The prevalence and associated factors of colorectal neoplasms in acromegaly: a single center based study

Metyrapone single administration, as a possible predictive tool of its dosage and timing in Cushing's syndrome

Metyrapone is commonly used in the initial management of Cushing's syndrome to reduce hypercortisolemia, but its optimal dosage and timing can vary significantly between patients. Currently, there are limited guidelines on adjustment methods for its administration to individual needs. This study aimed to evaluate responsiveness of each patient to metyrapone and identify the patient characteristics associated with the indices of cortisol responsiveness following a low-dose metyrapone. This single-center retrospective observational study included 15 treatment-naïve patients, 7 of whom had Cushing's disease and 8 had adrenal Cushing's syndrome. Serum cortisol levels were measured hourly from the time of administration of 250 mg of metyrapone up to four hours afterward. Parameters analyzed included the nadir of serum cortisol levels (Fnadir), the difference between basal and nadir serum cortisol levels (ΔF), the time to nadir, and the characteristics of the patients. As a result, cortisol suppression curves showed significant variability among patients, particularly in the time to nadir. While the median time to nadir was 2 hours, 20% of patients required 4 hours or more, and these responses were not associated with patient characteristics. Fnadir was positively correlated with early-morning serum cortisol levels, serum cortisol levels after low-dose dexamethasone suppression test (LDDST), and urinary free cortisol (UFC) levels, whereas ΔF was positively correlated with late-night serum cortisol levels, serum cortisol levels after LDDST, and UFC levels. In conclusion, the duration of response to metyrapone appeared unpredictable in patients with Cushing's syndrome and did not correlate with patient characteristics at baseline. Tracking the effect of metyrapone following a single low-dose administration may explain this variability and provide insights for optimizing individual dosing regimens. Further studies are required to validate these findings and guide more personalized treatment adjustments.

Newer parameters of the octreotide test in patients with acromegaly

PURPOSE

Predicting the therapeutic effects of first-generation somatostatin receptor ligands (fg-SRLs) is important when assessing or planning effective treatment strategies in patients with acromegaly. The oft-used maximum growth hormone (GH) suppression rate parameter of the octreotide test has a suboptimal predictive value. Therefore, this study explored newer parameters of the octreotide test for predicting the therapeutic effect of long-acting fg-SRLs.

METHODS

In this single-center retrospective study, the octreotide test parameters and the therapeutic effects of fg-SRL at 3 months were investigated in 45 consecutive treatment-naïve patients with acromegaly between April 2008 and March 2023. Additionally, the relationship between the octreotide test parameters and the therapeutic effects of fg-SRLs was investigated. Tumor shrinkage was evaluated based on changes in the longitudinal diameter of the macroadenomas. The area GH suppression rate-time under the curve (AUC) and the time to nadir GH level were calculated and compared with the maximum GH suppression rate.

RESULTS

The AUC estimated reductions in serum insulin-like growth factor I, and tumor shrinkage. The time to nadir GH level predicted tumor shrinkage more robustly than the maximum GH suppression rate in patients with macroadenoma.

CONCLUSION

The AUC and time to nadir GH level may potentially be newer parameters of the octreotide test for estimating the therapeutic effect of fg-SRLs.

Cancer Risk and its Association With Diabetes Mellitus in Patients With Acromegaly: A Two Center-based Study

OBJECTIVE

To compare the incidence of cancer in patients with acromegaly with that of the local population in China and explore possible risk factors.

METHODS

Data from 117 patients diagnosed with acromegaly at 2 centers between 2011 and 2022 were analyzed, and their cancer diagnoses were recorded. The cancer standardized incidence ratios (SIRs) and 95% confidence intervals (CIs) were calculated by comparison with those of the local population. The patients were divided into 2 groups, having cancer diagnosis or not. The relationships between cancer and sex, body mass index, age, growth hormone levels, diagnosis delay, tumor size, disease duration, treatment, disease status, and other comorbidities were analyzed.

