Breast cancer begins when abnormal cells in the breast grow and divide in an uncontrolled way. Because every patient’s situation is unique, our team at Illinois CancerCare focuses on early detection, accurate diagnosis, and personalized treatment plans designed to give you the best possible outcome. Breast cancer can occur in women and men, though it is much more common in women.  

Understanding the Breast

The breast contains lobules (glands that make milk), ducts (tubes that carry milk to the nipple), and stroma (fatty and connective tissue). Most breast cancers start in the ducts or lobules. Nearby lymph vessels and lymph nodes—especially under the arm (axilla)—are important pathways cancer cells can use to spread.  

Types of Breast Cancer

There are many kinds of primary brain tumors. In adults, common types include: 

Ductal carcinoma in situ (DCIS)

Noninvasive cancer limited to the milk ducts.

Lobular carcinoma in situ (LCIS)

Not a true cancer, but a marker of increased risk in both breasts. 

Invasive ductal carcinoma (IDC)

The most common invasive type; starts in ducts and grows into nearby tissue. 

Invasive lobular carcinoma (ILC)

Begins in lobules and grows into nearby tissue; can be harder to detect on imaging. 

Triplenegative breast cancer (TNBC)

Lacks ER, PR, and HER2; may grow and spread faster, treated primarily with chemotherapy ± immunotherapy. 

HER2positive breast cancer

Overexpresses the HER2 protein; often responds well to HER2targeted therapies. 

Inflammatory breast cancer (IBC)

Rare, aggressive form that can cause breast redness and swelling. 

Paget disease of the breast

Rare cancer affecting the nipple/areola skin. 
Your pathology report will include receptor status (ER/PR/HER2) and other biomarkers that help guide treatment.  

Signs & Symptoms

  • A new lump or mass in the breast or underarm 
  • Swelling, skin dimpling, or thickening 
  • Nipple changes (retraction, scaling) or discharge not related to breastfeeding 
  • Redness or flaky skin in the nipple/areola area 
  • Breast pain that is new and persistent

Many breast changes are not cancer, but any persistent change should be evaluated.  

Risk Factors

  • Age (risk increases after 50) 
  • Family history of breast or ovarian cancer; inherited mutations (e.g., BRCA1/BRCA2, PALB2) 
  • Personal history of certain benign breast conditions or prior breast cancer 
  • Radiation to the chest (especially at younger ages) 
  • Hormonal factors: early first period, late menopause, first pregnancy after 30 or never pregnant, long-term combined HRT 
  • Breast density, alcohol use, overweight/obesity after menopause, limited physical activity

Having a risk factor doesn’t mean you will develop breast cancer; many with breast cancer have no obvious risks.  

Screening

Screening aims to find cancer early, when it’s most treatable. 

  • Mammography: Standard screening test; frequency and start age are individualized (many average risk women start at age 40 after discussing benefits/harms with their clinician). 
  • Breast MRI + mammography for select highrisk individuals (e.g., BRCA mutation carriers). 
  • Breast density may influence screening strategies and followup. 

Talk with your clinician about your personal risk and screening plan.  

Diagnosis

If a screening test or symptom suggests cancer, your team may use: 

to characterize findings

in specific situations (e.g., extent of disease, dense tissue, high risk)

(typically core needle) to confirm the diagnosis and perform ER/PR/HER2 testing

(imaging or labs) when indicated by tumor size, nodes, or symptoms. These results determine cancer type, stage, and biology, which drive your treatment plan. 

Staging

Breast cancer staging uses TNM (Tumor size, Node involvement, Metastasis) plus tumor grade and biologic factors (ER/PR/HER2). Broadly: 

Stage 0

DCIS (noninvasive)

Stages I–III

Increasing tumor size and/or lymph node involvement, but no distant spread 

Stage IV (metastatic)

Cancer has spread to distant organs (e.g., bone, liver, lungs) 

Your doctor will explain your stage and what it means for treatment and prognosis.  

Treatment Options

Treatment is personalized based on stage, tumor biology, genomic features, overall health, and your goals. Care is coordinated by a multidisciplinary team

Surgery  

for some slowgrowing, asymptomatic tumors.

  • Breastconserving surgery (lumpectomy) or mastectomy 
  • Sentinel lymph node biopsy or axillary dissection when indicated 
  • Reconstruction options after mastectomy or lumpectomy 

Radiation therapy  

  • After lumpectomy and in selected postmastectomy settings 

Systemic therapy (before or after surgery, or for metastatic disease)   

  • Hormone therapy for ER/PRpositive cancers (e.g., tamoxifen, aromatase inhibitors) 
  • Chemotherapy (neoadjuvant or adjuvant; also used in metastatic disease) 
  • HER2targeted therapy for HER2positive tumors 
  • Targeted therapies (e.g., CDK4/6 inhibitors for HR+/HER2 metastatic disease; PARP inhibitors in select mutation carriers) 
  • Immunotherapy for select triplenegative cancers 

Your Illinois CancerCare team will discuss benefits and potential side effects and whether a clinical trial is right for you.  

Prognosis

Many breast cancers are highly treatable—especially when found early. Outcomes depend on stage, tumor biology, response to therapy, and overall health. Contemporary U.S. data show a 5-year relative survival ~92% for female breast cancer overall, but your doctor will explain what your individual features mean.  

Follow Up Care

Follow-up typically includes regular clinical visits, annual mammography (or MRI when appropriate), and monitoring for treatment effects (e.g., bone health on aromatase inhibitors, heart monitoring with certain HER2 therapies). Your schedule and tests are personalized to your diagnosis and treatment.  

Living With & Beyond Breast Cancer 

Illinois CancerCare offers comprehensive support, including counseling, nutrition guidance, rehabilitation, survivorship programs, genetic counseling, fertility preservation referrals, lymphedema resources, caregiver support, and access to clinical trials—all designed to help you and your loved ones navigate treatment and recovery. National organizations (e.g., ACS) also provide education and practical tools for patients and caregivers.  

Breast Cancer in Men

Men can develop breast cancer, most often presenting as a painless lump, nipple changes, or discharge. Evaluation and treatment principles are similar; hormonereceptorpositive disease is common in men. If you notice changes in the chest/breast area, please speak with your doctor.  

Why Choose Illinois CancerCare

  • Experienced multidisciplinary team in medical and radiation oncology, with surgical and plastic surgery partners 
  • Advanced diagnostics and timely, coordinated treatment planning 
  • Access to innovative treatments and clinical trials through our active research program 
  • Compassionate, patientcentered care focused on your goals and quality of life 

Sources & Patient Friendly References

All information was taken from the NCI (National Cancer Institute) and ACS (American Cancer Society).