AGA Clinical Practice Update on Approach to the Use of Noninvasive Colorectal Cancer Screening Options: Commentary.

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update Commentary is to review the available evidence and provide expert advice regarding the approach to using noninvasive colorectal cancer (CRC) screening options, including evidence for their effectiveness, selection of individuals for whom these tests are appropriate, implications of a positive non-colonoscopy screening test, and opportunities to enhance the quality of noninvasive CRC screening programs. This Clinical Practice Update was commissioned and approved by the AGA Institute Clinical Practice Updates Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the Clinical Practice Updates Committee and external peer review through standard procedures of Gastroenterology. This expert commentary reflects recently published studies in this field, as well as the experiences of the authors who are gastroenterologists with high-level expertise in CRC screening and prevention.

Effect of Cotinine-Verified Change in Smoking Status on Risk of Metachronous Colorectal Neoplasia After Polypectomy.

BACKGROUND & AIMS: Previous assessments of colorectal neoplasia (CRN) recurrence after polypectomy used self-report to determine smoking status. We evaluated the association between change in smoking status and metachronous CRN risk after polypectomy using cotinine level in urine to determine tobacco exposure. METHODS: We performed a retrospective study of participants in the Kangbuk Samsung Health Study in Korea who underwent a screening colonoscopy examination and measurement of cotinine in urine samples. Our analysis included 4762 patients who had 1 or more adenomas detected in an index colonoscopy performed between January 2010 and December 2014, and underwent a surveillance colonoscopy, 6 or more months later, until December 2017. RESULTS: Patients were classified into 4 groups based on the change in cotinine-verified smoking status from index to follow-up colonoscopy (mean interval, 3.2 ± 1.3 y), as follows: remained nonsmokers (n = 2962; group 1), smokers changed to nonsmokers (n = 600; group 2), nonsmokers changed to smokers (n = 138; group 3), and remained smokers (n = 1062; group 4). After adjustment for confounding factors, group 4 had a significantly higher risk of metachronous CRN than group 1 (hazard ratio [HR], 1.54; 95% CI, 1.36-1.73) and group 2 (HR, 1.63; 95% CI, 1.39-1.99). Group 4 also had a higher risk of metachronous advanced CRN than group 1 (HR, 2.84; 95% CI, 1.79-4.53) and group 2 (HR, 2.10; 95% CI, 1.13-3.89). Group 3 had a higher risk of metachronous CRN than group 1 (HR, 1.50; 95% CI, 1.14-1.97) and group 2 (HR, 1.62; 95% CI, 1.20-2.20). CONCLUSIONS: In a retrospective study of individuals with at least 1 adenoma, we found that cotinine-verified changes in smoking status between index and follow-up colonoscopy are associated with a risk of metachronous CRN. Helping patients quit smoking is important for effective prevention of colorectal cancer.

Urine-NMR metabolomics for screening of advanced colorectal adenoma and early stage colorectal cancer.

Although colorectal cancer (CRC) is considered one of the most preventable cancers, no non-invasive, accurate diagnostic tool to screen CRC exists. We explored the potential of urine nuclear magnetic resonance (NMR) metabolomics as a diagnostic tool for early detection of CRC, focusing on advanced adenoma and stage 0 CRC. Urine metabolomics profiles from patients with colorectal neoplasia (CRN; 36 advanced adenomas and 56 CRCs at various stages, n = 92) and healthy controls (normal, n = 156) were analyzed by NMR spectroscopy. Healthy and CRN groups were statistically discriminated using orthogonal projections to latent structure discriminant analysis (OPLS-DA). The class prediction model was validated by three-fold cross-validation. The advanced adenoma and stage 0 CRC were grouped together as pre-invasive CRN. The OPLS-DA score plot showed statistically significant discrimination between pre-invasive CRN as well as advanced CRC and healthy controls with a Q2 value of 0.746. In the prediction validation study, the sensitivity and specificity for diagnosing pre-invasive CRN were 96.2% and 95%, respectively. The grades predicted by the OPLS-DA model showed that the areas under the curve were 0.823 for taurine, 0.783 for alanine, and 0.842 for 3-aminoisobutyrate. In multiple receiver operating characteristics curve analyses, taurine, alanine, and 3-aminoisobutyrate were good discriminators for CRC patients. NMR-based urine metabolomics profiles significantly and accurately discriminate patients with pre-invasive CRN as well as advanced CRC from healthy individuals. Urine-NMR metabolomics has potential as a screening tool for accurate diagnosis of pre-invasive CRN.

