwanese expertise highlights the deceptive suggestions that follows most cancers screening. Survival charges at all times go up when there may be overdiagnosis as a result of persons are getting identified with a illness not destined to trigger dying.”

H. Gilbert Welch, MD, MPH, Senior Writer, Brigham’s Middle for Surgical procedure and Public Well being

Welch and co-authors word that the first limitation of their examine was that they may indirectly measure LDCT screening since it’s paid for out of pocket and never billed to an insurance coverage program. However knowledge on the rising variety of LDCT scanners at hospitals, direct-to-consumer promotion, and the sample of accelerating early-stage prognosis and steady late-stage prognosis all point out a rise in screening.

“Sadly, it is a recipe for overdiagnosis,” mentioned Welch. “Our findings recommend that LDCT must be provided solely to heavy people who smoke, to not lower-risk teams, and solely after the advantages have been weighed towards the harms, comparable to a false-positive prognosis, incidental findings, diagnostic procedures and radiation-induced cancers.”