Transsphenoidal Surgery Is Safe and Effective Treatment for Cushing’s Disease

Transsphenoidal surgery, a minimally invasive surgery to remove tumors in the pituitary gland, is safe and effective to treat Cushing’s disease, a 20-year history of cases in a Belgian hospital shows.

The surgery resulted in high remission rates (83%) in patients. It was also found to be safe, rarely leading to insufficient functioning of the pituitary gland.

The study, “Outcome of transsphenoidal surgery for Cushing’s Disease: a single-center experience over 20 years,” was published in the journal World Neurosurgery.

Surgical removal of tumors in the pituitary gland of the brain remains the gold standard for Cushing’s disease treatment.

Transsphenoidal surgery (TSS) usually leads to good remission rates ranging from 68-95%, depending on the location and type of tumor, the neurosurgeon’s expertise, follow-up period, and the definition of remission.

Today, TSS consists of surgery directed through the nose to get to the bottom of the skull, where the pituitary gland is located. The tumor is reached via the nasal cavity with no need for incisions on the face.

To address the safety and effectiveness of this type of surgery for treating Cushing’s, researchers retrospectively reviewed the outcome of 71 patients who received their first TSS at Saint-Luc Hospital, Belgium, between 1996 and 2017. Patients were followed for an average of 6.8 years (82 months).

Surgeons used a type of TSS that is image-guided with the help of a microscope which magnifies the surgeon’s vision.

Remission was defined as normal fasting cortisol level, normal 24-hour urinary-free cortisol, or prolonged need for hydrocortisone replacement for one year after surgery.

Replacement therapies are sometimes needed when the pituitary is not producing enough cortisol after surgery.

Patients were mostly women, ages 15 to 84. Some of them, 32%, required multiple surgeries.

In total, 46 patients out of 71 were in remission after the first surgery, 11 after the second surgery, one after the third, and one after the fourth intervention.

A successful first surgery, resulting in a one-year remission, was a positive indicator for patients, as it was associated with high final remission rates (95%).

However, if the first surgery failed, only 36% of patients achieved a final remission.

“Obtaining a lasting remission after a first TSS could be an interesting parameter to influence future therapeutic decisions [like] performing repeated surgery rather than choosing second-line therapies,” researchers wrote.

Overall, remission was achieved in 83% of patients who underwent a single or multiple TSS intervention, a recurrence rate comparable to previous reports.

Surgery was particularly successful for curing patients with macroadenomas — tumors larger than 10 mm — leading to a 92% remission rate.

Small tumors that were not visible on magnetic resonance imaging (MRI) scans were more difficult to treat, with only 71% of patients being cured. Still, such a remission rate was better than what is commonly reported for MRI-negative tumors. This is likely explained by a higher level of expertise by the surgeon.

Levels of cortisol one day after TSS were significantly lower in patients with long-term remission. However, high levels were still observed in a few patients, especially those who had Cushing’s disease for many years.

“Therefore, high cortisol levels in the postoperative early days do not always indicate persistent disease and later [cortisol] evaluation is warranted,” the researchers wrote.

Most complications from surgery were minor and transient, except for seven patients who developed diabetes. Only 8.8% of patients developed long-term failure of the pituitary gland, likely because physicians favored a less aggressive intervention plan to leave the pituitary gland as intact as possible.

However, such an approach may also explain why some patients had to undergo multiple surgeries to completely remove the tumor.

In addition, a longer duration of Cushing’s disease symptoms and higher cortisol levels before surgery could significantly predict a poorer likelihood of being cured by TSS.

“Neuronavigation-guided microscopic TSS is a safe and effective primary treatment for [Cushing’s disease], allowing high remission rates,” the researchers wrote.

From https://cushingsdiseasenews.com/2018/07/26/transsphenoidal-surgery-safe-effective-treatment-cushings-disease/

Oral Test for Adult Growth Hormone Deficiency Approved in US

The US Food and Drug Administration (FDA) has approved an orally available ghrelin agonistmacimorelin (Macrilen, Aeterna Zentaris), to be used in the diagnosis of patients with adult growth-hormone deficiency (AGHD).

