Table of Contents
- 1 Causes of cancer
- 2 Statistics
- 3 Cancer around the world
- 4 Survival rates
- 5 How does cancer develop
- 6 Characteristics of cancer cells
- 7 The different types of cancer
- 8 Symptoms of cancer
- 9 Vulnerable people:
- 10 Cancer risk factors
- 11 Can stress cause cancer?
- 12 Cancer prevention
- 13 Cancer Screening measures
- 14 Medical treatments for cancer
- 15 Possible types of medical treatment
- 16 Complementary approaches to fighting cancer
Cancer is a dreaded disease, often considered “the worst of all diseases”. It is one of the leading causes of death in the US. Today, more and more people are being diagnosed with cancer, but fortunately, many are being cured.
There are more than 100 types of cancer or malignant tumors that can appear in various tissues and organs.
In people with cancer, some cells multiply too much and uncontrollably. The genes in these cells are altered or mutated. Sometimes the cancer cells invade the surrounding tissues or separate from the original tumor and migrate to other parts of the body. These are called “metastases”.
Most types of cancer take several years to develop. They can occur at any age but are more common in people over 60.
Note: Benign tumors are not carcinogenic. Usually, they do not destroy surrounding tissues and do not spread throughout the body. However, they can put pressure on an organ or tissue.
Causes of cancer
The body has a multitude of tools to repair genetic “mistakes” or even destroy potential cancer cells. Sometimes these tools are defective for one reason or another.
Several factors can accelerate the onset of cancer or lead to the development of cancer. In fact, it is generally believed that it is a combination of risk factors that leads to cancer. Age is an important factor. However, it is now recognized that about two-thirds of cancers are due to lifestyle, especially smoking and diet. Exposure to carcinogenic substances in the environment (air pollution, toxic substances handled at work, pesticides, etc.) also increases the risk of cancer. Finally, it is said that hereditary factors account for 5% to 15% of cases.
Approximately 38.4% of Americans will be diagnosed with cancer during their lifetime.
According to the National Cancer Institute, an estimated 1,735,350 new cases of cancer will be diagnosed in the United States in 2018 and 609,640 people will die from it.
One in four Americans may die of cancer, regardless of gender. Lung and breast cancers are the most common types.
More cancers are being diagnosed than ever before, partly because of the aging population and the fact that cancer is detected more frequently.
Cancer around the world
The most common types of cancer vary around the world. In Asia, stomach, esophageal, and liver cancers are much more common, partly because people’s diets contain a high proportion of highly salted, smoked, and pickled foods. In sub-Saharan Africa, liver and cervical cancer are widespread due to hepatitis and human papillomavirus (HPV). In North America and Europe, lung, colon, breast, and prostate cancers are more common due to smoking, poor eating habits, and obesity, among other things. In Japan, red meat consumption, which has increased steadily over the past 50 years, has increased the incidence of colon cancer by seven times. Migrants generally contract the same diseases as the population of their host country.
No doctor can predict with certainty the course of cancer or the chances of survival of a particular person. However, survival statistics give an idea of how the disease develops in a large group of people.
A significant proportion of patients recover permanently from cancer. According to the National Cancer Institute, 5% of the population are cancer survivors.
The rate of recovery depends on a number of factors: the type of cancer (the prognosis is excellent for thyroid cancer but much less good for pancreatic cancer), the extent of the spread of cancer at the time of diagnosis, the malignancy of the cells, the availability of effective treatment, etc.
The most commonly used method for determining the severity of a cancer is the TNM (tumor, node, metastasis) classification for “tumor”, “node” and “metastasis”.
The T-stage (1 to 4) describes the size of the tumor.
Stage N (0 to 3) describes the presence or absence of metastases in adjacent nodes.
The M stage (0 or 1) describes the absence or presence of metastases that are distant from the tumor (in other organs).
How does cancer develop
The development of cancer usually takes several years, at least in adults. There are three stages:
- Initiation: The genes in a cell are damaged; this happens frequently. For example, carcinogenic substances in cigarette smoke can cause such damage. In most cases, the cell repairs the damage automatically. If the error is irreparable, the cell dies. This is called apoptosis or “suicide” of the cell. If the cell does not repair or destroy itself, the cell remains damaged and moves on to the next step.
- Promotion: External factors may or may not stimulate the formation of a cancer cell. These can be life habits such as smoking, lack of exercise, poor diet, etc.
- Progression: Cells proliferate and tumors are formed. In some cases, they may invade other parts of the body. In its growth phase, the tumor begins to cause symptoms like bleeding, fatigue, etc.
