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  • A disease in which cells begin to divide abnormally and uncontrollably and destroy tissue
  • Types include carcinomas, leukemia, lymphoma, melanoma, multiple myeloma, sarcomas
  • Treatments include surgery, chemotherapy, radiation, immunotherapy, hormone therapy
  • Involves Yale Cancer Center


Each year, over 1.7 million Americans are diagnosed with cancer. Ultimately, cancer touches nearly everyone’s life in some way. Whether for screenings, assessment of worrisome symptoms, diagnosis or treatment, eventually we all need to better understand this dreaded disease. 

As with most things, knowledge is power. The more you know about cancer, the better equipped you'll be to help yourself or a loved one who is awaiting a biopsy result or has already heard the words no one ever wants uttered: "It's cancer."

Practicing at Smilow, our Yale Medicine doctors are committed to collaborative, coordinated care that is personalized to you. Each treatment plan is unique. Depending on your needs and priorities, your comprehensive treatment plan may include surgery, radiation, chemotherapy, immunotherapy, or a combination of therapies. Our expert physicians are leaders in personalized cancer care; every patient’s cancer is analyzed using innovative tumor profiling techniques.

Our physicians and surgeons advance cancer care by developing, testing and introducing innovative technologies, techniques and treatments to the global medical community. We conduct ongoing clinical research and provide opportunities for our patients to gain access to new therapies not easily available elsewhere to help you or your loved one become a survivor.

What is cancer?

Cancer can affect almost any and every part of the body. It begins when cells in the body begin to divide abnormally and uncontrollably. Cancer can start in one area of the body and spread, or metastasize, to other organs or to the bone. There are several main types of cancer. Here’s an overview:

  • Carcinomas are found in epithelial cells, which are tissues lining both the inside and outside of the body. These include breast, colon and prostate cancers, as well as skin cancers such as basal cell carcinoma and squamous cell carcinoma.
  • Leukemia  is cancer that forms in the blood cells and bone marrow.
  • Lymphoma is a type of cancer that begins in the lymphocytes when there’s a build-up of immune cells (T- or B-cells) in the lymph nodes or elsewhere in the body.
  • Melanoma  begins in the pigment-producing cells of the body. These cells, called melanocytes, create melanin in the skin and the eyes.
  • Multiple myelomas affect plasma cells in the blood.
  • Sarcomas form in the soft tissues of the body— muscles, fat, tissues surrounding joints, tendons, blood and lymph vessels and nerves.

Sometimes cancer takes the form of a tumor (though not all tumors are cancerous). Types of tumors include:

  • Brain and spinal cord tumors
  • Germ cell tumors begin in the cells that produce sperm or eggs. 
  • Neuroendocrine tumors occur in the endocrine system where hormones are released into the blood in response to cues from the nervous system.
  • Carcinoid tumors are slow-growing and generally affect the gastrointestinal system.

What are the basic facts people should know about cancer?

 According to the National Cancer Institute, the most common types of cancer today are:

  • Breast 
  • Lung and bronchus 
  • Prostate 
  • Colon and rectum 
  • Bladder 
  • Melanoma (skin cancer)

Cancer trends:

  • Nearly 40 percent of American men and women will be diagnosed with cancer in their lifetimes.
  • There are more than 100 different kinds of cancer.

How can you avoid cancer?

While you may not be able to prevent cancer, you may be able to reduce your chances by making healthy lifestyle choices and avoiding certain risks. Here are the factors researchers believe contribute to cancer:

Tobacco use: First and secondhand smoking and other tobacco use has been linked to cancer.

Health choices: Being overweight, not exercising, eating poorly and consuming alcohol are all risk factors for developing cancer.

Exposures: Exposure to ultraviolet light from the sun or tanning beds has been linked to an increased risk for skin cancer. Other types of exposure associated with a greater risk for skin cancer include radiation, radon and nuclear weapons.