Macimorelin stimulates the secretion of growth hormone from the pituitary gland into the circulatory system. Stimulated growth-hormone levels are measured in four blood samples over 90 minutes after oral administration of the agent for the assessment of growth-hormone deficiency.

Prior to the approval of macimorelin, the historical gold standard for evaluation of adult growth-hormone deficiency was the insulin tolerance test (ITT), an intravenous test requiring many blood draws over several hours.

The ITT procedure is inconvenient for patients and medical practitioners and is contraindicated in some patients, such as those with coronary heart disease or seizure disorder, because it requires the patient to experience hypoglycemia to obtain an accurate result.

Adult growth-hormone deficiency is a rare disorder characterized by the inadequate secretion of growth hormone from the pituitary gland. It can be hereditary; acquired as a result of trauma, infection, radiation therapy, or brain tumor growth; or can even emerge without a diagnosable cause. Currently, it is treated with once-daily injections of subcutaneous growth hormone.

“Clinical studies have demonstrated that growth-hormone stimulation testing for adult growth-hormone deficiency with oral…macimorelin is reliable, well-tolerated, reproducible, and safe and a much simpler test to conduct than currently available options,” said Kevin Yuen, MD, clinical investigator and neuroendocrinologist, Barrow Neurological Institute, and medical director of the Barrow Neuroendocrinology Clinic, Phoenix, Arizona, in a press release issued by Aeterna Zentaris.

“The availability of…macimorelin will greatly relieve the burden of endocrinologists in reliably and accurately diagnosing adult growth-hormone deficiency,” he added.

Aeterna Zentaris estimates that approximately 60,000 tests for suspected adult growth-hormone deficiency are conducted each year across the United States, Canada, and Europe.

“In the absence of an FDA-approved diagnostic test for adult growth-hormone deficiency, Macrilen fills an important gap and addresses a medical need for a convenient test that will better serve patients and health providers,” said Michael V Ward, chief executive officer, Aeterna Zentaris.

Macrilen is expected to be launched in the United States during the first quarter of 2018.

It is also awaiting approval in the European Union.

Follow Lisa Nainggolan on Twitter: @lisanainggolan1. For more diabetes and endocrinology news, follow us on Twitter and on Facebook.

From https://www.medscape.com/viewarticle/890457

Increase in Glucose Uptake by Cushing’s Disease-associated Tumors Could Improve Early Detection

An increase in glucose uptake by Cushing’s disease-associated pituitary tumors could improve their detection, new research shows.

The study, “Corticotropin releasing hormone can selectively stimulate glucose uptake in corticotropinoma via glucose transporter 1,” appeared in the journal Molecular and Cellular Endocrinology.

The study’s senior author was Dr. Prashant Chittiboina, MD, from the Department of Neurosurgery, Wexner Medical Center, The Ohio State University, in Columbus, Ohio.

Microadenomas – tumors in the pituitary gland measuring less than 10 mm in diameter – that release corticotropin, or corticotropinomas, can lead to Cushing’s disease. The presurgical detection of these microadenomas could improve surgical outcomes in patients with Cushing’s.

But current tumor visualization methodologies – magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) – failed to detect a significant percentage of pituitary microadenomas.

Stimulation with corticotropin-releasing hormone (CRH), which increases glucose uptake, has been suggested as a method of increasing the detection of adenomas with 18F-FDG PET, by augmenting the uptake of 18F-FDG – a glucose analog.

However, previous studies aiming to validate this idea have failed, leading the research team to hypothesize that it may be due to a delayed elevation in glucose uptake in corticotropinomas.

The scientists used clinical data to determine the effectiveness of CRH in improving the detection of corticotropinomas with 18F-FDG PET in Cushing’s disease.