RESULTS

Eight (6.8%) of 117 patients were diagnosed with cancer. The incidence of overall (SIR = 3.29, 95% CI = 1.42-6.94), colorectal (SIR = 16.67, 95% CI = 4.45-42.67), and thyroid cancers (SIR = 14.29, 95% CI = 1.73-51.60) was increased, but that of lung cancer (SIR = 4.17, 95% CI = 0.50-15.05) was not. Diagnostic delay (10.1[8.6-14.3] vs 3.8[1.3-9.0]; P = .005) and duration of acromegaly (12.8[8.9-16.4] vs 5.6[2.3-10.9]; P = .008) were prolonged in the cancer group. Diabetes mellitus (odds ratio = 7.01, 95% CI = 1.23-39.99) was an independent risk factor for acromegaly with cancer.

CONCLUSION

Acromegaly patients are at a higher risk of cancer and its association with diabetes mellitus. Considering the rarity of the disease, an Acromegaly Cancer Registry Center should be established in China as soon as possible.

Prevalence of clinical signs, symptoms and comorbidities at diagnosis of acromegaly: a systematic review in accordance with PRISMA guidelines

OBJECTIVE

Diagnostic delay is high in acromegaly and leads to increased morbidity and mortality. The aim of this study is to systematically assess the most prevalent clinical signs, symptoms and comorbidities of acromegaly at time of diagnosis.

DESIGN

A literature search (in PubMed, Embase and Web of Science) was performed on November 18, 2021, in collaboration with a medical information specialist.

METHODS

Prevalence data on (presenting) clinical signs, symptoms and comorbidities at time of diagnosis were extracted and synthesized as weighted mean prevalence. The risk of bias was assessed for each included study using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data.

RESULTS

Risk of bias and heterogeneity was high in the 124 included articles. Clinical signs and symptoms with the highest weighted mean prevalence were: acral enlargement (90%), facial features (65%), oral changes (62%), headache (59%), fatigue/tiredness (53%; including daytime sleepiness: 48%), hyperhidrosis (47%), snoring (46%), skin changes (including oily skin: 37% and thicker skin: 35%), weight gain (36%) and arthralgia (34%). Concerning comorbidities, acromegaly patients more frequently had hypertension, left ventricle hypertrophy, dia/systolic dysfunction, cardiac arrhythmias, (pre)diabetes, dyslipidemia and intestinal polyps- and malignancy than age- and sex matched controls. Noteworthy, cardiovascular comorbidity was lower in more recent studies. Features that most often led to diagnosis of acromegaly were typical physical changes (acral enlargement, facial changes and prognatism), local tumor effects (headache and visual defect), diabetes, thyroid cancer and menstrual disorders.

CONCLUSION

Acromegaly manifests itself with typical physical changes but also leads to a wide variety of common comorbidities, emphasizing that recognition of a combination of these features is key to establishing the diagnosis.

Clinical Characteristics and Associated Factors of Colonic Polyps in Acromegaly

PURPOSE

To investigate the clinical characteristics and associated factors of colonic polyps in patients with acromegaly.

METHODS

Clinical characteristics and colonoscopy findings of 86 acromegaly patients who received treatment were retrospectively reviewed, and colonoscopy findings and the correlation with growth hormone (GH)-secreting pituitary adenoma (GHPA) volume and hormonal/metabolic levels were analyzed.

RESULTS

The prevalence of colonic polyps in acromegaly patients was 40.7% and increased significantly with advanced age, especially in those ≥50 years. Multiple polyps (62.8%) and colonic polyps in the left colon (54.2%) were detected more frequently. Compared to acromegaly patients without polyps, those with polyps displayed higher insulin-like growth factor-1 × upper limit of normal (IGF-1×ULN) levels (P=0.03). IGF-1 levels and GHPA volumes in patients with polyps showed increasing trends, although the differences were not significant. GH levels were higher in patients with polyps of diameter ≤5 mm than those with polyps of diameter >5 mm (P=0.031). The univariate and multivariate logistic regression analysis revealed that GHPA volumes (OR: 1.09, 95% CI: 1.01-1.20; P=0.039) and IGF-1×ULN Q2 levels (OR: 6.51, 95% CI: 1.20-44.60; P=0.038) were independent factors for predicting the risk of colonic polyp occurrence in acromegaly patients. A nomogram was prepared to evaluate the risk of colonic polyps in acromegaly patients.