Characteristics of cancer cells
The multiplication is out of control. The cells are constantly reproducing, despite the growth-inhibiting signals they receive from the body.
Loss of utility: The cells no longer fulfill their original functions.
Immortality: The “suicide” process of the cell is no longer possible.
Resistance to the immune system’s defenses: Cancer cells avoid their usual “killers”, the NK cells, and other cells that supposedly limit their progression.
Formation of new blood vessels in the tumor (angiogenesis): This is essential for tumor growth.
Occasional invasion of nearby tissue and other parts of the body: These are called metastases.
The changes that occur in the genes of the cell when it becomes cancerous are transferred to its descendant cells.
The different types of cancer
Each type of cancer has its own characteristics and risk factors.
- Cervical Cancer
- Colorectal Cancer
- Endometrial Carcinoma
- Stomach cancer
- Liver Cancer
- Throat Cancer
- Esophageal Cancer
- Pancreatic Cancer
- Skin Cancer
- Brain Cancer
- Lung Cancer
- Prostate Cancer
- Breast Cancer
- Testicular Cancer
- Blood Cancer
- Oral Cancer
- Ovarian Cancer
- Thyroid Cancer
- Kaposi Sarcoma
- Penile Cancer
- Bone Cancer
- Bladder Cancer
- Non-Hodgkin’s Lymphoma
- Hodgkin’s disease
- Renal Cell (Kidney) Cancer
- Vaginal Cancer
Symptoms of cancer
Cancer manifests itself in many different ways. It usually progresses over many years, often without causing symptoms. The following symptoms can be signs of cancer. If present, consult a doctor.
- A palpable mass, especially if it becomes enlarged: a lump in the breast, under the skin, in a lymph node, etc.
- A mole or spot on the skin that changes in appearance, color, and size or bleeds.
- Bleeding: Blood in sputum, urine, or stool. In women: vaginal blood loss during the cycle or after menopause.
- Persistent symptoms: unexplained coughing and hoarseness for more than 4 weeks, difficulty swallowing, nausea and vomiting, pain that does not heal after 3 weeks, diarrhea, or constipation for 6 weeks or longer.
- A retraction or leaking of the nipples.
- Recurring severe headaches.
- Extreme fatigue.
- Rapid and unexplained weight loss.
- Some families are more affected by cancer. There are cancer predisposition genes that are passed on from one generation to the next. This can be the case with breast, ovarian, and colon cancer. Even in people with a genetic predisposition to cancer, the risk of developing cancer one day depends largely on lifestyle and where you live and work.
- People who already had cancer
Cancer risk factors
Scientific research has discovered risk factors for most cancers. It is also estimated that two-thirds of cancers are caused by lifestyle. However, it is very difficult to determine the responsibility for each of the following risk factors in a person’s life, as the disease develops over several years and is often multifactorial.
The two main risk factors
- Tobacco: Smoking accounts for almost a third of cancer deaths and is not only associated with lung cancer. The carcinogenic products contained in cigarette smoke increase the risk of various types of cancer: throat, bladder, liver, etc.
- Diet: According to the World Health Organisation, unhealthy diets account for around 30% of cancers in the West and 20% in developing countries: too many calories, too much red meat and delicatessen, too much fat, salt, sugar, and too little fruit, vegetables, and whole grains.
Other important risk factors
- Overweight and obesity: These physical conditions increase the risk of many cancers.
- Alcohol: The digestion of ethanol produces metabolites that alter the genes in cells (mutagens).
- Physical inactivity: People who are more active have a lower risk of certain types of cancer.
- Exposure to the sun: Ultraviolet (UV) rays can cause skin cancer in high doses and in the long term.
- Environmental contaminants (air, water, and soil): Risks of cardiovascular diseases, respiratory problems, and cancers are raised by the presence of toxic chemicals in the environment.
- Infections: In industrialized countries, it is assumed that 5% of cancer cases are caused by infections, 18% worldwide. Examples are papillomavirus (cervical cancer), hepatitis B and C viruses, and Helicobacter pylori (stomach cancer).
- Exposure to radioactive substances: The use of nuclear energy involves risks to the population. The Chernobyl reactor accident, for example, resulted in many deaths from cancer.
Can stress cause cancer?
The vast majority of doctors and psychologists who answer this question deny that stress causes cancer. However, the influence of the psychological state on the development of cancer is still controversial.
