Breast Cancer – Causes, Symptoms, and Prevention
## **Introduction**
Breast cancer is one of the most common cancers affecting women worldwide. It occurs when abnormal cells in the breast tissue grow uncontrollably, forming a lump or tumor. These cells can begin in the **milk ducts** (ductal cancer) or the **lobules** (lobular cancer) where milk is produced. While most breast tumors grow slowly, early detection is crucial because a lump may take up to 10 years to become noticeable.
## **Structure of the Breast**
The breast is made up of lobules (milk-producing glands), ducts (tubes that carry milk to the nipple), fatty tissue, lymph nodes, and blood vessels. Cancers can develop in any of these structures, which determines how the disease behaves and spreads.
## Different kinds of breast cancer
### **1. Non-Invasive Breast Cancer**
Breast cancer that is non-invasive means that the cancer cells have not spread to nearby tissues and remain within the ducts or lobules. The most common type is **Ductal Carcinoma in Situ (DCIS)**. DCIS is not life-threatening, but if left untreated, it can progress into "invasive breast cancer."
### **2. Breast Cancer That Is Invasive or Metastatic** Invasive breast cancer occurs when cancer cells spread beyond the ducts or lobules into surrounding breast tissue. These cells can enter the bloodstream or lymphatic system and travel to other parts of the body, such as the bones, liver, or lungs.
## Based on receptors, the most common types of breast cancer Breast cancer is often classified by the presence or absence of certain receptors on cell surfaces:
1. **Hormone Receptor-Positive (ER/PR Positive):**
Estrogen or progesterone trigger the growth of these cancers. Hormone-blocking treatments can effectively slow or stop their growth.
2. **HER2-Positive Breast Cancer:**
These cancers overproduce a protein called HER2/neu. Targeted drugs like trastuzumab (Herceptin) are effective for treating this type.
3. **Triple Negative Breast Cancer (TNBC):**
Because it lacks estrogen, progesterone, and HER2 receptors, this aggressive form is more challenging to treat. TNBC represents about 15% of all breast cancers.
## Stages of Breast Cancer (TNM Classification) Breast cancer staging helps doctors determine the severity and spread of the disease. The **TNM system** stands for:
* **T:** Tumor size
* **N:** Involvement of lymph nodes * **M:** Metastasis is the process of spreading throughout the body.
### **Stage 1**
* **Stage 1A:** Tumor ≤ 2cm, no spread.
* **Stage 1B:** Tiny cancer cells found in lymph nodes.
### **Stage 2**
* **Stage 2A–2B:** Tumor 2–5cm, may or may not involve lymph nodes.
### **Stage 3**
* **Stage 3A–3C:** Cancer has spread to nearby lymph nodes or chest wall.
### **Stage 4**
* Cancer has spread (metastasized) to distant organs such as lungs, bones, liver, or brain.
## **Global Prevalence of Breast Cancer**
* Worldwide: More than 500,000 women die and 1 million are diagnosed each year. * Europe: 400,000 new cases annually; 17% of female cancer deaths occur there. * **North America:** Over 200,000 new cases yearly; second leading cause of cancer death among women after lung cancer.
## **Causes and Risk Factors of Breast Cancer**
Several factors increase the risk of developing breast cancer:
* **Age:** Most cases occur in women over 50.
* Genetics: Family history or inherited BRCA1/BRCA2 gene mutations. * Reproductive history: First pregnancy after 35 years of age or never. * **Hormonal exposure:** Long menstrual life or postmenopausal hormone therapy.
* **Lifestyle:** Obesity, alcohol consumption, physical inactivity, and high-fat diet.
* **Radiation exposure** from diagnostic imaging.
* **Use of birth control pills** for extended periods.
## **Early Signs and Symptoms of Breast Cancer**
Early detection can save lives. Look for the following symptoms:
* A new lump in the breast or underarm
* Swelling or thickening in part of the breast
* Dimpling or puckering of the skin
* Redness or flaky skin on the nipple or breast
* Pain or pulling in of the nipple
* Unusual nipple discharge (especially blood)
* Change in breast size or shape
* Visible veins or skin erosion on the breast
## **Diagnosis and Testing**
### **1. Biopsy Procedures**
* **Fine Needle Aspiration (FNA):** Removes fluid or cells from the lump.
* **Core Biopsy:** Extracts a tissue sample for analysis.
* [Surgical Biopsy]: Gets rid of some or all of the lump.
### **2. Tests in the lab * Tests on the hormone receptors to see if hormone therapy helps cancer * **HER2 Test:** Identifies HER2-positive cancers for targeted treatment.
### **3. Tests of the Image** *Mammogram and ultrasound: Early detection of tumors * **CT Scan & MRI:** Check spread to organs.
*Bone Scan: Identifies bone-on-bone spread. * **PET Scan:** Shows active cancer cells in the body.
## Options for Treatment and Medication
### **1. Surgery**
Surgical removal is often the first-line treatment.
Common types include:
* **Lumpectomy:** Removes the tumor and surrounding tissue.
* **Partial Mastectomy:** Removes a quarter of the breast tissue.
* **Total Mastectomy:** Removes the entire breast.
* **Breast Reconstruction:** Restores the breast shape after mastectomy.
### **2. Radiotherapy**
Uses high-energy rays to kill remaining cancer cells. Often used after surgery to prevent recurrence.
### **3. Chemotherapy**
Involves anti-cancer drugs administered orally or intravenously to destroy cancer cells. Fatigue, nausea, and hair loss are all common side effects.
### **4. Hormonal Therapy**
Drugs like Tamoxifen block the effects of estrogen and progesterone on cancers with hormone receptors positive.
### **5. Targeted Therapy**
These drugs attack specific molecules that fuel cancer growth, such as HER2-positive tumors. They are more precise and have fewer side effects than chemotherapy.
## **Prevention and Early Detection of Breast Cancer**
Reducing risk factors and practicing healthy habits can help prevent breast cancer:
* **Exercise regularly:** Physical activity helps control weight and reduce risk.
Keep a healthy weight, particularly after menopause. * **Eat a balanced diet:** Include foods rich in carotenoids (fruits and vegetables).
* Avoid drinking alcohol and hormone therapy for an extended period of time: * **Breastfeed if possible:** Breastfeeding for at least six months reduces risk.
* **Know your family history:** Genetic counseling can guide preventive steps.
* **Minimize radiation exposure:** Avoid unnecessary imaging tests.
* **Get regular screenings:** Mammograms help detect cancer early when treatment is most effective.
## **Conclusion**
Breast cancer remains one of the leading causes of cancer-related deaths among women. However, with **early detection, healthy lifestyle changes, and timely treatment**, survival rates have improved significantly. Regular screenings, awareness, and preventive measures are the key to reducing the global burden of breast cancer.