Cancer Information

What is cancer?

Cancer is not one disease, but many diseases that occur in different areas of the body. Each type of cancer is characterized by the uncontrolled growth of cells. Under normal conditions, cell reproduction is carefully controlled by the body. However, these controls can malfunction, resulting in abnormal cell growth and the development of a lump, mass, or tumor. Some cancers involving the blood and blood-forming organs do not form tumors but circulate through other tissues where they grow.

A tumor may be benign (non-cancerous) or malignant (cancerous). Cells from cancerous tumors can spread throughout the body. This process, called metastasis, occurs when cancer cells break away from the original tumor and travel in the circulatory or lymphatic systems until they are lodged in a small capillary network in another area of the body. Common locations of metastasis are the bones, lungs, liver, and central nervous system.

The type of cancer refers to the organ or area of the body where the cancer first occurred. Cancer that has metastasized to other areas of the body is named for the part of the body where it originated. For example, if breast cancer has spread to the bones, it is called “metastatic breast cancer” not bone cancer.

How did I get cancer?

Although every patient and family member wants to know the answer to this question, the reason people develop cancer is not well understood. There are some known carcinogens (materials that can cause cancer), but many are still undiscovered. We do not know why some people who are exposed to carcinogens get cancer and others do not. The length and amount of exposure are believed to affect the chances of developing a disease. For example, as exposure to cigarette smoking increases, the chance of developing lung cancer also increases. Genetics also plays an important role in whether an individual develops cancer. For example, certain types of breast cancer have a genetic component.

The Marin Cancer Institute is a center for prevention, screening, and treatment of cancer. Staying healthy through good diet and exercise is paramount whether you have cancer or not. Knowing the right age to begin certain screenings, and performing self-exams, are the best ways to detect the earliest traces of cancer. With the latest technology such as digital mammography, technicians at MCI can greatly improve your chances of detecting cancer at its earliest stage — when chances for cure, and staying cancer-free longer post treatment — are highest.

Thank you for Marin General Hospital Marin Cancer Institute for this information.

This page references content from the California Cancer Care website.

To read more about cancer visit the Marin General Hospital Marin Cancer Institute website.

What you need to know about cancer

National Cancer Institute

Millions of Americans are living with a diagnosis of cancer. This National Cancer Institute (NCI) booklet (NIH Publication No. 06-1566) has information about this disease. You will read about possible causes, screening tests, symptoms, diagnosis, and treatment. You will also find suggestions for coping with cancer.

Researchers are learning more about what causes cancer, and how it grows and progresses. And they are looking for new and better ways to prevent, detect, and treat it. Researchers also are looking for ways to improve the quality of life for people with cancer during and after their treatment.

The National Cancer Institute website has lots of information, including these topics:

  • Introduction
  • Understanding Cancer
  • Risk Factors
  • Screening
  • Symptoms
  • Diagnosis
  • Staging
  • Treatment
  • Complementary and Alternative Medicine
  • Nutrition and Physical Activity
  • Follow-up Care
  • Sources of Support
  • The Promise of Cancer Research