Colorectal cancer has surpassed lung cancer as the number one cancer killer in Hong Kong in recent years. Colorectal cancer mainly evolves from polyps, and the evolution process often lasts for more than 10 years. If diagnosed at the early stage, it can be removed surgically, but many patients are diagnosed at an advanced stage. In the past, single chemotherapy was the traditional treatment option for patients with advanced disease, but with the development of medicine, a combination of chemotherapy and targeted drugs has been introduced in recent years, which has been clinically proven to have the function of inhibiting the growth of cancer cells, enabling patients to live longer. Dr. Chen, a clinical cancer specialist, said that more than 50% of colorectal cancer patients are diagnosed at stage 3 or 4, i.e., advanced stage, when cancer cells have often metastasized to lymph glands, liver, lungs, peritoneum or bones, etc. If the five-year survival rate is used as a guideline, nearly 40% to 60% of stage 3 patients can survive for five years, while the probability that stage 4 patients can survive for five years is less than 15%. However, with advances in medicine, advanced stages are not the end of the road, and even though drugs cannot achieve a cure, they can play a role in extending life expectancy. However, not all patients are suitable for combination chemotherapy regimens, and Dr. Chen emphasized that the decision to use a single or combination chemotherapy regimen for patients will be based on the actual situation. For example, if the patient has a long-term disease or is old and frail, the doctor will not use a combination chemotherapy regimen, and, before using the regimen, the patient will be tested for KRAS and NRAS genes to see which target drug is more suitable, according to experience, about half of the patients can use drugs targeting epidermal growth factor. In addition, clinical results show that the new generation of anti-angiogenic target drugs with chemotherapy is more effective than single chemotherapy, and the survival rate of patients with advanced colorectal cancer at 30 months after using them is nearly doubled.