In our clinical work, we often encounter many cancer patients who ask their doctors about “how long they can live” after they are diagnosed. Some doctors, based on their past experience, will give a general survival time: three years, one year, six months, three months ……. Patients and their families often use this as the basis to decide whether to continue treatment or to prepare for the afterlife early. We also often see scenes in TV dramas where the doctor looks down in contemplation and then says to the cancer patient’s family, “Your XX, may not live for XX months/years, you’d better plan for the rest of his/her life”. Do doctors really know how long each cancer patient will live as the director portrays? If this is really the case, then the doctor has become a god, right? Also, there are some “enthusiastic” people who, upon hearing that someone has XX cancer, will beat their chest and say, “I’m sure I won’t live for XX months/years, I have a relative who also has this cancer and lived for XX years and left”, scaring that person half to death. Is it really possible to accurately predict how long a cancer patient will live? Is it really scientific to predict the survival period of cancer patients? Modern clinical medicine has developed from empirical medicine and evidence-based medicine to today’s precision medicine. The essence of precision medicine is individualized diagnosis and treatment according to individual and disease-specific conditions. There are many factors that affect the survival of cancer patients, such as social factors, environmental factors, patient’s psychology, treatment methods, whether there are comorbidities, biological characteristics of cancer pathological typing, immunohistochemistry, physical health status, immune function and many other factors. I have been practicing general surgery for more than 30 years, and some advanced cancer patients have lived more than 20 years after reasonable treatment, which is far more than expected; some patients have died for a short time due to comorbidities or distant metastases, which is also unexpected. So is there any basis for doctors to predict survival? Can they be trusted? Is it scientific? Here we can say for sure that individual patients are very different and also affected by the above factors! It is also irresponsible! It is just subjective speculation. Clinically, the survival of patients with different types of cancer varies greatly, and the survival of patients with the same type of cancer can also vary greatly. Therefore, it is only scientific to predict the survival of patients based on their actual conditions. Some experts say that “any talk about survival in isolation from the actual situation of the patient is a hooligan”! This is not a gross statement. I agree with this view. What are the factors that affect the survival of cancer patients from the clinical point of view? 1. Psychological factors of patients: Some patients, after learning that they have cancer, are like thunderbolts and have a nervous breakdown, and from then on, they cannot think of food or sleep at night, and from then on, they suffer from depression and fear of cancer, which leads to malnutrition and decrease of body immunity, and naturally, they cannot live long. On the contrary, if you face your disease wisely and optimistically, actively cooperate with doctors’ treatment, and actively participate in recreational activities and physical exercise, you can live for a long time, and even if there is recurrence, you can survive with cancer. Cancer cells grow fast and their growth and proliferation speed far exceeds the proliferation speed of normal tissues and cells in human body. The degree of malignancy of cancer is directly related to the degree of differentiation of cells from its tissue. The higher the degree of tumor differentiation, the lower the malignancy, the slower the growth of cancer cells, the later the metastasis, and the clinical prognosis is good; the lower the degree of differentiation, the higher the malignancy of tumor (i.e. the more malignant), the faster the growth of cancer cells, the earlier the metastasis, and the clinical prognosis is poor. For example, small cell lung cancer and melanoma have the worst prognosis and are prone to early local recurrence or metastasis to brain, liver and bone. Clinically, squamous carcinoma, papillary thyroid cancer, breast cancer, colon cancer, etc. generally have slower growth, late metastasis, low recurrence rate and higher 5-year survival rate. Therefore, the “good” and “bad” tumor cells determine the growth rate, metastasis rate and treatment effect of tumor, and also determine the length of life of patients. In addition, for the same kind of cancer, those with early stage and complete eradication treatment have better prognosis, while those with late stage and treatment cannot achieve radical resection (mostly palliative resection) have extremely poor prognosis. The choice of treatment modality has a great impact on the prognosis and survival time of cancer patients! In clinical practice, there are many patients who believe in biased prescriptions, ancestral secret recipes, or fear surgery and post-surgery radiotherapy after cancer discovery, and are treated in irregular medical institutions, small clinics or on their own indiscriminately, resulting in deterioration and delayed treatment, which of course has bad treatment effect and poor prognosis. Ms. Chen Xiaoxu, who played the role of Lin Daiyu in the first version of the movie popping up in the Red Chamber, was partial to the rumor that Buddhist disciples must keep their bodies intact and refused surgery after suffering from breast cancer, resulting in a red-headed death that fits the fate of Lin Daiyu. Whether the surgery met the requirement of radical cure; whether the surgery was operated according to the standard (such as whether the scope of surgery was adequate); whether the tumor-free principle (i.e. non-contact, isolation techniques to prevent tumor implantation and metastasis of tumor with hematological and lymphatic metastasis) was implemented in the pre-surgical examination and during the surgery, there are numerous reports that the five-year survival rate of patients differed greatly between those who implemented and did not implement the tumor-free principle during the surgery! And this is often ignored by unregulated doctors! At present, we have entered the era of precision medicine, for example, through genetic testing of resected cancer specimens and patients’ blood, it will be clear which gene mutation triggered the tumor in patients, and more importantly, we can screen the sensitivity of chemotherapy drugs, so that chemotherapy after surgery can be targeted and the effect of chemotherapy can be improved. It can also be believed that the near future will usher in a new era of gene intervention therapy for cancer treatment. All these can seriously affect the survival time of patients. Patients have no choice in what kind of disease they suffer from, while patients have the right to know and decide on the treatment. We often see that patients who are bold and have a good understanding of their disease are treated well, which is frankly a matter of mentality. 4. Whether cancer patients have other underlying diseases and comorbidities. Chronic underlying diseases such as hypertension, diabetes and kidney disease can limit the choice of surgical methods or drugs. For example, if a radical resection could have been done, a smaller surgery (palliative surgery) can only be done to avoid the risk, considering the patient’s own condition. The intensity of drug therapy is also insufficient, which, of course, greatly reduces the effectiveness of treatment. In addition, patients with chronic underlying diseases have lower immune system function than normal people, and their survival time is certainly not as long as that of patients with good physical conditions. At present, the kps score is often used internationally to assess the general condition of malignant tumor patients, which is also used as an important reference indicator for treatment selection. A significant correlation between kps and survival of malignant tumors was found …… The better the general condition, the longer the survival period. And cachexia, including dyspnea, prosopagnosia, malaise, pain, debility, anorexia, agitation and weight loss, and also some hematological indicators (WBC>11×109/L and Lym%<12%, low peripheral blood ALB, high LDH value, etc.), can be important independent factors to assess the prognosis of patients with advanced disease. But even so, can physicians accurately predict the survival of patients? Some scholars have established clinical survival prediction models by integrating the above factors, and the accuracy rate fluctuates from 25%-70% even when assessed by clinical oncologists with extensive experience! So, the cold, boring statistics of doctors are far from the actual situation of patients! It is also extremely inhumane in a sense. While various predictive models can help improve clinical predictability, predictive outcomes should not be interpreted in a blind or polarized manner. Each patient is unique and we can only observe but not determine his/her ultimate survival time. Patients entrust their lives almost entirely to their physicians, fully trusting what they say, and it can be counterproductive for physicians to irresponsibly anticipate how long a patient will survive. Therefore, as a doctor, you should enhance the patient's confidence in overcoming the disease, face it rationally, and actively cooperate with the doctor's treatment.