What is Cancer?
The human body is made up of billions of cells which form the building blocks of our tissues and organs. The replication of these cells is what gives it the ability to form complex systems that support life forms. The abnormal or uncontrolled replication of these cells is known as cancer. There are over 200 different types of cancer, but the most common ones are breast cancer, prostate cancer, lung and bronchial cancer, colon and rectum cancer, bladder cancer, melanoma of the skin, non-Hodgkin lymphoma, kidney and renal pelvis cancer, thyroid cancer, leukemia, pancreatic cancer and endometrial cancer.
Around 1.7 million new cases of cancer are diagnosed in the United States each year, and over 700,000 people die from the disease yearly. According to the National cancer institute, the number of new cases of cancer in the United States is 454.8 per 100,000 men and women per year and the number of cancer deaths is 171.2 per 100,000 men and women per year. Tobacco use is responsible for about 22% of cancer deaths, while obesity, poor diet, lack of physical activity, and excessive drinking of alcohol account for 10%. Other factors include infections, environmental pollutants and exposure to ionizing radiation.
In most developing countries, nearly 20% of cancers are caused by infections such as human papillomavirus, hepatitis B and hepatitis C. These factors act at least partly by changing the genes of a cell. Cancers can be largely prevented by maintaining a healthy weight, not drinking too much alcohol, avoiding tobacco ,eating plenty of vegetables, fruits and whole grains, not eating too much processed food and red meat, vaccination against certain infectious diseases and avoiding too much sunlight exposure. Early detection through screening is useful for cervical and colorectal cancer.
What are The 5 main cancer groups?
Cancers are divided into groups according to the type of cell they start from. These include
- Brain tumours
How Cancer Does Develops?
Cancer develops when the body’s normal control mechanism stops working. As a result, old or worn out cells do not die but instead grow out of control, leading to the creation of more abnormal cells. When these extra cells aggregate, they may form a mass of tissue called a tumor. However, some cancers such as leukemia, do not form tumors. Cells become abnormal if their DNA becomes damaged. When there are very few abnormal cells, they are effectively kept under control by the body’s immune system, as a result they are unable to do any harm to the body. However, when they divided uncontrollably, they form lumps or growths which completely overwhelm the body’s defense mechanisms.
How Does Cancer Spread? How cancer cells spread
The place where a cancer originates in the body is called the primary site or primary cancer. If cancer cells spread to another part of the body, the new area is referred to as a secondary cancer or a metastasis. Some cancers can spread to more than one area of the body leading to the formation of multiple secondaries or metastases. There are several mechanisms by which cancer spreads. Cancer cells can be carried in the lymphatic system or blood stream to other parts of the body. In order to spread, some cells from the primary cancer must split, and move to another part of the body and start growing there. If the cancer cells go into small blood vessels they can secure access into the bloodstream (circulating tumor cells).
How Cancer is Detected
Cancer is usually diagnosed by an expert who has visualized the cell or tissue samples under a microscope. In some other instances, specific test are carried out on the proteins, DNA, and RNA of the cells which can help physicians determine if there is cancer. These Tests are very important as they can detect many other kinds of diseases and conditions. For example, if doctors are not sure a lump is cancer, they may cut a little piece of the lump and have it tested for cancer or other conditions that can cause growths that may look like cancer.
Laboratory Test for Cancer Detection
The level of certain substances in the body (high or low) can be a sign of cancer. Laboratory tests are conducted using samples such as blood, urine, or other body fluids that measure the levels of these substances. The results of the test help doctors to reach a diagnosis. However, this parameter is not a definitive clue or sign of cancer, other parameters must be matched before a conclusion can be reached. Stand-alone laboratory tests are not used for cancer diagnosis.
Imaging procedures relies on the creation of pictures of certain areas of the body that help the physician see whether a tumor is present. Imaging procedure in cancer detection include:
- CT scan: this involves the use of an x-ray machine that is linked to a computer which takes a series of detailed pictures of body organs. Dye or other contrast material may be administered to highlight areas inside the body, making the pictures easier to read.
- Nuclear scan: for this scan, an injection of a small amount of non-toxic radioactive material, which is sometimes called a tracer is given. It travels through the bloodstream and settles in certain bones or organs. A scanner then detects and measures the radioactivity. The scanner creates pictures of the bones or organs on a computer screen or on a film for interpretation and inference.
