Breast cancer

The Function of the Breast Tissue and Complications Associated with Breast Cancer

Breast tissue is composed of glandular structures (lobules and ducts), fat, and connective tissue. Though its primary biological function is milk production via lobules and ducts during and after pregnancy, it also plays a significant role in hormonal signalling and local metabolic regulation. Any disease affecting the breast may disrupt these functions and have profound impacts on physical and emotional health.

Breast cancer begins when cells in the breast tissue undergo malignant transformation due to genetic or environmental factors. While not always as immediately life-threatening as some other cancers, breast cancer remains one of the leading causes of cancer-related deaths globally. Awareness and education are crucial in early detection, and interventions may include lifestyle changes, regular screening, and stepping up monitoring protocols.

Categories Associated With Primary and Secondary Breast Tumours

Primary Breast Cancer

Originates within the breast tissue itself. Common types include:

• Ductal Carcinoma In Situ (DCIS): Non-invasive cancer found in the milk ducts.
• Invasive Ductal Carcinoma (IDC): Begins in the ducts, then invades surrounding tissue; the most common type.
• Invasive Lobular Carcinoma (ILC): Originates in lobules and may spread in a single-file pattern.
• Less common types include inflammatory breast cancer, Paget’s disease of the nipple, and rare histologic variants (e.g., medullary, mucinous, tubular carcinoma).

Secondary (Metastatic) Breast Cancer

Refers to cancer that has spread to distant organs such as the bone, liver, lung, or brain. Though it originates in the breast, its metastatic nature reflects advanced disease.

Causes and Risk Factors

Chronic hormonal exposure, genetic predisposition, environmental influences, and lifestyle habits can elevate breast cancer risk:

• Genetic factors: Mutations in BRCA1/2, PALB2, TP53
• Hormonal factors: Early menarche, late menopause, prolonged estrogen exposure
• Reproductive history: Nulliparity, first full-term pregnancy after age 30
• Breast density: High mammographic density is linked to increased risk
• Obesity & sedentary lifestyle
• Alcohol consumption
• Radiation exposure (particularly during adolescence)

Signs and Symptoms of Breast Cancer

Early breast cancer may be asymptomatic. As it progresses, common symptoms include:

• A painless lump or thickening in the breast or underarm
• Changes in breast size, shape, or appearance
• Skin dimpling or puckering
• Nipple retraction or pain
• Unusual nipple discharge (possibly bloody)
• Redness or rash on the breast or nipple
• Swelling or warmth in part of the breast

Diagnosis of Breast Cancer

Comprehensive evaluation includes:

• Medical History & Physical Examination: Assessing lumps, skin or nipple changes.
• Imaging: Mammography (screening & diagnostic), breast ultrasound, and MRI for high-risk patients or further evaluation.
• Biopsy: Core needle biopsy (standard); fine-needle aspiration or surgical excision for definitive histopathology.
• Pathology & Biomarker Testing: Hormone receptor (ER/PR) status, HER2 overexpression, Ki-67 proliferation index.
• Staging Workup: Regional lymph node evaluation (sentinel node biopsy), imaging (CT, bone scan, PET-CT) if metastatic disease is suspected.

Best Treatment for Breast Cancer

Treatment depends on tumour type, stage, biomarkers, and patient health. It’s divided into:

A. Traditional Treatments

• Surgical Procedures: Lumpectomy (breast-conserving surgery), mastectomy (unilateral or bilateral), axillary surgery (sentinel lymph node biopsy ± dissection).
• Radiation Therapy: Typically administered post-lumpectomy. Techniques include external-beam radiation and intraoperative radiation therapy (IORT).
• Systemic Chemotherapy: Neoadjuvant (before surgery) or adjuvant (after surgery). Common regimens: anthracyclines, taxanes, cyclophosphamide.

B. Advanced Treatments

• Targeted Therapies: HER2-targeted agents (trastuzumab, pertuzumab, T-DM1), CDK4/6 inhibitors (palbociclib, ribociclib, abemaciclib).
• Hormonal (Endocrine) Therapy: Tamoxifen, aromatase inhibitors, ovarian suppression depending on menopausal status.
• Advanced Radiation Techniques: Accelerated partial breast irradiation, hypofractionated schedules, brachytherapy.
• Immunotherapy: Pembrolizumab for triple-negative breast cancer; combination trials ongoing.
• PARP Inhibitors: Olaparib, talazoparib for BRCA1/2 mutation carriers.

Prevention and Lifestyle Management

• Genetic counselling/testing for high-risk individuals.
• Regular screening: mammography every 1–2 years starting at age 40–50 (or earlier if risk factors present).
• Clinical breast examination annually; MRI screening for high-risk groups.
• Healthy lifestyle: balanced diet, exercise, maintaining healthy weight, limiting alcohol.
• Chemoprevention: tamoxifen or raloxifene for high-risk individuals.
• Risk-reducing surgeries (prophylactic mastectomy/oophorectomy) for mutation carriers.
• Breastfeeding may modestly reduce risk.

Prognosis and Survival Rates

Prognosis varies widely:

• Early-stage localized breast cancer often has a 5-year survival >90%.
• Regional lymph node involvement reduces it to approximately 70–85%.
• Distant metastasis (stage IV) has a 5-year survival around 30%, though advancements in targeted therapy and immunotherapy are improving outcomes.

Conclusion

Breast cancer is a multifaceted disease with diverse pathological and clinical presentations. A thorough understanding of risk factors, vigilant screening, tailored treatment strategies, and healthy lifestyle choices can significantly improve outcomes. Emerging targeted therapies and immunotherapies hold promise in enhancing survival, particularly when used alongside traditional treatments.