Treatment for Rare Cancer May Help Cushing’s Patients

The cancer medicine bexarotene may hold promise for treating Cushing’s disease, a study suggests.

The study, “Targeting the TR4 nuclear receptor with antagonist bexarotene can suppress the proopiomelanocortin signalling in AtT‐20 cells,” was published in the Journal of Cellular and Molecular Medicine.

Cushing’s disease is caused by a tumor on the pituitary gland, leading this gland to produce too much adrenocorticotropic hormone (ACTH). Excess ACTH causes the adrenal glands to release too much of the stress hormone cortisol; abnormally high cortisol levels are primarily responsible for the symptoms of Cushing’s.

Typically, first-line treatment is surgical removal of the pituitary tumor. But surgery, while effective in the majority of cases, does not help all. Additional treatment with medications or radiation therapy (radiotherapy) works for some, but not others, and these treatments often have substantial side effects.

“Thus, the development of new drugs for CD [Cushing’s disease] treatment is extremely urgent especially for patients who have low tolerance for surgery and radiotherapy,” the researchers wrote.

Recent research has shown that a protein called testicular receptor 4 (TR4) helps to drive ACTH production in pituitary cancers. Thus, blocking the activity of TR4 could be therapeutic in Cushing’s disease.

Researchers conducted computer simulations to screen for compounds that could block TR4. This revealed bexarotene as a potential inhibitor. Further biochemical tests confirmed that bexarotene could bind to, and block the activity of, TR4.

Bexarotene is a type of medication called a retinoid. It is approved to treat cutaneous T-cell lymphoma, a rare cancer that affects the skin, and available under the brand name Targretin.

When pituitary cancer cells in dishes were treated with bexarotene, the cells’ growth was impaired, and apoptosis (a type of programmed cell death) was triggered. Bexarotene treatment also reduced the secretion of ACTH from these cells.

In mice with ACTH-secreting pituitary tumors, bexarotene’s use significantly reduced tumor size, and lowered levels of ACTH and cortisol. Cushing’s-like symptoms also eased; for example, bexarotene treatment reduced the accumulation of fat around the abdomen in these mice.

Additional cellular experiments suggested that bexarotene specifically works on TR4 by changing the location of the protein. Normally, TR4 is present in the nucleus — the cellular compartment that houses DNA — where it helps to control the production of ACTH.

But with bexarotene treatment, TR4 tended to go outside of the nucleus, leading to lower ACTH production. The researchers noted that other mechanisms may also be involved in the observed effects of bexarotene.

“In summary, our work demonstrates that bexarotene is a potential inhibitor for TR4. Importantly, bexarotene may represent a new drug candidate to treat CD,” the researchers concluded.

Thyroid cancer: Cushing syndrome is a lesser-known warning sign – what is it?

Thyroid cancer survival rates are 84 percent for 10 years or more if diagnosed early. Early diagnosis is crucial therefore and spotting the unusual signs could be a matter of life and death. A sign your thyroid cancer has advanced includes Cushing syndrome.

What is it?

What is Cushing syndrome?

 

Cushing syndrome occurs when your body is exposed to high levels of the hormone cortisol for a long time, said the Mayo Clinic.

The health site continued: “Cushing syndrome, sometimes called hypercortisolism, may be caused by the use of oral corticosteroid medication.

“The condition can also occur when your body makes too much cortisol on its own.

“Too much cortisol can produce some of the hallmark signs of Cushing syndrome — a fatty hump between your shoulders, a rounded face, and pink or purple stretch marks on your skin.”

In a study published in the US National Library of Medicine National Institutes of Health, thyroid carcinoma and Cushing’s syndrome was further investigated.

The study noted: “Two cases of thyroid carcinoma and Cushing’s syndrome are reported.

“Both of our own cases were medullary carcinomas of the thyroid, and on reviewing the histology of five of the other cases all proved to be medullary carcinoma with identifiable amyloid in the stroma.

“A consideration of the temporal relationships of the development of the carcinoma and of Cushing’s syndrome suggested that in the two cases with papillary carcinoma these conditions could have been unrelated, but that in eight of the nine cases with medullary carcinoma there was evidence that thyroid carcinoma was present at the time of diagnosis of Cushing’s syndrome.

