What is Cancer – Types, Stages, Cancer Diagnosis
What Is Cancer?
To know about cancer type, it’s first important to understand what cancer is: basically, the production of abnormal cells.
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.
The body is programmed to routinely replenish cells in different organs. As normal cells age or get damaged, they die off. New cells take their place. This is what’s supposed to happen. Abnormal cell growth refers to a buildup of extra cells. This happens when:
These extra cells slowly accumulate to form a tissue mass, lump, or growth called a tumor. These abnormal cells can destroy normal body tissue and spread through the bloodstream and lymphatic system.
There are 4 main types of cancer:
Cancer is usually named by the site it began. This site is called the primary. For example, breast cancer is called breast cancer because the cancer cells began in the breast.
A tumor or lump does not automatically mean cancer. Some tumors are benign.
Benign vs. Malignant: What’s the Difference?
Benign means not cancerous. A benign tumor can get larger but does not spread to other tissues or organs.
Malignant means cancerous. A malignant tumor’s cells can invade nearby tissue and lymph nodes and then spread to other organs. These cells are destructive.
Regular screenings help to diagnose Cancer – such as mammograms, or gynecological exams like Pap tests. Cancer can also be diagnosed after symptoms appear such as pain, lumps, or other medical issues. Depending on the type of cancer different methods are used for diagnosis.
Below are some common methods used to diagnosis cancer:
Biopsy: During a biopsy a sample of the tumor or suspicious cells are removed so a pathologist can determine if the cells are cancerous. A biopsy can be a small in-patient procedure or a surgery to remove the entire suspicious area. A biopsy can also be performed with a needle that removes a very small bit of tissue or fluid.
Blood tests: During a blood test, a small amount of blood is withdrawn. The blood sample is then sent to the lab to test for various tests such as blood cell counts, protein levels, or tumor markers. Blood tests are very helpful in diagnosis blood cancers such as leukemia and lymphoma.
Your doctor can use the imaging methods described below to view the tumor or suspicious cells, but a biopsy and the resulting pathology report tells if the cells are cancerous or not.
Computed tomography (CT) scan: A CT scan is an imaging test. CT scans take multiple x- rays from different angles to capture “slices” of the inside of the body. These slices are then reassembled on a computer to create a 3-D image of organs and tissues. During a CT scan you may receive contrast either through an IV or by drinking it. Contrast is a special liquid that help certain organs and tissues show up better on imaging results. During the exam, you will lie on a platform and the platform will be slid in and out of a doughnut shaped machine that takes the images.
Colonoscopies: A colonoscopy is used to examine the bowel’s interior surface for abnormalities like polyps. In this procedure, the doctor inserts a flexible tube into the bowel. The tube contains a camera. The colonoscopy lets the doctor examine the inside of the entire colon and rectum. If the doctor discovers a poly or abnormal tissue, it may be removed for further testing. Colonoscopies are used to diagnose colorectal cancer.
Mammograms: A mammogram is an X-ray image of your breast. In a mammogram, the technician presses the breasts between two firm surfaces. This spreads out the breast tissue and allows the X-ray machine to get good pictures of the breasts. The doctor will use these pictures to check for changes in the breast tissue and also to check for cancer. Mammograms are also done once a lump is detected—to show a more detailed picture of the mass.
Mammograms are used to diagnose breast cancer:
Magnetic resonance imaging (MRI): An MRI is an imaging test. Unlike CT scans or PET scans, MRIs do not use x-rays to take these images. MRIs use a powerful magnet and radio waves to create images of inside the body. MRIs are often used for imaging the breasts, brain, spine, joints, and soft tissues, but they can be used in other ways. An MRI may be done with IV contrast. During an MRI you will be slid into a doughnut shaped machine. MRI machines are generally smaller than CT or PET scan machines.
Pap tests: During a pap test a doctor uses a small brush or spatula to remove cells from the cervix. These cells can then be examined for caner or other changes. Pap tests are used to diagnose cervical cancer.
Physical Exam: For this your doctor thoroughly checks your body for any signs of disease or changes such as lumps or swollen lymph nodes.
Positron emission tomography (PET) scan: A PET scan is an imaging test involving injection of radioactive glucose (sugar). A PET scan takes images of areas of the body that pick up the radioactive glucose. Cancer cells take up more glucose than normal cells, so cancer cells can be seen on the image. During the exam, you will lie on a platform and the platform will be slid in and out of a doughnut shaped machine that takes the images.
Skin Check: During a skin check your doctor thoroughly checks your skin for suspicious looking moles or skin changes. Skin checks are used to diagnose skin cancer and melanoma.
X-Rays: X-rays are used to take images of the inside of the body using low dose radiation.
To help understand how serious the cancer is a system called cancer staging is used.
The stage of solid tumour cancers depend on the size of the cancer, lymph node involvement, and if there is any spread of the tumour. This information helps your doctor plan the right course of treatment.
The TNM staging system is used for all types of solid tumor cancer. The letters TNM describe the amount and spread of cancer in your body.
With blood cancers, doctors use some different factors for staging such as presenting symptoms, lymph node involvement, and blood cell counts.
Stages are usually often labeled using Roman numerals 0 through IV (0-4). Higher numbers mean cancer has spread and the cancer is more advanced.