Breast Cancer Basics
An overview of what breast cancer is, how it's found and diagnosed, the different types, and the treatments available today.
What Is Breast Cancer
Breast cancer is a cancer that develops in the tissue of the breast. It's one of the most common cancers affecting women, and with early detection and appropriate treatment, many people go on to have good outcomes.
Breast cancer usually begins in the ducts (the tubes that carry milk) or the lobules (the glands that produce milk).
Breast cancer can be invasive, meaning cancer cells have grown into surrounding breast tissue. In situ lesions, such as ductal carcinoma in situ (DCIS), contain abnormal cells that remain confined to where they began.
Keeping up with recommended screening and being aware of what is normal for your breasts can help you notice changes early.
Breast Cancer Risk Factors
Several factors are known to be associated with breast cancer risk:
- β’Age
- β’Family history
- β’Genetic factors (such as BRCA1/BRCA2)
- β’Hormonal and reproductive factors
- β’Lifestyle factors
That said, breast cancer can develop even without any of these risk factors present. Because of this, it matters for every woman to understand the basics and pay attention to changes in her body.
Symptoms
Not every lump is cancer; many turn out to be benign. Possible breast cancer symptoms include:
- β’A lump in the breast (often painless)
- β’Changes to the skin of the breast (dimpling, redness, or a texture resembling orange peel)
- β’Nipple inversion or a change in shape
- β’Nipple discharge (particularly if it contains blood)
- β’A change in the size or shape of the breast
- β’A lump under the arm
If you notice a change that concerns you, seeing a doctor sooner rather than later matters. Finding a cancer early can open up more treatment options. Early breast cancer often has no noticeable symptoms at all, which is why regular screening matters even when nothing feels wrong.
Screening and Diagnosis
Diagnosing breast cancer usually involves combining several tests rather than relying on just one.
Mammogram
An X-ray of the breast, useful for detecting small lumps and fine calcifications.
Ultrasound
Helps determine the nature of a lump, for example, whether it's solid or fluid-filled.
MRI
Used selectively rather than routinely, for example in some high-risk screening, evaluating how far a finding extends, or specific diagnostic situations.
Biopsy
A small sample of tissue from the area of concern is examined under a microscope. This is the test that confirms whether cancer is present.
After a diagnosis is confirmed, additional tests may be recommended to determine the stage. Depending on the cancer's features, symptoms, and examination findings, these may include CT, bone scan, PET/CT, or other imaging.
A biopsy is an important step toward an accurate diagnosis. Waiting for results can be stressful, but getting the diagnosis right is what makes the right treatment plan possible.
Types of Breast Cancer
Breast cancer is classified in a few different ways β by where it starts and by its underlying biology. The type affects what treatment approach makes sense.
By Where It Starts
Invasive ductal carcinoma
The most common type of breast cancer, starting in the ducts and spreading into surrounding tissue.
Invasive lobular carcinoma
Starts in the lobules, the second most common type after ductal carcinoma.
Ductal carcinoma in situ (DCIS)
Abnormal cells confined within a milk duct that have not invaded surrounding breast tissue. It is often called stage 0 or non-invasive breast cancer, although the US National Cancer Institute describes it as a precancerous condition rather than invasive cancer.
Inflammatory breast cancer
A relatively rare type, marked by redness and swelling of the breast skin. It tends to progress quickly, so prompt medical attention matters.
By Biological Subtype
Breast cancer is also classified by which receptors the cancer cells carry β a classification that plays a major role in deciding treatment.
Hormone receptor-positive
Grows in response to oestrogen and/or progesterone.
HER2-positive
Has high levels of the HER2 protein.
Triple-negative
Negative for both hormone receptors and HER2.
The right treatment depends on the specific type and subtype. Working through this with your doctor helps build a treatment plan suited to your situation.
Treatment Options
Treatment is chosen based on the type of cancer, its stage, and each person's individual health. Most treatment plans combine more than one approach.
Surgery
Removes the cancer β breast-conserving surgery (lumpectomy) removes the tumour and surrounding tissue, mastectomy removes the entire breast, and sentinel lymph node biopsy checks whether cancer has spread to the lymph nodes under the arm, often done at the same time as surgery when needed.
Radiation therapy
Uses high-energy X-rays to destroy microscopic cancer cells that may remain and reduce the risk of local recurrence, often used after surgery.
Chemotherapy
Uses medication to slow or destroy the growth of cancer cells, given either before surgery to shrink a tumour, or after surgery to reduce the chance of recurrence.
Hormone therapy
Used for hormone receptor-positive breast cancer, works by blocking the hormones that help the cancer grow.
Targeted therapy
Targets specific features that help cancer cells grow. For example, trastuzumab targets HER2 and is used for HER2-positive breast cancer; other targeted therapies are also used for certain hormone receptor-positive and triple-negative cancers.
Immunotherapy
Uses the body's own immune system to fight cancer, sometimes used for certain triple-negative breast cancers.
Treatment can come with side effects. Staying in close communication with your medical team about managing them, and about support for daily life, matters throughout. Treatment plans are built around your specific cancer, health, and life circumstances, and seeking a second opinion is a valid way to feel confident in your choice.
Advanced Cancer
Advanced breast cancer (stage IV, or metastatic breast cancer) means the cancer has spread beyond the breast to other organs, such as the bones, lungs, liver, or brain.
Metastatic breast cancer is generally considered treatable but not curable with current therapies. Treatment aims to control the cancer for as long as possible, relieve symptoms, help people live longer, and preserve quality of life.
Treatment options for advanced cancer
Systemic therapy: Chemotherapy, hormone therapy, targeted therapy, or immunotherapy, used to slow the cancer's progression.
Radiation therapy: Sometimes used to relieve pain or ease symptoms at a site of metastasis.
Surgery: May be used, when appropriate, to relieve specific symptoms.
Palliative care: Aims to ease pain and anxiety and improve quality of life, sometimes introduced from an early stage alongside other treatment.
An advanced cancer diagnosis still leaves many treatment and support options available. Working through what matters most to you with your medical team, family, and support groups can help shape how you want to move forward.
Advances in treatment continue to improve outcomes for many people with advanced breast cancer. Some people live for years with metastatic breast cancer while receiving treatment, although experiences vary widely depending on the cancer subtype, response to treatment, and individual health.
Participating in a clinical trial may provide access to newer treatments or treatment approaches, and is worth discussing with your doctor to see whether it may be a good fit for you. And palliative care plays a valuable role at every stage of advanced breast cancer, supporting not just physical symptoms but emotional wellbeing too.
Sources
- US National Cancer Institute (NCI): breast cancer overview, DCIS, staging tests, and treatment types
- American Cancer Society (ACS): breast cancer types, subtypes, treatment approaches, and guidance on metastatic (stage IV) breast cancer
- US National Comprehensive Cancer Network (NCCN) and other published clinical literature on targeted therapy and immunotherapy in breast cancer subtypes, cited in aggregate for general patterns rather than as individual citations throughout this page
This content is intended for general understanding only. Always speak with your doctor about your specific diagnosis, symptoms, or treatment options. If it's an emergency or you're unsure, contact a medical facility right away.
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