- Ultrasound: an ultrasound device emits sound waves that humans cannot hear. The waves bounce off tissues inside the body like an echo. Using these echo, the computer creates a picture of areas inside the body (sonogram).
- MRI: magnetic resonance imaging involves the use of computer linked to a strong magnet used to make detailed pictures of areas of the body.
- PET scan: these scans show how organs and tissues are working. Under this procedure, an individual receives an injection of a tracer before the machine takes 3D pictures that show where the tracer collects in the body.
- X-rays: X-rays employ the use of low dose radiation to create pictures showing the inner parts of the body.
A biopsy is a procedure which involves the removal of a sample of tissue. The sample can be removed in many ways .These include:
- With an instrument called an endoscope(endoscopy)
- With a needle: The doctor uses a needle to withdraw tissue or fluid. (fine needle aspiration biopsy)
- With surgery: Surgery may be excisional (removes the entire tumor) or incisional (removes just part of the tumor).
A pathologist then looks at the tissue under a microscope to determine if it is cancer
Does It Mean I Have Cancer If the Doctor Orders For Gene Testing?
It is not exactly so , if you come from a family line with a known history for cancer then conducting gene testing is a wise idea to evaluate your risk. Genetic testing help to estimate the chance of developing cancer during a lifetime. It does this by searching for specific changes in genes, chromosomes, or proteins. These changes are known as mutations. Genetic tests are available for breast, ovarian, colon, thyroid, and some other cancer
BRCA1 and BRCA2 gene mutation testing can provide 4 possible outcomes or results:
- A positive result
- A negative result
- An ambiguous result
- An uncertain result.
A positive test result shows that an individual has inherited a known harmful mutation in BRCA1 or BRCA2 and, has a higher risk of developing certain cancers during their lifetime.
How Cancer Affects the Body
Cancer and its treatments can cause several changes in the body. Some cancers may block certain channels in the body and stop some particular body systems from working so well. Other cancers and cancer treatments can also change the number of blood cells circulating in the blood. Changes in physique, appearance and cancer treatment affect how a person views his or her personality, abilities, potentials, values, and interests. It can also influence an individual’s relationship with others.
Common body changes from cancer
It is important to note that not all cancer treatments and or therapies cause physical changes, but when they do, such changes may either be temporary or permanent. Physical body changes associated with cancer and its treatment may include:
- Hair loss
- Scars from surgery
- Skin changes, including rashes and burns
- Swelling of the face, arms, or legs
- Decreased physical skills, including athletic abilities, balance, and agility
- Weakness or loss of stamina
- Loss of a body part
- Weight loss
- Weight gain
- Changes in sexual function, such as early menopause in women, loss of sexual interest, or erectile difficulties in men
- Infertility, or the inability to conceive a child
How Cancer Can Affect Your Sexual health
Cancer and intimate relationships has become a burning subject owing to the increase rate in cancer and the desires for partners to be intimate. Sexual desire and energy levels change during cancer treatment, this is completely normal. However, these fluctuations can affect how a person feels about sexual desirability and desire for sex. These feelings, in turn, complicate relationships which are very important at this point in the life of the person involved. Maintaining a healthy sex life can be difficult with cancer because here are so many physical and emotional factors involved.
Fertility levels with cancer
Getting pregnant while on cancer treatment is not advisable due to the increased likelihood of congenital abnormalities (birth defects) during the period. During cancer treatment, many women may experience cessation of period or irregular menstruation while in the men the sperm count in men may reduce significantly.
How Cancer Cells Work
In normal cells, many genes intricately control the cell division processes. Normal growth requires a balance between those that suppress these process and those genes that promote cell proliferation. Cells become cancerous when mutations occur in the various genes that control cell proliferation making them go out of control. Findings from the Cancer Genome Project, indicates that most cancer cells possess 60 or more mutations. Some chemotherapy drugs like Herceptin work to counteract these mutations by blocking the action of proteins that signal growth (overactive receptor tyrosine kinases RTKs).
How Cancer Grows
How does cancers get bigger? The cancer cells grow and divide at an uncontrollable rate to create more cells which eventually form a tumor. These tumors may contain several millions of cancer cells. As the tumors get bigger, its center gets further and further away from the vessels that supply blood to the area leading to less supply of oxygen and other vital nutrients the tumor cells needs to survive. To make up for this shortfall, they send out signals, called angiogenic factors that encourage the formation and growth of new blood vessels into the tumor (angiogenesis). This new supply of nutrients and oxygen makes the cancer cells grow bigger in a very short time.
