27 June 2019
Breast cancer is one of the most common invasive cancers among women and the leading cause of cancer death in Singaporean women. Statistics from the National Cancer Centre show that breast cancer alone accounts for approximately 29.1% of cancer diagnosis among Singaporean women.
Cancer occurs as a result of genetic mutations or other abnormal changes in genes responsible for regulating cell growth. Normally, your body cells replace themselves through an orderly cell growth cycle – healthy new cells develop to replace dead ones.
However, gene mutations can trigger abnormal and uncontrollable cell growth. This means that some cells gain the ability to multiply without cell death. The excess body cells then form a tumour which can be benign or malignant.
Benign (non-cancerous) tumours grow slowly, are not dangerous to your health, and do not spread to other parts of your body. However, malignant (cancerous) tumours can easily spread beyond the original tumour to other body parts if left unchecked.
The term breast cancer refers to a malignant tumour that has developed from cells in your breast. In most cases, breast cancer starts in the duct or lobules before spreading to other parts of your body.
The risk of developing breast cancer can either be absolute or relative.
Absolute risk describes the likelihood of an individual developing breast cancer over a certain time period, in view of the average for the whole population.
For example, if your current age is 40, the probability of developing invasive breast cancer in the next 10 years is 1.45%, or 1 in 69.
Relative risk refers to the likelihood of a group of people developing breast cancer compared to another group with different behaviours, physical conditions, or environment.
For example, women who have two or more drinks per day have a 50% higher risk of breast cancer, relative to women who do not drink.
In order to understand your individual breast cancer risk, both absolute and relative risks must be considered. If your current age is 40 (absolute risk of 1.45% of developing breast cancer in the next 10 years), and you have two or more drinks per day (relative risk that is 50% higher than those who do not drink), your individual breast cancer risk will be (1.45% x 1.5 = 2.175%).
The exact cause of breast cancer remains unclear, but several risk factors may increase your chances of developing breast cancer. However, having any of these risk factors does not directly equate to you developing cancer.
The risk of developing breast cancer tends to increase with age. Most women who are diagnosed with breast cancer are older than 50 years. But, younger women may also be affected.
Breast cancer can also affect men, but the risk is significantly lower compared to women. When breast cancer is diagnosed in men, it is usually at an advanced stage because of the small size of the male breast.
If a first-degree relative such as your mother or sister had breast cancer, your risk of getting breast cancer is increased. Having two or more first-degree relatives with breast cancer history increases your risk further.
This is especially true if the relative developed the condition before menopause or if it affected both of her breasts. The risk may also increase if your biological father or brother was diagnosed with breast cancer.
Certain aspects of your reproductive history may increase your risk of breast cancer. For instance, not having children or having your first child after the age of 35 increases your risk. Same for the onset of periods before the age 11 and cessation of periods after the age of 55. These risk factors are associated with either an early or prolonged exposure to estrogen and progesterone.
Changes to two genes, namely BRCA1 and BRCA2, can lead to breast cancer. In fact, between 5 to 10% of breast cancer cases are associated with genetic factors.
Women with a BRCA1 or BRCA2 gene mutation, have increased chances of developing breast cancer. These genes also raise your risk for ovarian cancer and are linked to male breast cancer as well.
Women who have had breast cancer are more likely to develop breast cancer the second time. Some non-cancerous breast diseases such as Lobular Carcinoma In Situ (LCIS) and Atypical Lobular Hyperplasia (ALH) are associated with a higher risk of getting breast cancer.
Women who take postmenopausal progesterone or estrogen medications to alleviate their signs of menopause symptoms are at a higher risk of developing breast cancer.
Research shows that workplace exposure to certain endocrine disrupting chemicals and carcinogens can cause breast cancer.
In its early stages, breast cancer does not show any symptoms. However, as the tumour grows, you may notice the following signs:
Keep in mind that these symptoms may appear with other conditions that are not necessarily breast cancer. Nonetheless, if one or both of your breasts develop an abnormal pain or lump that does not go away or feels abnormal, seek a doctor’s advice right away. It could save your life.
The truth is that your chances of developing breast cancer are greatly affected by the various lifestyle choices that you make. Simple lifestyle changes can make a huge difference when it comes to preventing breast cancer.
Consider these simple breast cancer prevention tips:
Early diagnosis of breast cancer can greatly improve survival rate. If you are diagnosed at Stage 0 or Stage 1 breast cancer, where the cancer cells are localised in breast tissue, you have a 99% 5-year relative survival rate as compared to 27% for advanced stages, where cancer cells have already spread to lymph nodes and other body parts.
Regular screening is recommended for women of age, or younger if you are at high risk. While you could feel completely healthy with no symptoms, your body could also be harbouring early stages of breast cancer.
Although screenings may not prevent breast cancer, it ensures that the cancer cells do not go undetected and do not have a chance to proliferate for a long time.
General screening recommendations for women with average risk:
Mammography is the most commonly used breast cancer screening method. This technique involves the use of low-energy x-rays to capture the image of your breast that reveals any underlying abnormalities.
Imaging your breast improves your doctor’s ability to detect small tumours and recommend appropriate action to be taken. The increased detection of small tumours and abnormal tissues using mammography can significantly reduce the number of deaths from breast cancer.
Suspicious tissues, lumps, and other abnormalities may be detected during your screening process. However, it is not always possible to tell from the screening results whether the tumour or lump is cancerous or benign. To determine whether you are at risk of developing breast cancer, your doctor will recommend further imaging test or biopsy to be performed.
Breast cancer is a condition that causes the cells in your breast to grow out of control. It can occur in both men and women, but it is more prevalent among women. If left unchecked, breast cancer can spread outside your breast tissue through the circulatory or lymphatic systems to other parts of your body.
It occurs in four distinct stages and rarely presents symptoms during the early stages. The cause of breast cancer is unknown, but various risk factors may increase your risk of developing breast cancer. Regular checks and screening can help in early detection of breast cancer to increase your chances of survival.