MicroRNA-15a expression measured in urine samples as a potential biomarker of renal cell carcinoma.

INTRODUCTION: Currently, there is no accurate diagnostic molecular biomarker for renal cell carcinoma (RCC). The aim of this study was to assess the expression of microRNA-15a (miR-15a) in urine of patients with RCC and to evaluate its potential as a diagnostic molecular biomarker. MATERIALS AND METHODS: In total, 67 patients with solid renal tumors were enrolled: clear-cell RCC (ccRCC, n = 22), papillary RCC (pRCC, n = 16), chromophobe RCC (chRCC, n = 14), oncocytoma (n = 8), papillary adenoma (n = 2) and angiomyolipoma (n = 5). MiRNA-15a expression levels measurement in urine were performed using qPCR. Urine of 15 healthy volunteers without kidney pathology was used as control. RESULTS: We observed a difference in mean miR-15a expression values in groups of pre-operative patients with RCC, benign renal tumors and healthy persons (2.50E-01 ± 2.72E-01 vs 1.32E-03 ± 3.90E-03 vs 3.36E-07 ± 1.04E-07 RFU, respectively, p < 0.01). There was no difference in miR-15a expression between ccRCC, pRCC and chRCC (p > 0.05). Direct association between RCC size and miR-15a expression values was obtained (Pearson correlation coefficient-0.873). On the 8th day after nephrectomy, mean expression value in patients with RCC decreased by 99.53% (p < 0.01). MiR-15a expression differentiated RCC from benign renal tumors with 98.1% specificity, 100% sensitivity at a cut-off value of 5.00E-06 RFU, with AUC-0.955. CONCLUSIONS: MiR-15a expression measured in urine may be used as diagnostic molecular biomarker for RCC.

Comparing metabolite profiles of habitual diet in serum and urine.

BACKGROUND: Diet plays an important role in chronic disease etiology, but some diet-disease associations remain inconclusive because of methodologic limitations in dietary assessment. Metabolomics is a novel method for identifying objective dietary biomarkers, although it is unclear what dietary information is captured from metabolites found in serum compared with urine. OBJECTIVE: We compared metabolite profiles of habitual diet measured from serum with those measured from urine. DESIGN: We first estimated correlations between consumption of 56 foods, beverages, and supplements assessed by a food-frequency questionnaire, with 676 serum and 848 urine metabolites identified by untargeted liquid chromatography mass spectrometry, ultra-high performance liquid chromatography tandem mass spectrometry, and gas chromatography mass spectrometry in a colon adenoma case-control study (n = 125 cases and 128 controls) while adjusting for age, sex, smoking, fasting, case-control status, body mass index, physical activity, education, and caloric intake. We controlled for multiple comparisons with the use of a false discovery rate of <0.1. Next, we created serum and urine multiple-metabolite models to predict food intake with the use of 10-fold crossvalidation least absolute shrinkage and selection operator regression for 80% of the data; predicted values were created in the remaining 20%. Finally, we compared predicted values with estimates obtained from self-reported intake for metabolites measured in serum and urine. RESULTS: We identified metabolites associated with 46 of 56 dietary items; 417 urine and 105 serum metabolites were correlated with ≥1 food, beverage, or supplement. More metabolites in urine (n = 154) than in serum (n = 39) were associated uniquely with one food. We found previously unreported metabolite associations with leafy green vegetables, sugar-sweetened beverages, citrus, added sugar, red meat, shellfish, desserts, and wine. Prediction of dietary intake from multiple-metabolite profiles was similar between biofluids. CONCLUSIONS: Candidate metabolite biomarkers of habitual diet are identifiable in both serum and urine. Urine samples offer a valid alternative or complement to serum for metabolite biomarkers of diet in large-scale clinical or epidemiologic studies.

