By MAXWELL ADEYEMI

Body cells reproduce on a regular basis, occasionally, these cells grow and divide out of control and defy the social norm of cell division. The excessive growth creates a mass known as a tumour. If the cells are normal cells, they are referred to as benign tumours, but if the cells are abnormal cells which do not function as the normal cells, they are referred to as malignant tumours. When these abnormal cell divisions occur in the breast, they are called breast cancers.

Breast cancer is the most common cancer among women. Increasing age is the most common risk factor for developing breast cancer, with 66 per cent of breast cancer patients being diagnosed after the age of 55. It is the leading cause of cancer death among women ages 35-54. All women, especially as they age, are at some risk for developing breast cancer. The risks for breast cancer in general aren’t evenly spread among ethnic groups, and the risk varies among ethnic groups for different types of breast cancer.

Types of breast cancer

The most common types of breast cancer are:

Infiltrating (invasive) ductal carcinoma. This cancer starts in the milk ducts of the breast. It then breaks through the wall of the duct and invades the surrounding tissue. This is the most common form of breast cancer, accounting for 80 per cent of cases.

Ductal carcinoma in situ is ductal carcinoma in its earliest stage, or precancerous (stage zero). In situ refers to the fact that the caner hasn’t spread beyond its point of origin. In this case, the disease is confined to the milk ducts and has not invaded nearby breast tissue. If untreated, ductal carcinoma in situ may become invasive cancer. It is almost always curable.

Infiltrating (invasive) lobular carcinoma. This cancer begins in the lobules of the breast where milk is produced but has spread to surrounding tissues. It accounts for ten to 15 per cent of breast cancers. This cancer can be more difficult to diagnose with mammograms.

Lobular carcinoma in situ is a marker for cancer that is only in the lobules of the breast. It is possible to occur in both or either breast. Thus, it is important for women with lobular carcinoma in situ to have regular clinical breast exams and mammograms.

Stages of breast cancer

Stage zero breast disease is when the disease is localised to the milk ducts.

Stage 1 breast cancer is smaller than two centimetres across and hasn’t spread anywhere – including no involvement in the lymph nodes.

Stage II breast cancer is one of the following:

The tumour is less than two centimetres across but has spread to the underarm lymph nodes (IIA).

The tumour is between two and five centimetres, with or without spread to lymph nodes.

The tumour is larger than five centimetres and has not spread to the lymph nodes under the arm (both IIB)

Stage III breast cancer is also called locally advanced breast cancer. The tumour is any size with cancerous lymph node