Cancer 101: All You Need to Know About Cancer

According to the 2013 report by the Institute of Medicine (IOM) currently 1.6 million Americans receive a cancer diagnosis each year and the number is climbing sharply. In fact, according to the IOM report, the strongest risk factor for getting cancer is age and on average that age is 66 years. The IOM estimates that the number of people with a new cancer diagnosis will increase to 2.3 million per year by 2030.

Cancer cells multiply causing symptoms of fatigue, weakness, pain, weight loss, along with the disruption of normal bodily functions. But what is cancer? Why does it take so long to appear? Where are the different places cancers can grow? Is there anything you can do to prevent or cure cancer? Read on to get the answers to all your queries.

What is Cancer?

According to the National Cancer Institute (NCI), cancer is a collection of interrelated diseases where your body’s cells divide or grow without stopping and spread into the surrounding tissues. Unlike normal cells which die and are replaced with healthy new cells when they become old or damaged; abnormal, old or damaged cells do not die and form tumors.

Cancer can start almost anywhere in the body. Many of us have had or have known someone who has had a cancerous tumor. Additionally, the NCI describes blood cancers, also called hematological cancers, as leukemia. Cancer tumors can be benign or malignant.

In fact, malignant tumors spread or encroach into adjoining tissue while benign tumors replicate the growth rate but do not invade surrounding tissues. Malignant cancer cells or malignancies can be lethal depending on their location and growth rate.

How is a Normal Cell Transformed into a Cancerous Cell?

Ever wondered how a normal cell transforms into a cancer cell? Cancer cells originate as a result of an alteration of a normal biological process of cell division. The cancer cells produce proteins or genes called oncogenes.

This oncogene causes the abnormal growth of the cancer cell. Normal cells have their specific functions whereas cancer cells do not. Cancer cells also ignore the signals that tell them to stop division.

Why does Cancer take so Long to Grow?

Dr. Ben Kim describes the pace at which cancer grows and spreads as doubling time. According to Dr. Kim, while doubling time differs from tumor to tumor, doubling time is the amount of time it takes for one cell to divide or for a group of cells to double in size.

Many cancer cells duplicate at a rate similar to your normal cells while other cells can duplicate faster than normal cells. A typical tumor cannot be detected until it grows larger than one millimeter when it contains around one million cells.

It might be surprising to know that a tumor does not become a problem until it grows to more than five centimeters. Simply stated, cancer just doesn’t appear and spread within a few months or even years, it takes quite some time for cancer cells to grow, spread, and become problematic.

What Are the Different Places Cancer Can Grow?

Cancer cells are mutations of normal cells and can be located anywhere in the body. The different places cancer or tumors can exist include:

  • Adrenal gland
  • Brain
  • Breast (female or male)
  • Bladder
  • Blood (leukemia)
  • Bone (multiple myeloma)
  • Cervix
  • Colon (large intestine, small intestine, and sigmoid colon)
  • Gall bladder
  • Head or neck (skull, esophagus, tongue, thyroid, larynx, mastoids, pharynx, and palate)
  • Kidney
  • Liver
  • Lung
  • Lymph nodes (lymphoma)
  • Ovary
  • Pancreas
  • Penis
  • Rectum
  • Soft tissue (sarcoma)
  • Stomach
  • Skin (melanoma)
  • Testes
  • Uterus
  • Uvula
  • Vagina

Signs and symptoms will depend on the location of the tumor and its ability to grow. Faster growing tumors are known as “aggressive” and can replicate or grow faster than other tumors. Also, certain tumors spread or metastasize to specific areas depending on the vascular and lymph circulatory systems.

Metastatic cancer or mets pertain to the spread of the cancer cells. The NCI also explains that when the primary cancer metastasizes to a secondary location, it is known as the primary cancer metastasis and treated as a stage IV primary cancer. The chart below demonstrates the common sites of metastasis.

Primary Cancer SiteMain Metastatic Sites
BladderBone, Liver, Lung
BreastBone, Brain, Liver, Lung
ColonLiver, Lung
KidneyAdrenal gland, Bone, Brain, Liver, Lung
LungAdrenal gland, Bone, Brain, Liver, Other Lung
MelanomaBone, Brain, Liver, Lung, Skin, Muscle
OvaryLiver, Lung
PancreasLiver, Lung
ProstateAdrenal gland, Bone, Liver, Lung
RectalLiver, Lung
StomachLiver, Lung
ThyroidBone, Liver, Lung
UterusBone, Liver, Lung, Vagina


The reason why all primary cancer sites metastasize to the liver or the lung is that all of your blood circulates through the liver to get rid of wastes and to the lung picking up oxygen to feed the cells in your body.

Is There Anything You Can Do to Prevent or Cure Cancer?

Cancers typically grow slowly over a long period of time and are not detected until certain signs or symptoms appear, so once cancer cells appear they are not easy to prevent or cure. However, we know that the sooner the cancer is identified and the cancer cells are treated with either chemotherapy or radiation therapy the better the outcome and the longer you survive.

Normal cells can be altered and transformed into cancer cells when foreign chemicals or carcinogens are introduced into the body. According to the American Cancer Society, carcinogens are substances and exposures that can transform normal cells into cancer cells. There are many environmental factors or exposures and just a few are listed below:

  • Nutrition/diet
  • Tobacco use
  • Ultraviolet light
  • Radon gas
  • Infectious agents
  • Radiation treatments
  • Medical treatments
  • Immunosuppressant drugs
  • Household exposure
  • Air pollution

The key to prevention is to avoid the carcinogens listed above. Moreover, chemotherapeutic treatment or radiation treatment have been known to shrink, slow the growth, or completely kill the cancer cells so that cancer can be cured. However, for those of us who will get cancer at some time in their life, early detection is critical.

Early detection means early treatment which results in better outcomes and longer survival. Early detection through diagnostic testing is also known as cancer screening. Cancer screenings like mammography for breast cancer, a fecal occult blood test for colon cancer, digital rectal exam and measuring of the prostate-specific antigen (PSA), skin examination for melanoma, and low dose lung screening CAT scans for lung cancer.

In the coming weeks and months, we will inform and educate our readers on cancer and specific tumor sites following the calendar for cancer awareness. For example, October is breast cancer awareness month while November is lung cancer awareness month.

“What Is Cancer?” Cancer web site;, last accessed October 17, 2017.
Chow, A., “Cell Cycle Control by Oncogenes and Tumor Suppressors: Driving the Transformation of Normal Cells into Cancerous Cells,”, last accessed October 17, 2017.
Dr. Kim, B., “How Fast Does Cancer Grow?” Dr Ben Kim web site, Sep 08, 2015;
“Metastatic Cancer,” Cancer web site;, last accessed October 17, 2017.
“Known and Probable Human Carcinogens,” Cancer web site;, last accessed October 17, 2017.

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