Breast cancer in men, what is it?

A breast cancer is a malignant tumor that starts from cells of the breast. A malignant tumor is a group of cancer cells that may grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body. Breast cancer occurs mainly in women, but men can get it, too. Many people do not realize that men have breast tissue and that they can develop breast cancer.

Normal breast structure

To understand breast cancer, it helps to have some basic knowledge about the normal structure of the breasts.

The breast is made up mainly of lobules (milk-producing glands in women), ducts (tiny tubes that carry the milk from the lobules to the nipple), and stroma (fatty tissue and connective tissue surrounding the ducts and lobules, blood vessels, and lymphatic vessels).

Until puberty (usually around 13 or 14), young boys and girls have a small amount of breast tissue consisting of a few ducts located under the nipple and areola (area around the nipple). At puberty, a girl's ovaries make female hormones, causing breast ducts to grow, lobules to form at the ends of ducts, and the amount of stroma to increase. In boys, hormones made by the testicles keep breast tissue from growing much. Men's breast tissue has ducts, but only a few if any lobules.

Like all cells of the body, a man's breast duct cells can undergo cancerous changes. But breast cancer is less common in men because their breast duct cells are less developed than those of women and because their breast cells are not constantly exposed to the growth-promoting effects of female hormones.

The lymph (lymphatic) system of the breast

The lymph system is important to understand because it is one of the ways that breast cancers can spread. This system has several parts.

Lymph nodes are small, bean-shaped collections of immune system cells (cells that are important in fighting infections) that are connected by lymphatic vessels. Lymphatic vessels are like small veins, except that they carry a clear fluid called lymph (instead of blood) away from the breast. Lymph contains tissue fluid and waste products, as well as immune system cells. Breast cancer cells can enter lymphatic vessels and begin to grow in lymph nodes.

Most lymphatic vessels in the breast connect to lymph nodes under the arm (axillary nodes). Some lymphatic vessels connect to lymph nodes near the breast bone (internal mammary nodes) and either above or below the collarbone (supraclavicular or infraclavicular nodes).

It's important to know if the cancer cells have spread to lymph nodes. If they have, there is a higher chance that the cells could have gotten into the bloodstream and spread (metastasized) to other sites in the body. This is important to know when you are choosing a treatment. The more lymph nodes with breast cancer cells (positive lymph nodes), the more likely it is that the cancer might be found in other organs as well. Still, not all men who have positive lymph nodes develop metastases, and in some cases a man can have negative lymph nodes and later develop metastases.

As I have 3 sons, I like to share as much as I can to make awareness, male breast cancer is also an awful disease.