CONCLUSION

The acromegalic patients are a population with a high prevalence of colonic polyps. GHPA volumes and IGF-1×ULN levels may be predictors of colonic polyp occurrence.

Insulin-Like Growth Factor 1 (IGF-1) Signaling in Glucose Metabolism in Colorectal Cancer

Colorectal cancer (CRC) is one of the most common aggressive carcinoma types worldwide, characterized by unfavorable curative effect and poor prognosis. Epidemiological data re-vealed that CRC risk is increased in patients with metabolic syndrome (MetS) and its serum components (e.g., hyperglycemia). High glycemic index diets, which chronically raise post-prandial blood glucose, may at least in part increase colon cancer risk via the insulin/insulin-like growth factor 1 (IGF-1) signaling pathway. However, the underlying mechanisms linking IGF-1 and MetS are still poorly understood. Hyperactivated glucose uptake and aerobic glycolysis (the Warburg effect) are considered as a one of six hallmarks of cancer, including CRC. However, the role of insulin/IGF-1 signaling during the acquisition of the Warburg metabolic phenotypes by CRC cells is still poorly understood. It most likely results from the interaction of multiple processes, directly or indirectly regulated by IGF-1, such as activation of PI3K/Akt/mTORC, and Raf/MAPK signaling pathways, activation of glucose transporters (e.g., GLUT1), activation of key glycolytic enzymes (e.g., LDHA, LDH5, HK II, and PFKFB3), aberrant expression of the oncogenes (e.g., MYC, and KRAS) and/or overexpression of signaling proteins (e.g., HIF-1, TGF-β1, PI3K, ERK, Akt, and mTOR). This review describes the role of IGF-1 in glucose metabolism in physiology and colorectal carcinogenesis, including the role of the insulin/IGF system in the Warburg effect. Furthermore, current therapeutic strategies aimed at repairing impaired glucose metabolism in CRC are indicated.

Increased risk of preneoplastic colonic lesions and colorectal carcinoma in acromegaly: multicenter case-control study

PURPOSE

Current international guidelines recommend colonoscopy in patients with acromegaly at the time of diagnosis, even though the risk of developing colorectal neoplasm is still controversial. The main objective of this Argentine multicenter study was to analyze through screening colonoscopy the presence of advanced neoplastic lesions considered as precancerous, in patients with acromegaly compared to a control group.

METHODS

This is a case-control retrospective study. Full length colonoscopy of 70 acromegalic patients and 128 control subjects were studied. Polyps were classified into non pre-cancerous lesions and advance neoplastic lesions which included advanced adenomas (preneoplastic) and colorectal carcinomas.

RESULTS

Thirty three out of 70 acromegalic patients and 32 out of 128 subjects controls presented polyps in the colonoscopy [47.1% vs 25%, p = 0.002, OR 2.68]. Non precancerous polyps were found in 11 (15.7%) and 23 (17.9%) (p = 0.690), while advanced neoplastic lesions were found in 22 (31.4%) and 9 (7.0%) (p = 0,0001 - OR: 6.06) patients and controls respectively. Advanced adenomas and colorectal carcinomas were found in 18 (27.3%) and 9 (7.0%) (p = 0,0006-OR: 4,57), and 4 (5.7%) and 0 (0.0%) p = 0.0063) of patients and controls respectively. The presence of insulin resistance was the only statistically significant associated factor among acromegalic patients with and without colonic polyps.

CONCLUSIONS

Our findings show an increased risk of preneoplastic colonic lesions and colorectal carcinoma in patients with chronic and sustained GH excess compared to a control group. This supports the recommendation to perform screening colonoscopy at diagnosis of acromegaly.

Characterization of an intestine-specific GH receptor knockout (IntGHRKO) mouse

OBJECTIVE

Growth hormone (GH) has been reported to enhance the intestinal barrier; as such, recombinant GH has been administered for several intestinal diseases. However, excess GH action has been implicated in increasing the risk of intestinal dysfunction. The goal of this study was to examine the direct effects of GH on the small and large intestines to clarify the role GH plays in intestinal function through the use of a mouse model.

DESIGN

An intestinal epithelial-specific GH receptor (GHR) knockout (IntGHRKO) mouse line was generated using Cre-lox with the villin promoter driving Cre expression. The generated mice were characterized with respect to growth and intestinal phenotypes.

