Q1: What is colorectum?
A1: Colorectum is the large intestine that people often talk about. The large intestine is connected to the small intestine and to the anus. The main basic function of the large intestine is to absorb water and dry up liquid feces into solid feces. Note: The upper part of the small intestine is connected to the stomach, and the upper part of the stomach is connected to the esophagus, which is connected to the pharynx (laryngopharynx) and the mouth] Q2: What colorectal cancer?
A2：Cancer is a collective term for more than 100 different diseases formed by uncontrollable abnormal growth of cells. Cancer not only destroys normal tissues and organs in the area where the lesion occurs, but also can be transferred to other parts of the body for destruction, thus consuming human nutrition, wearing down human will, destroying human functions, endangering human life and other evil consequences. Colorectal cancer is a disease in which the normal cells covering the surface of the colon and rectum begin to undergo the following changes: uncontrolled cell growth and cells no longer die for metabolism. Colorectal cancer is usually caused by non-cancerous polyps that turn into cancerous tumors (i.e., malignant tumors) over time. Colorectal cancer is the third most common cancer in the world today and the third most common cause of cancer-related deaths.
Q3: What kind of people will get colorectal cancer?
A3: Most commonly, patients with colorectal polyps, as polyps are non-cancerous or precancerous lesions that grow over time. About 10% of polyps are flat, which is a high-risk lesion for cancer. Secondly, older people, usually over 50, are at high risk and need to start regular checkups to screen for colorectal cancer. The third is patients with Inflammatory Bowel Disease (IBD), such as Crohn Disease (CD) and Ulcerative Colitis (UC). The fourth is a person with a long-term habitual diet of saturated fats, such as red meat eaters. The fifth is a person with a personal or family history of cancer. The sixth is obese patients. The seventh is a smoker. The eighth is other factors such as race (e.g. black people).
Q4: How to find out if I have colorectal cancer?
A4: When there is a change in bowel habit, such as diarrhea, constipation (it is very difficult to remove the stool) or always feel that the bowel stool cannot be completely removed, it should be taken seriously that you may have colorectal cancer. When the stool is bright bright red blood or dark red blood, colorectal cancer should be considered. When the stool becomes thinner or finer than usual, colorectal cancer should be considered. Consider the possibility of colorectal cancer when there is some stomach discomfort, such as frequent intestinal gas and distension, feeling of fullness or abdominal cramps. When there is unexplained weight loss, frequent fatigue or unexplained anemia (iron deficiency), consider the possibility of colorectal cancer. The earlier these symptoms are detected and the earlier you find a doctor to get a diagnosis of colorectal cancer, the earlier you get a better chance of treatment, which is often referred to as “early diagnosis and early treatment” by doctors.
Q5：What should I do if I find out my symptoms are like colorectal cancer?
A5: Seek help from a general surgeon/gastrointestinal surgeon as soon as possible. The real diagnosis needs to be confirmed by pathology after biopsy. A blood test such as carcinoembryonic antigen (CEA), an indicator of tumor, should be performed before confirming the diagnosis. Staging of the disease requires radiologists to perform imaging (e.g. CT) and pathologists to confirm. Endoscopic ultrasound and Magnetic Resonance Imaging (MRI) are also used for colorectal cancer staging.
Q6: Why is it important to treat colorectal cancer earlier after diagnosis?
A6: Treating patients as early as possible will give them a better prognosis, which means that the earlier the tumor is treated, the longer the patient’s survival and better quality of life. Happily, early diagnosis of colorectal cancer gives patients very good results in early treatment, and we often see many patients with early colorectal cancer still alive 30 to 40 years after surgery. I have relatives who are still alive in 2015 after colorectal cancer surgery in the 1980s, and their health is so good that they can’t be seen at all if they don’t talk to outsiders. Doctors often emphasize that “early detection, early diagnosis, early treatment” is based on scientific evidence and is the experience accumulated by doctors over the years. Of course, there is more than one way to improve the treatment level, so I will not talk about it here.
Q7: What can I do to prevent colorectal cancer early?
A7：First, if there is a family history of Hereditary nonpolyposis Colorectal Cancer (HNPCC, also known as Lynch Syndrome), the risk of getting colorectal cancer is as high as 70% to 90%, which is several times higher than that of the general population. Patients with Lynch syndrome account for about 5-10% of all colorectal cancer cases, and the average age of patients at diagnosis is about 45 years. Genetic testing can detect the most common HNPCC gene.