POSTSURGICAL RECURRENT CUSHING DISEASE: CLINICAL BENEFIT OF EARLY INTERVENTION IN PATIENTS WITH NORMAL URINARY FREE CORTISOL.

OBJECTIVE: To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC). METHODS: The design was a single-center, retrospective chart review. Patients treated by the authors from 2008-2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST). RESULTS: We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements. CONCLUSION: LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker. ABBREVIATIONS: ACTH = adrenocorticotropic hormone CD = Cushing disease CS = Cushing syndrome CV = coefficient of variation DST = dexamethasone suppression test IPSS = inferior petrosal sinus sampling LNSC = late-night salivary cortisol QoL = quality of life TSS = transsphenoidal adenoma resection UFC = urinary free cortisol.

Can We Identify Nephrogenic Adenoma in Urine Cytology Specimens? A Study Evaluating Previously Described Cytomorphologic Features in Correlation With PAX8 Immunohistochemical Staining Results.

OBJECTIVES: The aim of this study is to determine if the diagnosis of nephrogenic adenoma (NA) can be made on cytologic criteria alone and if pair box gene transcription factor 8 (PAX8) is useful in the diagnosis of NA in daily cytology practice. METHODS: Cytologic features of NA previously described in a literature were used to identify NA cells in urinary specimens. Subsequently, all cytology and corresponding biopsy specimens were stained with the PAX8 immunohistochemistry stain. The stains were examined; the results were tabulated. RESULTS: A total of 44 specimens were reviewed (35 with corresponding biopsy specimens diagnosed as NA and nine negative for NA diagnosis on corresponding biopsy specimens). Of them, 14 demonstrated features previously described as NA. None of atypical cells that were morphologically suspicious for NA showed positive staining, whereas all of the corresponding biopsy sections demonstrated nuclear PAX8 positivity. Only rare lymphocytes present in cytology specimens showed nuclear staining with PAX8. CONCLUSIONS: Assuming that the results of the PAX8 stain performed are accurate at least in most cases, as suggested by the presence of internal positive controls, our study shows that the previously described cytologic features of NA cannot be used as diagnostic criteria, since they are not characteristic for this entity.

Temozolomide for aggressive ACTH pituitary tumors: failure of a second course of treatment.

INTRODUCTION: Temozolomide (TMZ) is an oral alkylating agent that has been used over the past 8 years to treat aggressive pituitary tumors resistant to conventional therapy. To date, only 25 patients treated with TMZ for ACTH producing pituitary tumors (14 adenomas and 11 carcinomas) have been reported. MATERIALS AND METHODS: We present a retrospective review of the medical records of three patients with aggressive ACTH producing adenomas treated with TMZ. In the three cases there was evidence of progression to conventional therapy before starting TMZ. We used the conventional scheme for the treatment of gliomas until completing 7, 12 and 6 cycles respectively. Reduction in tumor size was evident after the 3rd, 5th and 4th cycle of TMZ and progression free survival was 25, 19 and more than 12 months in the three patients respectively. Improvement of the ocular and visual symptoms was evident after the 4th cycle of treatment in all cases. Normalization of urinary free cortisol levels was achieved after the 3rd and 9th cycle in the two cases with hypercortisolism. Two of the three patients received a second course of treatment when the disease progressed but it did not stop tumor progression. The principal side effects were G3 neutropenia, G1 and G2 thrombocytopenia, G1 lymphopenia, asthenia and nausea. CONCLUSION: The treatment with TMZ is effective and safe in patients with aggressive corticotrophin tumors resistant to conventional therapy. Nevertheless once the disease progresses, a second course of treatment does not seem to be effective.

