SCLC develops in the neuroendocrine cells in your lung. These cells make up about
When these cells become cancerous, they can produce excess hormones. Some people with SCLC develop a condition called ectopic Cushing syndrome. This syndrome is characterized by the excess production of hormones that increase levels of cortisol in your blood. Ectopic means the syndrome develops from tissues that don’t normally produce this hormone.
Keep reading to learn more about the connection between SCLC and Cushing syndrome.
Some paraneoplastic syndromes develop due to an overreaction of your immune system to the cancer that damages healthy cells. Other syndromes, like ectopic Cushing syndrome, develop due to the excess production of hormones by cancer cells.
SCLC is the type of cancer most associated with paraneoplastic syndromes. They’re thought to develop in about 10% of people with SCLC.
Ectopic Cushing syndrome makes up about
- mediating your body’s stress response
- controlling blood pressure
- increasing the breakdown of glucose
Usually, cortisol is produced in the following pathway:
- A part of your brain called the hypothalamus produces corticotropin-releasing hormone (CRH).
- CRH stimulates the release of adrenocorticotropic hormone (ACTH) from your anterior pituitary gland.
- ACTH stimulates the release of cortisol from your adrenal glands.
In people with ectopic Cushing syndrome, cancer cells produce
Most people develop weight gain as an initial symptom, but about
- muscle weakness
- peripheral edema, swelling in your lower legs or hands
- high blood pressure
- weight gain
- moon face, a full and puffy face
- purple stretch marks
Symptoms can develop before or after lung cancer is diagnosed.
How do ectopic Cushing syndrome and Cushing syndrome compare?
People with ectopic Cushing syndrome tend to have electrolyte disturbances and muscle weakness rather than
These symptoms are caused by chronically elevated levels of cortisol, but ectopic Cushing syndrome generally causes a sudden increase.
Doctors run a variety of tests to examine your hormone levels and differentiate ectopic Cushing syndrome from Cushing syndrome.
Diagnostic tests may include:
- 24-hour urine sample to measure your cortisol and creatinine levels
- blood tests such as:
- fasting glucose test
- electrolyte tests, specifically looking at potassium levels
- imaging, such as computed tomography (CT) scans or magnetic resonance imaging (MRI) to look for the tumor
- low dose and high dose dexamethasone tests, where you’re given the steroid dexamethasone to see how your cortisol levels change
Treatment for ectopic Cushing syndrome should start as soon as possible to minimize complications. Treatment consists of targeting the underlying cancer, lowering cortisol levels, and treating specific symptoms that develop.
- radiation therapy
- surgical removal
- laser therapy
- endoscopic stent placement to open your airways
Steroids may help reduce circulating levels of cortisol.
Examples of treatments for specific complications include:
The outlook for people with ectopic Cushing syndrome largely depends on the outlook of the underlying cancer. Complications are very common when cortisol levels in your urine rise above 5 times of the upper limit of normal. It can cause fatal complications even if cancer is well controlled.
Ectopic Cushing syndrome is associated with a
- advanced cancer stage
- poor response to therapy
- greater susceptibility to infection
- increased risk of blood clots
SCLC in general has a poor outlook. The
Ectopic Cushing syndrome is a potential complication of cancer, and in particular, of SCLC.
Ectopic Cushing syndrome occurs when cancer cells produce too much of the hormone ACTH, which raises levels of cortisol in your blood.
Treatment of ectopic Cushing syndrome primarily involves treating the underlying cancer and taking medications to bring cortisol levels back into a normal range.
SCLC with ectopic Cushing syndrome is generally associated with a poorer outlook than SCLC alone, but your doctor can give you the best idea of what to expect.