Based on a large number of studies, scientists have tried to identify a personality most likely to develop cancer. It is known as a type C personality and describes people who have a tendency to constantly suppress their feelings and resign themselves easily to them. Based on personality tests, some research has been able to predict up to 40% of cancers that could occur 15 years later. However, other studies have not found a clear link between personality type and cancer development.
It is known that stress and depression weaken the immune system, which in principle could contribute to the development of a tumor. However, this has not been proven. Depressed people with cancer who participate in trials may tend to report more negative events than average, which may distort the results. However, some authors have suggested that the combination of a type C personality and chronic stress increases the risk of cancer. This would be particularly true for people who feel helpless for long periods of time.
Not seeing a doctor in time also means the person is ignoring the signs.
Main preventive measures
Quit smoking as soon as you can. There are many programs that are designed to help smokers quit so don’t hesitate to use them.
Follow the basic rules of an anti-cancer diet as much as you can. Some foods have anti-cancer properties, others may have the opposite effect. Here are the general recommendations.
Consume a variety of fresh fruits and vegetables, at least 5 servings per day. Preferably :
- Cruciferous vegetables (broccoli, cabbage, cauliflower, etc.)
- Allium Vegetables (onion, garlic, shallot)
- Dark green vegetables
- Citrus fruits (lemon, lime, orange, grapefruit)
- Berries (blueberries, raspberries, strawberries, etc.)
- Whole grains
- Turmeric. Ideally, turmeric should be eaten with pepper, which greatly increases the absorption of turmeric by the body
- Green tea.
Eliminate or avoid as much as possible:
- Excess calories, fat, and salt
- Refined sugar and white flour
- Industrially processed foods
- Red meat and delicatessen (ham, bacon, sausage, etc.)
- Marinated, canned, smoked, fried, or processed food
- Meat cooked over the flame (barbecue). Softening meat in a marinade containing an acidic element (such as lemon juice) reduces the formation of these toxins.
- Alcohol consumption
In light of recent studies, no regular alcohol consumption seems to be safe. The National Cancer Institute advises women to limit their alcohol consumption to less than one drink per day and men to less than two drinks per day.
According to some experts, organic fruits, vegetables, and whole grains have a better nutritional value than their industrial counterparts. However, this has not yet been proven.
Other preventive measures
Be physically active: at least 30 to 45 minutes of physical activity per day.
Protect yourself from sexually transmitted infections. Get Tested for STDS to be sure you are not already infected.
Avoid contact with carcinogenic substances (herbicides and pesticides, radiation, etc.) Respect the safety measures affixed to the products.
Do not expose yourself to the sun for long periods without adequate protection.
Find ways to cope better with prolonged stress or anxiety (meditation, deep breathing, and psychotherapy if necessary).
Of course, the fight against cancer requires not only individual but also collective action: reducing greenhouse gas emissions, planning cities to encourage physical activity, etc.
Other measures to prevent the onset of the disease
Based on the results of several studies it is recommended to take an additional 25 µg (1,000 IU) of vitamin D daily in autumn and winter. People with a higher risk of vitamin D deficiency – including the elderly, people with darker skin pigmentation, and people who are rarely exposed to the sun – should do the same throughout the year. Studies show that this type of vitamin D intake reduces the risk of prostate, breast, and colorectal cancer.
For people at high risk of cancer, and only for them, certain medicines are sometimes given as a preventive measure. For example, finasteride to prevent prostate cancer and tamoxifen to prevent breast cancer.
Cancer Screening measures
For certain types of cancer, early detection significantly increases the chances of survival. In some cases, screening is limited to people whose family members have or have had cancer. Read our specific fact sheets about the different types of cancer to find out more.
Medical treatments for cancer
Cancer treatment depends on a variety of factors: type of cancer, size, and location, course of illness, and state of health of the person. It usually takes several months. After that, regular follow-up care is offered due to the possibility of a relapse.
Depending on the degree of development of cancer, 3 therapeutic approaches are possible:
- A curative treatment, which aims to cure cancer.
- An adjuvant treatment, which is carried out in parallel with the main treatment in order to increase the chances of recovery (e.g. hormone therapy before or after prostate cancer surgery).
- Palliative treatment aimed at relieving symptoms or prolonging life when the chances of recovery are very low.
Cancer treatment is a challenge: killing diseased cells while maintaining healthy cells. Radiotherapy, for example, also destroys healthy cells in the vicinity of the tumor. Some chemotherapies affect the whole body, especially fast-growing cells such as those in the scalp, digestive tract, and blood. In this case, the side effects can be considerable: reduced immune function, anemia, digestive problems, and hair loss. Researchers are working on developing drugs that only attack cancer cells.
