It ranks second among cancers, and 80% of patients are diagnosed in the middle and late stages

Colorectal cancer is a common malignant tumor in the gastrointestinal tract. In China, the number of new cases of colorectal cancer is second only to lung cancer, making it the second most common cancer. In 2020, more than 550,000 people in China were newly diagnosed with colorectal cancer, accounting for 12.2% of the number of newly diagnosed cancers in China.

Colorectal cancer patients have no obvious symptoms in the early stage and are often misdiagnosed as hemorrhoids, dysentery, colitis and other diseases. The interim results of the "Survey on the Current Status of Diagnosis and Treatment of Patients with Mid- to Late-Stage Colorectal Cancer in China" project show that 83% of colorectal cancer patients in my country are in the mid- to late-stage when first diagnosed, and 44% of them have already developed metastases to the liver, lungs and other parts.

What factors are related to the occurrence of colorectal cancer? How to achieve early diagnosis? How to carry out scientific, standardized and comprehensive treatment to improve the survival rate of patients?

01 Cause

The accumulation of human genome mutations and intestinal microenvironmental disorders are high-risk factors for colorectal cancer. More and more studies have shown that up to 90% of the disease risk is caused by intestinal microenvironmental disorders.

About 1/4 of colorectal cancer patients have a family history of cancer, half of which are digestive tract tumors. Due to the change of normal cell genes, the patient inherits a susceptibility, and with certain stimulating factors, the tissue cells grow rapidly, thus developing into cancer, which is manifested as family hereditary.

The impact of dietary factors on the occurrence of colorectal cancer is mainly manifested as metabolic imbalance of intestinal flora. The human intestine has 100 to 1,500 species and nearly 40 trillion bacteria. The intestinal bacterial genome set is 150 times that of the human genome, so the intestinal flora is called the "second genome" of humans. The intestinal flora has the functions of participating in human immunity, maintaining nutrient metabolism and energy balance, producing essential vitamins, protecting the intestinal epithelium (mucosa) from pathogens and tissue development and regeneration. The intestinal microecological system is maintained by the flora and the human body. Maintaining the stability and balance of the structure and function of this system is of great significance to both the flora and the host.

Excessive consumption of processed foods, high-fat diets, insufficient fiber intake, stress, inflammation, and even excessive use of antibiotics in childhood can change the intestinal microbiota and induce intestinal dysbiosis, leading to a weakened host immune system and the development of various diseases, which may be the potential reason for the significantly increased risk of colorectal cancer in the younger generation.

02 Diagnosis

"Difficult to diagnose" is the primary problem facing the diagnosis and treatment of colorectal cancer.

The occurrence of colorectal cancer is closely related to diet and lifestyle, and is a multifactorial pathogenic process. The causes of disease or diagnostic markers in different intestinal segments are not the same. The lack of specific early diagnosis markers, unclear pathogenic mechanisms, and unknown pathogenic microenvironments are all "bottleneck" problems that restrict the accurate diagnosis of colorectal cancer.

In recent years, these bottlenecks have been overcome. A study covering 86,115 colorectal cancer patients showed that by establishing an efficient early and accurate screening system, the detection rate reached 157 per 100,000 people, which is about 6 times higher than the ordinary screening effect, greatly improving the early diagnosis rate of colorectal cancer patients.

Colorectal cancer early screening system based on multi-omics data: simple home sampling

In order to evaluate the intestinal microenvironment, we have developed a combined analysis system for intestinal microenvironment flora detection. Based on the new generation of gene sequencing technology to detect intestinal flora and combined with machine learning to accurately evaluate intestinal precancerous lesions and nutritional health indicators, we provide accurate, comprehensive and objective analysis of intestinal flora and host intestinal health status for people of all ages, making early detection, early prevention and early treatment of intestinal precancerous lesions (polyps, adenomas, inflammatory bowel disease, etc.) possible. The detection and analysis also includes analysis of the relationship between microorganisms and major nutrients, vitamins and trace elements. Through these contents, patients are guided to carry out precise nutritional supplementation, probiotic regulation and harmful bacteria intervention in the intestinal microenvironment.