“Medullary carcinoma of the thyroid is also probably related to this group of tumours. It is suggested that the great majority of the tumours associated with Cushing’s syndrome are derived from cells of foregut origin which are endocrine in nature.”

In rare cases, adrenal tumours can cause Cushing syndrome a condition arising when a tumour secretes hormones the thyroid wouldn’t normally create.

Cushing syndrome associated with medullary thyroid cancer is uncommon.

The syndrome is more commonly caused by the pituitary gland overproducing adrenocorticotropic hormone (ACTH), or by taking oral corticosteroid medication.

See a GP if you have symptoms of thyroid cancer, warns the NHS.

The national health body added: “The symptoms may be caused by less serious conditions, such as an enlarged thyroid, so it’s important to get them checked.

“A GP will examine your neck and can organise a blood test to check how well your thyroid is working.

“If they think you could have cancer or they’re not sure what’s causing your symptoms, you’ll be referred to a hospital specialist for more tests.”

 

Adapted from https://www.express.co.uk/life-style/health/1351753/thyroid-cancer-signs-symptoms-cushing-syndrome

Adrenal incidentalomas—do they need follow up?

Are adrenal incidentalomas, which are found by chance on imaging, really harmless? In this paper, the authors looked at 32 studies, including 4121 patients with benign non-functioning adrenal tumours (NFATs) or adenomas that cause mild autonomous cortisol excess (MACE).

Only 2.5% of the tumours grew to a clinically significant extent over a mean follow-up period of 50 months, and no one developed adrenal cancer. Of those patients with NFAT or MACE, 99.9% didn’t develop clinically significant hormone (cortisol) excess. This was a group (especially those with MACE) with a high prevalence of hypertension, diabetes, and obesity. This could be because adrenal adenomas promote cardiometabolic problems, or vice versa, or maybe this group with multimorbidities is more likely be investigated.

Adrenal incidentalomas are already found in around 1 in 20 abdominal CT scans, and this rate is likely to increase as imaging improves. So it’s good news that this study supports existing recommendations, which say that follow-up imaging in the 90% of incidentalomas that are smaller than 4 cm diameter is unnecessary.

From https://blogs.bmj.com/bmj/2019/07/03/ann-robinsons-journal-review-3-july-2019/

Rare Prostate Cancer Associated with Cushing’s Syndrome

A patient with depression developed Cushing’s syndrome (CS) because of a rare ACTH-secreting small cell cancer of the prostate, a case study reports.

The case report, “An unusual cause of depression in an older man: Cushing’s syndrome resulting from metastatic small cell cancer of the prostate,” was published in the “Lesson of the Month” section of Clinical Medicine.

Ectopic CS is a condition caused by an adrenocorticotropic hormone (ACTH)-secreting tumor outside the pituitary or adrenal glands. The excess ACTH then acts on the adrenal glands, causing them to produce too much cortisol.

Small cell cancer is more common in older men, those in their 60s or 70s. Sources of ectopic ACTH synthesis arising in the pelvis are rare; nonetheless, ACTH overproduction has been linked to tumors in the gonads and genitourinary organs, including the prostate.

Still, evidence suggests there are less than 30 published cases reporting ectopic CS caused by prostate cancer.

Researchers from the Southern Adelaide Local Health Network and the Royal Adelaide Hospital in Australia described the case of an 84-year-old man who complained of fatigue, back pain, and lack of appetite.

Blood tests revealed mildly elevated prostate-specific antigen (PSA) and creatinine levels, which could indicate the presence of prostate cancer and impaired kidney function, respectively.

The patient had a history of locally invasive prostate cancer even though he didn’t experience any symptoms of this disease.

Ultrasound examination showed an enlarged prostate plus obstructed ureters — the tubes that carry urine from the kidney to the bladder. To remove the obstruction, doctors inserted a thin tube into both ureters and restored urine flow.

After the procedure, the man had low levels of calcium, a depressed mood, and back pain, all of which compromised his recovery. Imaging of his back showed no obvious reason for his complaints, and he was discharged.

