Epidemiology of adrenal tumours in Olmsted County, Minnesota, USA: a population-based cohort study

BACKGROUND

Adrenal tumours are commonly encountered in clinical practice, but epidemiological data mainly originate from referral centres. We aimed to determine incidence, prevalence, and rates of malignancy and hormone excess in patients with adrenal tumours in a standardised geographically well defined population.

METHODS

In this retrospective population-based cohort study we assessed the standardised incidence rate of adrenal tumours in all patients with tumours who lived in Olmsted County, MN, USA, from Jan 1, 1995, to Dec 31, 2017. The Rochester Epidemiology Project infrastructure, which links medical records across all health-care providers for the entire population of Olmsted County since 1966, was used to allow researchers to identify individuals with specific diagnoses, surgical interventions, and other procedures, and to locate their medical records, which were then used in the analysis. Incidence rates and prevalence were standardised for age and sex according to the 2010 US Population.

FINDINGS

An adrenal tumour was diagnosed in 1287 patients (median age 62 years; 713 (55·4%) were women; and 13 (1·0%) were children). Standardised incidence rates increased from 4·4 (95% CI 0·3-8·6) per 100 000 person-years in 1995 to 47·8 (36·9-58·7) in 2017, mainly because of the incidental discovery of adenomas less than 40 mm in diameter in patients older than 40 years. Prevalence of adrenal tumours in 2017 was 532 per 100 000 inhabitants, ranging from 13 per 100 000 in children (aged <18 years) to 1900 per 100 000 in patients older than 65 years. 111 (8·6%) of 1287 patients were diagnosed with malignancy (96 [7·5%] of whom has metastases), 14 (1·1%) with phaeochromocytoma, and 53 (4·1%) with overt steroid hormone excess. Malignancy was more common in children (62%) versus those older than 18 years (8%; p<0·0001), tumours discovered during cancer-staging or follow-up (43% vs 3% for incidentalomas; p<0·0001), tumours more than 40 mm in diameter (34% vs 6% for tumours <20 mm; p<0·0001), tumours with unenhanced CT attenuation of 30 Hounsfield units or more (20% vs 1% for <20 Hounsfield units; p<·0001), and bilateral masses (16% vs 7% for unilateral, p=0·0004).

INTERPRETATION

Adrenal tumour standardised incidence rates increased 10 times from 1995 to 2017. Population-based data revealed lower rates of malignancy, phaeochromocytoma, and overt steroid hormone excess than previously reported.

FUNDING

National Institutes of Health.

SAT-176 Epidemiology of Adrenal Tumors: A Population Based Study of 1287 Patients

Background: Adrenal tumors are reported in 5% of adults, with malignancy rates in 1–12%, and rates of overt hormonal excess in 1–15 %. However, most estimates originate from convenience samples. Our objective was to determine the incidence, prevalence and clinical presentation of adrenal tumors in a population-based setting.

Methods: We used a centralized epidemiologic database to identify patients diagnosed with adrenal tumors in a local community 1995 to 2017. The database is a unique medical records linkage system that allows access to hospital and community medical records for local residents (population 137,000). We calculated incidence rates (IR) as the number of new patients diagnosed while living in the study area, and prevalence as the number of patients living in the study area on Dec 31 2017. IR and prevalence were sex- and age-adjusted to the 2010 US Census population.

Results: Of 1,287 patients diagnosed with adrenal tumor, the median age of diagnosis was 62 years (IQR 52–72), 713 (55%) were women, and 13 (1%) were younger than 18 years at diagnosis. IR was highest in patients >65 YO, followed by patients 40–64 YO, 18–39 YO and <18 YO (142 vs 66 vs 9 vs 2 per 100,000 persons years). IR per 100,000 increased from 4.4 (CI95% 0.3–8.6) in 1995 to 47.8 (CI95% 36.9–58.7) in 2017. Overall prevalence in the population was 0.53% in 2017, ranging from 0.01% among 0–17 YO to 1.9% among +65 YO.

Malignant adrenal mass was diagnosed in 8.7% patients (4 patients with adrenal cortical carcinoma (0.3%) and 108 (8.4%) patients with other malignant mass). Pheochromocytoma was diagnosed in 11 (1.1%) patients and benign adrenal mass was diagnosed in 1,175 (90.2%) patients (1,076 (83.6%) with adrenal adenoma and 85 (6.6%) with other benign mass). Median tumor size was 15 mm (range 5–255), and 184 (14%) of patients had bilateral tumors. Only 255 (20%) patients had dexamethasone suppression test, 93 (36%) with cortisol>1.8 mcg/dl. Of 1,076 adrenal adenomas, 53 (4.9%) had overt hormone excess, 140 (13%) had nonfunctioning adrenal adenomas, and 88 (8.2%) had mild autonomous cortisol secretion. Hormonal work up for was incomplete in 795 (73.9%) adenomas. Patients discovered incidentally (1,050, 81.6%) had a lower rate of malignancy and hormone excess (5.3% vs 52% of patients with non-incidental discovery, p <0.001). Rate of malignancy was highest in children (67% vs 8% >18YO, p<0.001), bilateral tumors (16% vs 8% unilateral, p<0.001), tumors ≥4 cm (33% vs 7% in < 4 cm, p<0.001).

Conclusion: IR of adrenal tumors increased 10-fold since 1995, and was highest in patients >65 YO. 8.7% of tumors were malignant, with a majority represented by malignant adrenal tumors other than adrenal cortical carcinoma. The risk of malignancy was highest in non-incidental discovery, children, and tumors > 4 cm. Overt hormone excess was diagnosed in 4.5% of patients. The majority of patients with adrenal adenomas had a suboptimal work up for hormone excess.

Acute liver failure caused by hepatitis E virus genotype 3 and 4: A systematic review and pooled analysis

BACKGROUND & AIMS

Acute liver failure caused by hepatitis E virus genotype 3 and 4 has been rarely described. Because of the presence of a short golden therapeutic window in patients with viral acute liver failure from other causes, it is possible that early recognition and treatment might reduce the morbidity and mortality. We performed a systematic review and pooled analysis of acute liver failure caused by hepatitis E virus genotype 3 and 4.

METHODS

Two reviewers appraised studies after searching multiple databases on June 12th, 2017. Appropriate tests were used to compare hepatitis E virus genotype 3 vs 4, suspected vs confirmed genotypes, hepatitis E virus-RNA positive vs negative, and to discern important mortality risk factors.

RESULTS

We identified 65 patients, with median age 58 years (range: 3-79), and a male to female ratio of 1.2:1. The median bilirubin, ALT, AST and alkaline phosphatase (expressed by multiplication of the upper limit of normal) levels were 14.8, 45.3, 34.8 and 1.63 respectively. Antihepatitis E virus IgG, antihepatitis E virus IgM and hepatitis E virus-RNA were positive in 84%, 91% and 86% of patients respectively. The median interval from symptoms onset to acute liver failure was 23 days, and 16 patients underwent liver transplantation. Final outcome was reported in 58 patients and mortality was 46%. Age was a predictor of poor prognosis in multivariate analysis. No important differences were found between patients infected with genotype 3 vs 4, patients with confirmed vs suspected genotypes, or patients with positive vs negative RNA.

CONCLUSION

Acute liver failure caused by hepatitis E virus genotype 3 and 4 is rare, similar between genotypes, occurs commonly in middle-aged/elderly patients and has a very high mortality. Age is predictive of poor prognosis in multivariate analysis.