Medical studies and research have shown that breast cancer is actually slightly more common in the left breast than the right breast in women. While no direct cause could be found for this discovery, certain factors have become known as the underlying cause for breast cancer being more common in the left breast. 

Before you learn why breast cancer left breast is more common, it is vital that you understand the risk is only slightly higher for the left breast. For women with a risk of breast cancer, the chances of malignant tumours surfacing stand possible for any of the breasts. There are several breast cancer screening methods available today that you still need to go through for both breasts to keep your cancer risk in check. 

With that being said, let’s take a closer look at some of the factors that may cause breast cancer to be more common in the left breast.

Reasons Why Experts Think Breast Cancer is More Common on The Left

The reasons listed below are not conclusive to cause a higher risk of breast cancer in the left breasts. However, these reasons are considered to be a contributing factor to this surprising fact. The additional risk is only explored in certain medical researches and the risk has been characterised as only a 5% to 10% higher risk for breast cancer in the left breast. This marginal risk increase doesn’t mean a significant divergence of your overall breast cancer risk. It also doesn’t mean that you should neglect your right breast during screening tests or personal screenings. Right side breast cancer is also equally a risk and should not be taken lightly.

1. More People Are Right Handed

This is one of the most commonly attributed reason why women have higher risk of breast cancer in the left breast. This is because more people are naturally right handed and when examining their breasts, they naturally examine the left breast first. It leads to a higher number of lump screenings in the left breasts, which leads to a larger number of malignant tumour screenings in the left breasts. Since the left breasts are examined more comparatively, it is touted as a reason why the cancer is diagnosed more on the left breasts.

2. The Left Breast is Larger

Breasts are almost never symmetrical with one breast being larger than the other. In most cases, the left breast is slightly larger than the right one. However, this is not a contributing factor for an increased risk of breast cancer in the left breast. The only case where the left breast being larger has an increased risk of breast cancer is when the person is suffering from obesity and the breasts are denser than usual. A larger breast or breast size doesn’t equate to a higher risk of breast cancer be it for the left or the right breast.

3. Breastfeeding Using The Right Breast

Women often choose to breastfeed using their right breasts. This is just a normal coincidence and a choice many women make subconsciously as a practical choice. However, as you may know, breastfeeding decreases the risk of breast cancer. Studies have shown women breastfeeding for upto 12 months can decrease their risk of breast cancer by 4.7%. This is why when women breastfeed using their right breast more often, it can marginally increase the risk of breast cancer in the left breast. However, this is not a tested hypothesis and has not been medically tested as of yet.

Conlusion

The risk of breast cancer left breast is just marginally higher and even though it is true, the real cause for this phenomenon is not medically understood yet. So, if you are experiencing breast cancer symptoms or are going through breast cancer screenings, be sure to screen for lumps and other symptoms of breast cancer on both your breasts. 

Presence of lumps on both breasts could be a sign of cancer metastasis where the cancer has spread from one breast to the other. Adequate screening and a timely diagnosis can help make breast cancer treatment easier. At MASSH we specialise in minimally invasive surgical treatments for breast cancer and can help you get precise and safe breast cancer treatment that allows quick recovery. 

For more information about breast cancer treatment at MASSH, check out our website. Our world class infrastructure and experienced team of surgeons offer highly directed and precise surgical treatments that remove malignant tumours with minimal risk of peripheral damage to surrounding structures. Visit us today to consult with our specialists and take the first step towards a cancer free life.