Preanalytical validation and reference values for a mass spectrometric assay of serum vanillylmandelic acid for screening of catecholamine secreting neuroendocrine tumors.

BACKGROUND: Urinary vanillylmandelic acid (VMA) is used to diagnose and monitor catecholamine secreting neuroendocrine tumors (NETs). We developed and validated a new liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for determination of serum VMA. METHODS: We used serum samples from healthy volunteers (n=314) and patients suspected for NET (n=36). Deuterated VMA as an internal standard was added to samples before solid phase extraction (SPE) and LC-MS/MS analysis. We studied the effects of sample storage, sampling device and a meal on serum VMA and metanephrine concentrations. Diurnal variation and age-dependent reference intervals were established. The diagnostic performance was compared with a urinary HPLC assay for VMA and metanephrines and a serum metanephrine LC-MS/MS assay. RESULTS: Serum VMA is stable at least for one day at +4°C, seven days at room temperature and 98 days at -20°C. Type of sampling device was not critical, but elevated serum VMA occurs after a meal (p = 0.031). Serum VMA increased with age. Therefore, we suggest clinical cut-off values of 62 nmol/L, 80 nmol/L and 108 nmol/L for age groups 18-50 yrs, 51-70 yrs and > 70 yrs, respectively. Comparison between a urinary VMA HPLC assay and serum VMA LC-MS/MS assay showed good correlation. CONCLUSIONS: Our LC-MS/MS assay is fast and sensitive and suits well for use in a clinical laboratory. Compared to 24-h urine collection our serum assay enables well controlled sampling and convenient preanalytical steps.

Urinary PGE-M in colorectal cancer: predicting more than risk?

Progress in cancer chemoprevention has been hindered by a lack of validated biomarkers of risk and interventive response. The identification of accurate, reliable, and easily measurable risk and response biomarkers within the field of cancer prevention could dramatically alter our approach to the disease. Colorectal cancer is associated with substantial morbidity and a limited 5-year survival rate for late-stage disease. The identification of biomarkers to predict (i) those most at risk of clinically significant colorectal neoplasia in conjunction with or building upon current risk models and/or (ii) those most likely to respond to potential colorectal chemopreventive agents, such as aspirin and NSAIDs, would significantly advance colorectal cancer risk management. Urinary PGE-M is an established indicator of systemic prostaglandin E2 production and has previously been demonstrated to predict risk of advanced colorectal neoplasia in a handful of studies. In the July 2014 issue, Bezawada and colleagues confirmed those earlier risk associations and demonstrated that PGE-M can also predict responsiveness to aspirin/NSAIDs in a small subset of women undergoing lower endoscopy in the Nurse's Health Study. PGE-M has the potential to define subsets of the population that may derive greater chemopreventive benefit from NSAIDs, as well as the potential to optimize the use of expensive and/or invasive screening tests. Additional larger and more diverse prospective studies meeting the criteria for phase IV biomarker studies are needed to advance the development of PGE-M as a noninvasive biomarker of both risk and chemopreventive response in populations at risk for colorectal cancer.

Urinary PGE-M levels are associated with risk of colorectal adenomas and chemopreventive response to anti-inflammatory drugs.