Chronic infections: Immune responses to certain types of infection  can also contribute to cancer. Infections that are linked with greater odds of developing cancer include the human papillomavirus (HPV) and Epstein-Barr virus (EBV). Other infections such as H. pylori, hepatitis C virus, hepatitis B virus and Chlamydia psittaci promote cancers by inducing chronic but ineffective immune responses.

Genes: Sometimes cancer can be inheritable and may run in families.

How is cancer diagnosed?

If a doctor suspects cancer, he or she may want to send you for diagnostic tests. These three options help confirm or rule out cancer:

Imaging tests: If your symptoms suggest cancer, an X-ray, ultrasound or computerized tomography (CT) scan may be ordered to give your doctor a closer look at the area (such as the lungs or ovaries, for example). Depending on the results, a biopsy may be performed for further testing.

Biopsy: If your imaging tests look abnormal or you have other symptoms, such as a lump, that suggest cancer, a biopsy may be performed to take tissue samples from areas. Once collected, biopsy samples are sent for pathology examination to look for cell abnormalities, says Natalia Buza, MD, a Yale Medicine pathologist. Pathologists are specially trained physicians who evaluate tissue samples under a microscope. “It is a very important task for a pathologist to identify what type of tumor it is—a benign tumor, which is great news for the patient. Or, if it is a malignant (cancerous) tumor in the specimen, we can identify what disease process caused the abnormality and the patient’s symptoms,” she says. With this information, your doctor can determine what kind of treatment is best for you.

Blood tests: If cancer is suspected, blood may be drawn and sent to a lab. The blood is then evaluated under a microscope by a lab medicine pathologist to determine if cancer is present in the blood on a cellular level or not.

What are the treatment options for cancer?

Thanks to advances in medicine, more people now survive cancer than ever before. In 1992, cancer survivors made up about 2.5 percent of the United States population. In 2022, experts predict that more than 5 percent of the population will have survived cancer. 

Depending on the type of cancer you or a loved one has, where it’s located and how early it has been detected, your doctor will create a treatment plan for you. Cancer treatments include:

Surgery: A mass can be removed by a surgeon in the operating room.

Chemotherapy: This is a type of medication therapy used to kill cancer cells. It can be administered orally or through an infusion treatment.

Radiation therapy: During this type of therapy, radiation in high doses is targeted at a mass to kill or shrink cancer cells in a targeted area.

Immunotherapy: This treatment recruits and amplifies your body’s own immune system to fight off cancer.

Hormonal therapy: Hormones can be used to help slow or stop certain kinds of cancer. 

Interventional oncology procedures: A variety of minimally invasive interventional oncology treatments offer new options for cancer patients, including chemoembolization, radioembolization, radiofrequency ablation, cryoablation and microwave ablation

What distinguishes Yale Medicine in caring for cancer?

Yale Medicine doctors and researchers are innovators in cancer screening, diagnosis and treatment. Our patients often have access to innovative treatments not easily available elsewhere. Doctors from Yale School of Medicine pioneered the use of chemotherapy in 1947 and are leaders in immunotherapy, for instance.

We have been a National Cancer Institute (NCI)-designated Cancer Center for over 40 years. Yale Cancer Center is one of only 51 centers in the nation to have this designation.

We take a multidisciplinary approach to cancer care. Our team of Yale Medicine oncologists, surgeons, scientists, interventional and therapeutic radiologists, and nurses work together to create the right care plan for you using precision medicine.

Our team cares for you and your loved ones' needs every step of your journey—from screening to diagnosis to treatment—and beyond. We deliver care at Smilow Cancer Hospital. Now we also bring the full expertise of our care teams into your community at 11 Smilow Cancer Hospital Care Centers located close to your home.

As part of our 360-degree approach, to cancer care, we offer our unique Survivorship Program. This program brings together doctors and experts from across disciplines to help patients and families with every aspect of life after cancer diagnosis, including nutrition, exercise and sexual intimacy changes after treatment. 

Building on scientific discoveries from Yale School of Medicine researchers, we are dedicated to interdisciplinary cancer research in basic science, translational research, and prevention for you and every member of your family.