Definition: what is breast cancer?
Breast cancer is caused by the presence of abnormal cells which multiply uncontrollably in the breast and can spread throughout the body through the blood or lymphatic vessels. The progression of breast cancer can last from several months to several years.
To better understand breast cancer, it is important to know how it is formed. The breast is made up of fat and glands as well as ducts. The glands are used to produce milk, whilst the ducts known as “mammary ducts” are used to transport the liquid to the teat. There are different types of breast cancer that affect different areas and progress in different ways.
The two most noteworthy types are:
- non-invasive (or non-infiltrating) breast cancer: it is known as non-invasive when the tumour only affects the lobules and ducts and does not extend to the tissue around them. In this category is in situ ductal carcinoma, which is the most common non-invasive cancer in women. It forms on the inside of the lactation ducts of the breast. In less common situations there is the in situ lobular carcinoma, which affects the breast lobules.
When screening is done early, these cancers don’t often spread, and their treatment is curative. Nevertheless, without treatment, they can continue to grow and become “invasive”.
- invasive cancers: it is known as invasive cancer when the disease spreads to the tissues around the lactation ducts, although still remaining within the breast. In the absence of treatment, the tumour can generate metastases, and spread in other parts of the body. There are various types of invasive cancers: ductal carcinoma, lobular carcinoma, inflammatory carcinoma, etc.
Contrary to popular belief, breast cancer can affect men, but they only represent 1% of cases.
Causes: what are the risk factors of breast cancer?
It is very difficult to exactly explain why this cancer appears in an individual. However, research has allowed us to identify certain factors that support its occurrence. Among them, they primarily include genes BRCA1 and BRCA2. Some mutations of these genes cause an increased risk of cancers in the breasts and ovaries.
Furthermore, breast cancers caused by a genetic predisposition only represent a small percentage of cases (between 5 and 10%) and contrarily, cancers known as non-hereditary, represent 90-95% of cases. With breast cancer being a hormone-dependant cancer, it is possible that things that are able to increase the rate of oestrogen such as early puberty, late menopause or exposure to endocrine disruptors for example, can also increase this risk.
Symptoms: how to screen breast cancer
Breast cancer symptoms aren’t always really visible, but some can be detected by touching the breast. These symptoms mostly include the appearance of bumps extending to a centimetre which aren’t too painful.
The breast can also change unusually in size or shape. The teat can shrink and retract towards the inside and it is possible to note spontaneous flows from it. The patient can also detect dimples or widening wrinkles on the surface of the skin and as soon as any of these signs start to appear, it is important to quickly consult a doctor.
With the help of a clinical test, the doctor can give the first diagnosis which will then be confirmed by a mammography. This is because breast cancer isn’t the only reason why breast tissue varies and changes appearance. Other factors can also have this effect, such as pregnancy, the menstrual cycle, an infection or a cyst. Because of that, a nodule detected in the breast doesn’t necessarily mean cancer.
Breast cancer develops in three quarters of cases in women aged over 50, but it can also appear in younger women, especially in those with a genetic predisposition. Breast cancer is the main cause of death in women between the ages of 35 to 65.
Treatment: how to treat breast cancer
Treating breast cancer depends on the type and stage of development however, surgery is inevitable. In order to know more about the characteristics of the cancer, there are different tests that can be done: an oestrogen hormone test and a progesterone hormone test, in order to know if the growth of the cancer can be stimulated by hormones.
The HER2 test is only used for invasive cancer. It is done in order to know the degree of activation of the HER2 gene, when it is considerably activated, it is an indication that the cancer is likely to grow more quickly. Then comes the treatment, of which there are 5 categories:
- Surgery: This is often the first treatment employed and it is used to remove the cancerous tumour. In the case of breast cancer, this operation is called a mastectomy. It can be partial, segmental (only one part of the breast is removed) or total. The choice of the type of mastectomy relies, among other things, on the size of the tumour, its location in the breast and its type. Patient preference can also be taken into account.
- Radiotherapy: A partial mastectomy is always followed by radiotherapy. It is used to destroy the cancerous cells that remain and reduce the risk of the tumour reappearing.
- Chemotherapy: This cancer treatment uses a class of drugs called antineoplastics or chemotherapy agents. Generally administered after surgery, chemotherapy destroys the cancerous cells of the tumour which would spread to the rest of the body.
- Hormonal therapy: In the majority of cases combined with surgery, radiotherapy or chemotherapy, hormonal therapy is employed when the hormonal tests show that the cancer development is very stimulated by sexual hormones. These drugs slow down or stop the progression of the cancer by blocking the hormone action. They include antioestrogens and aromatase inhibitors.
- Targeted therapy: In women who are affected by invasive breast cancer, the cancerous cells overexpress the HER2 gene, causing an acceleration in the growth of the tumour. In this case, medication is administered using an intravenous injection called trastuzumab, which specifically block the HER2 action.
Nowadays, the increase in use of mammograms is used to screen breast cancers earlier. As soon as they are detected, the better the care will be, which means a decrease in the mortality of breast cancer.