How cancer is staged
Cancer Staging is a series of process for finding how much cancer is in an individual’s body and where they are located. This is how the physician determines the stage of a person’s cancer. Although each person is unique, cancers with the same stage of development tend to have similar outlooks and are often treated the same way. Another important question most people ask is why is staging needed? Physicians need to determine the amount of cancer and where it is in the body to be able to select the best treatment options for the patient.
How Is Cancer Staged
Cancer staging depends on the type of cancer and tissue involved. Cancer staging is carried out using various types of examinations and tests to determine the stage of the cancer. Imaging tests like ultrasound, x-rays, CT scans, MRIs and PET scans may also give information about how much and where cancer is in the body.
Types of staging
Staging is carried out when a person is first diagnosed, before the commencement of any treatment. The main types of staging are:
This is an estimate of the extent of proliferation of the cancer cells based on results of physical exams, imaging tests and tumor biopsies. The clinical stage is an important part of deciding the best treatment option to adopt. It is also the baseline employed for comparison when looking at how the cancer cells respond to treatment.
This involves surgery to remove the cancer and nearby lymph nodes. It can be done to determine how much cancer is in the body and take out tissue samples. The pathologic stage uses the results of the exams and tests mentioned as well as what is learned about the cancer during surgery.
Cancer staging systems
There are several types of staging systems, but the most common one for most types of cancers is the TNM staging system.
The TNM Staging system
Under the TNM system, each cancer is assigned a letter or number to describe the tumor, node, and metastases.
- T stands for original (primary) tumor.
- N stands for nodes. Which tells whether the cancer has spread to the nearby or distant lymph nodes
- M stands for metastasis. Which tells whether the cancer has spread to distant parts of the body
The T category
- TX = means the tumor cannot be measured.
- T0 = means there is no evidence of a primary tumor (it cannot be found).
- T1is = means that the cancer cells are only growing in the most superficial layer of tissue, without growing into deeper or underlying tissues.
Numbers after the T (such as T1, T2, T3, and T4) m describe the size of tumor
The N category
The N category describes whether the cancer has spread into nearby lymph nodes.
- NX = means the nearby lymph nodes cannot be evaluated.
- N0 = means nearby lymph nodes do not contain cancer.
Numbers after the N (such as N1, N2, and N3) might describe the size
The M category
The M category tells whether the cancer has spread
- M0 means that no distant cancer spread or metastasis was found.
- M1 means that the cancer has spread to distant organs or tissues
How cancer is treated
The cancer treatment options depend largely on the type and stage of cancer including possible side effects. The management of cancer usually involves a multidisciplinary team due to the broad impact of the condition. Some available treatment plans include:
Bone Marrow/Stem Cell Transplantation: This is also known as bone marrow transplant. It involves the replacement of diseased bone marrow with highly specialized stem cells that develop into a healthy bone marrow.
2. Chemotherapy: This involves the use of drugs that kill cancer cells.
3. Immunotherapy and Vaccines: These are vaccines that use the body’s immune system to fight cancer.
4. Personalized and Targeted Therapies: These are therapies that targets a cancer’s specific genes, proteins, or the tissue environment that contributes to cancer development growth and survival.
5. Radiation Therapy: This involves the use of high-energy x-rays and other particles to kill cancer cells.
6.Surgery: This is the oldest type of cancer therapy. It involves the surgical removal of the tumors containing the cancer cells or the diseased organ.
What is Breast cancer brain metastases?
Breast cancer brain metastases (BCBMs) are common in persons with advanced stages of the disease. Around 15–30 % of all patients with metastatic breast cancer develop brain metastases (BM) during the course of the disease. Performance status and breast cancer sub type are the major determinants of the course of the disease and survival time following a diagnosis of brain metastasis.
What Treatment Options are Available for Breast cancer brain metastases?
Treatment options for patients with breast cancer brain metastases includes:
- Surgical resection
- Whole-brain radiation therapy (WBRT)
- Stereotactic radiosurgery (SRS)
4. Chemotherapy and targeted therapy
What is Maintenance Therapy in cancer management
Maintenance therapy refers to the ongoing use of use of drugs to destroy or kill cancer cells. It also includes other treatments that help lower the risk of recurrence or return of cancer.
