Breast Cancer | Cancer


Breast Cancer

UC Davis Comprehensive Cancer Center offers world-class care for people with breast cancer. Our experts provide thorough diagnosis and treatment options using the latest techniques.

Medically reviewed on June 13, 2023.

Woman getting a mammogram with another provider nearby

Compassionate Breast Cancer Care

Breast cancer is the most common type of cancer diagnosed in American women, other than skin cancer. It’s the second leading cause of cancer death in women, after lung cancer.

At UC Davis Comprehensive Cancer Center, our compassionate breast cancer specialists diagnose and treat all stages of breast cancer. We offer the most up-to-date therapies while giving you the support you need.


Types of Breast Cancer

Breast cancer is when cancer forms in the tissues of your breast. This cancer can also affect surrounding tissues or spread to other parts of your body.

There are two main types of breast cancer:

  • Invasive ductal carcinoma: This breast cancer starts in your breasts’ milk ducts and can spread to other breast tissue. It’s the most common type of breast cancer.
  • Invasive lobular carcinoma: This breast cancer starts in your breasts’ milk-producing glands (lobules) and can spread to other breast tissue. About 10% of breast cancers are lobular carcinoma.

Breast Cancer Symptoms

Many people have no symptoms in the early stages of breast cancer. As tumors grow, they may change the look and feel of your breasts.

Common Symptoms

Some common symptoms of breast cancer include:

  • Change in the size and shape of your breast
  • Dimpling of breast skin
  • Lumping, thickening or swelling in your breast or armpit
  • Nipple discharge
  • Nipple turned inward (retraction)
  • Pain in your breast or nipple
  • Scaling, peeling, crusting, redness or flaking of breast skin, nipple or dark skin around the nipple (areola)

Emergency Symptoms

If you have any of these symptoms, seek immediate medical care or call 911:

  • High fever
  • Severe pain in your chest

Breast Cancer Causes

Breast cancer can form when breast cells grow abnormally. They continue to build up, forming a lump or growth. The cells may also spread (metastasize) to other tissues in your body.

While some breast cancer cases are genetic, researchers don’t always know exactly what causes breast cancer.

Inherited Breast Cancer Genes

About 5% to 10% of breast cancers result from gene changes (mutations) passed from parents to children. BRCA1 and BRCA2 are the best-known gene mutations.


Breast Cancer Risk Factors

Certain factors can increase your breast cancer risk, including: 


Women age 55 and older have a higher risk of breast cancer.

Alcohol Use

Drinking alcohol raises your risk of breast cancer. The risk increases with the more alcohol you drink.

Dense Breast Tissue

Women who have dense breasts have a higher risk of breast cancer.

Earlier Period or Later Menopause

Women have increased risk of breast cancer if they started their period before age 12 or menopause after age 55.

Ethnicity and Race

White women are at higher risk of breast cancer than Black women. However, Black women are more likely to get a breast cancer diagnosis before age 40.

Family History of Breast Cancer

Having a mother, sister or daughter with breast cancer nearly doubles a woman’s risk.

Having a Child at an Older Age or Never Giving Birth

Your breast cancer risk increases if you have your first child after age 30 or have never given birth to a child.

Hormone Use

Hormone replacement therapy (HRT) that combines estrogen and progesterone after menopause increases breast cancer risk. Birth control pills also increase your risk.

Not Enough Physical Activity

Women who aren’t very physically active, especially after menopause, have a higher breast cancer risk.

Obesity or Overweight

Being obese or overweight after menopause increases your chances of developing breast cancer.

Personal History of Breast Cancer or Breast Conditions

Having breast cancer increases your risk of getting it again. Having non-cancerous (benign) breast conditions, such as lobular carcinoma in situ (LCIS) or atypical ductal hyperplasia (ADH), also puts you at higher risk.

Radiation Therapy

Women who had radiation therapy to their chest as a teen or young adult have a much higher risk of breast cancer.


