In most cases of breast cancer, there is no known cause. Women who had children over 30 and women whose periods started when they were very young, or whose menopause occurred late, seem to run a slightly greater risk of developing breast cancer. In some families, genes are inherited which place women in a higher risk situation of developing breast cancer. There is some evidence to suggest that women who eat a diet high in animal fat may have a very slightly increased chance of developing breast cancer.
Breast cancer is rare in women under thirty and occurs most frequently in later life. Men can also develop breast cancer but it is one hundred times less common than in women. 

How common is Breast Cancer?

Breast cancer is a common and serious condition. Worldwide approximately 1 million people per year develop the disease and in Ireland approximately 1,700 women are diagnosed with breast cancer every year. Some 650 women die from the disease annually. The risk of developing breast cancer increases with age and breast cancer is the most common killing cancer in women. 

What to look out for?

In the vast majority of women, breast cancer is first noticed as a lump in the breast. There are, however, other signs to be aware of:

  • Breast: Change of size or shape, dimpling of the skin, lump or thickening
  • Nipple: Becomes turned in, pulled up or down, lump or thickening, blood-stained discharge, rash on nipple or surrounding area
  • Arm: Swelling in armpit

Pain in your breasts is not usually a symptom of breast cancer. In fact, many healthy women find their breasts feel lumpy and tender before a period, and some types of benign breasts lumps are painful.

It is important to note that nine out of ten breast lumps are benign and are not cancers. 

What to do?

Any woman who notes changes in her breasts or is concerned about them should seek her General Practitioner's advice immediately. The doctor can assess the changes and, if necessary, refer her to a consultant for further assessment. Remember, early detection of the disease is your best chance of a cure. 

How to reduce the risk?

  • Be breast aware and be aware of normal developmental changes
  • Carry out breast self-examination
  • Maintain a normal body weight
  • Exercise regularly
  • Eat a balanced diet 

How Breast Cancer is detected?

Women over 50 years are advised to have a mammogram (x-ray examination of the breasts) every two-three years. BreastCheck is our National Breast Cancer Screening Service in Ireland. This service is free for women between the ages of 50 and 64 years. All women who receive an invitation from BreastCheck for screening are strongly advised to take advantage of this service. In addition to a mammogram, a careful examination of the breasts by your doctor is important. This screening can detect very small tumours and has resulted in saving many lives.


Some breast cancers can be treated by removing the lump, and applying radiotherapy to the rest of the breast (radiation treatment which destroys cancer cells). For some women the most appropriate treatment is removal of the breast (mastectomy). The patient will have the opportunity to discuss which option is best for her.

Chemotherapy is frequently used and involves the use of a combination of drugs to prevent the disease recurring.

Hormone treatment - e.g. Tamoxifen - may be used, especially in postmenopausal women.

These treatments are often used in combination. After treatment, regular check-ups are necessary to make sure that no further action is required. Most women lead normal lives after treatment for breast cancer.

Useful websites

This information has been reproduced with kind permission from The Marie Keating Foundation.