Possible types of medical treatment
If possible, the tumor is removed surgically and treatment is completed with radiation and chemotherapy to remove the remaining cancer cells. This is the oldest cancer treatment and probably the most effective if the tumor is still confined to an area of the body, that is if it has not invaded the surrounding tissue.
Using various sources of ionizing radiation, depending on the type of tumor, this treatment is often necessary after surgery. Its purpose is to destroy any remaining cancer cells and prevent local recurrence. Radiation also kills normal cells. Ionizing radiation is emitted either by a radiotherapy device or by radioactive substances that are introduced into the patient’s body in the vicinity of the tumor. In the United States, about half of cancer patients receive radiotherapy.
Chemotherapy involves the administration of chemical agents by injection or in the form of tablets that kill diseased cells. There are several different chemotherapeutic agents that have different mechanisms of action and side effects. Their use depends on the malignancy of the tumor, its origin, and its stage of development. It is often used in cases of recurrence of tumors and metastases. Sometimes chemotherapy is indicated before surgery in order to reduce the size of the tumor and facilitate its removal.
Hormone therapy can help to control and cure breast or prostate cancer, which is sometimes hormone-dependent (their growth can be stimulated by hormones such as estrogen or testosterone). It is often aimed at lowering levels of certain hormones in the body or preventing the tumor from using these hormones to grow.
The most important chemicals active in the immune system are cytokines – including interferons and interleukins. In patients whose immune system is already strong and whose cancer is still at an early stage, cytokines can be injected to boost the body’s immune function. In addition, new immune therapies are being developed. This involves the production of vaccines that stimulates the patient’s immune system to act against the tumor.
Bone marrow transplant
This treatment is only used for cancers that attack immune cells (e.g. lymphoma).
Tumor angiogenesis is the process by which new small blood vessels form around a tumor. These vessels allow the tumor to feed and grow. Its formation is stimulated by substances secreted by cancer cells. Several chemotherapies and hormonal preparations are used to stop the angiogenesis process so that the tumors “starve”.
The disease almost always has psychological effects, which vary in the different phases: diagnosis, treatment, compatibility with family and work, remission, etc. The diagnosis often leads to emotional shock. The feeling of losing control over one’s own life, even if it is only temporary, can be as disturbing as not knowing what awaits us.
The support of family, friends, and experts is very valuable in dealing with these difficult times. Caregivers may also need help.
Expert help can take many forms: seeing a psychologist, a psychotherapist, a psychiatrist, a social worker, or a nurse, participating in a support group, or meeting other patients on the internet.
Research conducted by Alastair Cunningham at the University of Toronto and David Spiegel at Stanford University shows that participation in group psychotherapy generally reduces stress, provides a greater appreciation of life, and helps give meaning to life. Other research, however preliminary and controversial, suggests that some cancer patients who undergo group psychotherapy with great personal commitment may live longer.
Foundations and societies dedicated to helping people with cancer offer a wide range of support services.
Please note. Experts warn against the simplistic equation that positive thinking can cure cancer, or that the illness is due to a psychological conflict.
If you’ve just found out you have cancer, it’s very likely you’ll feel disturbed and worried. It is normal for the first reaction to be one of panic. Despite medical advances, a cancer diagnosis is still very shocking. Get educated on your condition and stay away from people who offer ‘miracle cures’: There are no miracle cures. If you want to take unconventional paths, be cautious, and make sure that no one takes advantage and abuses your vulnerability.
The approach to cancer treatment should be comprehensive and involve first an often multidisciplinary team of doctors and, if you wish, complementary approaches that are appropriate for you.
The fight against cancer requires a lot of courage and determination. Do not be alone, trust your family, loved ones, and friends; if necessary, contact a support group.
Complementary approaches to fighting cancer
That’s important. People who want to participate in a comprehensive approach should discuss it with their doctor and choose therapists who have experience working with people with cancer. Self-treatment is not recommended. The following approaches may be appropriate if used as a supplement to medical treatment rather than a substitute. Delaying or stopping medical treatment reduces the chances of remission.
