An overview of breast cancer, symptoms to look out for, when to start thinking about routine screenings

Breast cancer is the second-most common cancer for women, according to the Centers for Disease Control and Prevention (CDC). The cancer is second only to certain skin cancers.

The cancer is more rare for men but still important to be mindful of, experts say. For every 100 cases of breast cancer diagnosed, one of those is found in a man, according to the CDC. For women, 1 in 8 will develop breast cancer in their lifetime.

Each year, about 240,000 women in the United States are diagnosed with breast cancer, and approximately 42,000 women die from the disease, the CDC reports.

KATIE COURIC'S BREAST CANCER: WHAT OTHER WOMEN CAN LEARN FROM HER DIAGNOSIS 

With breast cancer so common, it's important to familiarize yourself with signs and symptoms. The most common is the formation of a lump. If you notice this symptom, it's vital to speak with a doctor right away.

Even if you don't notice any symptoms, it's still a good preventative measure to get screened for the disease. This is typically done through a mammogram. Usually, women will begin getting routine mammograms beginning in their 40s.

Today, many in the public sphere have opened up about their diagnosis and the importance of getting screened for the disease. Actresses Julia Louis-Dreyfus and Christina Applegate are two of numerous celebrities who have spoken out about their breast cancer diagnosis.

Here's a deeper look into breast cancer and information on how you can be screened for the disease.

Breast cancer is a disease that occurs in breast tissue when cells in the breast "change and grow out of control," according to MedlinePlus, an online health information service produced by the U.S. National Library of Medicine.

The cells that cause breast cancer usually form a tumor, which is an abnormal mass of tissue.

Cancer cells and cancerous tumors (malignant) are dangerous because they can disrupt organ functions and kill healthy cells if left to spread. 

CANCER CAUSES: THESE 10 HIDDEN CARCINOGENS CAN RAISE THE RISK, ACCORDING TO AN ONCOLOGY EXPERT

This can cause serious harm or death if left untreated, according to a report from Medical News Today, a medical news website owned by Healthline Media.

Breast cancer is the second-most common cancer in women after skin cancer, says the National Cancer Institute.

The final step of diagnosing breast cancer is through a biopsy. 

A biopsy is done after an imaging test, like a mammogram is done and something is spotted that could be related to breast cancer.

The treatment for breast cancer commonly includes chemotherapy, hormone therapy or radiation.

The most common symptom to look out for that could be associated with breast cancer is a new lump or mass. 

If you do spot a new lump or mass form, it’s best to get it checked right away.

5 COMMON MYTHS AND MISCONCEPTIONS ABOUT BREAST CANCER, ACCORDING TO A DOCTOR 

Other symptoms that could be associated with breast cancer are swelling of the breast or part of the breast, pain in the breast or nipple area, nipple retraction (when the nipple begins to turn inward), nipple discharge, or red, flaky skin.

Breast cancer incidence rates steadily increase with age, but it remains low for women under the age of 40, CDC data shows.

While not all experts agree on whether women under age 40 should receive mammograms, young women in their 20s and 30s have been diagnosed with breast cancer, according to incidence data published by the CDC, which dates back to 2019.

Only about 9% of all breast cancer cases are found in women under age 45, according to the CDC. 

With increasing age, the risk factor begins to grow. Most breast cancers are diagnosed after age 50, according to the source. 

Since breast cancer is more commonly found in women 40 and older, medical professionals and organizations recommend routine breast cancer screenings for middle-aged and senior women.

One common breast cancer screening method is a mammogram. 

This method of screening has led to debates among experts.

Potential risks associated with mammography screening include over diagnosis, false positives, anxiety and radiation injury, according to a study published in the National Library of Medicine.

A mammogram is an X-ray procedure that helps doctors detect early signs of breast cancer, according to the CDC.

The machines used to conduct mammograms have plastic plates that flatten breasts so X-ray images can be taken and analyzed by radiologists for abnormalities.

Mammogram results are typically reported in a few weeks after the test is done. 

Women with dense breasts have a higher chance of getting breast cancer, the CDC reports. Some women have higher-density breasts if they’re younger in age, pregnant or breastfeeding, taking hormone replacement therapy or have a lower body weight.

"Dense tissue can hide cancers," the CDC wrote in a "What Does It Mean to Have Dense Breasts?" report.

