WHAT IS CANCER?
Cancer (also known as carcinoma and malignant tumor / tumour) is the uncontrolled growth of abnormal cells in the body. Cancerous cells, which are also called malignant cells, are characterised as being:
- aggressive - grow and divide without respect to normal limits,
- invasive - invade and destroy adjacent tissues, and
- sometimes metastatic - spread to other locations in the body and cause damage there.
These three malignant properties of cancers differentiate them from benign tumors, which are self-limited in their growth and do not invade or metastasize (although some benign tumor types are capable of becoming malignant).
TYPES OF CANCER
There are several main types of cancer.
- Carcinoma is a cancer that begins in the skin or in tissues that line or cover internal organs.
- Sarcoma is a cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue.
- Leukemia is a cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood.
- Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system.
- Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord. Also called malignancy.
The three most common cancers in men in the United States are:
- Prostate cancer
- Lung cancer
- Colon cancer
In women in the U.S., the three most common cancers are:
- Breast cancer
- Colon cancer
- Lung cancer
Some other types of cancers include:
- Brain cancer (in adults and in children)
- Cervical cancer
- Esophageal cancer
- Hodgkin`s lymphoma
- Kidney cancer
- Liver cancer
- Non-Hodgkin`s lymphoma
- Oral cancer (includes mouth cancer)
- Ovarian cancer
- Pancreatic cancer
- Penis cancer
- Skin cancer
- Stomach cancer
- Testicular cancer
- Thyroid cancer
- Uterine cancer (endometrial cancer)
- Vaginal cancer
- Vulvar cancer
A definitive diagnosis usually requires examination of a tissue biopsy specimen by a pathologist, although the initial indication of malignancy can be symptoms or radiographic imaging abnormalities. Most cancers can be treated and some cured, depending on the specific type, location, and stage.
For more information about these and other cancer treatments, please browse through the links on the right.For cost information about these and other cancer treatments, contact Healthbase.
CAUSES OF CANCER
There are many different kinds of cancers. Cancer can develop in almost any organ or tissue, such as the lung, colon, breast, skin, bones, or nerve tissue. Cancer may affect people at all ages, even fetuses, but risk for the more common varieties tends to increase with age.
Cancer may be caused by:
- Chemical carcinogens (cancer-causing substances) such as tobacco smoke and alcohol
- Ionizing radiation such as radon gas and UV rays from the sun
- Infectious diseases associated with viruses like human papillomavirus, hepatitis B and hepatitis C virus, Epstein-Barr virus, and - human T-lymphotropic virus
- Hormonal imbalances
- Immune system dysfunction like HIV
- Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth.
Some cancers are more common in certain parts of the world. For example, in Japan, there are many cases of gastric cancer, but in the U.S. this type of cancer is pretty rare. Differences in diet may play a role.
SIGNS AND SYMPTOMS
The following symptoms can occur with most cancers:
- Loss of appetite
- Night sweats
- Weight loss
Every symptom in the above list can be caused by a variety of conditions (a list of which is referred to as the differential diagnosis). Cancer may be a common or uncommon cause of each item.
Additionally, some cancers may show early signs while others remain asymptomatic until the disease has reached an advanced stage.
DIAGNOSTIC TESTS AND EXAMS
Tests to diagnose cancer vary based on the type and location of the tumor. Common tests include the following:
- Tissue Biopsy of the tumor
- Blood tests
- Bone marrow biopsy (for lymphoma or leukemia)
- Complete blood count (CBC)
- CT scan
CANCER STAGING / STAGES OF CANCER
The stage of a cancer refers to how much the cancer has grown and whether the tumor has spread from its original location. Knowing the stage of the disease helps the doctor plan a person`s treatment and estimate prognosis. Physical exams, imaging procedures, laboratory tests, pathology reports, and surgical reports provide information to determine the stage of the cancer.
Staging systems for cancer have evolved over time and continue to change as scientists learn more about cancer. However, the common elements considered in most staging systems are:
- Location of the primary tumor,
- Tumor size and number of tumors,
- Lymph node involvement (spread of cancer into lymph nodes),
- Cell type and tumor grade (how closely the cancer cells resemble normal tissue), and
- Presence or absence of metastasis.