In the scientific literature, there are several summaries of studies on complementary approaches that help in the fight against cancer. Most of the time, these strategies contribute to improving the quality of life. Many of them rely on the interaction between thoughts, emotions, and the physical body to create a sense of well-being. They can have an influence on the progression of the tumor. In practice, they can have one or the other of the following effects:
- Improve the feeling of physical and psychological well-being
- Bring joy and calm
- Reduce anxiety and stress
- Reduce fatigue
- Reduce nausea after chemotherapy treatments
- Improve the appetite
- Improve the quality of sleep.
The following is an overview of the evidence for the effectiveness of some of these approaches.
Based on previous clinical trials several committees and expert organizations (the National Institutes of Health, the National Cancer Institute, and the World Health Organization) have concluded that acupuncture is effective in reducing nausea and vomiting caused by chemotherapy.
As a result of the findings of 3 studies, it is now recognized that relaxation techniques, including visualization, significantly reduce the adverse effects of chemotherapy, such as nausea and vomiting and psychological symptoms such as anxiety, depression, anger, and feelings of helplessness.
All evidence from cancer studies suggests that massage, with or without aromatherapy, has short-term benefits for psychological well-being. These include improved relaxation and quality of sleep, reduced fatigue, anxiety and nausea, pain relief, and improved immune system response. Sometimes massage therapy is also offered in hospitals.
Manual lymphatic drainage, a type of massage, can reduce lymphedema after treatment for breast cancer.
Note: It’s best to choose a massage therapist who specializes in cancer treatment.
Discuss any contraindications to massage with your doctor. In general, massage is safe and does not contribute to the spread of metastases. However, as a precautionary measure, it is recommended to avoid any massage in the tumor area.
However, therapeutic massage is contraindicated in cases of fever, bone fragility, low platelet levels, hypersensitivity of the skin, wounds, or skin diseases.
Yoga practice has several positive effects on sleep quality, mood, and stress management, according to a number of studies that evaluated the effectiveness of yoga in patients with cancer or cancer survivors.
According to a study of 285 cancer patients, a complementary treatment that combines aromatherapy (essential oils), massage, and psychological support helps to reduce anxiety and depression more quickly than if only the usual care was used.
Art therapy, a form of psychotherapy that uses creativity as an opening to the inner self, can be useful for people with cancer, according to some clinical studies. In fact, art therapy seems promising to improve well-being, promote communication, and reduce the psychological stress that illness sometimes generates.
Dance therapy can have a positive effect on the quality of life, especially by reducing stress and fatigue caused by cancer. Dance therapy aims to increase self-perception and release tensions and blockages in the body’s memory. It can be performed individually or in groups.
Researchers have analyzed the results of 8 clinical studies on the usefulness of homeopathy for alleviating the side effects of chemotherapy or radiotherapy treatments or the menopause symptoms of women treated for breast cancer. In 4 of the studies, positive effects were observed after homeopathic treatments, such as a reduction in chemotherapy-induced oral inflammation. However, the other 4 studies showed negative results.
Nine small studies have investigated the effect of meditation (attention-based stress reduction) on people with cancer. All reported a reduction in several symptoms, such as less stress, less anxiety and depression, increased well-being, and a stronger immune system.
Some small studies have shown promising results. Some show a decrease in emotional and physical symptoms, a sense of relaxation, and an improvement in overall health and well-being.
Two clinical studies conducted on a small number of subjects suggest that regular qigong practice can reduce the adverse effects of chemotherapy and enhance immunity. Qigong is one of the branches of traditional Chinese medicine. It is believed to be a powerful force capable of activating autonomous healing mechanisms in the individual who practices it and perseveres in its practice. Most of the research concerns the strengthening of the respiratory system.
Several foundations or associations offer art therapy workshops, yoga, dance therapy, massage therapy, meditation ad Qi Gong. Do an online search for associations in your area if interested in these alternative practices.
Pros of naturopathy
In complementarity with medical treatments, the naturopathic approach aims to improve the health and quality of life of people with cancer and help the body fight cancer better. For example, with certain foods, medicinal plants, and food supplements, naturopathic medicine can support the liver and help the body release toxins. Naturopathic treatments are usually associated with significant changes in diet. In addition, special care is taken to monitor everything around the person (chemicals, food, etc.) that may contribute to the development of cancer. Antioxidant supplements (such as vitamins C and E), if used, should only be used under professional supervision, as some of them may interfere with the treatment.
Cohort studies have associated beta-carotene supplementation with a slightly increased risk of lung cancer. However, in its dietary form, beta-carotene can help prevent lung cancer. The National Cancer Institute recommends that smokers should not take beta-carotene supplements.
Warning! Natural health products should be used with caution, especially if they claim to lead to remission.