Use this guide one step at a time.
A breast cancer diagnosis brings several results and decisions at once, but they do not all need to be understood in one visit. The pathology, stage, grade, hormone-receptor status, and HER2 result help explain which treatments are relevant.
Subtypes and biomarkers
Breast cancer is first separated into in situ disease, such as ductal carcinoma in situ, and invasive cancer. Invasive ductal and invasive lobular cancers are common, while inflammatory and triple-negative breast cancers require distinct planning. The pathology report should include grade and tests for estrogen receptors, progesterone receptors, and HER2. These results define hormone-receptor-positive, HER2-positive, and triple-negative groups and help select hormone therapy, HER2-directed treatment, chemotherapy, or immunotherapy. HER2-low describes some tumors that are not HER2-positive but may qualify for particular drugs in advanced settings. Ki-67 may add information about cell division, although its role varies. A multigene tumor assay can sometimes help estimate recurrence risk and chemotherapy benefit in selected early hormone-receptor-positive, HER2-negative cancers. Inherited-gene testing answers a different question: it looks for variants present from birth, such as BRCA1 or BRCA2, that may affect treatment, surgery, and relatives.
What is breast cancer?
Breast cancer is a group of diseases rather than one uniform illness. Ductal carcinoma begins in milk ducts, while lobular carcinoma begins in milk-producing lobules. Ductal carcinoma in situ remains inside a duct; invasive cancers have entered surrounding breast tissue and can reach lymph nodes or distant organs. Pathology identifies the histologic type and grade. Biomarker testing usually evaluates estrogen receptors, progesterone receptors, and HER2, and selected cases may need inherited-gene or tumor-genomic testing. These results define clinically important groups, including hormone-receptor-positive, HER2-positive, and triple-negative breast cancer. Population screening can find cancer before symptoms develop, while diagnostic imaging evaluates a specific concern. Individual risk reflects age, family history, inherited variants, reproductive and hormonal factors, alcohol exposure, breast density, and prior chest radiation, but many people diagnosed have no strong known risk factor. Care depends on type, stage, biomarkers, health, and preferences.
Signs and symptoms
Early breast cancer may cause no noticeable change. Possible signs include a new lump in the breast or underarm, a firm or thickened area, swelling, or a change in breast size or shape. Nipple findings can include inversion, a new change in direction, or discharge that is not breast milk. Skin may become dimpled, puckered, scaly, swollen, red, or darker, and the nipple or areola may itch or tingle. Breast pain is less typical but persistent pain deserves assessment. Advanced disease can cause symptoms related to the involved organ, such as bone pain, shortness of breath, abdominal swelling, jaundice, headache, seizures, or vision changes. These symptoms often have noncancer causes, but a new or persistent breast change should be evaluated even after a recent normal mammogram.
Diagnosis and staging
Evaluation starts with medical and family history and a clinical breast examination. Diagnostic mammography, ultrasound, or breast MRI may characterize an abnormality. A biopsy is the only sure way to diagnose breast cancer; core-needle biopsy is commonly used, with surgical biopsy reserved for selected situations. Pathology reports the cancer type, invasiveness, grade, and biomarkers, including estrogen receptor, progesterone receptor, and HER2. Additional molecular or inherited-gene testing may be appropriate. Staging describes tumor extent, lymph-node involvement, and distant spread, using examination, pathology, sentinel-node biopsy, and selected imaging or laboratory tests. Breast staging also incorporates grade and biomarker findings, and sometimes multigene tests. Stages range from 0 for in-situ disease through IV for distant metastasis. Not everyone needs extensive imaging. The care team chooses tests according to clinical findings, and treatment depends on type, stage, biomarkers, overall health, and preferences. Results are reviewed together in a multidisciplinary treatment plan.
Established treatment paths
Treatment often combines local therapy with medicines that act throughout the body. Breast-conserving surgery removes the tumor with a rim of tissue and is commonly followed by radiation; mastectomy removes the breast and may be paired with reconstruction. Lymph-node assessment helps stage invasive disease. Radiation may also be used after mastectomy or for symptom control. Systemic choices depend strongly on biology. Hormone therapy is used for hormone-receptor-positive cancer. HER2-directed drugs treat HER2-positive disease, while chemotherapy may be recommended before or after surgery or for advanced cancer. Immunotherapy and other targeted drugs are options in selected triple-negative, inherited-variant, or metastatic settings. For some early cancers, genomic assays help estimate recurrence risk and whether chemotherapy is likely to add benefit. Metastatic disease is generally managed with sequential systemic treatments and focused local treatment when useful. Clinical trials may be appropriate at any stage. The exact plan depends on type, stage, grade, biomarkers, prior therapy, menopausal status, other health conditions, and the person’s priorities; benefits and possible effects on fertility, heart health, bones, nerves, and quality of life should be discussed.
Supportive care
Support can be tailored to the treatment sequence. Before surgery. Rehabilitation and a certified lymphedema therapist can address restricted movement, heaviness, or swelling after lymph-node surgery or radiation. Hormone therapy may affect hot flashes, vaginal or sexual health, mood, joints, and bones; chemotherapy can add nausea, neuropathy, fatigue, and infection risk. Fertility preservation may be time-sensitive. Nutrition, activity, sleep, counseling, peer support, and palliative care can be used alongside cancer treatment.
Profiles documenting breast cancer care
These profiles mention a matching cancer specialty in their published materials. Browse their locations, reported services, and practical details.
Sources
Source information checked: 2026-10-01. The links below identify the public and clinic-provided materials used for this page.
- NCI: Breast Cancer ↗Checked 2026-09-29
- NCI: Breast Cancer Signs and Symptoms ↗Checked 2026-09-29
- NCI: How Breast Cancer Is Diagnosed ↗Checked 2026-09-29
- NCI: Breast Cancer Treatment ↗Checked 2026-09-29
- NCI: Tests for Breast Cancer Biomarkers ↗Checked 2026-10-01
- NCI: Lymphedema ↗Checked 2026-10-01
How Cancer Clinic Finder compiles information · Suggest a factual correction