"Fibrous and glandular tissue looks white on a mammogram. So does a possible tumor," the CDC continued. "Because it’s hard to tell the difference between a tumor and dense breast tissue on a mammogram, a small tumor may be missed."

The U.S. Preventive Services Task Force — an independent, volunteer panel of national experts in disease prevention — says women who place a higher value on the potential benefit of mammography over potential harm can choose to begin breast cancer screening once every two years between ages 40 and 49 years.

The CDC says similar breast screening guidelines have been issued to women ages 40 to 49 with "average risk" by the American Cancer Society, American College of Physicians, American College of Obstetricians and Gynecologists, American College of Radiology, American College of Physicians and American Academy of Family Physicians.

Three out of the six aforementioned cancer organizations recommend annual mammograms for concerned women who are between the ages of 40 and 49, if they choose.

MELISSA ETHERIDGE RECALLS OLIVIA NEWTON-JOHN’S SUPPORT DURING HER OWN BATTLE AGAINST BREAST CANCER

Women who are age 50 and older are generally advised to get mammograms done annually or bi-annually.

All cancer organizations advise women to speak with a health care provider to weigh the potential benefits and risks of getting a mammogram.

Alongside age, family history is another big risk factor for breast cancer.

"Having one first-degree relative with breast cancer doubles a woman’s risk," Dr. Kathleen Kiernan Harnden, director of breast oncology at the Inova Schar Cancer Institute in Annandale, Virginia, told Fox News Digital.

EXERCISE LOWERS THE RISK OF BREAST CANCER, STUDIES SHOW 

Other risk factors highlighted by the CDC are reproductive history, previous treatments using radiation therapy, having dense breasts, exposure to the drug diethylstilbestrol (DES), and genetic mutations.

Factors like low exercise, being overweight, taking hormones, reproductive history and drinking alcohol are other risks associated with the disease that fall within an individual's control, according to the CDC. 

There are certain questions a person should consider before making the decision to get a mammogram. 

Harnden said there are three questions all women should ask themselves before they request a mammogram consultation or appointment: 

Harnden recommends 3D mammography over 2D because multiple images are taken from different angles, which may make breast tissue analysis clearer.

One concern among those getting a mammogram is the radiation involved, but many experts believe the risks associated with breast cancer outweigh the risks associated with a mammogram.

Dr. Jessica Shepherd, a Dallas-based OB/GYN who is chief medical officer at Verywell Health, a health information website, said most breast cancer cases are diagnosed after age 50, which is why mammograms are usually done for women who are closer to that age marker.

"The dose of radiation from a mammogram is pretty low and very rarely poses a risk, making them a safe diagnostic tool, and typically someone only needs a mammogram once a year. Therefore, there is no risk of too much radiation exposure," Shepherd told Fox News Digital.

She noted that there is a "small link to an increased risk of breast cancer over time due to [mammogram] frequency and also size of the breasts," but "overall this increase in risk is very small."

CLICK HERE TO SIGN UP FOR OUR HEALTH NEWSLETTER

Delaying a breast cancer diagnosis has a higher risk than radiation exposure, Shepherd said.

"When caught early, breast cancer is highly treatable, and mammograms can be highly beneficial in these cases," Shepherd continued. "If [breast cancer is] allowed to advance, a patient may have to receive more complex treatment such as surgery or chemo, which is way more invasive than radiation exposure from a mammogram."

Other breast cancer screening methods exist for women who are not eligible or do not want to undergo a mammogram.

The CDC lists breast ultrasounds, breast MRI clinical breast examinations and self-checks as possible screenings for breast cancer.

Ultrasounds generate pictures, or sonograms, using sound waves, while MRIs are computerized body scans that generate pictures using magnets.

Clinical breast exams are conducted by a doctor or nurse. During exams, medical professionals check for abnormal lumps or other physically detectable changes in breast tissue by hand.

Women can check their breasts for common breast cancer symptoms, including lumps, pain and changes in size.

"You should report any changes that you notice to your doctor or health care provider," the CDC wrote in its "What Is Breast Cancer Screening?" guide.

"Having a clinical breast exam or doing a breast self-exam has not been found to lower the risk of dying from breast cancer," the CDC also said.

More screening alternatives, like nanotechnology and treatments with less radiation, are still being explored. Women diagnosed and those who do not have breast cancer can choose to participate in different clinical trials to help discover more screening alternatives and treatment options.

Cortney Moore contributed reporting.

For more Health articles, visit www.foxnews.com/health.