Tumor type affects survival in ectopic Cushing’s syndrome: Study
Patients live longer when tumor removed, cortisol controlled
Ectopic Cushing’s syndrome can have different outcomes depending on tumor type, with about 8 in 10 people with lung tumors and 4 in 10 with pancreatic tumors remaining alive five years after diagnosis, according to a meta-analysis study by researchers in Sweden.
Patients lived longer when the tumor could be fully removed and hypercortisolism, or higher-than-normal levels of cortisol, was better controlled, the study found. Most deaths were caused by tumor progression, hormone-related complications, or serious infections.
“These findings highlight the need for individualized, prompt interventions and administration of empiric antibiotics to improve survival,” wrote the researchers, who also noted “the importance of early, aggressive treatment of hypercortisolism.”
The study, “Survival probabilities in patients with ectopic Cushing’s syndrome – a systematic review and a single-arm meta-analysis,” was published in the European Journal of Endocrinology.
Cushing’s syndrome arises from excess cortisol in the body. It can be caused by a tumor in the brain’s pituitary gland producing too much adrenocorticotropic hormone (ACTH), which stimulates the adrenal glands to produce cortisol. This is called Cushing’s disease.
Estimating survival for ectopic Cushing’s patients
Excess ACTH can also come from a tumor located elsewhere in the body, resulting in ectopic Cushing’s syndrome. As in other types of Cushing’s syndrome, this can cause serious health problems, such as high blood pressure and diabetes, which can affect how long patients live.
“Estimating survival is essential for predicting prognosis, evaluating outcomes with standard care, planning clinical trials and providing better care for these patients,” the researchers wrote.
Yet most studies on survival have involved small groups of patients, they noted.
To gain insight into how long patients live after receiving an ectopic Cushing’s diagnosis, the researchers searched for past studies that looked at survival after one and five years. They identified 40 studies involving a total of 1,148 patients who received their diagnosis at a median age of 48.
Pooled data from the studies showed that most patients (78%) were alive one year after being diagnosed with ectopic Cushing’s syndrome. However, fewer than half (47%) were alive after five years. These results show that survival decreases over time, but this also depended on the type of tumor causing ectopic Cushing’s syndrome.
The survival rate was highest in patients with pulmonary neuroendocrine tumors, which form in the lungs, with 81% remaining alive after five years. For occult ectopic Cushing’s syndrome — cases in which the tumor could not be located — the five-year survival rate was 66%. Patients with thymic tumors — located in the thymus gland in the chest — had a five-year survival rate of 50%, while those with pancreatic tumors had the lowest, at 40%.
Eight studies, involving a total of 414 patients, reported on factors that influenced survival. Patients who had surgery to completely remove their tumors lived longer, the studies found. In contrast, patients had worse outcomes if their tumors could not be removed, had spread to other parts of the body, or were poorly differentiated — meaning they were made up of cells that looked abnormal and disorganized.
Worse outcomes were also linked to severe hormone imbalances, such as high levels of cortisol in the blood or urine, high levels of ACTH, low levels of potassium, and diabetes or new-onset hyperglycemia (higher-than-normal sugar in the blood).
The most common causes of death included progression of the underlying tumor (48%), complications secondary to hypercortisolism (17%), and severe infections or sepsis (16%).
Because hypercortisolism is linked to worse outcomes, and Cushing’s treatments can help bring cortisol closer to normal levels, the condition “should be promptly and adequately treated in all patients, especially in patients with curable tumors,” the researchers wrote.
More research is needed to better understand what affects survival in these patients, and “future studies would benefit from international collaboration,” they wrote.
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