RESULTS

IntGHRKO mice showed no significant changes in body length, weight, or composition compared to floxed controls. Male IntGHRKO mice had significantly shorter large intestines at 4 and 12 months of age. Intestinal barrier function was assessed by measuring the expression of tight junction related genes, as well as levels of serum endotoxin and fecal albumin. Results showed sex differences as males had an increase in occludin levels but normal serum endotoxin and fecal albumin; while, females had changes in fecal albumin levels with normal occludin and serum endotoxin. Evaluation of glucose tolerance and fat absorption also showed sex differences as females were glucose intolerant, while males had impaired fat absorption. Histopathology revealed a trend towards decreased villus height in males, which could explain the sex difference in glucose homeostasis.

CONCLUSIONS

Overall, the data demonstrate that disruption of GH on the intestinal epithelial cells modestly affects the intestinal gross anatomy, morphology, and function in a sex-specific manner.

Colonic Cancer and Acromegaly

Acromegaly results in a significantly increased morbidity and mortality due to cardiovascular and respiratory complications, as well as malignancies arising mainly from the colon. Furthermore, an increased lifetime risk of malignant transformation of pre-malignant colonic lesions relates to a worse overall prognosis from colorectal cancer, which is currently considered a major disease-related complication. In this review we provide some insight into colonic changes in this condition, summarize current knowledge and evidence on the use of colonoscopic screening in patients with acromegaly, and suggest a recommended screening protocol.

Colonoscopy examination requires a longer time in patients with acromegaly than in other individuals

This study aimed to determine the prevalence of colorectal neoplasms and to investigate the rate of and time required for cecal intubation in patients with acromegaly. A database search performed at our institution identified 29 patients with acromegaly who underwent colonoscopy. Data regarding the endoscopic, biological, and pathological examinations performed were retrospectively reviewed from the clinical records. Subsequently, the rate of and time required for cecal intubation were investigated in 23 patients with acromegaly and compared with the corresponding data of the control group. Control subjects were selected from a 2:1 matched historical control cohort, according to baseline characteristics. The mean age of the acromegaly group (17 female and 12 male) was 60.4 ± 12.6 years. Twelve patients had adenoma (41.4%), eight patients had hyperplastic polyps (27.6%), three patients had sessile serrated adenoma/polyps (10.3%), and three patients had colon cancer (10.3%). Successful cecal intubation was achieved in all patients in both groups. The difference in the time required for successful intubation between the acromegaly group (15.7 ± 9.8 minutes) and the control group (8.7 ± 6.0 minutes) was statistically significant. Linear regression analysis revealed that increased patient age was significantly related to longer colonoscope insertion times. In conclusion, although cecal intubation during colonoscopy was successful in all participants, it required a longer time in patients with acromegaly. Our results underscore the importance of and certain technical difficulties involved in colonoscopy procedures in patients with acromegaly, especially in older patients.

Guidelines versus real life practice: the case of colonoscopy in acromegaly

PURPOSE

The aim of this study is to investigate guideline application and colonoscopy findings in real-life practice in acromegaly.

METHODS

We conducted a retrospective observational non-interventional and cross-sectional analysis on 146 patients with acromegaly (ACRO) referred to our clinic. We evaluated colonoscopy data, focusing on the correlation between colonoscopy findings and hormonal/metabolic values.

RESULTS

The total number of colonoscopies performed in ACRO patients increased from 6 in the period 1990-1994 to 57 in the period 2010-2014. Colonoscopy procedures were performed according to guidelines in 25% of ACRO patients at diagnosis, 51% at follow-up and 11% globally (both at diagnosis and follow-up). Among the 146 ACRO patients, 68% were subjected to at least one colonoscopy and in 32% of the cases a polyp was detected during the procedure. The presence of polyps was significantly associated with mean levels of growth hormone (GH), insulin-like growth factor 1 (IGF-1), fasting glucose and insulin levels (p < 0.05). Polyps were detected in 48% of untreated patients and in 26% of patients under treatment for acromegaly (p = 0.04). The general risk of polyps and adenomatous polyps in ACRO patients was higher compared to the control population of Veneto Region, Italy (odds ratio 1.33 and 1.16, respectively). No cancerous polyps were detected in our analysis.

