Meningiomas and the Polynesian population

Characterization of volumetric growth of intracranial meningiomas in Māori and Pasifika populations in New Zealand

BACKGROUND

Māori and Pasifika populations in New Zealand have a higher incidence and prevalence of intracranial meningioma (IM). We sought to evaluate the volumetric growth rate of meningiomas under surveillance in these populations.

METHODS

From July 2002 to October 2020, 336 patients with a total of 408 IM underwent conservative management with serial radiological surveillance at Auckland City Hospital and met the criteria for the study. Inclusion criteria included: age >16 at diagnosis, ≥2 appropriate scans one or more years apart. Exclusion criteria included previous cranial irradiation, a diagnosis of Neurofibromatosis and prior treatment of meningioma. Demographic and clinical data were obtained from the electronic medical records. Imaging data were recorded from the first and last scans. We utilized open-source image processing software (3D Slicer) for semi-automated segmentation and volume calculation. Consistent with previous literature, we calculated the relative growth rate (RGR, %/year) and annual volume change (AVC, cm³ /year) over time.

RESULTS

Four hundred and eight meningiomas were volumetrically characterized for a mean duration of 6.2 years. The Māori and Pasifika populations (n = 134/393) demonstrated a higher RGR (31.41 versus 14.33%/year) (P = 0.026) and AVC (2.05 versus 0.95 cm³ ) (P = 0.025) compared to the control population. They also presented at a younger age and had a higher rate of tumour multiplicity. Males represented only 17.6% of the cohort but exhibited a higher growth rate (AVC = 2.52 cm³ /year) than females (AVC = 0.99 cm³ /year) (P = 0034).

CONCLUSIONS

Māori and Pasifika populations in New Zealand have a higher incidence and volumetric growth rate of IM compared to a control population. This warrants further clinical, histopathological and genomic analysis.

The epidemiology of patients undergoing meningioma resection in Auckland, New Zealand, 2002 to 2011

The incidence of meningioma is known to vary by gender and ethnicity. This study aimed to describe the epidemiological characteristics of a 10-year cohort of patients undergoing meningioma resection at Auckland City Hospital, Auckland, New Zealand. Of particular interest was whether there was any difference in meningioma incidence and recurrence rates between New Zealand Maori and Pacific Island patients compared with other ethnic groups. The study was a retrospective analysis of 493 patients with pathologically confirmed meningioma over the period 1 January 2002 to 31 December 2011. Based on this neurosurgical cohort, the minimum incidence of meningioma in the Auckland region was 3.39 per 100,000 population per year (95% C.I. 3.02-3.80) for the study period. Meningioma was significantly more common in women than men by a ratio of 4.2:1. New Zealand Maori and Pacific Island patients had a significantly higher incidence of meningioma than other ethnic groups. New Zealand Maori had a meningioma incidence 2.74 times that of Europeans (95% C.I. 2.01-3.73, p < 0.001). Pacific Island patients had 2.03 times higher incidence of meningioma than Europeans (95% C.I. 1.42 - 2.89, p < 0.001). The overall meningioma recurrence rate was 21.6% with a mean follow-up of 77 months. Recurrence rates for meningioma among Pacific Island patients were significantly higher than for other ethnic groups (hazard ratio 1.73, p = 0.008). Multivariate analysis of clinical variables confirmed the significance of traditional prognostic factors such as WHO tumour grade and Simpson grade of surgical excision in predicting meningioma recurrence.

Pathology and genetics of meningiomas

This article constitutes a mini-review of the pathology and genetics of meningiomas. Meningiomas are the most common primary intracranial tumors. They are usually durally based and are often found adjacent to venous sinuses and dural infoldings. The majority of these tumors are WHO grade I, although a minority is WHO grade II, atypical, or WHO grade III, anaplastic. Grade II and III meningiomas show a greater tendency than Grade I tumors to recur and metastasize. The current WHO scheme recognizes 15 histologic subtypes of meningiomas. Nine of these are WHO grade I, three are grade II, and three are grade III. In addition to these histologic subtypes, meningiomas can also be graded on the basis of mitotic activity, evidence of brain invasion, growth pattern cellular density, nuclear atypia, and necrosis. Loss of the long arm of chromosome 22, which is usually associated with inactivation of the NF2 gene, is the most common genetic abnormality found in meningiomas. Other chromosomal abnormalities associated with tumorogenesis and increased gradeof meningiomas include loss of heterozygosity for chromosome 1p, loss of 14q, deletion of 9p21, abnormalities of chromosome 10 and 17q. Telomerase activity increases with meningiomas grade as well. The only proven environmental risk factor for meningiomas is ionizing radiation. Radiation-induced meningiomas are more often multiple and have higher recurrence rates than standard meningiomas.

Epidemiology of brain tumors

Brain tumors seemed to have increased in incidence over the past 30 years, but the rise probably results from use of new neuroimaging techniques. Treatments have not improved prognosis for rapidly fatal brain tumors. Established brain tumor risk factors (exposure to ionizing radiation, rare mutations of penetrant genes, and familial history) explain only a small proportion of brain tumors, and only one of these potentially is modifiable. Genetic and environmental characteristics likely play a role in familial aggregation of glioma and these factors are not identified. New concepts in brain tumor etiology and clinical management are the goal of research, with an aim at eradicating this devastating disease.

Increased prevalence of obesity and obesity-related postoperative complications in male patients with meningiomas

OBJECTIVE

The female preponderance of meningiomas may reflect hormonal influences on meningioma growth. We hypothesized that because obesity affects male steroid hormone synthesis, male patients with meningiomas might exhibit a high obesity rate, which, in turn, might increase their frequency of postoperative complications.

METHODS

We retrospectively reviewed male patients who underwent craniotomy for benign meningiomas at our institution between 2001 and 2005 (n = 32) and used male patients undergoing craniotomy for aneurysms (n = 32) or glioblastomas (n = 32) from 2001 to 2005 as control subjects. Body mass index (BMI) greater than 30 kg/m was considered obese.

RESULTS

Male patients with meningiomas had a higher average BMI (30.2 kg/m) than male patients with aneurysms (BMI = 27.5 kg/m) or gliomas (BMI = 25.9 kg/m) (P = 0.04). The obesity rate in men with meningiomas (47%) exceeded that in men with aneurysms (19%) or gliomas (3%) (P = 0.2). The median age-normalized BMI percentile was greater in men with meningiomas (67 th percentile) than in men with aneurysms (49th percentile) or gliomas (52 nd percentile) (P = 0.02). Deep vein thrombosis/pulmonary embolus was more common in men with meningiomas (19%) than in men with aneurysms (0%) or gliomas (3%) (P = 0.002). Wound infections were more common in men with meningiomas (6%) than in men with aneurysms (3%) or gliomas (0%) (P = 0.2). The 53% of obese patients with meningiomas who were readmitted with postoperative complications exceeded the 18% of nonobese patients with meningiomas who were readmitted (P = 0.03); complications included deep vein thrombosis and pulmonary embolus (27 and 12%, respectively, in obese and nonobese patients with meningiomas) and postoperative fever (53 and 35%, respectively, in obese and nonobese patients with meningiomas).

CONCLUSION

We found that many men with meningiomas are obese, suggesting a hormonal influence on meningiomas in men as well as women. Our results also underscore the high risk of postoperative complications in obese male patients with meningiomas.