An overview of breast cancer

In this article, clinical oncologist Dr Shiroma De Silva-Minor explains the types of breast cancer and her approach to patient care.

Breast cancer is the most common cancer among women, with nearly 57,000 new cases each year in the UK, accounting for almost a third of all new cancer cases. Breast cancer is the most common cancer in the UK, accounting for 15% of all new cancer cases. It is the leading cause of death among women between the ages of 40 and 55. While it mainly affects women, men can also develop breast cancer.

The good news is that survival rates have more than doubled in the past 40 years due to advances in early diagnosis and treatment. Identifying breast cancers early allows more effective treatments and better long-term outcomes, so it is important to attend regularly for breast screening and to examine your own breasts.

How does breast cancer develop?

Breast cancer begins with abnormal cells developing in breast tissue. It can be confined to the breast or may spread beyond your breast and into other parts of your body. The most common type of breast cancer begins in the ducts designed to carry milk to the nipple. But cancer also may occur in the small sacs that produce milk, called lobules, or in other breast tissue. Breast cancer varies widely, and the treatment options are selected to match your individual needs.

The types of breast cancer

Breast cancer may occur in several different forms, such as the five types below:

Breast cancer in situ, DCIS and LCIS. Many breast tumours detected early, typically by mammography, are classified as 'carcinoma in situ' or 'precancerous'. These early cell changes may develop into invasive breast cancer. The two types of breast cancer in situ are:
DCIS (ductal carcinoma in situ) means that abnormal cells are found only in the lining of a milk duct of the breast and have not spread outside the ducts. There are several types of DCIS. If not removed, some may change over time and become invasive cancers, while others may not. DCIS is sometimes called intraductal carcinoma.
LCIS (lobular carcinoma in situ) means that abnormal cells are found in the lining of the milk lobules. Although LCIS is not an actual breast cancer at this non-invasive stage, it is a warning sign of an increased risk of developing invasive cancer. LCIS is sometimes found in a biopsy for another lump or unusual change detected on a mammogram.
Invasive breast cancer. These cancer cells form in the ducts or the milk lobules and spread to the breast tissue around them. Tumours can be found during a breast examination or through screening, such as a mammogram. The size of the tumour, what it looks like under the microscope and whether it has spread to the lymph nodes determine the severity of the cancer. This information, along with the molecular subtype of breast cancer, will inform the optimal gold standard therapies.
Metastatic (stage IV) breast cancer. Metastatic cancer begins in the breast but spreads outside the breast through the blood or lymph system to other organs. Women usually develop metastatic disease in the months or years following the diagnosis of breast cancer, but in a minority, there will already be metastasis at the time of diagnosis of breast cancer. This is more likely if the breast cancer is large, aggressive or has spread to many regional lymph nodes. Metastases from breast cancer most commonly spread to the bones, lungs, liver or brain.
Locally advanced breast cancer. Inflammatory breast cancer is a rare but very serious and aggressive type of breast cancer. The breast may look red and feel warm. A patient may see ridges, welts or hives on the breast, or the skin may look wrinkled. It is sometimes misdiagnosed as an infection.
Recurrent breast cancer. Recurrent disease means that the cancer has come back or recurred after treatment. It may come back in the breast, in the soft tissues of the chest or chest wall, regional lymph nodes, or another part of the body.

My approach to breast cancer

I understand that being given a diagnosis of breast cancer is incredibly stressful and frightening. But there is room for much optimism at every stage. I believe in empowering my patients with the information and knowledge they may want to guide their decision making, to achieve the best outcomes. I have devoted much of my professional life to understanding and treating solely breast cancers, as I believe the nuances of this vast and expanding area of oncology require total dedication. As a clinical oncologist, I am also able to offer both radiotherapy and chemotherapy/ systemic therapies and therefore have an overview of the entire therapeutic pathway and the full armoury of treatments and not just one aspect of your care. I will always advise on the best evidence-based treatments, tailored to your particular situation and taking into account your personal beliefs and preferences. I consider all aspects of the treatment pathway, with a holistic approach considering diet, exercise, mental and sexual health and aiming to minimise toxicity. My team and I are here to support you and your family in any way that we can, through your cancer journey.