Cancer is the uncontrolled growth of abnormal cells in the body. Cancer develops when the body’s normal control mechanism stops working. Old cells do not die and instead grow out of control, forming new, abnormal cells. These extra cells can form a tissue mass, called a tumor. Some cancers, such as leukemia, do not form tumors.
Cancer is the second leading cause of death in the world. But survival rates are improving for many types of cancer, thanks to improvements in cancer screening and cancer treatment.
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What is cancer?
The human body is made up of trillions of living cells. Within each cell are genes that control and control the functions of the cell. Normal cells constantly grow and divide, over time these cells die and are replaced by new ones.
In most people, this natural cell replacement happens in an organized and orderly manner. However, this process is sometimes broken. Unlike normal healthy cells, cancer cells do not die. Instead, they continue to grow and divide uncontrollably. These defective cells can form a tissue called a tumor.
What is a tumor?
The tumor may be benign or malignant. Tumors that are in one position and do not spread to other parts of the body are considered benign. These are not cancerous and are rarely life threatening although they can sometimes cause problems, especially when they are too large.
On the other hand, malignant tumors can destroy and invade other normal tissues in your body, leaving you seriously ill. However, not all cancers form tumors like those that are uncommon in leukemia, these cancers usually start in the bone marrow and enter the bloodstream.
Cancer cells can spread as they move to other parts of the body through the blood and lymph systems, forming new tumors, a process called metastasis. Even when the cancer spreads, it is always named based on where it happened the first time. For example, cancer that starts in the breast is called breast cancer, if it spreads to other parts of the body, like the liver or bone, it is called metastatic breast cancer.
There are many different cancers, it’s important to know what type of cancer you have in order to be treated properly.
What are the most common forms of cancer?
Cancer can occur anywhere in the body.
- Women: breast cancer is one of the most common diseases.
- Men: prostate cancer is the most common.
Lung cancer and colorectal cancer affect both men and women in high numbers.
There are five main types of cancer:
- Carcinoma begins in the skin or tissues lining the internal organs.
- Sarcomas develop in bone, cartilage, fat, muscle or other connective tissue.
- Leukemia begins in the blood and bone marrow.
- Lymphoma begins in the immune system.
- Central nervous system cancer develops in the brain and spinal cord.
Symptoms of cancer
The signs and symptoms caused by cancer will vary depending on which part of the body is affected.
Some general signs and symptoms associated with, but not specific to, cancer, include:
- A lump or thick area can be felt under the skin
- weight changes, including unintended losses or increases
- skin changes, such as yellowing, darkening or redness of the skin, sores that don’t heal, or changing existing moles
- Changes in bowel or bladder habits
- persistent cough or shortness of breath
- Difficulty swallowing
- Persistent indigestion or discomfort after eating
- Persistent, unexplained muscle or joint pain
- Persistent, unexplained fever or night sweats
- Unexplained bleeding or bruising
How does cancer begin?
Carcinogenesis is a multi-stage process in which the cell’s genetic material is damaged, changing the cell from normal to malignant. The damage gradually accumulates in the cell’s regulatory system for growth.
Cancer begins with a genetic defect. Human genetics mean that genes are in the cell structure called chromosomes. Genes control cellular functions, such as their distribution. Genes can undergo changes or mutations if the cell’s regulatory system fails. A genetic error will usually not be enough to cause cancer. Cancer that develops when mutations take place in genes plays an important role in regulating cell growth and differentiation.
There are two types of cancer genes:
- Oncogenes: are genes that create cancer, which trigger causing uncontrolled distribution of cell tissue
- The tumor suppressor genes or anti-cancer genes have a carcinogenic effect due to their cessation of activity.
Damage to the genes occurs continuously in many cells. But the human body contains a defense system that has been developed for a long time and this can repair damage. If the system breaks down, damaged cells may begin to uncontrollably divide, eventually leading to cancer.
Complications of cancer
Cancer and its treatment can cause many complications, including:
- Pain: Pain may be due to cancer or cancer treatment, although not all cancers are painful. Medications and other effective methods can treat cancer-related pain.
- Fatigue: Fatigue in people with cancer has many causes, but it can often be managed. Fatigue associated with chemotherapy or radiation treatments is common, but it is usually temporary.
- Shortness of breath; Cancer or cancer treatment can cause shortness of breath. Treatments can bring relief.
- Nausea: Certain cancers and cancer treatments can cause nausea. Your doctor can sometimes predict when treatment may cause nausea. Medications and other treatments can help you prevent or reduce nausea.
- Diarrhea or constipation: Cancer and cancer treatment can affect the intestines and cause diarrhea or constipation.
- Weight loss: Cancer and cancer treatment can cause weight loss. Cancer steals food from normal cells and deprives them of nutrients. This is usually not affected by how many calories or what foods are eaten; It’s hard to treat. In most cases, using an artificial diet through the tube into the stomach or veins doesn’t help change weight loss.
- Chemical changes in your body: Cancer can disrupt the normal chemical balance in your body and increase the risk of serious complications. Signs and symptoms of chemical imbalance can include excessive thirst, frequent urination, constipation and confusion.
