TNM staging system
One tool doctors use to describe cancer staging is the TNM system. Doctors use the results of diagnostic tests and scans to answer the following questions:
• Tumor (T): Does the tumor grow on the wall of the colon or rectum? How many layers are violated?
• Lymph nodes (N): Has the tumor spread to the lymph nodes? If so, where and how much?
• Metastasis (M): Has the cancer spread to other parts of the body? If yes, where and how much?
Combine the above results to determine the cancer stage of each person.
There are five stages: stage 0 (zero) and stages I to IV (1 to 4). This staging provides a common way to describe cancer, so doctors can work together to plan the best treatment.
The following are more details of each part of the TNM system for colorectal cancer :
Using the TNM system, use “T” plus a letter or number (0 to 4) to describe how the primary tumor penetrates into the intestine. Some stages are also divided into smaller groups, which can describe tumors in more detail. Specific tumor information is as follows.
TX: Primary tumor cannot be evaluated.
T0: There is no evidence of cancer in the colon or rectum.
Tis: refers to carcinoma in situ (also called carcinoma in situ). Cancer cells are only found in the epithelium or primary layer, they are the top layer arranged inside the colon or rectum.
T1: The tumor has grown to the submucosa.
T2: The tumor has developed into a muscular layer, a thicker and thicker layer of muscle, which invades the muscle.
T3: The tumor grows through the muscularis and enters the serosa. It is a thin layer of connective tissue under the outer layer of certain parts of the large intestine, or it has grown into the tissue around the colon or rectum.
T4a: The tumor has grown to the surface of the visceral peritoneum, which means that it has penetrated all layers of the colon to grow.
T4b: The tumor has grown or attached to other organs or structures.
Lymph node (N)
The “N” in the TNM system stands for lymph nodes. Lymph nodes are tiny bean-shaped organs located throughout the body, which help the body fight infections as part of the immune system. The lymph nodes near the colon and rectum are called local lymph nodes. All others are distant lymph nodes found in other parts of the body.
NX: Regional lymph nodes cannot be evaluated.
N0 (N plus zero): No spread to regional lymph nodes.
N1a: There are tumor cells in 1 area of lymph nodes.
N1b: There are tumor cells in 2 to 3 regional lymph nodes.
N1c: Tumor cell nodules found in structures near the colon do not appear to be lymph nodes, but nodules.
N2a: There are tumor cells in 4 to 6 regional lymph nodes.
N2b: There are tumor cells in 7 or more regional lymph nodes.
The “M” in the TNM system describes cancer that has spread to other parts of the body, such as the liver or lungs. This is called a distant transfer.
MX: Remote transfer cannot be evaluated.
M0: The disease has not spread far to the body.
M1a: The cancer has spread to other parts of the body except the colon or rectum.
M1b: The cancer has spread to more than one part of the body outside the colon or rectum.
Doctors also described this type of cancer by grading (G), which describes the similarity of cancer cells to healthy cells when viewed under a microscope.
The doctor compares cancer tissue with healthy tissue. Healthy tissue usually contains many different types of cells grouped together. If the cancer looks similar to healthy tissue and contains different cell groups, it is called a differentiated or low-grade tumor. If cancer tissue looks very different from healthy tissue, it is called a poorly differentiated or high-grade tumor. The grade of cancer may help doctors predict the rate of cancer development. In general, the lower the tumor grade, the better the prognosis.
GX: Unable to determine tumor grade.
G1: The cells are more like healthy cells (called good differentiation).
G2: The cells are somewhat like healthy cells (called moderate differentiation).
G3: The cells do not look like healthy cells (called poorly differentiated).
G4: Cells are almost not like healthy cells (called undifferentiated).
Colorectal cancer staging
The doctor assigns stages of cancer by combining T, N, and M classifications.
Stage 0: This is called carcinoma in situ. The cancer cells are only in the mucous membrane or lining of the colon or rectum.
Stage I: The cancer has grown through the mucosa and invaded the muscularis of the colon or rectum. It did not spread to nearby tissues or lymph nodes (T1 or T2, N0, M0).
Stage I Colorectal cancer
Stage IIA: The cancer has grown through the colon or rectal wall and has not spread to nearby tissues or nearby lymph nodes (T3, N0, M0).
Stage IIB: The cancer has grown through the muscle layer to the abdomen of the abdomen, called the visceral peritoneum. It did not spread to nearby lymph nodes or other places (T4a, N0, M0).