Combining the microbiome-epigenetics-proteomics joint detection technology, a fecal multi-omics colorectal cancer early screening kit was developed. Traditional colonoscopy screening is the gold standard for colorectal cancer screening, but it has shortcomings such as poor compliance, invasive damage, and strict intestinal preparation, making it unsuitable as a large-scale screening method. This kit is a new colorectal cancer screening technology that does not require intestinal preparation. It has the advantages of being non-invasive, convenient, and accurate, with a detection rate of intestinal adenocarcinoma as high as 93%.

Colorectal cancer early screening system based on multi-omics data: reliable detection at hospital level

Medical experts call for increasing the public's awareness of high-risk factors for colorectal cancer and early screening and diagnosis, thereby effectively reducing the incidence and mortality of colorectal cancer.

03 Treatment

"Difficult to treat" is also one of the bottlenecks faced by the diagnosis and treatment of colorectal cancer. Insensitivity to treatment, poor tolerance to chemotherapy, and lack of precise treatment targets are the difficulties in the precise treatment of colorectal cancer.

The treatments for colorectal cancer recommended by the Chinese Guidelines for Diagnosis and Treatment of Colorectal Cancer (2020 edition) include surgical treatment, medical treatment, radiotherapy, etc. In the radiotherapy section, it is clearly stated that the main modes of radiotherapy or chemoradiotherapy for colorectal cancer are neoadjuvant or adjuvant therapy, radical treatment, conversion treatment, and palliative treatment. Among them, stereotactic radiotherapy is particularly recommended for the treatment of liver and lung metastases of colorectal cancer.

Innovative precision diagnosis and treatment case (left: whole liver lesion before transformation, right: resectable liver lesion after transformation)

The key to treatment is precision. In recent years, medical research in this field has made great progress. In response to the problems of nutritional imbalance and intestinal flora disorders in the treatment of colorectal cancer patients, characteristic metabolic probiotic enteral nutrition preparations related to colorectal cancer treatment have been developed to comprehensively intervene in the intestinal microorganisms and energy metabolism characteristics of tumor patients, and quickly improve the quality of life and tolerance and sensitivity to anti-tumor treatment in colorectal cancer patients with nutritional disorders. Due to tumor load, treatment side effects and other reasons, colorectal cancer patients have obvious energy replenishment disorders and weight loss, accompanied by intestinal flora disorders and reduced probiotic abundance. Through the supplementation of macronutrients (protein, fat, carbohydrates, dietary fiber), colorectal cancer patients are provided with a rich source of glucose-free energy. The zero-added sucrose formula can meet the nutritional intervention needs of colorectal cancer patients with diabetes. In addition, the supplementation of probiotics can improve the severely imbalanced intestinal flora in patients with colorectal cancer, inhibit the growth and adhesion of intestinal pathogens, downregulate the inflammatory response, relieve symptoms such as abdominal pain, bloating, constipation, diarrhea, etc., enhance the body's immunity, and reduce the production of toxic metabolites and harmful enzymes in the intestines, providing patients with precise and effective individualized treatment strategies.

In recent years, researchers have made major breakthroughs in improving the early diagnosis rate of colorectal cancer, achieving accurate preoperative staging assessment, and improving the accuracy of individualized treatment, achieving a 5-year survival rate of 94% for patients with stage I colorectal cancer, 82.2% for patients with stage II, 60.1% for patients with stage III, and 16.3% for patients with stage IV. Therefore, don't be afraid of cancer. You must screen and diagnose early, and after diagnosis, you must carry out active, scientific, and accurate treatment.

Author: Liu Linming

Reviewer: Professor Tang Weizhong, Affiliated Cancer Hospital of Guangxi Medical University

Source: Guangxi Science and Technology Popularization and Communication Center