Women are at much higher risk of developing breast cancer than men.


Breast Cancer Diagnosis

At UC Davis Health, we recommend that women have regular breast cancer screening tests. That way, cancer can be detected and treated in an early stage.

Tests we suggest to help diagnose breast cancer include:

  • Clinical breast exam: We check your breasts for any abnormalities or lumps. We also check the lymph nodes under your armpits.
  • Mammogram: We do a low-dose X-ray of your breasts to screen for breast cancer. We recommend yearly mammograms starting at age 40. Women at high risk under age 40 should talk to their provider about starting mammograms earlier.
  • Imaging tests: If we find an abnormality during a breast exam or mammogram, we may order an ultrasound or MRI for more detailed pictures.
  • Biopsy: A surgeon or radiology physician removes a small sample of tissue from your breast. We check it for cancer cells under a microscope.

Breast Cancer Treatments at UC Davis Health

At UC Davis Comprehensive Cancer Center, we offer complete care for people with all stages of breast cancer. We determine your treatment options based on the type, stage, size and location of breast cancer, as well as whether it has spread. We personalize your treatment plan based on what will work best for you and your unique situation.


Most women with breast cancer have surgery. A surgical oncologist may remove the breast cancer along with some healthy tissue around it (lumpectomy). A mastectomy is when they remove the entire breast.

Learn about surgical oncology
Radiation Therapy

High-energy X-rays can destroy breast cancer cells. We may use radiation therapy after a lumpectomy or mastectomy, or if breast cancer has spread to other parts of the body (metastatic cancer).

Learn more about our radiation therapy services

Chemotherapy (chemo) uses drugs to kill breast cancer cells. We may use chemo before surgery, after surgery or for metastatic cancer.

Find out more about chemotherapy treatments
Targeted Therapy

We can inject drugs that focus on specific parts of breast cancer cells, which cause the cells to die. We often use targeted therapy after surgery or for advanced breast cancer.

Hormone Therapy

Hormone therapy prevents some types of breast cancer cells from getting hormones they need to grow. We may use hormone therapy before or after surgery, or for metastatic cancer.

Learn about hormone therapy at UC Davis Health

We use medications that help your immune system attack breast cancer cells. We usually give immunotherapy through an intravenous (IV) infusion.

Get more information about immunotherapy

Preventing Breast Cancer

While there’s no way to completely prevent breast cancer, you can do things to help lower your risk.

Limiting alcohol intake

Reducing or stopping your alcohol intake can reduce your breast cancer risk.

Breast Cancer Screenings

You can get regular breast cancer screenings, such as mammograms, from your physician. These screenings can help catch signs of cancer early before it spreads.


Women who breastfeed their children for at least a few months can reduce their risk of breast cancer.

Breast Self-Exams

Checking your breasts regularly for changes or lumps can help to detect any breast cancer sooner.

Healthy Weight

Staying at a healthy weight can help reduce your breast cancer risk.

Preventive Medications and Surgery

If you’re at high risk of breast cancer, prescription medicines may reduce your risk. If you have a BRCA gene mutation, you may choose to have your breasts removed (prophylactic mastectomy).

Physical Activity

Exercising most days of the week may help decrease breast cancer risk.

"Invasive Lobular Carcinoma (ILC),",

"Breast Cancer Risk Factors You Cannot Change," American Cancer Society, 

Breast cancer causes

1 in 3Of new cancers in women each year

Average risk

1 in 8Chance an American woman will develop breast cancer in her lifetime

Source: American Cancer Society: Key Statistics for Breast Cancer

Request an Appointment

Our cancer specialists provide thorough evaluations and personalized treatment plans. Learn more about how to make an appointment at UC Davis Comprehensive Cancer Center.



UC Davis Health Referring Physicians

For providers in UC Davis Medical Group or our Cancer Care Network

External Referring Physicians

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