The TNM system is one of the most commonly used staging systems. TNM Staging is used for solid tumors. This system is based on the extent of the tumor (T), spread to lymph nodes (N), and metastasis (spread to other parts of the body) (M). A number is added to each letter to indicate the size or extent of the tumor and the extent of spread. A T1N2M0 cancer would be a cancer with a T1 tumor, N2 involvement of the lymph nodes, and no metastases (no spreading through the body).
- Tumor (T) refers to the primary tumor and carries a number of 0 to 4.
- N represents regional lymph node involvement and can also be ranked from 0 to 4.
- Metastasis is represented by the letter M, and is 0 if no metastasis has occurred or 1 if metastases are present.
Within the TNM system, a cancer may also be designated as recurrent, meaning that it has appeared again after being in remission or after all visible tumor has been eliminated. Recurrence can either be local, meaning that it appears in the same location as the original, or distant, meaning that it appears in a different part of the body.
Most cancers can be described as stage 0, stage I, stage II, stage III, or stage IV. For many cancers, TNM combinations correspond to one of five stages. Criteria for stages differ for different types of cancer. For example, bladder cancer T3 N0 M0 is stage III; however, colon cancer T3 N0 M0 is stage II.
In general, the various stages are defined as follows:
- Stage 0: Carcinoma in situ i.e. the malignant cells have not yet invaded the deeper epithelial tissue or spread to other parts of the body. A cancers in this stage is an early cancer that is present only in the layer of cells in which it began.
- Stage I (stage 1): Cancers are localized to one part of the body.
- Stage II (stage 2) and stage III (stage 3): Stage II cancers are locally advanced, as are Stage III cancers. Whether a cancer is designated as Stage 2 or Stage 3 can depend on the specific type of cancer; for example, in Hodgkin`s Disease, Stage II indicates affected lymph nodes on only one side of the diaphragm, whereas Stage III indicates affected lymph nodes above and below the diaphragm. The specific criteria for Stages II and III therefore differ according to diagnosis.
- Stage IV (stage 4): Cancers have often metastasized, or spread to other organs or throughout the body.
The goals of cancer treatment are to:
- Kill or remove cancer cells
- Prevent or delay the cancer from coming back
- Treat cancer symptoms (if the cancer cannot be cured)
Treatment of cancer varies based on the type of cancer, its location and stage, as well as the general state of the patient (performance status). Cancer may be treated by:
- Radiation therapy or radiotherapy
- Targeted therapies
- Hormonal therapy
- Symptom control
- Stem cell therapies
- A number of experimental cancer treatments are also under development
- If the cancer is confined to one location and has not spread, the most common goals for treatment are surgery and cure. This is often the case with skin cancers, as well as cancers of the lung, breast, and colon.
- If the tumor has spread to local lymph nodes only, sometimes these can also be removed.
- If surgery cannot remove all of the cancer, the options for treatment include radiation, chemotherapy, or both. Some cancers require a combination of surgery, radiation, and chemotherapy.
For more information about the various cancer treatments in use or in development stage, please browse through the links on the right.
MEDICAL TOURISM FOR THE TREATMENT OF CANCER
Today, medical tourism has become a widely adopted way of obtaining care. Medical tourism means traveling to another city or country for care that`s either not available or not affordable in your own area or country. Read more about medical tourism here.
Medical tourism for the treatment of cancer has become widely acceptable as well. Cancer care centers overseas in countries such as India, Singapore, Turkey, Mexico, etc. offer state-of-the-art treatments for cancers that range from chemotherapy to radiation therapy to stem cell therapies and surgery.
Some of the latest treatments offered abroad include:
- CyberKnife radiation therapy
- Gamma knife radiosurgery
- Proton therapy
- HIFU or high intensity focused ultrasound treatment
For more information about these and other cancer treatments, please browse through the links on the right.
For cost information about these and other cancer treatments, contact Healthbase.