Second, familial adenomatous polyposis (FAP), which typically presents as hundreds to thousands of small benign (non-cancerous) polyp nodules in the colon, has an almost 100% chance of becoming cancerous if left untreated. patients are often diagnosed in their 40s. Mutations in the APC gene have been found to cause FAP, and genetic testing is available for those with a history of similar disease.
Third, various colorectal cancer screening tests are available for prevention and detection. Colonoscopy is the best screening method, which is to insert a fiber flexible tube into the colorectum for intestinal lumen examination, and painless colonoscopy is also feasible for those who are psychologically nervous. It is simple and non-invasive. However, due to the large number of patients in China, there are simply not that many radiologists, and the shortage of radiologists to spend a lot of time to do CT virtual endoscopy, imagine the time spent on a few patients, a large number of other patients who will diagnose it? Furthermore, the physicians who do CT virtual endoscopy need a certain amount of time for specialized training to become proficient in diagnosing colorectal cancer. However, its sensitivity is not high enough because it can be detected only when the tumor itself breaks down and bleeds or when the tumor causes bleeding in the surrounding tissues. Therefore, there is a cross-over relationship between different examinations, so as not to miss a tumor. Dual gas-barium imaging is a test that involves filling the anus with about 400 ml of barium and then injecting gas into the anus in a different position to evaluate the colorectum in terms of intestinal lumen structure and peristaltic function. Stool DNA testing is another form of genetic testing. Under normal circumstances, there are no DNA molecules in the stool, but if the stool contains shed mucosal cells, mucus, blood, and other objects, there will be DNA molecules, and the person’s DNA can be detected, and these DNA fragments with genetic messages are what we know as genes. In 2014, an article published in the New England Journal of Medicine showed that fecal DNA testing is likely to replace colonoscopy as a better way to screen for colorectal cancer. With the booming development of genetic testing technology in China, patients will be able to take their own stool for DNA testing in the near future to do a better job of maintaining their health.
Note: In recent years, domestic genetic testing technology has been rapidly developed and heavily promoted, and it is no longer a rare thing. If you have a family member or a member of your family who developed colorectal cancer before the age of 50, please consult with your doctor promptly, and genetic testing can be performed to reduce the risk of developing colorectal cancer. Angelina Jolie, a famous Hollywood actress, was diagnosed with colorectal cancer after her mother was 57 years old and younger. Jolie had a genetic test for breast cancer when she was 37 years old because her mother died of breast cancer at 57 and her sister-in-law died of breast cancer at 61, and she found that her risk of breast cancer was 87%.
Q8: Why is TNM staging needed for early treatment of colorectal cancer?
A8: Staging is a way to describe the tumor or cancer, such as the size of the tumor, or whether the tumor invades into the surrounding area and the location of the invasion. Colorectal cancer staging is the most important tool for gastroenterologists to determine the prognosis of patients, and the treatment of colorectal cancer directly depends on the tumor stage.
TNM staging is the most commonly used staging method for colorectal cancer; T refers to Tumor, the size and location of the tumor; N refers to lymph Nodes, whether the lymph nodes around the tumor are involved; and M refers to Metastasis, whether the tumor has metastasized to other parts of the body. Some of the stage phases are further divided into subgroups to describe the details of the tumor in more detail.
Sometimes we hear about re-staging of colorectal cancer, which refers to the more advanced stage of the tumor, often after radiotherapy or neoadjuvant therapy which leads to down-staging of the tumor, and the assessment of whether the tumor is down-staged after treatment is called re-staging. Usually, surgeons will perform radical surgical treatment when the tumor is down-staged to the appropriate stage. Colorectal cancer recurrence refers to the emergence of new tumor after treatment.
Q9: What exactly is the relationship between TNM stage and treatment of colorectal cancer?
A9：T-stage of colorectal cancer.
T0 stage, i.e. carcinoma in situ, refers to tumor tissue located in the mucosal layer of colorectum.
Stage T1 refers to tumor tissue breaking through the colorectal mucosal layer and involving the muscular mucosal layer to the submucosal layer.
Stage T2 refers to the tumor tissue breaks through the submucosal layer and invades the intrinsic muscular layer, but does not penetrate the intrinsic muscular layer to involve the subplasma layer of the colon or the rectal mesentery of the rectum.