Stage IIC: The tumor has spread through the wall of the colon or rectum and has grown into nearby structures. It did not spread to nearby lymph nodes or other places (T4b, N0, M0).
Stage IIIA: The cancer has grown through the muscular layer of the inner layer or intestine, and has spread to the tissues around the colon or rectum. 1-3 lymph nodes or tumor nodules appear around the colorectum, but there is no non-proliferation to other parts of the body ( T1 or T2, N1 or N1c, M0; or T1, N2a, M0).
Stage IIIB: The cancer has grown through the intestinal wall or surrounding organs, and has grown into 1 to 3 lymph nodes or tumor nodules in the tissue around the colon or rectum. It did not spread to other parts of the body (T3 or T4a, N1 or N1c, M0; T2 or T3, N2a, M0; or T1 or T2, N2b, M0).
Stage IIIC: Colon cancer, no matter how deep it grows, has spread to 4 or more lymph nodes, but has not spread to other distant parts of the body (T4a, N2a,
M0; T3 or T4a, N2b, M0; or T4b , N1, N2, M0).
Stage IVA: The cancer has spread to a single distant part of the body, such as the liver or lungs (any T, any N, M1a).
Stage IVB: The cancer has spread to more than a part of the body (any T, any N, M1b).
Recurrent cancer: Recurrent cancer is cancer that recurs after treatment. The disease can be found in the colon, rectum, or another part of the body. If the cancer does recur, there will be another round of examination to understand the extent of the recurrence. These tests and scans are usually similar to what was done during the original diagnosis.
Colorectal cancer: treatment options
In cancer diagnosis and treatment, doctors of different types often work together to create an overall treatment plan that usually includes or combines patients with different types of treatment. This is called a multidisciplinary team. For colorectal cancer, this usually includes surgeons, oncologists, radiation oncologists, and gastroenterologists. Gastroenterologists are doctors who specialize in gastrointestinal function and disorders. The cancer care team also includes various other health professionals, including doctor assistants, oncology nurses, social workers, pharmacists, consultants, nutritionists, etc.
The following is a description of the most common colorectal cancer treatment options, followed by a brief description of the treatment options listed by stage. Treatment options and recommendations depend on several factors, including the type and stage of cancer, possible side effects, and patient preference and overall health. Your care plan may also include treatment of symptoms and side effects, which are an important part of cancer care. Take the time to understand all your treatment options and talk to your doctor about the goals of each treatment and what you can expect when receiving treatment.
Studies have shown that various treatments provide similar benefits to patients regardless of their age. However, elderly patients may have unique treatment challenges. In order to treat each patient, all treatment decisions should consider the following factors:
• Patient’s medical condition
• The patient’s overall health
• Potential side effects of the treatment plan
• Other medicines the patient has taken
• Patient’s nutritional status and social support
Surgery is the removal of tumors and some surrounding healthy tissue during surgery. This is the most common treatment for colorectal cancer and is often referred to as surgical resection. A portion of the healthy colon or rectum and nearby lymph nodes will also be removed. A cancer surgeon is a doctor who specializes in treating cancer with surgery. A colorectal surgeon is a specialist who has been trained to treat diseases of the colon, rectum and anus.
In addition to surgical resection, other colorectal cancer surgery options include:
Laparoscopic surgery of colorectal cancer
Some patients may be able to undergo laparoscopic colorectal cancer surgery. With this technique, the incision is smaller and the recovery time is usually shorter than standard colon surgery. Laparoscopic surgery is as effective as conventional colon surgery to remove cancer. Surgeons performing laparoscopic surgery have been specially trained in this technique.
Rectal cancer colostomy
A small percentage of patients with rectal cancer may require colostomy. This is a surgical procedure that connects the colon to the abdomen to provide a way for excreta to leave the body. This excrement is collected in a pouch worn by the patient. Sometimes, a colostomy is only temporary to help the rectal wound heal, but it may also be permanent. Using modern surgical techniques, using radiation therapy and chemotherapy before surgery, most people undergoing rectal cancer treatment do not need a permanent colostomy.
Radio frequency ablation (RFA) or cryoablation
Some patients may be able to perform radiofrequency ablation on the liver or lungs to remove tumors that have spread to these organs. Other methods include the use of energy heating in the form of radio frequency waves called RFA, or cryoablation. Not all liver or lung tumors can be treated with these methods. RFA can be performed through skin or surgery.
