Breast cancer is also known as breast carcinoma. It is an uncontrolled growth of epithelial cells within the breast. It’s the second most common type of cancer in women, but it can also on rare occasions affect men as well. Breast cancer is also the second leading cause of cancer deaths in women while lung cancer is in the first position. This is largely due to the fact that most of the time breast cancers don’t cause any pain or discomfort until they spread to nearby tissues.
In this article, Dr. Sandeep Nayak explains the causes & symptoms of breast cancer. Dr. Sandeep Nayak is one of the best oncologist in India. He is an expert in Laparoscopic and Robotic surgery. Dr. Nayak says that it is better to understand breast anatomy before going deep into the causes of breast cancer. So, let’s look into the anatomy of the breast.
The breasts are milk-producing glands that sit on the chest wall on either side of the breastbone. They lie on top of our ribs and the pectoral muscles and are divided into three major parts. The glandular tissue that makes the milk is made up of 15 to 20 lobules. Inside each of these, a bunch of grape-like structures called the alveoli are present which are modified sweat glands surrounded by a basement membrane made largely of collagen. Zooming in on the alveoli there’s a layer of alveolar cells that secrete breast milk into the lumen. Lumen is the space in the center of the gland. Wrapping around the alveolus our special myoepithelial cells that squeeze down and push the milk out of the lumen of the alveolus down the lactiferous ducts and out one of the pores of the nipple.
Now surrounding the glandular tissue is the stroma which contains adipose tissue which makes up the majority of the breast. Suspensory ligaments called Cooper’s ligaments run through the stroma and helps to keep it in place. These ligaments attach to the inner surface of the breast on one end and the pectoralis muscle on the other. Just beneath the skin covering our breast, there’s a network of tiny lymphatic vessels. They drain the lymph which is a fluid containing cellular waste products and white blood cells. These lymphatic vessels mainly drain into a group of lymph nodes in the armpit.
Causes of Breast Cancer
The cells of glandular tissue have receptors for certain hormones like estrogen and progesterone which are released by the ovaries & prolactin, which is released by the pituitary gland. These hormones stimulate the alveolar cell division and increase in number which makes the lobule enlarged. Without these hormones the glandular cells particularly the alveolar cells can’t survive and undergo apoptosis, which is programmed cell death. For example after menopause estrogen production stops which leads to the death of the alveolar cells and over time that breast tissue gets
replaced by fat. During the menstrual cycle, there are increased secretion of estrogen and progesterone from the ovaries, and right after menstruation that secretion decreases. As a result, during every menstrual cycle, the alveolar cells go through division and apoptosis. Men have some breast tissue as well, but they lack milk-secreting cells. Each time cells divide there’s a chance of genetic mutation, and a mutation can lead to tumor formation.
Women Breast cancer
- With more number of menstrual cycles, there is an increased risk of tumor formation. Things that increase the number of menstrual cycles, like the early age of menarche which is the first menstrual bleeding and the late age of menopause can be the reason for breast cancer.
- Medications containing estrogen hormones also increase the risk of breast cancer in women. 3. There are also other environmental risk factors such as ionizing radiation from chest x-rays and CT scans.
- Mutations in tumor suppressor breast cancer genes brca1 or brca2 are both autosomal dominant mutations, which can be inherited and cause familial breast cancer in addition to breast cancer. They also increase the risk of ovarian cancer.
Male breast cancer –
Male breast cancer is usually caused by inherited mutations in the brca1 and 2 genes. Once a cancer-causing mutation does occur the affected cell which is most commonly an epithelial cell begins to grow and replicate out of control forming a tumor. This tumor also called an in situ
carcinoma is initially localized within the basement membrane and can be of two types. The first type is called ductal carcinoma in situ or DCIS.
The second type is called lobular carcinoma in situ or LC.
- The first symptom of breast cancer is a hard painless lump or swelling. It is most commonly seen in the upper and outer part of the breast.
- Swelling under the armpit might occur if cancer is spread to the axillary lymph nodes. 3. Breast cancer can make the affected breast immobile and fixed or stuck onto the chest wall. It happens due to infiltration if cancer cells spread into the pectoral muscles.
- Another symptom is the dimpling of the skin over the breast due to the involvement of the skin. 5. Fibrosis of lactiferous ducts and suspensory ligaments might cause retraction or pulling in of the nipples.
- If pageant disease is present, it will cause itching, redness, crusting, and discharge from the nipple.