Stage T3 refers to the tumor tissue breaking through the intrinsic muscular layer to the subplasma layer of the colon and the plasma layer or the rectal mesentery of the rectum, but not penetrating the plasma layer or the rectal fascia of the rectum.
T4 stage refers to tumor tissue breaking through the plasma membrane layer or rectal fascia of the rectum and involving adjacent organs.
Regional lymph node N stage.
Nx stage refers to regional lymph node information is not available.
N0 stage refers to no regional lymph node metastasis.
Stage N1 refers to tumor metastasis to one to three lymph nodes around the colorectum.
Stage N2 refers to tumor metastasis to ≥4 lymph nodes around the colorectum.
Stage N3 refers to tumor metastasis to any lymph nodes along the major blood vessels.
M-stage of distant metastasis.
Mx stage means the presence or absence of distant metastasis cannot be determined.
M0 stage means no distant metastasis.
Stage M1 refers to the presence of distant metastasis.
AICC/UICC clinical staging and its clinical management.
Stage 0 refers to Tis (carcinoma in situ), N0 and M0. The common clinical management of this stage is: polyp removal surgery.
Stage I refers to T1~T2 stage, N0 stage, M0 stage, and the common clinical management in this stage is: surgical removal of tumor and some surrounding lymph nodes.
Stage II refers to T3~T4 stage, N0 stage and M0 stage. The common clinical management of this stage is: when the lymph nodes are not involved, (1) the common clinical management of colon cancer is: surgery to remove the tumor, and some patients need chemotherapy after surgery to remove the tumor; (2) the common clinical management of rectal cancer is: surgery to remove the tumor as well as radiotherapy.
Stage III refers to any T-stage, N1-N3 stage, M0 stage. The common clinical management of this stage is: when local lymph nodes are involved, (1) the common clinical management of colon cancer is: surgical removal of tumor and chemotherapy; (2) the common clinical management of rectal cancer is: surgical removal of tumor and radiotherapy.
Stage IV refers to any T-stage, any N-stage, M1 stage. The common clinical treatment for this stage is: when tumor metastasis occurs, the common clinical treatment for colorectal cancer is chemotherapy, surgery or resectable tumor, and metastasectomy is feasible for some carefully selected patients.
Q10: How exactly does colorectal cancer come under treatment?
A10：As already mentioned, the treatment of colorectal cancer is mainly based on the stage of the tumor. The treatment method cannot be single, and the treatment of colon and rectum is different. There are mainly surgery, chemotherapy, radiotherapy, targeted therapy and so on.
Surgery is the basis for curing colorectal cancer, mainly removing the tumor along with the adjacent normal colorectum and lymph nodes to obtain satisfactory surgical results, which may require temporary or permanent colostomy, the latter being an artificial anus – an opening in the abdomen to allow the feces in the colon to pass out of the body, with the patient often dangling a plastic bag.
Chemotherapy is the application of typical antitumor drugs to kill cancer cells, commonly 5-fluorouracil (5-FU), leucovorin, oxaliplatin, irinotecan, and capecitabine, often in combination. Adjuvant chemotherapy is often administered postoperatively to maximize the patient’s chance of cure. Neoadjuvant chemotherapy is often administered preoperatively. Palliative chemotherapy is used in patients whose tumors cannot be surgically removed to delay or reverse tumor-related symptoms, thereby improving the patient’s quality of life and extending the patient’s survival time frame.
Radiotherapy is the application of high-energy X-rays to treat rectal cancer before or after surgery to kill cancer cells. There are two main methods of giving radiotherapy: one is extracorporeal isotope radiotherapy and the other is intraoperative one-time placement of isotope radiotherapy substances.
Anti-angiogenic therapy is a targeted therapy that uses anti-angiogenic drugs to block the blood vessels supplying the tumor, thereby “starving” the cancer cells. Anti-angiogenic drugs are usually given at the same time as chemotherapy drugs. Bevacizumab has been approved by the FDA and is being used clinically to treat stage IV colorectal cancer.
Targeted therapy is the targeted blockade of colorectal cancer tumor cells while causing minimal damage to normal cells. Currently, the FDA only allows cetuximab and panitumumab for the treatment of non-mutant KRAS gene colorectal cancer.