Gene expression and serum levels of insulin-like growth factors (IGFs) and IGF-binding proteins in a case of non-islet cell tumour hypoglycaemia

Doege-Potter Syndrome: A Presumptive Case of Metastatic Hemangiopericytoma with Persistent Hypoglycemia in a 27-Year-Old Male

Doege-Potter syndrome (DPS) is a rare paraneoplastic condition characterized by hypoinsulinemic hypoglycemia from a solitary fibrous tumor. The underlying mechanism is the secretion of a prohormone form of insulin-like growth factor II (IGF-II) by the tumor, which causes decreased release of glucose into the circulation. We report the case of a 27-year-old Filipino male with presumptive DPS from a recurrent right temporo-zygomatic hemangiopericytoma (HPC). The complexity of DPS requires a multidisciplinary approach. Early screening for metastases from HPC may prevent the undesirable sequelae of the disease process.

Late Onset of Non-islet Cell Tumor Hypoglycemia Managed via Multidisciplinary Treatment in a Patient with a Solitary Fibrous Tumor

Solitary fibrous tumor (SFT) is a rare subtype of soft tissue sarcoma (STS). We herein describe a case of late onset of non-islet cell tumor hypoglycemia (NICTH) that was managed via multidisciplinary treatment in a patient with SFT. A 67-year-old man previously diagnosed with SFT 4 years prior to this presentation and treated with several rounds of surgery, presented with massive tumors. Eighteen months following his prescribed chemotherapy, the patient developed hypoglycemia. He was diagnosed with NICTH, after confirming the presence of high molecular weight insulin-like growth factor-2. This case suggests that paraneoplastic syndrome can occur even in cases of rare cancers, such as STS.

Management of non-islet-cell tumor hypoglycemia: a clinical review

CONTEXT

Non-islet cell tumor hypoglycemia (NICTH) is a rare but serious paraneoplastic syndrome in which a tumor secretes high molecular weight IGF-II, causing hypoglycemia. Complete tumor resection is curative but is often delayed or unfeasible. There is no clear "standard of care" for managing these patients.

EVIDENCE ACQUISITION

PubMed searches were conducted for: "non-islet-cell tumor hypoglycemia," "NICTH," "Doege-Potter," "Doege-Potter syndrome," "high molecular weight IGF-II," and "big IGF-II." Relevant articles were reviewed in detail. We limited our review to English-language articles, focusing on 1988-2013 (corresponding with the elucidation of the pathophysiology of NICTH).

EVIDENCE SYNTHESIS

The available literature exists as case reports or small case series, with a void of higher-order treatment studies. Thus, an evidence-based approach to data synthesis was difficult. Nevertheless, the available literature is presented objectively with an attempt to describe clinically useful trends and findings in the management of NICTH.

CONCLUSIONS

Appropriate identification of NICTH and prompt and complete tumor resection represents ideal management. However, when prompt resection is not feasible, iv glucose or dextrose often does not suffice to prevent hypoglycemia. In such cases, we suggest consideration of local antitumor therapies for disease control and trial of glucocorticoids alone or in combination with GH. Continuous glucagon infusion can be successful if the patient has a positive response to a glucagon stimulation test, and parenteral nutrition may allow higher glucose delivery, but both are limited by the need for continuous iv infusion. Diazoxide and octreotide have no role in NICTH.

A rare cause of hypoglycaemia

We describe the case of a 77-year-old man who was admitted with recurrent episodes of altered behaviour. These episodes were related to insulin-like growth factor II (IGF-II) mediated hypoglycaemia. Imaging revealed a large retroperitoneal mass and he underwent debulking surgery uneventfully. Histopathology revealed a solitary fibroma with intense immunostaining positive for CD34 and vimentin, suggesting a mesenchymal origin of the tumour. Later he received chemo/radiotherapy and is on prednisolone with abatement of hypoglycaemic episodes.

Hypoglycemia from IGF2 overexpression associated with activation of fetal promoters and loss of imprinting in a metastatic hemangiopericytoma

CONTEXT

The mechanism of IGF2 overexpression in non-islet-cell tumor hypoglycemia is not understood.

OBJECTIVE

We investigated the imprinting control and promoter usage for IGF2 expression to identify a mechanism for increased IGF-II production in non-islet-cell tumor hypoglycemia.

PATIENT AND METHODS

A patient with metastatic hemangiopericytoma was studied. Tissue from the original hemangiopericytoma, metastatic tumor, and uninvolved liver was analyzed for IGF-II immunohistochemistry. IGF2, a paternally imprinted gene, shares a control region with maternally imprinted H19, a putative tumor suppressor. IGF-II and H19 mRNA expression was compared in metastatic tumor and uninvolved liver by quantitative RT-PCR. Imprinting of IGF2/H19 genes and IGF2 promoter usage in metastatic tumor was investigated by RT-PCR and sequence analysis, and the methylation pattern in the IGF2/H19 imprinting control region was analyzed.

RESULTS

IGF-II protein expression was increased in metastatic tumor vs. uninvolved liver and original tumor. In the metastatic tumor, IGF-II mRNA was increased 60-fold, but H19 mRNA was comparable to uninvolved liver; loss of imprinting of IGF2, but not H19, was identified; no major change in methylation of the IGF2/H19 imprinting control regions was observed; and transcripts from four different IGF2 promoters were detected, compared to two in uninvolved liver.

CONCLUSIONS

IGF-2 overexpression, newly acquired in the metastatic tumor, was associated with loss of IGF2 gene imprinting and different promoter usage. The imprinting control mechanism governing the IGF2/H19 locus was intact, as evidenced by normal levels of H19, maintenance of H19 imprinting, and no major change in methylation of the imprinting control regions.