Prostaglandin E2 (PGE2) promotes colorectal carcinogenesis. Overall, systemic PGE2 production can be assessed by measuring its major metabolite, PGE-M, in urine. We examined the potential role of PGE-M as a biomarker for colorectal adenoma risk and chemopreventive response to anti-inflammatory drugs. We conducted a prospective case-control study nested within the Nurses' Health Study. Among women who previously provided a urine sample, we identified 420 cases diagnosed with colorectal adenoma during follow-up and matched them to 420 endoscopy-negative controls. We measured urinary PGE-M using an LC/MS assay. Compared with women in the lowest quartile of urinary PGE-M, women in the highest quartile had a multivariate OR of 1.40 (95% confidence interval (CI), 0.92-2.14) for any adenoma; 0.91 (95% CI, 0.48-1.72) for low-risk adenoma (solitary adenoma <1 cm in greatest diameter with tubular/unspecified histology); and 1.66 (95% CI, 1.04-2.67) for high-risk adenoma (adenoma ≥1 cm in greatest diameter and/or tubulovillous, villous or high-grade dysplasia histology or multiple adenomas of any size or histology). Regular use of anti-inflammatory drugs (≥2 standard tablets of aspirin/NSAIDs per week) was associated with a significant reduction in adenoma risk (multivariate OR, 0.61; 95% CI, 0.43-0.87) in women with high baseline PGE-M (quartiles 2-4), but not low PGE-M (quartile 1).Urinary PGE-M is associated with an increased risk of high-risk adenoma. Anti-inflammatory drugs seem to reduce adenoma risk among women with high, but not low PGE-M. Urinary PGE-M may serve as a biomarker to define subsets of the population who may obtain differential chemopreventive benefit from anti-inflammatory drugs.

Sources of variability in metabolite measurements from urinary samples.

BACKGROUND: The application of metabolomics in epidemiological studies would potentially allow researchers to identify biomarkers associated with exposures and diseases. However, within-individual variability of metabolite levels caused by temporal variation of metabolites, together with technical variability introduced by laboratory procedures, may reduce the study power to detect such associations. We assessed the sources of variability of metabolites from urine samples and the implications for designing epidemiologic studies. METHODS: We measured 539 metabolites in urine samples from the Navy Colon Adenoma Study using liquid chromatography-mass spectrometry (LC-MS) and gas chromatography-mass spectroscopy (GC-MS). The study collected 2-3 samples per person from 17 male subjects (age 38-70) over 2-10 days. We estimated between-individual, within-individual, and technical variability and calculated expected study power with a specific focus on large case-control and nested case-control studies. RESULTS: Overall technical reliability was high (median intraclass correlation = 0.92), and for 72% of the metabolites, the majority of total variance can be attributed to between-individual variability. Age, gender and body mass index explained only a small proportion of the total metabolite variability. For a relative risk (comparing upper and lower quartiles of "usual" levels) of 1.5, we estimated that a study with 500, 1,000, and 5,000 individuals could detect 1.0%, 4.5% and 75% of the metabolite associations. CONCLUSIONS: The use of metabolomics in urine samples from epidemiological studies would require large sample sizes to detect associations with moderate effect sizes.

Urinary 1-methylhistidine and 3-methylhistidine, meat intake, and colorectal adenoma risk.

Self-reported red and processed meat intake has been positively associated with colorectal adenoma and cancer; however, measurement error in self-reported data can attenuate risk estimates, increasing the need for improved exposure assessment methods to better understand this association. A controlled feeding study revealed that urinary 1-methylhistidine and 3-methylhistidine levels were dose-dependently associated with meat intake; our aim was to examine these analytes in relation to colorectal adenoma. Individuals undergoing routine cancer screening by sigmoidoscopy or colonoscopy were recruited for a colorectal adenoma case-control study; participants completed a food frequency questionnaire and a meat questionnaire, and donated urine. Urinary 1-methylhistidine and 3-methylhistidine levels were measured in 131 case-control pairs (age, sex, and smoking matched); odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by logistic regression. Although the mean self-reported red meat intake was higher in cases (59 g/day) than in controls (48 g/day), the mean urinary 1-methylhistidine and 3-methylhistidine levels did not differ by case status (P=0.72). Neither urinary 1-methylhistidine nor urinary 3-methylhistidine was associated with colorectal adenoma (OR continuous=0.90, 95% CI: 0.53-1.54; OR continuous=0.90, 95% CI: 0.69-1.17, respectively). A variable combining self-reported red meat intake with urinary 1-methylhistidine and 3-methylhistidine levels was not associated with colorectal adenoma. Analyzing urine samples from multiple days from 17 individuals revealed intraclass correlations of 0.52 and 0.49 for 1-methylhistidine and 3-methylhistidine, respectively; this variability could result in attenuated risks. Urinary 1-methylhistidine and 3-methylhistidine levels, measured in one sample, were not associated with colorectal adenoma.