How cancer patients die
As cancer cells proliferate, they affect vital organs thereby impairing function. This can often spiral into uncontrolled infection and other conditions that overwhelm the body’s usual resources which leads to death. The 8 signs of imminent death identified from a cancer study include: decreased response to verbal stimuli, a decreased response to visual stimuli, and an inability to close eyelids, nonreactive pupils, a drooping of the nasolabial fold, hyperextension of the neck, upper gastrointestinal bleeding and grunting of vocal cords.
How cancer looks
Cancer cells differ from normal cells in many ways. Although how they look ultimately depends on the type of cancer, most cancer cells are cauli flower shaped.
How cancer crossed the color line
How Cancer Crossed the Color Line Is a project authored by Keith Wailoo which reveals how scientist, physicians, and public health officials engaged in a less cynical but similarly deficient crusade that unconsciously and consciously ignored people of color.
What are the causes of pain in cancer?
Majority of cancer pain is caused by tumors. Tumors can cause pain by :
- Pressing on bones
- Pressing on nerves
- Pressing on other organs in the body.
- Sometimes cancer treatment such as chemotherapy drugs can cause burning sensation at the spot where you have the injection or numbness and tingling in the hands and feet.
- Radiotherapy can cause skin redness and irritation.
How cancer affects the brain Function
Cancer and cancer treatment has a huge impact on mental health. It affects the cognitive functions of the brain in many ways. These include:
- Learning new tasks
- Remembering names
- Paying attention and concentrating
- Finding the right words
- Organizing thoughts
- Remembering where things are (keys, glasses, etc.)
- Post-traumatic stress disorder (PTSD) nightmares or flashbacks about the cancer experience
Why Cancer Happens
There is no known reason why cancer happens. However different cancers have been associated with different risk factors. The most common risk factors for cancer are tobacco, age, sun exposure, radiation exposure, chemicals, some viruses and bacteria, family history of cancer, alcohol, poor diet, certain hormones, lack of physical activity, or being overweight.
Why Cancer Patients Lose Weight
Cancer is a highly catabolic (breaking down of body cells) process. About half of all cancer patients suffer from a wasting syndrome known as cachexia. The wasting is the immediate cause of about 75% of all cancer deaths. Researchers increasingly suggest that the “brown fat” is the major culprit.
Why cancer comes back
Cancer treatment that does not completely eradicate cancer cells is mostly the cause of relapse. The cancer cells sometimes left behind after treatment continue to divide abnormally leading to the eventual return of cancer. Local recurrence is when cancer returns in the same area of the body while metastasis is when it reoccurs in a different part of the body
Why cancer cannot be cured
The major reason for this phenomena is the fact that cancer is not just one disease. The same type of tumors in two patients can vary substantially and respond differently to medication. This huge diversity and the speed of spread accounts for why cancer cannot be cured
Why cancer rates are increasing?
Several factors accounts for the increase in cancer diagnoses globally. There are three main reasons which account for most of the cancer cases in the United States these are:
- Older people get cancer most often, and we are getting older.
- Obesity which has become a pandemic has opened the door to several types of cancer.
- Release of toxic substances into the environment due to industrialization.
- Global warming.
- Increasingly unhealthy lifestyle choices.
- Increase in the incidence of certain types of infection associated with some types of cancer like Human papillomavirus which is transmitted sexually is linked with the increasing rates of cancer of the cervix, vagina, vulva, anus and penis.
Why Cancer Research?
Finding a cure for cancer depends greatly on cancer research and innovative thinking. The more we learn about cancer cells and how they proliferate, the more we are able to understand why certain treatments work and other do not work.
Cancer Research UK is one of the major organizations leading cancer research and awareness in the world. As the world’s largest independent cancer research charity, the organization was formed in 2002 by the merger of The Cancer Research Campaign and the Imperial Cancer Research Fund with the objective of reducing the number of deaths from cancer. Its activities are conducted in institutes, hospitals and universities across the UK almost entirely funded by the public.
Understanding what cancer is oncluding facts, symptoms and treatment is the first step to overcoming the disease.
Public Health Nigeria an Interdisciplinary public health movement focused on health education, advancing fair public health policies, promoting fitness, healthy diets, responsible behavior, community health and general well-being.