Biopharmaceutical Cancer Genomics

The adrenals are small glands that sit above each of the kidneys. The kidneys are located deep inside the upper part of the abdomen.

The adrenal gland is made up of 2 parts. The outer part, called the cortex, is where the adrenal cortical tumors develop. The function of the cortex is to produce certain hormones for the body. These hormones all possess a similar chemical structure and are called steroids. They include:

• Cortisol, which causes changes in metabolism that help the body to handle stress.
  
  

• Aldosterone, which helps the kidneys regulate the amount of salt in the blood and tissues of the body.
  

• Androgens and estrogens: In men, the testicles produce most of the androgens (male hormones). The ovaries produce most of the estrogens (female hormones) in women. However, the adrenal glands produce small amounts of both androgens and estrogens in men and women.
  

The inner portion of the adrenal gland, called the medulla, is really an extension of the nervous system. Nervous system hormones such as norepinephrine and epinephrine (also called adrenaline) are made in the medulla. Tumors of the adrenal medulla, such as pheochromocytomas and neuroblastomas, are not discussed in this document. (For more information on neuroblastomas, refer to the American Cancer Society document,

Neuroblastoma.)

Adrenal Cortex Tumors

There are 2 main types of adrenal cortex tumors. Most are benign (non-cancerous) and are called adenomas. Adrenal cortex cancers are rare.

Adrenal cortex adenomas: Most tumors of the adrenal cortex are benign adenomas. These are small tumors, usually less than 5 centimeters (about 2 inches) in diameter. They usually occur in only 1 adrenal gland, but sometimes affect both glands.

Most people with adrenal adenomas have no symptoms and are unaware that they have an adrenal tumor. Some of these adenomas are discovered "incidentally" when CT or MRI scans of the abdomen are done because of unrelated health problems. Many are "nonfunctional" adenomas, which means the metabolic pathways that produce steroid hormones are not functioning and the cells are not producing enough steroid hormones to cause any problems.

Some adenomas produce too much adrenal steroid hormone, which may or may not cause symptoms. Many of the hormone-related symptoms of adenomas and carcinomas (cancers) are the same. These symptoms are discussed in the section,
Can Adrenal Cortical Cancer Be Found Early? Adenomas are much more likely than carcinomas to produce high levels of aldosterone and to lead to high blood pressure, however.

Adenomas can be cured by removal of the adrenal gland that contains the adenoma. The operation can be done through an incision in the front of the abdomen or in the back. A new technique called laparoscopic adrenalectomy allows the surgeon to remove the adrenal gland with an adenoma through an instrument called a laparoscope. The laparoscope is a thin tube with a tiny video camera on the end that is inserted through a small surgical opening in the patient's side. Other instruments inserted through this tube or through other very small incisions are used to remove the adrenal gland. Laparoscopic surgery is an option for removing adenomas but is not recommended for adrenal cancers.

Some adrenal adenomas that cause hormone-related symptoms can be treated effectively with medications that block the production or actions of these hormones. This option is especially attractive for patients with other serious medical problems who might not be able to withstand a major operation. And some small, incidentally discovered adenomas that are not causing any symptoms do not need any treatment at all.

The remainder of this document refers to adrenal cancers only, and not to adenomas.

Adrenal cortical cancer: The type of cancer that develops in the cortex of the adrenal gland is called adrenal cortical carcinoma. It is discovered for 1 of 2 reasons. The first is that it produces hormones that cause body changes such as weight gain and fluid retention, early puberty in children, or excess facial or body hair growth in women.

The second reason these are discovered is that they become very large and cause symptoms by pressing on other organs in the abdomen. This can cause pain, a feeling of fullness, and weight loss because it is hard to eat very much. Generally, adrenal cortical cancers are much larger than adrenal adenomas. An adrenal tumor larger than 5 or 6 centimeters (about 2 to 2 1/2 inches) is usually malignant or cancerous. In one study, the average size was about 4 to 5 inches.

Most cancers in the adrenal gland do not start there and are not adrenal cortical cancers. Instead, they start in other organs and then metastasize (spread) through the bloodstream to the adrenal glands. For example, lung cancers and breast cancers often spread to the adrenals. Even when they spread to the adrenals, however, they are still considered to be metastatic lung cancer or metastatic breast cancer. Their treatment is described in the American Cancer Society documents on these cancers.