Side effects of colorectal surgery
Communicate with your doctor in advance about the possible side effects of a specific operation and ask how to prevent or mitigate it. In general, the side effects of surgery include pain and tenderness in the surgical area. Surgery may also cause constipation or diarrhea, which usually disappears. People with colostomy may have irritation around the stoma. If you need to have a colostomy, a doctor or nurse who is a specialist in colostomy management can teach you how to clean the area and prevent infection.
Many people need to have bowel movements again after the operation, which may take some time and help. If you cannot regain good bowel function control, you should talk to your doctor.
Radiation therapy in colorectal cancer
Radiation therapy uses high-energy x-rays to destroy cancer cells. It is commonly used to treat rectal cancer, because this tumor tends to recur at the place where it originally started. Doctors who specialize in radiation therapy for cancer are called radiation oncologists. Radiation treatment plans (plans) are usually given by a specific number of treatments and reused over a period of time.
• External radiation therapy. External radiotherapy uses a machine to emit X-rays to where the cancer is. Radiation therapy usually lasts 5 days a week for several weeks.
• Stereotactic radiotherapy. Stereotactic radiotherapy is an exogenous radiation therapy that can be used if the tumor has spread to the liver or lungs. This type of radiation therapy can provide a large, precise dose of radiation to a small area of focus. This technique can avoid normal liver and lung tissue that may be removed during surgery. However, not all cancers that spread to the liver or lungs can be treated in this way.
• Other types of radiation therapy.
For some people, specialized radiotherapy techniques, such as intraoperative radiotherapy or brachytherapy, may help get rid of a small portion of cancer that cannot be eliminated during surgery.
• Intraoperative radiation therapy.
Intraoperative radiotherapy uses a single high-dose radiotherapy during surgery.
Brachytherapy in colorectal cancer
Brachytherapy uses radioactive “seeds” placed in the body. In brachytherapy, a product called SIR-Spheres, a small amount of radioactive material called yttrium-90 is injected into the liver to treat colorectal cancer that has spread to the liver because the surgery is no longer suitable, and some studies have shown that yttrium -90 may help slow down the growth of cancer cells.
Neoadjuvant radiotherapy for rectal cancer
For rectal cancer, radiation therapy called neoadjuvant therapy can be used before surgery to shrink the tumor, making it easier to remove the tumor. It can also be used to destroy any remaining cancer cells after surgery. Both methods are effective in treating this disease. Chemotherapy is usually used at the same time as radiation therapy, which is called combined radiochemotherapy to improve t
he effectiveness of radiation therapy. Chemotherapy and radiotherapy are usually used for rectal cancer before surgery to avoid colostomy or reduce the chance of cancer recurrence. One study found that radiation therapy plus chemotherapy before surgery had better effects and had fewer side effects than postoperative radiation therapy and chemotherapy. The main benefits include a lower rate of cancer recurrence and less intestinal scarring with radiation therapy.
Side effects of radiation therapy
Side effects of radiation therapy may include fatigue, minor skin reactions, upset stomach, and difficulty defecating. It may also cause bloody stools through rectal bleeding or intestinal obstruction. After treatment, most side effects will disappear.
Chemotherapy in colorectal cancer
Chemotherapy uses drugs to destroy cancer cells, usually by preventing the cancer cells from growing and dividing. Chemotherapy is usually given by a medical oncologist, a doctor who specializes in treating cancer with drugs.
Systemic chemotherapy drugs enter the bloodstream and reach cancer cells throughout the body. Common methods of administering chemotherapy include intravenous administration or swallowing (oral) pills or capsules.
A chemotherapy regimen usually consists of a specific number of treatment cycles given within a certain period of time. Patients can receive 1 drug or a combination of different drugs at the same time.
Chemotherapy can be given after the operation to eliminate any remaining cancer cells. For some patients with rectal cancer, doctors will perform chemotherapy and radiation therapy before surgery to reduce the size of rectal tumors and reduce the chance of cancer recurrence.
Types of colorectal cancer chemotherapy drugs
Currently, the US Food and Drug Administration (FDA) has approved several drugs for the treatment of colorectal cancer. Your doctor may recommend class 1 or several drugs at different times during treatment. Sometimes these drugs are used in combination with targeted therapy drugs (see “Targeted Therapy” below).