CONCLUSION

In real-life practice, adherence to ACRO colonoscopy clinical guidelines was lower than expected. Among patients who underwent colonoscopy, the prevalence of colon polyps was higher for ACRO patients, suggesting the need for new strategies to ensure adherence to colonoscopy guidelines.

Controversies in the risk of neoplasia in GH deficiency

Growth hormone (GH) replacement in GH deficient (GHD) children secures normal linear growth, while in GHD adults it improves metabolic status, body composition and quality of life. Safety of GH treatment is an important issue in particular concerning the controversy of potential cancer risk. Unlike in congenital IGF-1 deficiency, there is no complete protection against cancer in GHD patients. Important modifiable risk factors in GHD patients are obesity, insulin resistance, sedentary behavior, circadian rhythm disruption, chronic low grade inflammation and concomitant sex hormone replacement. Age, family history, hereditary cancer predisposition syndromes or cranial irradiation may present non-modifiable risk factors. Quantifying the risk of cancer in relation to GH therapy in adult GHD patients is complex. There is evidence that links GH to cancer occurrence or promotion, but the evidence is progressively weaker when moving from in vitro studies to in vivo animal studies to epidemiological studies and finally to studies on GH treated patients. GH-IGF inhibition in experimental animals leads to decreased cancer incidence and progression. Epidemiological studies suggest an association of high normal circulating IGF-1 or GH to cancer incidence in general population. Data regarding cancer incidence in acromegaly are inconsistent but thyroid and colorectal neoplasias are the main source of concern. Replacement therapy with rhGH for GHD is generally safe. Overall the rate of de novo cancers was not increased in studies of GH-treated GHD patients. Additional caution is mandated in patients with history of cancer, strong family history of cancer and with advancing age. Childhood cancer survivors may be at increased risk for secondary neoplasms compared with general population. In this subgroup GH therapy should be used cautiously and with respect to other risk factors (cranial irradiation etc). We believe that the benefits of GH therapy against the morbidity of untreated GH deficiency outweigh the theoretical cancer risk. Proper monitoring of GH treatment with diligent cancer surveillance remains essential.

Acromegaly incidence, prevalence, complications and long-term prognosis: a nationwide cohort study

DESIGN

Valid data on acromegaly incidence, complications and mortality are scarce. The Danish Health Care System enables nationwide studies with complete follow-up and linkage among health-related databases to assess acromegaly incidence, prevalence, complications and mortality in a population-based cohort study.

METHOD

All incident cases of acromegaly in Denmark (1991-2010) were identified from health registries and validated by chart review. We estimated the annual incidence rate of acromegaly per 10(6) person-years (py) with 95% confidence intervals (95% CIs). For every patient, 10 persons were sampled from the general population as a comparison cohort. Cox regression and hazard ratios (HRs) with 95% confidence intervals (95% CIs) were used.

RESULTS

Mean age at diagnosis (48.7 years (CI: 95%: 47.2-50.1)) and annual incidence rate (3.8 cases/10(6) persons (95% CI: 3.6-4.1)) among the 405 cases remained stable. The prevalence in 2010 was 85 cases/10(6) persons. The patients were at increased risk of diabetes mellitus (HR: 4.0 (95% CI: 2.7-5.8)), heart failure (HR: 2.5 (95% CI: 1.4-4.5)), venous thromboembolism (HR: 2.3 (95% CI: 1.1-5.0)), sleep apnoea (HR: 11.7 (95% CI: 7.0-19.4)) and arthropathy (HR: 2.1 (95% CI: 1.6-2.6)). The complication risk was also increased before the diagnosis of acromegaly. Overall mortality risk was elevated (HR: 1.3 (95% CI: 1.0-1.7)) but uninfluenced by treatment modality.

CONCLUSION

(i) The incidence rate and age at diagnosis of acromegaly have been stable over decades, and the prevalence is higher than previously reported. (ii) The risk of complications is very high even before the diagnosis. (iii) Mortality risk remains elevated but uninfluenced by mode of treatment.