Urinary protease inhibitor Serpin B3 is higher in women and is further increased in female patients affected by aldosterone producing adenoma.

A correct diagnosis of primary aldosteronism (PA) requires adrenal venous sampling (AVS) for the classification of subtypes (bilateral hyperplasia, BAH, or adenoma, APA). Since such testing is not easily practicable, appropriate markers for the definition of subtypes are desirable. We hypothesized that an aldosterone excess was associated with abnormalities in urinary proteome, specific for PA subtypes. The project work was divided into 3 phases: (1) screening/identification by proteomic analysis and further characterization by RT-PCR and immunohistochemistry of the candidate protein; (2) clinical validation by quantitative ELISA assay of 57 (33 M, 24 F) PA patients and 50 normotensive controls (21 M, 29 F); (3) analysis of adrenal tissue of 8 individuals who had undergone adrenalectomy for APA or other adrenal tumors. The proteomic analysis showed a different expression of Serpin B3 Inhibitor-SCCA1 (SB3) in APA and BAH patients. Urine SB3 concentrations in normotensive controls, quantified by ELISA assay and normalized by urinary creatinine, resulted much lower in males (6.72 ng SB3 per mg creatinine, C.I. 4.43-10.19) than in females (20.56 ng SB3 per mg creatinine, C.I. 12.43-33.99, p < 0.00001). SB3 concentrations were not significantly different in males affected by different PA subtypes (BAH, n = 19 and APA, n = 14) compared with normotensive subjects (n = 21). In contrast, in PA females, SB3 was significantly higher in APA (n = 13) than in BAH patients (n = 11) or in normotensive controls (n = 29) (P < 0.01 and <0.05, respectively). Neither messenger RNA nor SB3 protein were identified in tissue obtained from adrenal tumors and from the surrounding normal gland. In conclusion urine SB3 concentrations are physiologically much lower in males than in females. Hypertensive women, affected by APA, present urinary SB3 concentrations significantly higher than women affected by BAH.

[Postoperative management of patients with sellar tumors through monitoring urine volume and urine electrolytes].

OBJECTIVE: To determine the value of urine volume and urine electrolytes in postoperative management of patients with sellar tumors. METHODS: Medical records of 103 patients with sellar tumors in the West China Hospital from January 2009 to December 2009 were retrospectively reviewed. The patients were managed either based on blood electrolytes (Group A, n = 56) or based on urine volume and urine electrolytes (Group B, n = 47). The incidence of balance disturbance of water and electrolytes was compared between the two groups. RESULTS: The levels of blood electrolytes were normal in both groups 3 days after operations despite significant loss of electrolytes through urine. Balance disturbance of water and electrolytes was revealed 4-7 days after operations. Group B had a lower incidence of balance disturbance of water and electrolytes (17.02%, 8/47) compared with Group A (73.21%, 41/56, P < 0.05). No gender difference in the incidence of balance disturbance of water and electrolytes was found. Higher incidence of balance disturbance of water and electrolytes was found in craniopharyngioma (P < 0.05, vs. pituitary adenoma) and in the patients undergoing craniotomy (P < 0.05, vs. transsphenoidal approach) in Group A, but not in Group B. CONCLUSION: Better management of balance disturbance of water and electrolytes can be achieved for patients with sellar tumors through monitoring urine than through blood. It can also simplify the postoperative management of patients with sellar tumors.