Eight days later, the patient went to the emergency room of a large public hospital because of back pain radiating to his left buttock. The man also had mild proximal weakness on both sides. He was thinner, and had low levels of calcium, high blood pressure and serum bicarbonate levels, plus elevated blood sugar. In addition, his depression was much worse.

A psychiatrist prescribed him an antidepressant called mirtazapine, and regular follow-up showed that his mood did improve with therapy.

A computed tomography (CT) scan revealed a 10.5 cm tumor on the prostate and metastasis on the lungs and liver. Further testing showed high serum cortisol and ACTH levels, consistent with a diagnosis of Cushing’s syndrome.

But researchers could not identify the ACTH source, and three weeks later, the patient died of a generalized bacterial infection, despite treatment with broad-spectrum antibiotics.

An autopsy revealed that the cancer had spread to the pelvic sidewalls and to one of the adrenal glands. Tissue analysis revealed that the patient had two types of cancer: acinar adenocarcinoma and small cell neuroendocrine carcinoma — which could explain the excess ACTH.

Cause of death was bronchopneumonia, a severe inflammation of the lungs, triggered by an invasive fungal infection.

Investigators believe there are things to be learned from this case, saying, “Neither the visceral metastases nor aggressive growth of the pelvic mass noted on imaging were typical of prostatic adenocarcinoma. [Plus], an incomplete diagnosis at death was the precipitant for a post-mortem examination. The autopsy findings were beneficial to the patient’s family and treating team. The case was discussed at a regular teaching meeting at a large tertiary hospital and, thus, was beneficial to a wide medical audience.”

Although a rare cause of ectopic ACTH synthesis, small cell prostate cancer should be considered in men presenting with Cushing’s syndrome, especially in those with a “mystery” source of ACTH overproduction.

“This case highlights the importance of multidisciplinary evaluation of clinical cases both [before and after death], and is a fine example of how autopsy findings can be used to benefit a wide audience,” the researchers concluded.

https://cushingsdiseasenews.com/2018/10/16/rare-prostate-cancer-prostate-associated-cushings-syndrome-case-report/

Rare Nasal Cancer May Have Caused Cushing’s Syndrome

A very rare case of Cushing’s syndrome developing as a result of a large and also rare cancer of the nasal sinuses gives insights into how to screen and treat such an anomaly, of which fewer than 25 cases have been reported in literature.

Paraneoplastic esthesioneuroblastoma (ENB), a very rare type of nasal tumor, may sometimes produce excess adrenocorticotrophic hormone (ACTH), leading to symptoms of Cushing’s syndrome, according to a recent case report that describes a case of ACTH-secreting ENB. The report aims to demonstrate the importance of recognizing its pathophysiology and treatment.

The case report, “A Case of Cushing’s Syndrome due to Ectopic Adrenocorticotropic Hormone Secretion from Esthesioneuroblastoma with Long Term Follow-Up after Resection,” was published in the journal Case Reports in Endocrinology.

It describes a 52-year-old Caucasian male who had a history of high blood pressure, severe weakness, abnormal production of urine, extreme thirstiness, and confusion.

He was scheduled to undergo surgery for a 7-centimeter skull base mass; the surgery was postponed due to severe high serum potassium concentrations and abnormally high pH levels. His plasma ACTH levels also were elevated and Cushing’s syndrome was suspected. Since imaging of the chest, abdomen, and pelvis did not show any ectopic (abnormal) sources of ACTH, the ENB was suspected to be the source.

Surgery was performed to remove the tumor, which was later found to be secreting ACTH. Consequently, following the procedure, his ACTH levels dropped to normal (below detection limit) and he did not need medication to normalize serum potassium levels. He then underwent subsequent chemoradiation and has shown no sign of recurrence 30 months after the operation, which is considered to be one of the longest follow-up periods for such a case.

Researchers declared it “a case of olfactory neuroblastoma with ectopic ACTH secretion that was treated with resection and adjuvant chemoradiation.”

“Given the paucity of this diagnosis, little is known about how best to treat these patients and how best to screen for complications such as adrenal insufficiency and follow-up,” they wrote. “Our case adds more data for better understanding of this disease.”

From https://cushingsdiseasenews.com/2018/04/03/rare-nasal-cancer-caused-cushings-syndrome-case-report-says/

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