Worried about colon cancer but afraid to do colonoscopy?

For medical professionals read only Reference Fecal immunochemical tests may be a test Colorectal cancer is the most common type of malignant tumor of the gastrointestinal tract, with the highest incidence in people aged 41-65 years, and the prevalence in men is higher than that in women
.

In some developed areas of our country, the incidence of colon cancer has climbed to the second place among malignant tumors, and a considerable number of patients are diagnosed as advanced stage, with poor prognosis
.

Early screening, early diagnosis, and early treatment are the keys to improving the prognosis of colorectal cancer patients[1,2]
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Colonoscopy is currently the most accurate method for screening bowel cancer and precancerous lesions commonly used in clinical practice.
However, colonoscopy is an invasive examination and requires good bowel preparation.
The sensitivity and specificity of the simple and easy fecal occult blood test (FOBT) are difficult to meet the requirements of screening
.

In recent years, Fecal Immunochemical Test (FIT) has been repeatedly proposed as an alternative to colonoscopy due to its convenient sampling (similar to ordinary stool examination), low cost, and high sensitivity
.

Figure 1 The four popular colorectal cancer screening methods in foreign countries are from the New York Health Center [3] But can FIT completely replace colonoscopy? What are the advantages and limitations of FIT? This 6-year randomized controlled study (SCREESCO) involving more than 270,000 people published in the international journal "The Lancet-Gastroenterology and Hepatology" by scholars from the Karolinska Institutet in Stockholm, Sweden [4] gave part of the answer
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Figure 2 Study published in The Lancet-Gastroenterology and Hepatology SCREESCO study: FIT has similar cancer detection rates to colonoscopy The colonoscopy group (31,140 people), the FIT group (60,300 people), and the control group (186,840 people)
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Patients who were invited for colonoscopy and FIT screening were tested accordingly at age 60
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In the colonoscopy group, 35.
1% had a colonoscopy (one), while 55.
5% in the FIT group had participated in at least one round of testing; 41.
4% completed two rounds of FIT screening, 90.
8% FIT Positive patients underwent follow-up supplemental colonoscopy
.

Figure 3 Schematic diagram of FIT detection sampling It is worth mentioning that the FIT hemoglobin threshold set by SCREESCO Institute is 10 μg/g, which is more stringent than previous FIT related tests [5]
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"Most past studies have set the hemoglobin cutoff for FIT at 20-40 μg/g, and we hope to use a lower threshold to screen for cancer, precancerous lesions, and adenomas
," the researchers said.

Figure 4 Study groupings and The results of the protocol study showed that colorectal cancer was detected in 49 (0.
16%) and 121 (0.
20%) subjects in the colonoscopy group and the FIT group, respectively (RR 0.
78, 95%CI 0.
56–1.
09).
Adenomas were detected in 637 (2.
05%) subjects in the colonoscopy group, which was significantly higher than in the FIT group (968, 1.
61%; RR 1.
27, 95% CI 1.
15–1.
41); compared with FIT Compared with colonoscopy, more right-sided colon adenomas were detected; 2 perforations and 15 major bleeding occurred in 16,555 colonoscopies over 6 years, and no intervention-related deaths occurred
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Patients in the FIT group required fewer colonoscopies to diagnose a cancer than those in the colonoscopy group (49 vs 218) [5]
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It can be seen from the research results that the cancer detection rate of FIT is similar to that of colonoscopy, and subjects in the FIT group are more likely to be screened; in addition, prior FIT examination can help patients reduce the number of colonoscopy and pain
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Colonoscopy was able to detect more adenomas than FIT, despite the researchers' extremely low hemoglobin threshold
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Can FIT replace colonoscopy for early cancer screening? Not yet! Although FIT has shown great potential in the screening of colorectal cancer, the ultimate goal of early screening is still to intervene as soon as possible, remove polyps, and prevent canceration, which cannot be carried out by FIT, and FIT is not effective in adenomas.
There is no advantage in screening
.

In addition to the SCREESCO study, a 2012 study by Dr.
Enrique Quintero et al.
published in the New England Journal of Medicine [6] also gave similar conclusions—the FIT group had more subjects than the colonoscopy group.
Likely to be involved in screening; at baseline screening, a similar number of subjects with colorectal cancer were detected in both study groups; while more adenomas were found in the colonoscopy group
.

In other words, FIT is more like a precise FOBT for colon cancer screening, and it is also like an "experience card", which can help clinicians and patients better understand the status of gastrointestinal bleeding and predict Possible lesions and risks
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On the whole, FIT may be more useful for physical examination centers and health management, and the final diagnosis and treatment still need to rely on colonoscopy
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References: [1] Kang Qingjie (review), Xiang Zheng (reviewer).
Research progress of colon cancer screening and diagnosis and treatment [J].
Chongqing Medicine, 2015(28): 4001-4003.
DOI: 10.
3969/j.
issn .
1671-8348.
2015.
28.
037.
[2]Ju-Fang Shi,Le Wang,Jian-Chao Ran,et al.
cancer.
2021 Jun 01;127(11).
https://doi.
org/10.
1002/cncr.
33445 .
[3] https://www1.
nyc.
gov/assets/doh/downloads/pdf/cancer/fit-fact-sheet-sc.
pdf[4] Forsberg, Anna et al.
The lancet.
Gastroenterology & hepatology, S2468-1253 (21)00473-8.
14 Mar.
2022, doi:10.
1016/S2468-1253(21)00473-8[5]https://#[6]Quintero E.
Castells A.
Bujanda L.
et al.
N Engl J Med.
2012;366:697-706