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    Home > Active Ingredient News > Digestive System Information > These groups of people are at high risk for colorectal cancer! Please keep this screening guide

    These groups of people are at high risk for colorectal cancer! Please keep this screening guide

    • Last Update: 2023-01-05
    • Source: Internet
    • Author: User
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    Expert interpretation, come and see ~


    2022 Asia-Pacific Digestive Disease Week Conference and the 22nd National Gastroenterology Academic Conference of the Chinese Medical Association has been successfully concluded
    on November 20 。 In the conference on the 17th, Professor Han-Mo Chiu from National Taiwan University Hospital and Professor Finley Macrae from Royal Melbourne Hospital respectively gave keynote speeches on colorectal cancer (CRC) screening in the general population and high-risk groups, which was also an interpretation
    of the "Third Asia-Pacific Consensus Recommendation on Colorectal Cancer Screening and Post-Polypectomy Surveillance".

    Figure 1 "Third Asia-Pacific consensus recommendation on colorectal cancer screening and post-polypectomy surveillance"
    CRC screening
    in the general population Dietary changes accompanying economic development, the middle age of the baby boomer, and the maturation of more screening methods have provided the prerequisites for CRC screening, and evidence from large-scale clinical studies in recent years has also supported the initiative
    of CRC screening in the general population.

    Figure 2 Human Development Index is positively correlated
    with age-standardized CRC incidence ▌Professor Han-Mo Chiu introduced CRC screening recommendations for the general population:
    1.
    For Asian populations, risk stratification and follow-up testing according to degree are reasonable
    (I, A):

    for the general population, the sequence of non-invasive examination-diagnostic colonoscopy-treatment should be taken
    .
    The fecal immunochemical test (FIT) is a non-invasive test that is suitable for a wide range of procedures
    .
    Taiwan's colorectal cancer screening program has confirmed that CRC accounts for about 1/20 of FIT-positive people, and this test helps to identify high-risk people
    in the population.

    2.
    Multiple hazard stratification systems are developing in parallel, and there is no advantage or disadvantage between each system
    (II-2, A).


    Based on the risk factors identified in the Asian population, the Asia-Pacific CRC Working Group developed a scoring system, the Asia-Pacific Colorectal Cancer Screening (APCS) score, which stratifies
    the risk of advanced colorectal tumor (AN) in asymptomatic subjects.
    Risk factors included in the score included age, sex, family history, and smoking history, and were easy
    to use.
    Some scholars have meta-analyzed and evaluated the risk prediction ability of more than ten hazard stratification systems, and believe that there are no advantages and disadvantages
    among them.
    In practice, clinicians can choose the appropriate scoring system
    based on the patient's ethnicity.

    3.
    For Asians, quantitative FIT is recommended annually/every 2 years or colonoscopy every 10 years
    (II-2, A).


    A 2021 epidemiological study published in JAMA concluded that annual or biennial FIT is economical and effective for CRC screening, compared with colonoscopy that is more sensitive and expensive
    .
    A population-based study in Taiwan concluded that FIT could reduce CRC mortality by 35% while reducing the incidence
    of advanced CRC by 29%.

    4.
    Fecal or blood-based molecular testing, capsule colonoscopy, and CT colonography are not supported by sufficient evidence as a means of initial screening for CRC
    (III,A).


    A Japanese study noted that CT colon imaging sensitivity was lower
    when identifying flat lesions of 6-9 mm.
    Moreover, unlike the more popular CT colon imaging methods in North America, Europe and other countries, there are still many Asian countries that do not have this method, so it is not recommended as a preliminary screening method
    in Asia.

    Meta-analyses have pointed out that capsule colonoscopy sensitivity ranged from 79% to 96% and specificity of 66% in the ability to identify > 6mm polyps; The ability to identify > 10mm polyps ranges from 84% to 97% in sensitivity and 91% to 99% in
    specificity.

    Fecal-based multi-target fecal DNA screening has also entered the public eye in recent years, but there is currently no data support based on Asian populations and is expensive, and it is not suitable for initial screening, and blood-based molecular testing has similar problems
    .

    Therefore, Professor Han-Mo Chiu believes that the above cutting-edge screening methods are only suitable for people who are not willing to undergo colonoscopy screening, and are not suitable for the general population for
    the time being.

    5.
    There is a trend of CRC rejuvenation
    (< 50 years old)</b21> in Asian populations,

    At present, it is believed that the causes and mechanisms of CRC in young people are different from those in older patients, and obesity and metabolic syndrome are both underlying factors and are closely related
    to socioeconomic development and dietary lifestyle.

    Figure 3 Significant increase in the incidence of CRC in the population after birth in 1965.
    6
    In Asian populations, it has not been shown that lowering the
    age of CRC screening to < 50 years has health economic significance</b20>
    Although the onset of CRC is younger, several groups in the United States, including the Oncology Society, have adjusted the age of onset of CRC screening
    .
    However, current studies based on Asian populations are not sufficient to support lowering the age of initiation of screening, and it remains to be evaluated
    based on data from large populations.

