Breast Cancer

Breast Cancer is a disease in which the mammary gland cells grow uncontrolled.

Author:	Doctor Anny Palencia
Reviewed by:	Ana Codallo, CTO
Last Updated on Aug 18, 2023

The breast has three main parts: the lobules, the ducts, and the connective tissue. The different types of breast cancer will depend on the area of the breast that is affected.

• The lobules of mammary glands produce milk.
• The ducts (milk ducts) are the tubes that carry milk from the lobule to the nipple.
• Connective tissue is a framework that supports and surrounds all breast parts. It comprises fibrous and adipose tissue.

  Most breast cancers start in the ducts or lobules.

Cancer can spread outside the breast through blood vessels or lymph nodes; this spread is called metastasis.

What Is the ICD 10 Code for Breast Cancer?

The ICD / ICD 10 code for Breast Cancer is "C50" (Malignant neoplasm of breast).

Symptoms of Breast Cancer

Breast cancer can be asymptomatic in many people, especially in the early stages. Each person may have different symptoms. Among the most common symptoms of breast cancer, we have:

• A lump or mass in one of the breasts of variable size. It may be as small as a pea.
• Thickening, swelling, or lump in the breast or in the armpit region, which does not disappear even with menstruation.
• Irritation, pain, or sinking in the skin of the breast or nipple.
• Redness or scaling on the skin of the nipple.
• Changes in the size, shape, or curvature of the breast.
• Clear or bloody discharge from the nipple.
• Any area in either breast of recent onset that presents as a spot, elevation, or ulceration; the site may or may not be painful.

Types of Breast Cancer

The different types of breast cancer depend on their location and their ability to spread:

Cancers in Situ

These types of cancers do not extend beyond the duct or lobule where they originated. In turn, they can be:

• Ductal carcinoma in situ (DCIS): Found in the milk ducts and does not spread. It is the earliest stage of the disease, or stage 0, but if left untreated, it can become invasive. It is generally curable.
• Lobular carcinoma in situ (LCIS): This is when cancer-like cells grow in the lining of the milk-producing glands but do not penetrate the wall of the lobules. According to the American Cancer Society, lobular carcinoma in situ is not cancer because it does not spread beyond the lobules, even if not treated. But it increases the risk of invasive cancer in any of the breasts later.

Types of Breast Cancer Invasive Cancers

This type appears when cancer has spread into the surrounding breast tissue. These include the following:

Invasive or Infiltrating Ductal Carcinoma (IDC)

The most common type and represents 80% of invasive cancers. It begins in the milk ducts and crosses the duct wall, invading the breast's fatty tissue.

Invasive Lobular Carcinoma (ILC)

This type accounts for about 10% of invasive breast cancers; it begins at the level of the lobules and spreads to surrounding tissues or other parts of the body. It also has some subtypes:

• Adenoid cystic (or adenocystic) carcinoma: These resemble cells found in salivary glands.
• Low-grade adenosquamous carcinoma: It is rare and slow growing.
• Medullary carcinoma: Rare, soft in consistency.
• Carcinoma mucinous: Rare, slippery, and viscous material.
• Papillary carcinoma: Rare, more common in postmenopausal women, has finger-like projections.
• Tubular carcinoma: Slow-growing and tube-shaped.

Triple-Negative Breast Cancer

It is a type of breast cancer in which receptors for hormones or proteins that are usually present in most breast cancer cases are not present.

Receptors for breast cancer include receptors for the female hormones, estrogens, progestins, and receptors for a protein called human epidermal growth factor (HER2).

The receptors are like keys to the cancer gate; if there are no receptors, the treatments are ineffective because they do not open those gates.

In these cases, the treatment is a lumpectomy (removal of the tumor) or a mastectomy (removal of the entire breast). Chemotherapy is then applied to finish killing any cancer cells that may remain. In some cases, chemotherapy or radiation therapy is used before surgery to reduce the size of the tumor and limit its spread.

