Detection of biomarkers with high early cure rate of colorectal cancer can help prolong life | Targeted therapy

Even in the metastatic and spreading stage of colorectal cancer, accurate detection of biomarkers can lead to targeted drugs or immunotherapy, or combined therapy to improve survival. (Shutterstock)

March is National Bowel Cancer Awareness Month. According to the American Cancer Society (ACS), colorectal cancer is the third most common and deadly cancer in the United States. More than 50,000 Americans die from this cancer every year.

The colon of colorectal cancer (CRC) refers to the large intestine, and the rectum is the part of the passage connecting the colon and the anus. Therefore, colorectal cancer is often called colorectal cancer. Among all cancers, colorectal cancer has a relatively good prognosis. In particular, early detection of colorectal cancer has a high cure rate, so regular screening for high-risk groups is very important.

If you are diagnosed with colorectal cancer, you should follow the doctor’s advice and do further relevant testing and treatment. Even in the metastatic and spreading stage of colorectal cancer, accurate detection of biomarkers can lead to targeted drugs or immunotherapy, or combined therapy to improve survival. In addition, it can also help doctors predict the prognosis of patients’ diseases, evaluate the efficacy and recurrence after treatment, etc.

Biomarker testing for colorectal cancer involves the analysis of tumor biopsies, blood samples, or other body fluids. The test for biomarkers in circulating tumor DNA (ctDNA) in a blood sample is known as a liquid biopsy. In addition, relevant sources of information on biomarkers may also come from radiological images (CT scans, X-rays, congratulatory impartial scans) or surgical reports.

The National Comprehensive Cancer Network (NCCN) and the European Society for Medical Oncology (ESMO) recommend that all patients with colorectal cancer, regardless of stage, be tested for microsatellite stability/instability (MSS/MSI) biomarkers ;Patients with stage IV/metastatic colorectal cancer should also be tested for RAS (KRAS and NRAS) and BRAF biomarkers. In addition, NCCN also recommends that patients be tested for the biomarker HER2.

Here are some specific biomarker tests for colorectal cancer:

● Microsatellite Stability (MSS): To detect the ability of human tumor cells to carry out DNA mismatch repair, which is the correction of errors that occur in DNA when cells grow and divide.
● Microsatellite Instability (MSI-High): Detects defects in DNA mismatch repair (also known as dMMR) in tumor cells. Immune checkpoint inhibitors are an effective treatment for MSI-High.
● KRAS detection: KRAS is a member of the RAS gene family involved in the control of cell growth and cell survival. Wild-type (normal, non-mutated) KRAS tumors can be treated with EGFR inhibitors. Patients in ongoing clinical trials may be treated with a combination of traditional chemotherapy and targeted therapy.
● NRAS detection: NRAS is a member of the RAS gene family involved in the control of cell growth and cell survival. Tumors without NRAS mutations (normal, wild-type) can be treated with EGFR inhibitors, and colorectal cancers with NRAS mutations can be treated with a combination of traditional chemotherapy and targeted therapy.
● BRAF detection: BRAF is a gene involved in the control of cell growth. Tumors with BRAF mutations can be treated with BRAF inhibitors, a type of targeted therapy.
● Carcinoembryonic Antigen (CEA) Detection: Not all colorectal cancers have this protein, but most colorectal cancer patients may produce it. Measuring CEA before, during, and after cancer treatment can provide information about cancer-related efficacy, progression, and whether it recurs.
● HER2 detection: HER2 is a gene and codes for a protein involved in cell growth and cell survival. Amplification of the HER2 gene or overexpression of the protein can lead to uncontrolled cell growth, and some abnormal cells that should die survive. Patients can be treated with targeted therapy with HER2 inhibitor drugs.
● Tumor mutation burden (TMB) detection: This is a measure of the number of mutations in the tumor’s genes (tumor DNA), not a test for a specific mutation. TMB-High patients may be candidates for immunotherapy.
● NTRK fusion detection: NTRK fusion is a mutation, it is rare in colorectal cancer, but patients with MSI-High, TMB-High and wild-type KRAS, NRAS and BRAF have a higher NTRK fusion rate. NTRK fusion-positive patients can receive targeted therapy with TRK inhibitors.
● PIK3CA detection: PIK3CA is a gene involved in the control of cell growth, cell survival and cell migration. PIK3CA inhibitors are treatments targeting PIK3CA mutations that are already used to treat breast cancer and are being tested in clinical trials for colorectal cancer.