    7.
    Advanced age should not be a reason for healthy people not to undergo screening
    (III, C).


    8.
    However, when the age is over 85 years and the most recent screening is negative, no subsequent screening may be considered, as this group is unlikely to benefit from subsequent screening
    (III, C).


    Clinicians should pay more attention to the history of past diseases in this group and target the management of past or existing chronic diseases
    .

    Screening
    of patients with high-risk CRC After Professor Han-Mo Chiu introduced screening opinions for the general population, Professor Finley Macrae further focused on high-risk groups (family history, CRC screening
    for people with CRC or advanced adenomas).

    9.
    When receiving patients with CRC, medical workers should always ask about family history to determine whether there is a possibility of hereditary CRC syndrome
    (IIIA).


    Figure 4 List of CRC pathogenic genes The
    family history of CRC can be divided into three categories:

    (1) There is a recognized family genetic syndrome;


    (2) an immediate family member (FDR) with CRC; may be very young (< 50 years) or older (> 50 years) at diagnosis;


    (3) Patients with FDR with documented advanced adenomas or
    SSLs.


    A positive family history increases the risk of
    developing CRC.
    In addition, some people with a positive family history tend to develop CRC
    at a young age.
    Therefore, it is necessary to develop surveillance guidelines for individuals with a family history of colorectal cancer or advanced adenomas
    .

    10.
    Patients diagnosed with two FDRs with colorectal cancer or advanced adenomas at any age should be screened 10 years before the youngest FDR diagnosis age, or
    colonoscopy (II-2, A) every 5 years after the age of 40 (whichever is earlier).


    In terms of screening modalities, Australian guidelines recommend quantitative immunoassay fecal occult blood testing (iFOBT) starting at age 40 and colonoscopy screening
    starting at age 50.

    The Working Group made this recommendation because population-based clinical studies in many countries around the world showed that people with FDR who had CRC had a higher
    lifetime risk of CRC than the general population 。 A 2016 study in Hong Kong, China, which analyzed the risk of family history in patients with advanced adenomas, showed that FDR accounted for 11.
    5% of high-risk adenomas in this population, while in patients with non-advanced adenomas, the proportion of FDR with high-risk adenomas was only 2.
    5%, and the OR value was 6.
    05 (95% CI 2.
    7-13.
    4).

    Sweden's nationwide cohort study also supports this conclusion, as shown in the figure below, the risk of developing CRC in people with FDR is significantly higher than in the general population
    in terms of lifetime cumulative risk of CRC.

    Figure 5 Compared with the general population, those with FDR have a higher
    cumulative risk11.
    Age < 60 years old, and subjects with one FDR with CRC or advanced adenoma should start screening 10 years earlier than the youngest FDR diagnosis age, or after 40 years old</b20>

    The consensus is that advanced adenomas are consistent with the familial risk caused by CRC, and in terms of screening modality, Australian guidelines also recommend quantitative immunoassay fecal occult blood testing (iFOBT) from age 40 and colonoscopy screening
    at age 50.

    A meta-analysis of 63 studies totaling 9.
    28 million people showed that the risk of CRC in FDR increased the risk of CRC in individuals with an RR of 1.
    76, and when stratified by age at which FDR diagnosed CRC, the age of diagnosis was < 3.
    29 compared with > 40 years, and the age of diagnosis < 50 years compared with > 50 years RR was 2.
    81
    .
    It can be said that the younger the age at which FDR is diagnosed, the greater the risk of CRC in the individual
    .

    Another population-based clinical study included nearly 127,000 Utah populations who underwent colonoscopy, of whom 3,804 were diagnosed with CRC and defined as index cases
    .
    Compared with the general population, the risk ratio of CRC in index cases FDRs was 1.
    79, and when index cases were diagnosed with CRC at age < 60 years, the risk of CRC in FDRs was further increased, and the risk ratio was 2.
    11<b21>.
    The Swedish national database evidence also confirms this
    .

    Figure 6 Based on the Swedish national database, it can be seen that there is a difference in the risk of CRC caused by age at the time of initial diagnosis of CRC by FDR, and the higher the cumulative risk of CRC at the age of 10 years when FDR is about young, the FDR
    diagnosed with CRC at the age of 60 is 12.
    ≥ 60 years old Screening should begin at age 40 years of age, with screening modalities and strategies and intervals consistent with the general population
    (II-2, A).


    For patients with colorectal cancer or advanced adenomas, FDR screening should be started as early as possible
    .
    The age of initial screening depends on the age at which the prospector was diagnosed and the number of
    FDRs for colorectal cancer or advanced adenomas.
    The Asia-Pacific Working Group believes that there is a lack of large-scale cohort studies in the region to suggest alternatives and that international guidelines should be followed – i.
    e.
    the age at diagnosis of CRC or advanced adenomas in FDRs and their number as risk stratification criteria
    .

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