Breast cancer is the most common cancer in women worldwide. The estimated incidence of new breast cancer for women aged 40-44 years is 63.3/100,000. The incidence of breast cancer increases with age, with the highest incidence occurring after menopause.

Every year, Pakistan sees over 30,000 new cases of breast cancer, a prevalence that is growing rapidly and raising significant concern about the need for increased awareness and early detection efforts.

The risk of breast cancer increases with age. Most breast cancers are diagnosed in women over the age of 55.

In the early stages, breast cancer may not show any symptoms. The tumour may be too small to be felt. However, mammography can still detect tumours. Breast cancer symptoms:

• Palpable lump in the breast
• Swelling in all or part of the breast
• Skin irritation
• Breast skin pulling back
• Nipple discharge

Lumps in the breast or armpit area can be a sign of breast cancer. These lumps are usually diagnosed with mammography.

This may mean that the breast cancer has spread to the lymph nodes in that area. Sometimes these bumps may be there even if you can’t feel the lump. Therefore, see your doctor if you notice any abnormal changes.

Irritations such as redness, eczema, sores and cracking may occur in the breast. In addition, the breast appears similar to an orange peel.

There may be retraction of the breast skin or nipple. These are among the symptoms of breast cancer.

You should consult with your doctor if there is discharge from the nipple, and particularly if the discharge is red or pink.

Breast cancer is divided into stages depending on how large the tumour or tumours are and how far they have spread. The most widely used system for determining the stage of breast cancer is the TNM staging system.  Stages provide a prognostic indicator and guide treatment decisions.

Stage 0: Cancer cells have not gained the potential to spread. Non-invasive Breast Cancer (ductal or lobular carcinoma in situ) is defined as stage 0 disease. The cancer is still confined to the originating ducts or lobules and has not metastasised.

The most widely used system for determining the stage of breast cancer is the TNM staging system. Stages provide a prognostic indicator and guide treatment decisions.

Non-invasive Breast Cancer (ductal or lobular carcinoma in situ) is defined as stage 0 disease. The cancer is still confined to the originating ducts or lobules and has not metastasised.

Early Breast Cancer refers to locally or locoregionally invasive cancer (stage I, stage II and some stage IIIA tumours) that can be surgically removed.

Locally Advanced Disease refers to locoregionally invasive cancer (stage IIIB, stage IIIC and some stage IIIA tumours) that has not spread to adjacent tissues such as adjacent lymph nodes, skin or chest wall and cannot be surgically removed.

Metastatic Breast Cancer refers to stage IV disease only. Cancer cells have spread to distant parts of the body through the lymphatic system or the bloodstream. 

Stage 1: The tumour is less than 2 cm in size.

Stage 2: The size of the tumour is between 2 and 5 cm. This stage is divided into stages IIA and IIB.

Cancer in Stage IIA;

• It has spread to the axillary lymph nodes
• It has spread to the axillary lymph nodes and is 2 cm or smaller.
• It is between 2 cm and 5 cm and has spread to the axillary lymph nodes.

Cancer in Stage IIB;

• It is larger than 2 cm and smaller than 5 cm and has spread to the axillary lymph nodes. 
• It is larger than 5 cm but has not spread to the axillary lymph nodes.

Stage 3: Divided into 3A, 3B and 3C.

Cancer in Stage 3A;

• It is 2 cm or smaller. The cancer has spread to the lymph nodes in the axillary lymph area or the rib cage lymph nodes.
• It is larger than 2 cm but smaller than 5. The cancer has spread to the axillary lymph nodes or the lymph nodes of the rib cage.
• It is larger than 5 cm. The cancer has spread to the lymph nodes in the axillary lymph area or near the sternum.

Stage 3B: The tumour has spread to the skin of the breast or the lymph area near the rib cage, axillary lymph areas.

Stage 3C: The cancer has spread to the chest wall or breast skin.

Stage 4: The cancer has spread to other organs in the body.

Patients with a family history may be candidates for genetic testing. The most common mutations linked to breast cancer are BRCA1 and BRCA2 mutations. Individuals with this mutation are more likely to develop breast cancer.

In case of a palpable lump or suspicious area; the size of this mass and its relationship to the skin and chest muscles should be thoroughly examined.  Generally, irregularly circumscribed, painless and firm masses are more likely to be tumours. Other signs and symptoms: swelling of a part of the breast, skin irritation, unusual asymmetry, pain and retraction of the nipple, redness or scaling of the nipple or breast skin, or discharge. In some cases, the first sign of breast cancer is adenopathy, usually in an axillary lymph node.

In some patients with oestrogen/progesterone receptor-positive tumours who are candidates for hormonotherapy and for whom a definitive decision cannot be made in terms of chemotherapy, the Oncotype-DX test, a genetic test in breast tumour samples, has been used in recent years to guide this decision.

The Oncotype-DX test is a test that determines the risk of recurrence through the calculation of a recurrence score by looking for the presence in the tumour of 21 genes involved in cancer recurrence.

The decision regarding the treatment of the patient is based on the stage and size of the tumour, grade and metastasis potential, HER2 positivity, physical condition of the patient (WHO, Karnofsky scales), age, preference and psychological status of the patient. Treatment options in breast cancer are:

• Local
• Surgical
• Radiotherapy
• Systemic
• Hormone therapy
• Chemotherapy
• Biological treatment
• Supportive treatment

Once the cancer is diagnosed, surgery is the first step, unless the patient has a special condition.  Breast cancer surgery is divided into different groups:

Lumpectomy: Performed to remove only the tumour and some surrounding tissue.

Mastectomy: In this procedure, the entire breast is removed.

Sentinel Lymph Node Biopsy: Before surgery, the patient’s lymph nodes are checked for tumours. If no tumour is found in this procedure, no further treatment is required. However, if the opposite is the case, axillary-armpit lymph node dissection is used.

Axillary lymph node dissection: The aim of this procedure is to determine the stage of the disease. If cancer has spread to the axillary lymph nodes, treatment is applied.

Mammography can detect microcalcifications that may be specifically associated with malignancy. It is also used as a screening test.

Figure: A normal breast (left) and a breast with an invasive tumour (right)

Breast ultrasonography is widely used in the diagnosis of breast cancer to evaluate a specific abnormality detected in mammography. Ultrasonography can help differentiate between cysts and solid masses, benign and malignant tumours. 

- MRI, - CT, - PET

A biopsy is required for definitive diagnosis.

• Fine Needle Aspiration (FNA): The FNA technique is most likely used to differentiate benign cysts from tumours.
• Core Biopsy: Core biopsy is rapidly replacing FNA as the treatment of choice for breast cancer because of its ability to examine tissue structure under a microscope.
• Surgical Biopsy: Involves surgically removing the entire lump or abnormal area. This is more invasive but is sometimes required if needle biopsy results are inconclusive or if a larger tissue sample is needed.

The prognosis worsens as the cancer spreads to the lymph node and the number of cancerous nodes increases. Lymph node status is most often assessed using the following methods:

If there are more intracellular oestrogen receptors (ER) and progesterone receptors (PR) than normal, cancer can grow faster in the presence of these hormones. The test results show whether treatment that blocks oestrogen and progesterone can stop the cancer from growing.

When higher than normal levels of HER2 protein are present on the cell surface, the cancer can grow faster and is more likely to spread to other parts of the body.

Breast cancers with no (or very low) expression of ER, PR or HER2 receptors are known as triple negative breast cancers. These tumours are associated with a poor prognosis.