• Fluorouracil (5-FU, Adrucil)
• Irinotecan (Camptosar)
• Trifluorouridine / Tiracilidine (TAS-102, Lonsurf)
Some common treatment options for using these drugs include:
• 5-FU and Wellcovorin (Wellcovorin), vitamins increase the effectiveness of 5-FU
• Capecitabine, oral form of 5-FU
• 5-FU with leucovorin and oxaliplatin (called FOLFOX)
• 5-FU with leucovorin and irinotecan (called FOLFIRI)
• Irinotecan used alone
• Capecitabine and irinotecan (called XELIRI or CAPIRI) or oxaliplatin (called XELOX or CAPEOX)
• Any of the above drugs combined with the following targeted drugs (see below): cetuximab, bevacizumab or panitumumab
• FOLFIRI combined with targeted drugs (see below): ziv-aflibercept or lamucirumab
Chemotherapy side effects
Chemotherapy may cause vomiting, nausea, diarrhea, neuropathy, or aphthous ulcers. However, drugs that prevent these side effects can be used. Due to changes in administration methods, these side effects in most patients are not as severe as in the past. In addition, patients may be extremely fatigued and the risk of infection increases. Some medicines may also cause neuropathy, tingling or numbness in the feet or hands and feet. Hair loss is a rare side effect of drugs used to treat colorectal cancer.
If the side effects are particularly severe, the dose of the drug may be reduced or treatment may be delayed. If you are receiving chemotherapy, you should communicate with your medical team to understand when to let your doctor treat side effects. Once the treatment is over, the side effects of chemotherapy will disappear.
Targeted drug therapy in colorectal cancer
Targeted therapy is a treatment for cancer-specific genes, proteins, or tissue environments that contribute to cancer growth and survival. This treatment prevents the growth and spread of cancer cells while reducing damage to healthy cells.
Recent studies have shown that not all tumors have the same target. To find the most effective treatment, your doctor may perform genetic tests to determine the genes, proteins, and other factors in the tumor. This helps doctors better match each patient with the most effective treatment possible. In addition, many studies are now underway to learn more about specific molecular targets and new therapies directed at them. These drugs are becoming more and more important in the treatment of colorectal cancer.
Studies have shown that older patients can benefit from targeted therapy similar to younger patients. In addition, the expected side effects are controllable in elderly patients and young patients.
Classification of targeted therapy
For colorectal cancer, the following targeted therapies are available.
Anti-angiogenesis treatment in colorectal cancer
Anti-angiogenesis therapy is a targeted therapy. It focuses on preventing angiogenesis, which is the process by which tumors create new blood vessels. Since tumors require angiogenesis and provide nutrients, the goal of anti-angiogenesis therapy is to “starve” the tumor.
• Bevacizumab (Avastin)
When bevacizumab is combined with chemotherapy, it will increase the survival time of patients with advanced colorectal cancer. In 2004, the FDA approved bevacizumab combined with chemotherapy as the first choice or first-line treatment for advanced colorectal cancer. Recent research shows that it is also effective as a second-line treatment.
• Sikarga (Stivarga)
The drug was approved in 2012 for patients with metastatic colorectal cancer who have received certain types of chemotherapy and other targeted therapies.
• Ziv-aflibercept (Zaltrap) and lamucirumab (Cyramza)
Any of these drugs can be used in combination with FOLFIRI chemotherapy as a second-line treatment for metastatic colorectal cancer.
EGFR inhibitor is a targeted therapy. The researchers found that drugs that block EGFR may effectively prevent or slow the growth of colorectal cancer.
• Cetuximab (Erbitux). Cetuximab is an antibody made from mouse cells, which still has some mouse tissue structure.
• Panitumumab (Vectibix). Panitumumab is made entirely of human protein and does not cause allergic reactions like cetuximab.
Recent studies have shown that cetuximab and panitumumab have no effect on tumors with RAS gene mutations or changes. ASCO recommends that all patients with metastatic colorectal cancer who may receive anti-EFGR treatment, such as cetuximab and panitumumab, can detect RAS gene mutations. If the patient’s tumor has a mutation in the RAS gene, ASCO recommends against treatment with anti-EFGR antibodies.
Your tumor may also be tested for other molecular markers, including BRAF, HER2 overexpression, microsatellite instability, etc. These markers have not yet been approved by the FDA for targeted therapy, but there may be therapeutic opportunities in clinical trials that study these molecular changes.
Side effects of targeted therapy
Side effects of targeted therapy can include skin rashes on the face and upper body, which can be prevented or reduced by various treatments.
Treatment of cancer symptoms and side effects
Cancer and its treatment often cause side effects. In addition to slowing the growth of cancer or eliminating cancer, an important part of cancer treatment is to relieve a person’s symptoms and side effects. This method is called palliative treatment or supportive treatment, and it includes supporting the patient’s physical, emotional, and social needs.
