KUALA LUMPUR, Oct 17 — Breast cancer remains the most common cancer affecting women worldwide, with one out of every 19 women at risk each year In Malaysia.
With no cure yet in sight, life-saving early detection, and when the disease is in a localised stage, provides a five-year relative survival rate of 99 per cent, according to the American Cancer Society.
A rising misconception among women today is that one is safe from the disease if there is no history of breast cancer in the family. As a result, some women may take a more casual attitude towards the disease.
However, Dr Winnie Ng, clinical oncologist at Subang Jaya Medical Centre (SJMC), said: “Even if one has no known family history of cancer, external factors such as environmental exposures, prolonged exposure to female hormones and lifestyle features may contribute to an increased relative risk of breast cancer.”
Several risk factors may increase the chances of getting breast cancer. Risk factors can be categorised as modifiable and non-modifiable.
“There are numerous underlying causes of cancer. One cannot assume that only genetics play a part. Alcohol intake and smoking are also lifestyle factors that increase risk of breast cancer development,” said Dr Ng.
“Prolonged exposure to female reproductive hormones is also a known risk factor. These are women who reach first menstruation at an early age, have never been pregnant, or are at a late age during their first full-term pregnancy, or on oral contraceptive pills. Late menopause also increases the risk of developing breast cancer. Postmenopausal women who are on hormone replacement therapy or obese are associated with increased breast cancer risk too,” she added.
“Therefore, women with no family history of breast cancer should not take screening lightly as it is essential for early detection and recommended for women across all age groups, and those exposed to higher-risk factors. The easiest method of screening is by self-examination of the breast.”
Dr Ng added that a positive family history of breast cancer or inherited genetic mutations would fall within the second category of non-modifiable risk factors. In this instance, the risk of developing breast cancer increases by one and a half times to three-fold if a woman has a mother or sister with breast cancer.
Mutations in breast cancer-susceptible genes such as BRCA1 and BRCA2 are also associated with significant increase of breast cancer. Certain benign breast conditions also contribute to increased risk, while additional exposure to ionising radiation increases the risk of breast cancer, such as multiple diagnostic X-rays to the chest, or previous history of irradiation to the chest at an early age.
She further added that some early signs of breast cancer to watch out for are swelling in part of the breast or swollen lymph nodes under the arm, itchy or irritated breast, change in breast colour, or an increase in breast size or shape.
Through self-examination, one may notice the breast skin feels hard, tender, or warm, and there is redness, peeling or flaking of the nipple skin. Some may notice skin dimpling or their nipple turning inward, also known as nipple retraction. Some women may experience nipple discharge. These symptoms may or may not come with breast pain.
With the discovery of mutation in genes that can lead to breast cancer among certain groups of people, technology advancements like Next Generation Sequencing (NGS) have played a revolutionary role in genetic testing for BRCA1 and BRCA2.
According to Prof Dr Pathmanathan Rajadurai, consultant pathologist and laboratory director at SJMC, there are two types of genetic testing for breast cancer, namely germline testing, which detects mutations that can be inherited, and somatic testing, which detects mutations that arise sporadically in the tumour.
“NGS germline testing for BRCA1 and 2 mutation detection can be done if the patient has a strong family history of cancers such as breast, ovarian, prostate, or pancreatic malignancies. It is recommended that a patient has genetic counselling before and after testing for hereditary mutations so that the patient can make informed decisions about genetic testing. For example, counselling can help to determine if they are suitable candidates for hereditary testing,” he said.
In addition to new technology, recent breast cancer genomic research is also making headway in managing the disease in Malaysia and Asia. While genomic research data in the past was predominantly focused on Caucasians, as a result of a collaboration between Cancer Research Malaysia, SJMC and the University of Cambridge, the largest genetic and genomic database of Asian breast cancer to date has been created.
“It is important to build a database which is representative of different ethnic groups because the breast cancer susceptibility mutations can vary depending on the geographical origins and ethnic groups. Some of these mutations are only found in the Asian population and the identification of these susceptibility mutations is a key first step to better understanding how they can impact the risk of developing breast or ovarian cancer,” Dr Pathmanathan added.
With the race to find a cure still in progress, early detection and screening remain the most practical solutions to discover the disease early. While breast cancer is more prevalent among older women, younger women are also at risk.
Dr Ng noted that women below 40 are recommended to undergo a breast ultrasound as the appropriate screening method as their breasts are denser, while women above 40 are advised to go for a mammogram.
“A breast cancer diagnosis is not a death sentence. Self-tests and regular screenings can save lives,” she said.