Inflammatory Breast Cancer

It is a rare but rapidly spreading type of cancer where the breasts are red, swollen, and tender. It involves the obstruction of blood vessels and lymph nodes.

The diagnosis follows the same steps for other types of breast cancer, and the treatment depends on the stage found. The treatment includes surgery, radiation therapy, chemotherapy, estrogen modulators, and hormonal chemotherapy.

Other Types

Other less common types of breast cancer are:

• Paget's disease of the nipple: Affects the areola, which is the dark skin around the nipple.
• Phyllodes tumors of the breast: These are rare and grow rapidly but rarely extend beyond the breast.

Causes and Risk Factors of Breast Cancer

The sole cause of breast cancer is undetermined. There are several factors associated with breast cancer, which, together, increase the probability of suffering from this disease. You can modify some aspects but not others.

The main risk factor for breast cancer is being a woman over 50.

Men account for less than 1% of all breast cancer cases. In women, breast cancer is the second most common cancer diagnosed. And it is the second cause of death from cancer after lung cancer.

Regarding age, nearly two-thirds of women with breast cancer are 55 or older, and the rest are between 35 and 54 years of age, mostly.

Risk Factors for Breast Cancer: Non-Modifiable Risk Factors

• Age
• Genetic mutations: Changes (mutations) in the BRCA1 and BRCA2 genes can be inherited; these increase the risk of breast and ovarian cancer.
• Reproductive history: Exposure to hormones occurs during a woman's reproductive life. Therefore, if menarche, the onset of menstruation, is early (under 12 years) and menopause is late (over 55 years), the probability of suffering from breast cancer is more significant due to greater hormonal exposure.
• Having dense breasts: When the breasts have more supporting tissue (connective tissue) than fatty tissue, it is more difficult to see early lesions on a mammogram.
• Personal history: A more significant risk exists in a person who has already suffered from a benign breast condition, even more so if they have had any other type of breast cancer.
• Family history: When breast cancer occurs in first-degree relatives (mother, sister, or daughter), there is an increased risk of developing breast or ovarian cancer. This risk also increases if several relatives on the maternal or paternal side have a history of breast cancer. Having a male relative (first-degree) who has had breast cancer also increases the risk.
• Previous treatments with radiotherapy: Radiotherapy to the chest or breasts in people under 40 years of age, whether due to lymphoma or another cause, represents a greater risk of presenting breast cancer at some point in life.
• Exposure to Diethylstilbestrol: This drug was used between 1940 and 1971 to prevent abortion; therefore, if the mothers used it, the risk is more significant for the women who were the product of those pregnancies.

Risk Factors for Breast Cancer: Modifiable Risk Factors

• Physical activity: Physically active women have a lower risk of developing breast cancer.
• Overweight or obesity: Especially after menopause, the risk is more significant in these patients than those with a healthy weight.
• Hormone use: Hormone replacement therapy with estrogens and progestins for more than five years and some oral contraceptives increase the risk of breast cancer.
• Reproductive history: Not having children, not breastfeeding, starting to have children after 30, and never reaching term in pregnancies increases the risk of breast cancer.
• Alcohol intake: Studies have reported that the greater the alcohol consumed, the greater the probability of developing breast cancer.

Stages of Breast Cancer

There are different stages within the disease:

* Early-stage breast cancer, stage 0 or non-invasive: The disease is confined only to the breast without the involvement of lymph nodes; this is the so-called carcinoma in situ.

* Stage I breast cancer: The cancer is 2 cm or smaller and has not spread to lymph nodes.

* Stage IIA breast cancer: This stage includes three forms:

• There is no evidence of a tumor, but there is the involvement of the axillary lymph nodes without spreading to the body.
• The tumor is 2 centimeters across or less, involving axillary lymph nodes, but without spreading to the body. 
• The tumor is more than two but less than 5 centimeters across, with no axillary lymph node involvement.

Stage IIB breast cancer. The tumor can have two forms:

• It is more than 5 centimeters across but without axillary lymph node involvement.
• It measures more than two but less than 5 centimeters, involving axillary lymph nodes.