Palliative treatment is a treatment method focused on reducing symptoms, improving quality of life, and supporting patients and their families. Anyone, regardless of age, type and stage of cancer, needs palliative care. When palliative t
reatment is started as early as possible during cancer treatment, the effect is best. People often receive cancer treatment and treatment to relieve side effects at the same time. In fact, patients receiving these two therapies often have milder symptoms and a better quality of life, and report that they are more satisfied with the treatment.
Palliative care varies widely and usually includes medications, nutritional changes, relaxation techniques, emotional support and other therapies. You can also receive treatment options similar to eliminating cancer, such as chemotherapy, surgery, or radiation therapy.
Different cancer treatment options
In general, stages 0, I, II, and III are usually curable with surgery. However, many patients with stage III colorectal cancer and stage II patients receive chemotherapy after surgery to increase the chance of curing the disease. Patients with stage II and stage III rectal cancer received radiotherapy and chemotherapy before or after surgery. Stage IV is usually not curable, but treatable and can control the development of cancer and the symptoms of the disease. Participating in clinical trials is also a treatment option for each staged patient.
Stage 0 colorectal cancer
The usual treatment is polypectomy or polyp removal during colonoscopy. Unless the polyps cannot be completely removed, no additional surgery is required.
Stage I colorectal cancer
Surgical removal of tumors and lymph nodes is usually the treatment method.
Stage II colorectal cancer
Surgery is often the first treatment. Patients with stage II colorectal cancer should talk to their doctors about whether they need more treatment after surgery, because some patients receive adjuvant chemotherapy. Adjuvant chemotherapy is a post-operative treatment designed to destroy any remaining cancer cells. However, the cure rate of surgery alone is quite good, and for patients with this stage of colorectal cancer, the benefit of additional treatment is very small. For patients with stage II rectal cancer, radiation therapy is usually combined with chemotherapy before or after surgery. Additional chemotherapy can be given after the operation.
Stage III colorectal cancer
Treatment usually involves surgical removal of the tumor followed by adjuvant chemotherapy. Clinical trials are also available. For patients with rectal cancer, radiation therapy can be performed before and after surgery.
Metastatic (stage IV) colorectal cancer
If the cancer spreads from its primary site to another part of the body, doctors call it metastatic cancer. Colorectal cancer can spread to distant organs, such as the liver, lungs, and peritoneum, that is, the abdomen or women’s ovaries. If this happens, doctors may have different views on the best standard treatment plan. In addition, participation in clinical trials may be an option.
Your treatment plan may include a combination of surgery, radiation therapy and chemotherapy, which can be used to slow the development of the disease and often temporarily shrink the tumor. Palliative care is also important to help relieve symptoms and side effects.
At this stage, the use of surgery to remove the part of the colon where the cancer occurs usually does not cure the cancer, but it can help relieve colon blockage or other cancer-related problems. It is also possible to use surgery to remove parts of other organs containing cancer, called resection. If a limited number of cancers spread to a single organ, such as the liver or lungs, some people can be cured.
In colorectal cancer, if the cancer has spread to the liver, if surgery is possible (before or after chemotherapy), there is a chance of complete cure. Even if it is impossible to cure cancer, surgery may increase survival for months or even years. Determining which patients can benefit from cancer surgery that has been transferred to the liver is often a complex process that involves multiple specialists collaborating to plan the best treatment plan.
Opportunities for cancer remission and relapse
Cancer remission is when the body cannot detect cancer and has no symptoms. This may also be referred to as “no evidence of disease” or NED.
Relief may be temporary or permanent. This uncertainty has caused many people to worry that the cancer will return. Although many remissions are permanent, it is important to talk to your doctor about the possibility of cancer recurrence. Understanding your relapse risk and treatment options may help you prepare for cancer recurrence more effectively.
If the cancer does recur after treatment, it is called recurrent cancer. It may come back in the same place (called a local recurrence), nearby (regional recurrence) or in another place (remote recurrence).
When this happens, an inspection cycle will begin again to understand as much as possible about the relapse. After the examination is completed, the treatment plan usually includes the above treatment methods, such as surgery, chemotherapy and radiation therapy, but they can be used in different combinations or given at different rates. Your doctor may also recommend participating in a clinical trial that is studying treatment for this recurrent cancer. In general, the treatment options for recurrent cancer are the same as those for metastatic cancer (see above), including surgery, radiation therapy, and chemotherapy. No matter which treatment plan you choose, palliative care will be important to relieve symptoms and side effects.