- Brain and nervous system problems: Cancer can click on nearby nerves and cause pain and loss of function of a part of your body. Brain-related cancers can cause headaches and stroke-like signs and symptoms, such as weakness on one side of the body.
- Abnormal immune system response to cancer: In some cases the body’s immune system can react to the presence of cancer by attacking healthy cells. Called paraneoplastic syndrome, these reactions are very rare that can lead to a range of signs and symptoms, such as difficulty walking and seizures.
- Cancer spreading: As cancer progresses, it can spread (metastasize) to other parts of the body. Where the spread of cancer depends on the type of cancer.
- Cancer returned: Cancer survivors are at risk of cancer recurrence. Some cancers are more likely to recur than others. Ask your doctor what you can do to reduce your risk of recurrence. Your doctor can give you a follow-up care plan after treatment. This plan may include routine scans and exams in the months and years after your treatment, to look for cancer recurrence.
How is cancer treated?
The choice of treatment depends on the type of cancer, its stage, if the cancer has spread and your general health. The goal of treatment is to kill as many cancer cells as possible while reducing damage to nearby normal cells. Advances in technology make this possible.
The three main treatments are:
- Surgery: direct tumor removal
- Chemotherapy: using chemicals to kill cancer cells
- Radiation therapy: uses X-rays to kill cancer cells
The same type of cancer in one person is very different from cancer in another. In a single cancer, such as breast cancer, researchers are discovering the subtypes that each require a different treatment.
How to prevent cancer?
There is no sure way to prevent cancer. But doctors have identified several ways to reduce your risk of cancer, such as:
- Quit: If you smoke, quit. If you do not smoke, do not start. Smoking is linked to several types of cancer – not just lung cancer. Stopping now will reduce your risk of future cancer.
- Avoid excessive sun exposure: Ultraviolet (UV) rays from the sun can increase the risk of skin cancer. Limit your sun exposure by staying in the shade, wearing protective clothing or applying sunscreen.
- Eat a healthy diet: Choose a diet rich in fruits and vegetables. Choose whole grains and lean protein.
- Exercise most days of the week: Regular exercise has been linked to a lower risk of cancer. Aim for at least 30 minutes of exercise most days of the week. If you’ve never exercised regularly, start slowly and work your way up to 30 minutes or so.
- Maintain a healthy weight: Being overweight or obese can increase the risk of cancer. Work to achieve and maintain a healthy weight through a combination of a healthy diet and regular exercise.
- Drink alcohol in moderation, if you choose to drink: If you choose to drink, limit yourself to one glass a day if you are a woman of any age or a man older than 65 years, or two cups of a date if you are a man 65 years old or younger.
- Cancer screening schedule: Talk to your doctor about which types of cancer screening tests are best for you based on your risk factors.
- Ask your doctor about immunizations: Some viruses increase the risk of cancer. Vaccination can help stop viruses, including hepatitis B, increase the risk of liver cancer, and human papilloma (HPV), which increases the risk of cervical and other cancers. Ask your doctor whether vaccination against these viruses is appropriate for you.
Source of Cancer Reference:
- Source mayoclinic.org Cancer article: https://www.mayoclinic.org/diseases-conditions/cancer/symptoms-causes/syc-20370588 , updated 12/12/2018.
- Source en.wikipedia.org Cancer article: https://en.wikipedia.org/wiki/Cancer , updated November 16, 2019.
- A reputable source thuoclp.com summarizes the article Learn about cancer: https://index-china.com/learn-about-cancer/, updated 12/3/2020.
Assoc.Prof.Dr. Tran Ngoc Anh is currently Hanoi Medical University Hospital, Associate Professor, Department of Internal Medicine, Gastroenterology and Head of Department of General-Uematology of Hanoi Medical University. Consulting doctor at ThuocLP Pharmacy.
Professional qualifications, Academic degrees – Education:
Graduated from General Practitioner System, Hanoi Medical University
Graduated with a Master degree in Internal Medicine, Hanoi Medical University
Graduated from the training program specialized in Gastrointestinal, Henri Mondor Institute Center, University of Paris 6, French Republic 1996-1997; 1999
Graduated from the training program specialized in Gastrointestinal, North Royal Sydney Hospital, Australia; 2002
Graduated from a training program specialized in chronic liver diseases, Pizza, Italy 2009
Graduated with a PhD in Gastrointestinal, Hanoi Medical University
Associate Professor, Gastroenterology, Hanoi Medical University
Training and Scientific Research:
Published more than 200 articles in domestic and international specialized journals
Editor of many monographs and participates in compiling 2 textbooks.
Guide many students and graduate students of Hanoi Medical University
Manager of many grassroots research projects
Certificate of Good Clinical Practice (GCP: 2012, 2015), Ministry of Health
Specialized certificates: General gastrointestinal endoscopy, Interventional gastrointestinal endoscopy, General gastrointestinal ultrasound, Interventional gastrointestinal ultrasound (Bach Mai BV), Chronic liver disease.