When a nephrectomy cures hypoglycaemia

A 40-year-old woman presented with a 10 day history of episodic vagueness, speech disturbance and blurred vision. Episodes typically occurred in the morning after awaking from sleep and resolved with food ingestion. She had no past medical history, did not drink alcohol and was not on any medication. Physical examination was normal with no evidence of endocrinopathy. After 10 h of fasting, she became hypoglycaemic with evidence of neuroglycopenia, which resolved with intravenous dextrose. Biochemical investigations revealed decreased glucose, insulin and C-peptide values with an increased excess insulin-like growth factor II: excess insulin-like growth factor I (IGF-II: IGF-I) ratio. Radiological examinations of the abdomen and pelvis revealed a heterogenous 10.5 cm left renal mass. The patient underwent a radical left nephrectomy. She had complete resolution of hypoglycaemic events. Histology revealed a renal sarcoma, grade 2/3. This is the first report in the literature involving a renal sarcoma causing non-islet cell tumour hypoglycaemia via excess IGF-II secretion.

External validation of IMP3 expression as an independent prognostic marker for metastatic progression and death for patients with clear cell renal cell carcinoma

BACKGROUND

High-quality external validation studies have recently been highlighted to be of paramount importance for proper translation of prognostic markers into the clinical setting. To that end, the authors examined associations of the insulin-like growth factor-II mRNA binding protein, IMP3, with clinical and pathologic features of clear cell renal cell carcinoma (ccRCC) in an independent cohort of patients to validate recent work showing IMP3 as a prognostic marker for RCC progression and death.

METHODS

The authors studied 716 consecutive tumor specimens from patients treated with surgery at the study institution for unilateral, sporadic, noncystic ccRCC between 1990 and 1999. Tissues were stained and scored for IMP3 expression and these expression levels were correlated with clinical and pathologic features as well as clinical outcomes including progression to distant metastases and death from RCC.

RESULTS

It was observed that 213 ccRCC specimens (29.8%) expressed tumor cell IMP3. IMP3 expression was associated with advanced stage and grade of primary tumors as well as other adverse features including coagulative tumor necrosis and sarcomatoid differentiation. After multivariate adjustment for ccRCC prognostic features, positive IMP3 expression was still found to be associated with a 42% increase in the risk of death from RCC (hazards ratio [HR], 1.42; P= .024). Among the subset of patients with clinically localized disease, positive IMP3 expression was associated with a nearly 5-fold increased risk of distant metastases (HR, 4.71; P< .001).

CONCLUSIONS

Using a large and independent cohort of ccRCC patients, the authors confirmed that tumor cell IMP3 expression represents an independent predictor of aggressive ccRCC tumor behavior.

The effectiveness of different treatment options for non-islet cell tumour hypoglycaemia

OBJECTIVE

To compare the outcome of different treatment options used in several cases of non-islet cell tumour hypoglycaemia (NICTH).

PATIENTS

Eight cases of NICTH were referred for diagnosis and monitoring following either surgical or medical treatment.

METHODS

Serum samples collected throughout the time-course of each case were analysed for glucose, insulin, C-peptide, IGF-I, total IGF-II, total IGF-II to IGF-I ratio and, in most of the cases, big IGF-II.

RESULTS

Surgical excision was successful in the relief of symptoms and normalization of the biochemical parameters. Therapeutic treatment with glucocorticoids confirmed previous studies showing the suppressive effect on tumour (big) IGF-II production. The present data show that the effect was dose-dependent and reversible if doses were below a critical level.

CONCLUSIONS

Within the limits of the cases studied, and the time-scales involved, moderate- to high-dose glucocorticoid therapy had immediate beneficial influence on symptomatic hypoglycaemia and, if tolerated in the long term, was effective in correcting the underlying biochemical dysfunction, unlike other therapeutic regimens. This effectiveness was only achieved when the dose exceeded a threshold level specific to the patient. In addition, reduction of the dose or withdrawal of the drug caused a return of the abnormal biochemical profile. Surgical removal of the malignancy, where this was an option, was successful within the periods studied.

Nasogastric feeding enhances nutritional status in paediatric liver disease but does not alter circulating levels of IGF-I and IGF binding proteins

OBJECTIVE

Complications of childhood cirrhosis include abnormal growth and malnutrition, associated with abnormalities in circulating IGFs and IGFBPs. Controlled studies suggest that intensive enteral feeding enhances nutritional status. The aim was to ascertain whether nasogastric feeding improves nutritional status in clinical practice and to assess the effect of feeding on serum IGF-I and IGFBPs.

PATIENTS

Thirty-three children (median age 0.6 years) with biliary atresia and failure to thrive who were treated with nasogastric feeding.

MEASUREMENTS

Height, weight and triceps skin fold thickness were measured prior to feeding and regularly for 1 year or until feeding was stopped. Serum IGF-I and IGFBPs were measured by immunoassay at the same intervals.

RESULTS

The median duration of feeding was 3.7 months. Twenty-two stopped feeding after liver transplantation, while 10 stopped electively and 1 boy died. Before feeding, the children were losing weight and height centile. Triceps skin fold thickness, weight and height SD scores improved with feeding. Baseline serum IGF-I and IGFBP-3 were low, while IGFBP-1 and IGFBP-2 were raised. IGF-I and IGFBP-1 did not change with feeding. IGFBP-2 fell and reached a nadir by 3 months, while IGFBP-3 rose temporarily for 4-6 weeks.

CONCLUSIONS

Nasogastric feeding improves body composition in paediatric liver disease but circulating IGF-I and IGFBPs remain abnormal and do not play a major role in mediating these changes. This does not exclude a paracrine or autocrine effect of IGF-I.