Quantification of urinary 18-hydroxycortisol using LC-MS/MS.

BACKGROUND: Urinary 18-hydroxycortisol has been investigated as a marker of aldosterone-producing adenoma (APA). The aim of this study was to develop and validate a method for the measurement of 18-hydroxycortisol using liquid chromatography-tandem mass spectrometry (LC-MS/MS). METHODS: Urine was collected over a 24-hour period in patients with APA (n = 11), idiopathic hyperaldosteronism (IHA, n = 9), and essential hypertension (EH, n = 6). 18-Hydroxycortisol was extracted in solid-phase, and measured by LC-MS/MS based on selected reaction monitoring. RESULTS: The method allowed quantification of 18-hydroxycortisol with a lower quantification limit of 0.26 nmol/L, intra- and inter-assay coefficients of variation of <3.4% and a range of analytical recovery of 98.0-103.7%. Urinary 18-hydroxycortisol excretion for APA, IHA and EH were determined as 725 (SD 451), 102 (SD 68) and 88 (SD 76) nmol/day, respectively. CONCLUSIONS: The proposed method met the basic analytical requirements and was considered to be useful in the screening and differential diagnosis of APA.

Comparison of 24-h urinary aldosterone level and random urinary aldosterone-to-creatinine ratio in the diagnosis of primary aldosteronism.

BACKGROUND: Historically, urinary aldosterone level measurement was a commonly employed confirmatory test to detect primary aldosteronism (PA). However, 24-h urine collection is inconvenient and cumbersome. We hypothesized that random urinary aldosterone measurements with correction for creatinine concentration might be comparable to 24-h urinary aldosterone levels (Uald-24 h) in the diagnosis of PA. METHODS: The non-concurrent prospective study was conducted between June 2006 and March 2008 in patients admitted for confirmation of aldosteronism by salt loading test. A 24-h urine sample, which was collected during hospitalization on the day before saline infusion testing after restoration of serum hypokalemia, was collected from all subjects. Moreover, participants were asked to collect a first bladder voiding random urine sample during clinic visits. Uald-24 h and the random urinary aldosterone-to-creatinine ratio (UACR) were calculated accordingly. RESULTS: A total of 102 PA patients (71 patients diagnosed of aldosterone-producing adenoma, 31 with idiopathic hyperaldosteronism) and 65 patients with EH were enrolled. The receiver operating characteristic curve showed comparable areas under the curves of UACR and Uald-24 h. The Bland-Altman plot showed mean bias but no obvious heteroscedasticity between the two tests. When using random UACR >3.0 ng/mg creatinine as the cutoff value, we obtained a specificity of 90.6% to confirm PA from essential hypertension. CONCLUSIONS: Our study reinforce that the diagnostic accuracy of random UACR was comparable to that of Uald-24 h in PA patients. With the quickness and simplicity of the UACR method and its equivalence to Uald-24 h, this assay could be a good alternative diagnostic tool for PA confirmation.

Significance of HCG to distinguish parathyroid carcinoma from benign disease and in adding prognostic information: a hospital based study from Nepal.