Stage IIIA breast cancer, also called locally advanced breast cancer, includes:

• Tumors larger than 5 centimeters spread to internal mammary or axillary lymph nodes.
• Any size tumor with cancerous lymph nodes adhering to each other or surrounding tissue.

Stage IIIB breast cancer is a tumor of any size that has spread to the skin or chest wall, causing breast ulceration; there is no spread to other body parts.

Stage IIIC breast cancer: Tumor of any size which has spread more than stage IIIB and to 10 or more lymph nodes. No spread to other parts of the body.

Stage IV breast cancer: It is a metastatic tumor, that is, it has spread to other areas far from the breast, such as bones, lungs, liver, brain, or distal lymph nodes.

Diagnosis of Breast Cancer

When a palpable lump or mass appears in the breast, or a striking image on the mammogram, screening for breast cancer begins by broadening the history, including information about the history of breast or ovarian cancer and other risk factors for this disease. After the questioning and the corresponding physical examination, testing begins, including:

• Ultrasound or also called breast echography.
• Mammography can be the initial one or magnification of an area that drew the physician's attention from a previous study.
• Magnetic Resonance Imaging (MRI) consists of a body scan with a magnet connected to a computer, creating detailed images of the inside of the breasts.
• Biopsy, in which the doctor removes tissue or fluid from the breast to study it under a microscope to check for cancer cells.

For this test there are several ways to do it:

* Fine needle aspiration

* Core needle biopsy

* Surgical biopsy (open technique)

* Lymph node biopsy

* Image-guided biopsy

Breast Cancer Treatment

Breast cancer has several types of treatment, and generally, they can be applied together depending on the type of cancer and the degree of dissemination. These include:

• Surgery: Removal of cancerous tissue, trying to leave healthy edges.
• Chemotherapy: In which certain drugs shrink the tumor and kill cancer cells; this includes pills, intravenous medications, or both simultaneously.
• Hormone therapy: Aims to compete with tumor receptors to prevent cancer from getting the hormones it needs to grow.
• Biological therapy: It stimulates the immune system to control cancer cells and modulate some symptoms secondary to other treatments.
• Radiation therapy: In which radiation kills cancer cells.

Mastectomy

A mastectomy is the complete surgical removal of the breast and nearby lymph nodes, the latter to check for the spread of cancer cells.

Breast Reconstruction

It involves placing a breast prosthesis under the muscle through the same scar as the mastectomy. Sometimes this procedure requires several surgeries when the existing tissue is insufficient to support the implant.

What Is Fibroadenoma?

Fibroadenoma is a benign breast tumor generally appearing in young women; its cause is reproductive hormones.

It is a soft or firm lump that is mobile on palpation and can be painful. The diagnosis requires an ultrasound, and its treatment is surgical removal; otherwise, it can last many years or a lifetime.

Dr. Steven Alexander Narod: KOL #1 for Breast Cancer

According to KOL's technology, Dr. Steven Alexander Narod is the top ranking Key Opinion Leader (worldwide) for Breast Cancer. You can see Dr. Steven Alexander Narod's KOL resume and other concepts for which they rank #1 worldwide.

Steven Alexander Narod University of Toronto, Women's College Hospital Women's College Research Institute 6th Floor 76 Grenville Street Toronto ON M5S 1B2

KOL #1 (worldwide) for: Breast Cancer

Dr. Steven Narod is one of the world's foremost breast cancer researchers with over 700 publications to date. He is based at Women's College Hospital at the University of Toronto where he is the Canada Research Chair in Breast Cancer. He's a professor with the Dalla Lana School of Public Health and the Department of Medicine at the University of Toronto. His work has critically examined assessment of risk for women with breast and ovarian cancers. He has also researched cancer genetics, cancer prevention and treatment.

Biography courtesy of: https://www.cbc.ca/radio/ideas/the-2016-killam-prize-1.3591240

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