Overview

Breast cancer is one of the most common cancers in women. It can be treated effectively when detected early, with a survival rate of up to 99% if found and treated promptly.

The cause of breast cancer is not yet clearly defined. Some people with no risk factors still develop the disease, while others with risk factors do not. Research shows that lifestyle, environmental, and hormonal factors can increase the risk. About 5–10% of cases are linked to inherited genetic mutations.

According to GLOBOCAN 2020, breast cancer is the most common cancer in Vietnam with 21,555 new cases, accounting for nearly 25.8% of all cancers in women.

• Breast cancer cells usually form in the milk glands or the ducts that carry milk to the nipple.
• In some cases, cancer cells can also develop in other breast tissue.
• Breast cancer cells spread through the lymphatic system.

Risk factors

• Gender: Women have a higher risk of breast cancer than men.
• Age: Risk rises in women over 50, though more cases under 35 are being recorded.
• Inherited genes: Women carrying the BRCA1 and BRCA2 genes have higher risk, especially when young, and may develop cancer in both breasts.
• Personal history: Having had cancer in one breast increases the risk in the other.
• Family history: A first-degree relative who had breast cancer, especially at a young age.
• Radiation exposure: Prior radiation or chemotherapy, or exposure to high-radiation environments.
• Obesity and overweight from an unhealthy diet and inactivity.
• Menstruation: Early menarche (before 12) or late menopause.
• Hormone medication: Use of estrogen and progesterone hormone replacement.
• Pregnancy: Pregnancy after 35 or never having been pregnant.
• Short breastfeeding duration also increases risk.
• Frequent alcohol use increases the risk of breast cancer and other conditions.

Stages of breast cancer

Breast cancer is divided into 4 main stages, determined by imaging and pathology results.

Stage I: A small tumor confined to breast tissue or lymph nodes near the chest.
Stage II: Cancer cells in the breast and/or a few nearby lymph nodes.
Stage III: “Locally advanced breast cancer” — the tumor spreads locally, is usually large, invades the skin or chest wall, and reaches nearby lymph nodes.
Stage IV: Cancer cells have spread to distant organs such as bones, lungs, or the brain (metastatic breast cancer).

Breast cancer screening

Regular mammography is the most effective method to detect breast cancer even before specific symptoms appear. It uses a low-intensity X-ray beam directed at the breast tissue to capture images. The earlier the detection, the higher the chance of successful treatment, and in most cases breast-conserving surgery is possible. The technique is performed on each breast: the breast is placed on a flat surface and compressed with a flat plate to obtain a clear image of the breast tissue.