How often should non-smoking young women be screened for lung cancer?

The author advocates "low risk, low age and low frequency" | Source of Yan Xiaoliu | "Medical Community" public account If the low-dose spiral CT (LDCT) is emphasized once a year in the low-risk population of lung cancer, what will be the result? On January 18, local time, "JAMA-Internal Medicine" released a Taiwanese study that pointed out that this may lead to a large number of overdiagnoses
.

The paper claims to be the first evidence that the widespread use of LDCT screening in the population leads to overdiagnosis
.

Its statistics found that from 2004 to 2018, the incidence of early-stage lung cancer in women in Taiwan, China increased by more than six times, and the 5-year survival rate doubled, but the incidence and mortality of advanced lung cancer were almost unchanged
.

As "an excellent screening program", the purpose should be to reduce disease progression and reduce lung cancer mortality through early detection and early treatment
.

Some comments pointed out that the study has shortcomings and limitations
.

Including no screening and no screening comparison, there is no comparison of male data in the same period
.

The title is "Overdiagnosis of Asian Women", but it does not include Asian multi-country data, does not consider ethnic specificity,
etc.

Young women frequently appear in the camera, and Wayne Gao of the School of Public Health, Taipei Medical University, China, is the first author of the aforementioned study to "promote widespread screening of LDCT
.
"
It wrote in the article that for Taiwan, China, the early 2000s were a critical juncture
.

At that time, LDCT opportunistic screening promoted by the media and hospitals began to appear in Taiwan, China
.

The public pays out-of-pocket expenses, about 150 to 230 US dollars (about 952-1460 yuan)
.

Sometimes screening is offered as a "public service" to certain groups of people for free, such as teachers, low- and middle-income groups,
etc.

Hospitals can benefit from follow-up tests, biopsies, and surgeries
.

There is a very high presence of young women in LDCT screening-related promotions
.

They lie or sit around high-precision CT equipment
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The advertising slogan is also quite memorable, such as, "People who have never done LDCT, especially women, should do it now" "Women are genetically more fragile and difficult to repair diseased cells, so LDCT screening should be performed regularly
.

" Wayne Gao et al.
It was found that from 2003 to 2019, the number of LDCT equipment in Taiwan doubled, from 357 to 623
.

It is impossible to distinguish whether "the public needs extensive screening, which leads to a large number of purchases", or "a large number of purchases promotes extensive screening"
.

Image from JAMA Intern Med "If the scope of LDCT screening is expanded and the criteria are relaxed, it will be difficult to reverse or shrink
.

" Wayne Gao et al.
said, but can the promotion of LDCT in low-risk groups really bring significant benefits? Because of this question, Wayne Gao, together with the Center for Surgery and Public Health of Brigham and Women's Hospital in the United States, used the Taiwan Cancer Registry System to conduct an ecological cohort study on the incidence of lung cancer in women
.

The study included data on women diagnosed with lung cancer between January 1, 2004, and December 31, 2018
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The analysis period was from February 13, 2020 to November 10, 2021
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The purpose of the study was to find two basic evidences: first, whether to increase the early morbidity rate; and second, whether to reduce the late morbidity rate
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The former can demonstrate that screening contributes to "early detection"; the latter verifies the effectiveness of early intervention to support the positive significance of widespread screening
.

The clinical significance of LDCT in low-risk groups is limited.
The results show that from the perspective of epidemiological characteristics, with the introduction of LDCT screening, the incidence of lung cancer in Taiwanese women increased significantly from 2004 to 2018, but the mortality rate remained stable
.

In other words, early detection and early intervention did not improve prognosis
.

Yellow is the incidence curve; dark blue is the mortality curve
.

Let's look at the incidence of lung cancer at different stages
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Taiwan's female population is about 12 million
.

Between 2004 and 2018, 57,898 people were diagnosed with lung cancer (median age at diagnosis decreased from 68 years in earlier years to 65 years)
.

Taking 2004 as the base year, after adjusting for age, the incidence of early-stage (stage 0-I) lung cancer increased from 2.
3 to 14.
4 per 100,000 people (absolute difference 12.
1, 95% CI 11.
3-12.
8), an increase of 6 times more
.

However, no reduction was observed in advanced (stage II-IV) lung cancer
.

The associated incidence increased from 18.
7 per 100,000 population to 19.
3 (absolute difference 0.
6, 95% CI -0.
5-1.
7)
.

In addition, the 5-year survival rate of lung cancer during the study period is full of "confusing"
.

The data showed that the lung cancer death rate for women in Taiwan fell slightly, from 17 to 16 per 100,000 people
.

But the 5-year survival rate changed dramatically, from 18% in 2004 to 40% in 2013
.

