Cancer 101: What you need to know

Cancer 101: What you need to know

With Breast Cancer Awareness Month in full swing, the disease is on the minds of many. The thought of a friend or loved one being diagnosed can be unsettling. Just the mention of the disease leads to thoughts of long, arduous treatment and uncertain outcomes.

The explanations and terminology presented to you may seem overwhelming and difficult to process. But how much of that stress and uncertainty comes from simply not knowing what all those intimidating terms mean?

“A lot of the time, patients who’ve just been diagnosed with cancer aren’t sure what to expect,” says Dr. Deepti Singh, an oncologist at Advocate Illinois Masonic Medical Center in Chicago. “In reality, cancer doesn’t always require extremely aggressive treatment, and choosing a treatment method is a collaborative process between you and your treatment team to select the method that’s right for you. But when you recognize the word ‘cancer’ and everything else sounds like medical jargon, it’s easy to become overwhelmed.”

And with the new proposal by a panel of experts at the National Cancer Institute (NCI) to alter the definition of cancer, those murky waters may become even murkier.

Trying to clarify some of the terms you may hear, Dr. Singh offers the following definitions of some of the most important terms and concepts you may run into when it comes to cancer.


Benign: Lesions and growths that are non-cancerous and will not spread throughout the body. Examples of benign lesions include moles and freckles.

Carcinoma: Cancers originating in glands and organs, such as the skin, breasts, pancreas, liver and lungs. Recently, specialists at the NCI recommended reserving the word “carcinoma” exclusive to invasive cancers.

Invasive cancer: Cancers that spread to cells beyond those where it originated.

Leukemia: Cancer occurring in the blood.

Localized cancer: Cancers that do not spread beyond the area where it originated.

Lymphoma: Cancer that occurs in white blood cells called lymphocytes, which are part of the immune system.

Lymph nodes: Small glands located throughout the body that filter cancer cells and other foreign particles.

Malignant: Unlike benign tumors, these tumors are cancerous and can spread to other parts of the body. By growing and occupying space that is needed for the functionality of healthy cells, malignant tumors impede body functions and suck up body nutrients.

Melanoma: Cancer originating in skin pigmentation cells, which reveals itself in discoloration of the skin.

Metastasis: The process by which cancer spreads to other parts of the body beyond its primary site.

Primary site: The location of one’s original tumor prior to the appearance of any newer, secondary tumors.

Sarcoma: Cancers originating usually in bone, fat, muscle, cartilageor soft tissue.

Tumor: A swelling mass of tissue that may be either benign or malignant.

Biopsy: A procedure in which a small sample of tissue is removed and studied to determine if it is cancerous.

Mammogram: An X-ray photograph of the breast, generally to detect and evaluate breast changes to the breast and the presence of tumors. The American Cancer Society recommends women age 40 and older get a mammogram performed every year.

Risk factors: Characteristics or behaviors that increase your likelihood of developing cancer.

Stages: The method of quantifying the severity of a patient’s case. As cancer progresses, patients need different things from their treatment and their stage of cancer is one way to express that. The most widely used staging system, the TNM system, evaluates the size of one’s primary tumor, the condition of nearby lymph nodes and the extent of metastasis. In contemporary staging:

  • Stage I refers to a localized cancer that may be small enough to be surgically removed.
  • Stage II is an early advanced localized cancer.
  • Stage III is a late advanced localized cancer.
  • Stage IV refers to a cancer that has spread to different parts of the body.

Not every cancer has the same staging. Your physician and medical team can help determine your stage of disease by examination and sometimes CT imaging or xrays.


Adjuvant therapy: A general term describing any kind of treatment, such as radiation, chemotherapy or hormone therapy, that kills cancer cells that linger after an initial surgical treatment.

Biological therapy: Uses your body’s own immune system to fight cancer. It can be used alone or in conjunction with chemotherapy and radiation to treat cancer and manage side effects. “Patients undergoing biological therapy receive regular treatments in the form of pills, shots or an IV,” Dr. Singh explains. “When treatment is successful, biological therapy can work with your immune system to impede the growth rate of cancerous cells and prevent cancer from spreading through your body.” It is also sometimes called immunotherapy.

Chemotherapy: Unlike biological therapy, chemotherapy uses drugs to reduce the rate at which cancerous cells spread. It  can be administered in a doctor’s office or hospital on a regular schedule, and is often combined with other forms of treatment to be most effective at eliminating cancer. It can also be given in an oral form as well. In general, chemotherapy is used to shrink and destroy tumors before or after surgery or radiation.

Curative treatment: Treatment, such as chemotherapy or radiation, which is delivered with curative intent, is given in an attempt to cure cancer entirely. This can occur in the form of eliminating a tumor or preventing recurrence.

Genetic therapy: An experimental cancer treatment whereby genetic material is delivered either to cancerous cells to fight disease or to healthy cells to prevent disease.

Palliative treatment: Treatment, such as chemotherapy or radiation, which is given in an attempt to reduce the symptoms of cancer, but not cure it.

Radiation therapy: Uses powerful gamma rays and x-rays to shrink and kill cancerous cells. There are several kinds of radiation, External radiation, which transmits high-energy radiation from an external machine; internal brachytherapy, in which radioactive material is placed inside a patient’s body to deliver a strong dose of radiation to a precise area; and systemic radiation, which delivers radioactive drugs in liquid form either orally or via an IV. The NCI reports that about 50 percent of cancer patients undergo radiation therapy at some point during treatment.

Surgery: Surgery for cancer can be used not only as part of the diagnosis process but also as a means of treatment. There is preventive surgery, which pre-emptively removes body tissue that may become cancer. And for patients who already have cancer, there are debulking and curative surgical treatments, which partially eliminate and entirely eliminate tumors, respectively.

Dr. Singh recommends speaking with your physician to seek clarification on any terms that you are not familiar with and to never be afraid to ask too many questions.

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health enews Staff
health enews Staff

health enews staff is a group of experienced writers from our Advocate Health Care and Aurora Health Care sites, which also includes freelance or intern writers.