Prevalence of Simple Renal Cysts in Acromegaly

Objective Various organs are known to be affected by the comorbidities of acromegaly. However, the involvement of renal structural comorbidities, such as cysts, has so far remained largely unknown. In this single-center study, we aimed to determine the prevalence and factors associated with simple renal cysts in Japanese patients with acromegaly. Methods A total of 71 consecutive patients with acromegaly were analyzed, who all underwent abdominal ultrasonography at diagnosis between 1986 and 2012 at Kobe University Hospital. Results Of these 71 patients, 23 (32.4%) exhibited simple renal cysts. Acromegalic patients with renal cysts tended to be significantly older, had a higher prevalence of smoking- and higher nadir growth hormone (GH) levels during the oral glucose tolerance test (OGTT) than did those without renal cysts. A multivariate logistic regression analysis showed age, smoking, and nadir GH to be independent factors associated with renal cysts. Interestingly, the number of renal cysts positively correlated with both the basal GH levels and nadir GH levels during OGTT (r=0.66, p<0.05 and r=0.70, p<0.05, respectively). In addition, the mean diameter of renal cysts positively correlated with the systolic blood pressure (r=0.84, p<0.005). Conclusion This is the first report to show the prevalence of simple renal cysts in patients with acromegaly. Elevated nadir GH levels during OGTT were found to be associated with an increased risk of simple renal cysts. Therefore, an excessive secretion of GH may be related to the development of renal cysts.

The effect of a 10-week Nordic walking training program on the level of GH and LH in elderly women

OBJECTIVE

The aim of this study was to determine the effect of a 10-week Nordic walking training program on resting growth hormone (GH) and luteinizing hormone (LH) blood concentrations and their relationships to the values of inflammatory, metabolic, and muscle injury parameters in postmenopausal women with overweight and obesity.

METHODS

Thirty-two postmenopausal women with overweight or obesity (body mass index 30.5 ± 4.1 kg/m(2)), aged 59.6 ± 5.9 years were included in the investigation. Concentrations of GH, LH, C-reactive protein, total cholesterol, low density (LDL) and high density lipoprotein (HDL) cholesterol, triglycerides and albumin, as well as the plasma activity of muscle enzymes such as creatine kinase and lactate dehydrogenase, were examined before and after the participants finished a 10-week Nordic walking rehabilitation program.

RESULTS

After a 10-week rehabilitation period in accordance with a Nordic walking program, significant increases in blood concentrations of GH (median 47.5%) and HDL cholesterol (on average by 0.1%) as well as a decrease in LH values (on average by 19%), total cholesterol, LDL cholesterol and triglycerides (all on a similar average by between 0.1 and 0.2%), creatine kinase (on average by 14%), lactate dehydrogenase (on average by 4%), C-reactive protein (on average by 24%), and body mass index (on average by 5.7%) were found.

CONCLUSIONS

Nordic walking for postmenopausal women with overweight and obesity led to favorable hormonal responses, as well as improvement in muscle integrity and nutritional and inflammatory states, suggesting chronic, regular exercise as an effective tool in protecting against menopause-related catabolic processes.

Insulin/Insulin-like growth factors in cancer: new roles for the aryl hydrocarbon receptor, tumor resistance mechanisms, and new blocking strategies

The insulin-like growth factor 1 receptor (IGF1R) and the insulin receptor (IR) are receptor tyrosine kinases that are expressed in cancer cells. The results of different studies indicate that tumor proliferation and survival is dependent on the IGF1R and IR, and that their inhibition leads to reductions in proliferation and increases in cell death. Molecular targeting therapies that have been used in solid tumors include anti-IGF1R antibodies, anti-IGF1/IGF2 antibodies, and small molecule inhibitors that suppress IGF1R and IR kinase activity. New advances in the molecular basis of anti-IGF1R blocking antibodies reveal they are biased agonists and promote the binding of IGF1 to integrin β3 receptors in some cancer cells. Our recent reports indicate that pharmacological aryl hydrocarbon receptor (AHR) ligands inhibit breast cancer cell responses to IGFs, suggesting that targeting AHR may have benefit in cancers whose proliferation and survival are dependent on insulin/IGF signaling. Novel aspects of IGF1R/IR in cancer, such as biased agonism, integrin β3 signaling, AHR, and new therapeutic targeting strategies will be discussed.