OBJECTIVE: To differentiate between benign and malignant hyperparathyroidism on the basis of excretion of HCG and its malignant isoforms in urine. MATERIALS AND METHODS: This hospital based study was carried out using data retrieved from the register maintained in Manipal Teaching Hospital from 1st January, 2008 and 31st August, 2012. The variables collected were urinary HCG and HCG malignant isoform, calcium and parathyroid hormone. Preceding the study, approval was obtained from the institutional research ethical committee. Analysis was by descriptive statistics and testing of hypothesis. A p-value of <0.05 (two-tailed) was used to establish statistical significance. RESULTS: Out of the 20 cases, 10 were primary hyperparathyroidism and the remainder were parathyroid carcinomas. The urinary HCG 6.1∓0.6 fmol/mgCr was with in normal range in benign hyperthyroidism but was markedly elevated in three cases of malignant hyperparathyroidism (maximum value of excretion in urine for HCG was 2323 fmol/mgCr). The excretion of malignant isoform of HCG in urine was 0 in benign hyperparathyroidsm and in four cases of malignant hyperparathyroidism which fell into the category of persistantly low HCG. The maximum excretion of the malignant isoform of HCG in urine was 1.8, in the category of very high HCG. Calcium and parathyroid hormone were mildly raised in benign parathyroidism, while parathyroid hormone was markedly elevated in cases of malignant hyperparathyroidism falling into the category of very high HCG. CONCLUSIONS: The excretion of urinary HCG in urine has the ability to distinguish between parathyroid adenomas and carcinomas and thus has potential to become a marker of disease progression in malignant parathyroid disease.

Urinary prostaglandin E2 metabolite and risk for colorectal adenoma.

COX-2 is upregulated in most colorectal cancers. Most of the COX-2 tumor-inducing effects are believed to be mediated through overproduction of prostaglandin E(2) (PGE(2)), which can be measured using a urinary metabolite of PGE(2), PGE-M. Urinary PGE-M was assessed in a case-control study of colorectal adenoma. Included in the analysis were 224 cases with at least one advanced adenoma, 152 cases with multiple small tubular adenomas, 300 cases with only a single small tubular adenoma, and 364 polyp-free controls. There were no statistical differences in PGE-M levels between controls and cases with a single small tubular adenoma. However, cases with either an advanced adenoma or multiple small tubular adenomas had more than 25% higher levels of PGE-M than controls. Participants with the highest quartile level of PGE-M were approximately 2.5-fold more likely to have advanced or multiple small tubular adenoma in comparison with those with the lowest level of PGE-M [OR = 2.53; 95% confidence interval (CI), 1.54-4.14; P(trend) < 0.001]. The association was strongest among women. PGE-M level was associated with increased risk for multiple or advanced adenoma but not single small adenoma. Our study suggests that PGE-M may be a useful risk marker for assessing the risk of harboring clinically more important versus less important colorectal neoplasia.

Unilateral adrenalectomy improves urinary protein excretion but does not abolish its relationship to sodium excretion in patients with aldosterone-producing adenoma.

Experimental and human data suggest that adverse cardiovascular (CV) and renal effects of aldosterone excess are dependent on concomitant dietary salt intake. Increased urinary protein (Uprot) is an early sign of nephropathy independently associated with CV risk. We have previously reported a positive association between Uprot and urinary sodium (UNa) in patients with hyperaldosteronism, but not in patients with normal aldosterone levels. We aimed to determine whether Uprot is related to UNa in patients with aldosterone-producing adenoma (APA) and whether the degree of Uprot and strength of this relationship is reduced following correction of hyperaldosteronism. Subjects with APA (n=24) underwent measurement of 24 h Uprot and UNa before and after unilateral adrenalectomy (follow-up 15.0±11.9 months). Following surgery, mean clinic systolic blood pressure fell (150.4±18.2 vs 134.5±14.5 mm Hg, P=0.0008), despite a reduction in number of antihypertensive medications, and Uprot (211.2±101.6 vs 106.0±41.8 mg per day, P<0.0001) decreased. There was a positive correlation between Uprot and UNa both before (r=0.5477, P=0.0056) and after (r=0.5097, P=0.0109) adrenalectomy. Changes in UNa independently predicted Uprot reduction (P=0.0189). These findings suggest that both aldosterone levels and dietary salt contribute to renal damage, and that once glomerular damage occurs it is not completely resolved following correction of hyperaldosteronism. Our study suggests that treatment strategies based on reduction of aldosterone effects, by adrenalectomy or mineralocorticoid receptor blockade, in conjunction with low-salt diet would provide additional target-organ protection in patients with primary aldosteronism.