What is cancer- everything you need to know about cancer
Cancer is the name given to a collection of related diseases. In all types of cancer, some of the body’s cells begin to divide without stopping and spread into surrounding tissues.
Cancer can start almost anywhere in the human body, which is made up of trillions of cells. Normally, human cells grow and divide to form new cells as the body needs them. When cells grow old or become damaged, they die, and new cells take their place.
When cancer develops, however, this orderly process breaks down. As cells become more and more abnormal, old or damaged cells survive when they should die, and new cells form when they are not needed. These extra cells can divide without stopping and may form growths called tumors.
Many cancers form solid tumors, which are masses of tissue. Cancers of the blood, such as leukemias, generally do not form solid tumors.
Cancerous tumors are malignant, which means they can spread into, or invade, nearby tissues. In addition, as these tumors grow, some cancer cells can break off and travel to distant places in the body through the blood or the lymph system and form new tumors far from the original tumor.
Unlike malignant tumors, benign tumors do not spread into, or invade, nearby tissues. Benign tumors can sometimes be quite large, however. When removed, they usually don’t grow back, whereas malignant tumors sometimes do. Unlike most benign tumors elsewhere in the body, benign brain tumors can be life threatening.
Types of Cancer
There are more than 100 types of cancer. Types of cancer are usually named for the organs or tissues where the cancers form. For example, lung cancer starts in cells of the lung, and brain cancer starts in cells of the brain. Cancers also may be described by the type of cell that formed them, such as an epithelial cell or a squamous cell.
Stage refers to the extent of your cancer, such as how large the tumor is, and if it has spread. Knowing the stage of your cancer helps your doctor:
Understand how serious your cancer is and your chances of survival
Plan the best treatment for you
Identify clinical trials that may be treatment options for you
A cancer is always referred to by the stage it was given at diagnosis, even if it gets worse or spreads. New information about how a cancer has changed over time gets added on to the original stage. So, the stage doesn’t change, even though the cancer might.
To learn the stage of your disease, your doctor may order x-rays, lab tests, and other tests or procedures
The TNM staging system, are used for many types of cancer.Most staging systems include information about:
Where the tumor is located in the body
The cell type (such as, adenocarcinoma or squamous cell carcinoma)
The size of the tumor
Whether the cancer has spread to nearby lymph nodes
Whether the cancer has spread to a different part of the body
Tumor grade, which refers to how abnormal the cancer cells look and how likely the tumor is to grow and spread
The TNM system is the most widely used cancer staging system. Most hospitals and medical centers use the TNM system as their main method for cancer reporting. You are likely to see your cancer described by this staging system in your pathology report, unless you have a cancer for which a different staging system is used. Examples of cancers with different staging systems include brain and spinal cord tumors and blood cancers.
In the TNM system:
The T refers to the size and extent of the main tumor. The main tumor is usually called the primary tumor.
The N refers to the the number of nearby lymph nodes that have cancer.
The M refers to whether the cancer has metastasized. This means that the cancer has spread from the primary tumor to other parts of the body.
When your cancer is described by the TNM system, there will be numbers after each letter that give more details about the cancer—for example, T1N0MX or T3N1M0. The following explains what the letters and numbers mean:
Primary tumor (T)
TX: Main tumor cannot be measured.
T0: Main tumor cannot be found.
T1, T2, T3, T4: Refers to the size and/or extent of the main tumor. The higher the number after the T, the larger the tumor or the more it has grown into nearby tissues. T’s may be further divided to provide more detail, such as T3a and T3b.
Regional lymph nodes (N)
NX: Cancer in nearby lymph nodes cannot be measured.
N0: There is no cancer in nearby lymph nodes.
N1, N2, N3: Refers to the number and location of lymph nodes that contain cancer. The higher the number after the N, the more lymph nodes that contain cancer.
Distant metastasis (M)
MX: Metastasis cannot be measured.
M0: Cancer has not spread to other parts of the body.
M1: Cancer has spread to other parts of the body.
Other ways to describe cancer stage
The TNM system helps describe cancer in great detail. But, for many cancers, the TNM combinations are grouped into five less-detailed stages. When talking about your cancer, your doctor or nurse may describe it as one of these stages:
|Stage||What it means|
|Stage 0||Abnormal cells are present but have not spread to nearby tissue. Also called carcinoma in situ, or CIS. CIS is not cancer, but it may become cancer.|
|Stage I, Stage II, and Stage III||Cancer is present. The higher the number, the larger the cancer tumor and the more it has spread into nearby tissues.|
|Stage IV||The cancer has spread to distant parts of the body.|
Another staging system that is used for all types of cancer groups the cancer into one of five main categories. This staging system is more often used by cancer registries than by doctors. But, you may still hear your doctor or nurse describe your cancer in one of the following ways:
In situ—Abnormal cells are present but have not spread to nearby tissue.
Localized—Cancer is limited to the place where it started, with no sign that it has spread.
Regional—Cancer has spread to nearby lymph nodes, tissues, or organs.
Distant—Cancer has spread to distant parts of the body.
Unknown—There is not enough information to figure out the stage.
Statistics at a Glance: Cancer in the United States
- In 2018, an estimated 1,735,350 new cases of cancer will be diagnosed in the United States and 609,640 people will die from the disease.
- The most common cancers (listed in descending order according to estimated new cases in 2018) are breast cancer, lung and bronchus cancer, prostate cancer, colon and rectum cancer, melanoma of the skin, bladder cancer, non-Hodgkin lymphoma, kidney and renal pelvis cancer, endometrial cancer, leukemia, pancreatic cancer, thyroid cancer, and liver cancer.
- The number of new cases of cancer is 439.2 per 100,000 men and women per year (based on 2011–2015 cases).
- The number of cancer deaths is 163.5 per 100,000 men and women per year (based on 2011–2015 deaths).
- Cancer mortality is higher among men than women (196.8 per 100,000 men and 139.6 per 100,000 women). When comparing groups based on race/ethnicity and sex, cancer mortality is highest in African American men (239.9 per 100,000) and lowest in Asian/Pacific Islander women (88.3 per 100,000).
- In 2016, there were an estimated 15.5 million cancer survivors in the United States. The number of cancer survivors is expected to increase to 20.3 million by 2026.
- Approximately 38.4% of men and women will be diagnosed with cancer at some point during their lifetimes (based on 2013–2015 data).
- In 2017, an estimated 15,270 children and adolescents ages 0 to 19 were diagnosed with cancer and 1,790 died of the disease.
- Estimated national expenditures for cancer care in the United States in 2017 were $147.3 billion. In future years, costs are likely to increase as the population ages and cancer prevalence increases. Costs are also likely to increase as new, and often more expensive, treatments are adopted as standards of care.
2018 Cancer Statistics
Estimated new case will be diagnosed
Estimated will die from the desease
Percent Surviving 5 years