They found that CRH increased glucose uptake in human and mouse tumor cells, but not in healthy mouse or human pituitary cells that produce the adrenocorticotropic hormone (ACTH). Exposure to CRH increased glucose uptake in mouse tumor cells, with a maximal effect at four hours after stimulation.

Similarly, the glucose transporter GLUT1, which is located at the cell membrane, was increased two hours after stimulation, as was GLUT1-mediated glucose transport.

These findings indicate a potential mechanism linking CRH exposure to augmented glucose uptake through GLUT1. Expectedly, the inhibition of glucose transport with fasentin suppressed glucose uptake.

The researchers consistently observed exaggerated evidence of GLUT1 in human corticotropinomas. In addition, human corticotroph tumor cells showed an increased breakdown of glucose, which indicates that, unlike healthy cells, pituitary adenomas use glucose as their primary source of energy.

Overall, the study shows that corticotropin-releasing hormone (CRH) leads to a specific and delayed increase in glucose uptake in tumor corticotrophs.

“Taken together, these novel findings support the potential use of delayed 18F-FDG PET imaging following CRH stimulation to improve microadenoma detection in [Cushing’s disease],” researchers wrote. The scientists are now conducting a clinical trial to further explore this promising finding.

From https://cushingsdiseasenews.com/2017/10/12/glucose-uptake-in-cushings-disease-could-improve-presurgical-tumor-detection/

An Amusing Look At Hormones And The Pituitary Gland

A moment in the scheming mind of Professor Pituitary and his sidekick, Dr. Hypothalamus!! And… their minions, the Hormonal Kitties!

Low Oxytocin Levels Linked to Reduced Empathy

People suffering from low levels of oxytocin perform worse on empathy tasks, according to new research presented at the 2016 Society for Endocrinology annual conference.

The research suggests that hormone replacement could improve the psychological well-being of those living with low levels, according to researchers at the University of Cardiff.

Oxytocin is often referred to as the “love hormone” due to its role in human behavior, including sexual arousal, recognition, trust, anxiety, and mother-infant bonding. It is produced by the hypothalamus — an area of the brain that controls mood and appetite — and stored in the pituitary gland.

For the study, researchers investigated empathic behavior in people who they suspected of having reduced oxytocin levels due to one of two medical conditions caused in response to pituitary surgery.

The study assessed 20 people with cranial diabetes insipidus (CDI). In CDI, the body has reduced levels of ADH, a chemical also produced in the hypothalamus and structurally very similar to oxytocin.

The researchers also assessed 15 people with hypopituitarism (HP), a condition in which the pituitary gland does not release enough hormones.

These two patient groups were compared to a group of 20 healthy people.

The researchers gave all participants two tasks designed to test empathy, both relating to the recognition of emotional expression. They also measured each group’s oxytocin levels and found that the 35 CDI and HP participants had slightly lower oxytocin compared to the healthy people. The researchers noted that a larger sample is required to establish statistical significance.

The researchers also discovered that the CDI and HP groups performed significantly worse on empathy tasks, compared to the healthy control group. In particular, CDI participants’ ability to identify expressions was predicted by their oxytocin levels — those with the lowest levels of oxytocin produced the worst performances, according to the study’s findings.

“This is the first study which looks at low oxytocin as a result of medical, as opposed to psychological, disorders,” said Katie Daughters, lead researcher. “If replicated, the results from our patient groups suggest it is also important to consider medical conditions carrying a risk of low oxytocin levels.”

“Patients who have undergone pituitary surgery, and in particular those who have acquired CDI as a consequence, may present with lower oxytocin levels,” she continued. “This could impact on their emotional behavior, and in turn affect their psychological well-being. Perhaps we should be considering the introduction of oxytocin level checks in these cases.”

The researchers said they hope to expand their study to further replicate and confirm their findings. They added that the study presents only preliminary results, and has not been peer reviewed.

Source: Society for Endocrinology

From http://psychcentral.com/news/2016/11/06/low-oxytocin-levels-linked-to-reduced-empathy/112110.html

%d bloggers like this: