Breast cancer month: Understanding stages, symptoms and importance of early detection

Global breast cancer awareness month

Did you know that each year, over 2.3 million women receive a breast cancer diagnosis?[1] In Hong Kong alone, more than 5,000 women received a breast cancer diagnosis in 2021.[2] These alarming statistics highlight the importance of October as International Breast Cancer Awareness Month. Therefore, it is crucial to promote early detection of breast cancer by discussing its various stages and the available screening methods.

But first, what is breast cancer? How does it begin? 

Breast cancer is one of the most diagnosed cancers, alongside lung, colon, and stomach cancers. This type of cancer originates in the milk ducts or the milk-producing lobules of the breast.[8] Without early detection and treatment, it can spread to nearby breast tissue and even throughout the body, potentially leading to fatal outcomes. However, if detected early—specifically in stages 0 to 1—breast cancer is highly treatable and survivable with a five-year relative survival rate of 99%.[3]

Stages of breast cancer 

Stage 0

• Definition: Cancerous cells are limited to their original location. It is non-invasive and has not spread to surrounding tissue.[3]

Stage 1

• Definition: Earliest stage of invasive breast cancer. The tumor is small and has begun to spread to breast tissue or nearby lymph nodes within a small area.[3]

Stage 2

• Definition: Relatively early stage of invasive breast cancer. The cancer has grown but it is still contained in the breast tissue or growth has only extended to axillary lymph nodes.[3]

Stage 3

• Definition: A relatively large tumor (5cm+) that has spread out of the immediate, or local, area in the breast and into the lymph nodes or muscles close to the breast.[3]

Stage 4

• Definition: Advanced breast cancer that has spread from the original location to other organs/parts of the body.[3]

For more information, please visit National Breast Cancer Foundation

To lower the risks of breast cancer, we can detect it early with:

1. Breast self-exam

   • Breast self-examination is an effective early detection tool that you can perform in the comfort of your own home.[4]

2. Diagnostic mammogram (x-ray)

   • A diagnostic mammogram is a more detailed type of X-ray specifically designed for breast cancer detection. It involves taking X-rays of the breast from various angles to capture a small area with maximum detail.[4]

3. Breast ultrasound

   • A breast ultrasound is an imaging test that utilizes sound waves to examine the internal structure of the breasts.[4]

4. Breast MRI

   • A breast MRI captures detailed images of the internal structure of the breast using powerful magnets, radio waves, and a computer.[4]

5. Biopsy

   • Typically performed after an abnormal lesion is detected on a mammogram or ultrasound. This procedure involves the removal of tissue or fluid from the breast for pathological analysis.[4]

   
   

How to know if you should actively check for breast cancer

While anyone, regardless of gender, can be at risk for breast cancer, certain inherited genetic mutations—most notably the BRCA1 and BRCA2 mutations—can significantly increase that risk.5 For instance, on average, only 8 out of 100 women without the BRCA1/2 mutations will develop breast cancer, whereas 60 out of 100 women with the mutations will face a breast cancer diagnosis.6 Similarly, mutations in other genes, such as TP53 and CDH1, can also elevate breast cancer risk.[6]

Without awareness of whether you carry these genetic mutations, your risk of developing late-stage breast cancer may increase. However, understanding your genetic status empowers you to manage your risk more effectively. By taking proactive steps—such as undergoing regular screenings, considering risk-reducing surgeries, and exploring risk-lowering medications—you can significantly enhance your chances of early detection and successful treatment.[7]

Reference

1. World Health Organization. (2024, March 13). Breast cancer. World Health Organization. https://www.who.int/news-room/fact-sheets/detail/breast-cancer#:~:text=In%202022%2C%20there%20were%202.3,increasing%20rates%20in%20later%20life. 

2. Centre for Health Protection, Department of Health - Breast Cancer. Centre for Health Protection. (2024, January 12). https://www.chp.gov.hk/en/healthtopics/content/25/53.html 

3. NBCF team. (2024, August 1). Breast Cancer Stages . National Breast Cancer Foundation. https://www.nationalbreastcancer.org/breast-cancer-staging/ 

4. Centers for Disease Control and Prevention. (2024, September 11). Diagnosing breast cancer. Centers for Disease Control and Prevention. https://www.cdc.gov/breast-cancer/screening/diagnosis.html  

5. The American Cancer Society medical and editorial content team. (2021, November 19). Breast cancer risk factors you can’t change. Breast Cancer Risk Factors You Can’t Change | American Cancer Society. https://www.cancer.org/cancer/types/breast-cancer/risk-and-prevention/breast-cancer-risk-factors-you-cannot-change.html#:~:text=BRCA1%20and%20BRCA2%3A%20The%20most,proteins%20that%20repair%20damaged%20DNA. 

6. Susan G. Komen Patient Care Center . (2024, June 6). Breast Cancer Risk Factors: Inherited Gene Mutations. Fact Sheet - NCI. https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet#:~:text=The%20risks%20of%20developing%20breast,during%20their%20lifetime%20(2). 

7. National Cancer Institute . (n.d.). BRCA Gene Changes: Cancer Risk and Genetic Testing. Cancer causes and prevention . https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet#:~:text=The%20risks%20of%20developing%20breast,during%20their%20lifetime%20(2). 

8. American Cancer Society. (n.d.). Breast cancer risk factors you can’t change. Breast Cancer. https://www.cancer.org/cancer/types/breast-cancer/risk-and-prevention/breast-cancer-risk-factors-you-cannot-change.html#:~:text=BRCA1%20and%20BRCA2%3A%20The%20most,proteins%20that%20repair%20damaged%20DNA.