Wayne Gao et al pointed out that in the real world, an increase in early morbidity but not accompanied by a decline in late morbidity and mortality is a feature of overdiagnosis
.

According to its estimates, about 7,000 to 12,000 Taiwanese women were overdiagnosed, accounting for 12% to 20.
7% of lung cancer detections during the same period
.

This subset of lung cancers detected may be indolent, that is, very low-grade, slow-growing
.

Even without treatment, the tumor can survive for several years
.

Overdiagnosis can lead to overtreatment
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A side-by-side data is that from 2000 to 2018, claims related to thoracotomy (including lobectomy, segmentectomy and wedge resection) for women in Taiwan, China, increased significantly, from about 800 cases to 8,000 cases per year
.

Wayne Gao et al.
pointed out that their study is not to deny the significance of LDCT screening, but to emphasize that "it should only be offered to heavy smokers"
.

Citing the relevant screening recommendations in the United States, it stated that current smokers aged ≥ 50 years, smoking ≥ 20 pack years, or those who have quit smoking for less than 15 years should have an LDCT screening every year
.

Chen Haiquan, a professor of thoracic surgery at Fudan University Affiliated Cancer Hospital, commented that the relevant evidence in this study is slightly far-fetched
.

For example, the number of people who did not screen and did not do screening, and there is no male data to compare
.

The time point involving the widespread application of LDCT is unclear, and cannot be based solely on the number of CT devices
.

Second, the increased 5-year survival rate for early-stage cancer did not exclude treatment advances and changes in cancer pathology
.

It cannot be ruled out that this is precisely the benefit of extensive screening with LDCT
.

Finally, the study stated that the 5-year survival rate of lung cancer was based on European and American countries, and did not include Japan, South Korea, Singapore, etc.
, and did not consider ethnic specificity
.

Screening of low-risk and younger age groups should be done at a low frequency.
Wayne Gao et al.
said that the research corresponds to the current big theme: in recent years, with the intensification of tobacco control in various countries, the epidemiological characteristics of lung cancer in many countries have changed
.

A meta-analysis of 69 studies showed that lung cancer detection rates were similar in smokers and non-smokers
.

There are "high detection rates" in nonsmokers, young people, and women
.

Professor Chen Haiquan told the "medical community" that as of now, compared to the traditionally defined high-risk groups (older, smoking, male), there is no clear standard for how "young, non-smoking, female" should be screened
.

This may be a major challenge for lung cancer screening
.

Professor Chen Haiquan does not support "strengthening early screening of non-smoking women"
.

He pointed out that many young people in their 20s and 30s do an LDCT every year
.

The benefits do not necessarily outweigh the risks
.

Increased screening for "young, non-smoking, female" may lead to overdiagnosis bias
.

That is, patients are found, diagnosed with the disease, and included in the total number of diagnoses, but the length of their personal life cycle remains unchanged
.

In 2014, "JAMA-Internal Medicine" reported the study of Patz et al.
, and also obtained similar results
.

It speculates that more than 18% of lung cancers screened by LDCT in the United States may be indolent
.

For every life saved by LDCT screening, 1.
38 individuals were overdiagnosed
.

These overdiagnoses can cause unnecessary financial and emotional burdens, as well as increased treatment-related mortality
.

Professor Chen Haiquan said that for "low-risk groups" in the traditional sense - non-smoking, young, and female, screening at a younger age and lower frequency should still be promoted
.

For example, a person in their 20s and 30s who has had an LDCT this year and the result is negative and has no other high-risk factors can do it again in 5-10 years
.

"Is it possible that there is no problem with the test today, and the cancer cells start to grow the next day.
Can we wait for 10 years? Our research found that 96% of lung cancers screened in traditional non-high-risk groups are GGO-type lung cancers.
The vast majority of this type of lung cancer is indolent, with slow progression, and the possibility of developing rapidly progressive and invasive lung cancer is very low
.

Therefore, for rapidly developing invasive cancer, annual inspections cannot achieve early treatment
.

If it is indolent Cancer, 10 years later, may still be in the early stages of the disease
.

"Source: 1.
Association of Computed Tomographic Screening Promotion With Lung Cancer Overdiagnosis Among Asian Women.
JAMA Intern Med.
Published online January 18, 2022.
doi:10.
1001/jamainternmed.
2021.
77692.
What Happens When Lung Cancer Screening Targets Nonsmokers?.
Medpagetoday3 .
Overdiagnosis in low-dose computed tomography screening for lung cancer.
JAMA Intern Med.
2014 Feb 1;174(2):269-74.
doi: 10.
1001/jamainternmed.
2013.
12738.
Source: Medical Community Editor: Xu Liyan Proofreading: Zang Hengjia Edition: Xue Jiao's wonderful review in the past The more smoking, the better the effect of immunotherapy? The reason is.
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