Expression of Cyclooxygenase-2 and Its Correlation with Vasogenic Brain Edema in Human Intracranial Meningiomas

Recurrence/Regrowth in Grade I Meningioma: How to Predict?

The HLA-G and HLA-E molecules, Ki67, progesterone (PR), estrogen (ER) and androgen receptors (AR), p53, COX-2, and HER2 were studied to assess whether the biological behavior of grade I meningiomas is related to their expression. Tissue samples from 96 patients with grade I intracranial meningiomas were analyzed by immunohistochemistry on tissue microarray blocks (TMA) using antibodies specific for HLA-G, HLA-E, Ki67, PR, ER, AR, p53, COX-2, and HER2. Meningiomas were classified as small (≤2 cm, 1.0%), medium (>2 and ≤4 cm, 32.3%), and large (>4 cm, 66.7%). Tumor size was not related to recurrence/regrowth (p = 0.486), but was significantly correlated with peritumoral edema (p = 0.031) and intratumoral calcifications (p = 0.018). Recurrent meningiomas were observed in 14.6% of cases. Immunostaining for each marker was: HLA-G 100%; HLA-E 95.6%; PR 62%; ER 2.1%; AR 6.5%; p53 92.6%; COX-2 100%; HER2 0%; Ki67, mean 2.61 ± 2.29%, median 2.1%. Primary and recurrent meningiomas showed no significant relation with HLA-E and hormone receptors (p > 0.05), except for Ki67, where a higher median was observed in recurrent tumors than in primary (p = 0.014). The larger the tumor, the more severe the peritumoral edema, and the greater the presence of calcifications. Ki67 appears to be a good biomarker of recurrence/regrowth in grade I meningiomas.

Association between nonsteroidal anti-inflammatory drug use and brain tumour risk: a meta-analysis

AIMS

Several epidemiological studies have evaluated the association between nonsteroidal anti-inflammatory drugs (NSAIDs) and brain tumour risk. However, results from these studies have been inconsistent. The aim of this detailed meta-analysis is to review and summarize the evidence on this association.

METHODS

A comprehensive search for articles published up to September 2013 was performed. Studies evaluating the association between exposure to NSAIDs and risk of brain tumours were included. Random-effects meta-analytical models were used to calculate the relative risk (RR) and corresponding 95% confidence intervals (CIs). Sensitivity analyses, Galbraith plots and subgroup analyses were also performed.

RESULTS

Ten studies (six case-control studies, three cohort studies and one randomized controlled trial), published between 2003 and 2013, were included in this analysis. Compared with non-use, overall use of NSAIDs was not statistically significantly associated with brain tumour risk based on the random-effects models (RR = 1.01; 95% CI = 0.89, 1.15). No differences were observed when analyses were stratified by gender and brain tumour subtype. Specific analysis for aspirin and non-aspirin NSAIDs yielded similar results. However, a slightly increased risk of brain tumour in NSAID users was observed in cohort studies (RR = 1.32; 95% CI = 1.06, 1.64; P = 0.014). Furthermore, our analysis did not show a significant association between frequency and dose of aspirin use and brain tumour risk.

CONCLUSIONS

Use of NSAIDs (aspirin and non-aspirin NSAIDs) does not appear to be associated with brain tumour risk, but larger studies are needed to substantiate this relationship.

An observational study on the expression of cyclooxygenase-2 in meningioma

Background:

The cyclooxygenase-2 (COX-2) enzyme is overexpressed in different types of tumors and is known to be associated with malignant behavior of tumors. We determined the association of COX-2 expression and different grades of human meningioma.

Materials and Methods:

This retrospective study was conducted on specimens obtained from adult patients with meningioma. Meningioma was classified according to the WHO 2007 classification protocol (I, II, and III). COX-2 expression intensity was scored based on the percentage of immunopositive cells as 0: 0-10%; +1: >10% and a part of the cell membrane; +2: >10% and complete cell membrane; and +3: >30% and complete cell membrane. Scores of +2 or +3 were considered as COX-2 positive.

Results:

Ninety meningioma cases (mean age = 53.0 ± 13.2 years, 71.1% female) were studied. COX-2 was positive in 25% (17/68), 68.4% (13/19), and 100% (3/3) of cases with tumor grade I, II, and III, respectively (P < 0.001). There was a significant correlation between tumor grade and COX-2 expression score (Spearman's correlation coefficient = 0.422, P < 0.001).

Conclusions:

There is a strong association between COX-2 expression and tumoral grade in meningioma with more aggressive tumors expressing COX-2 with more intensity. Prospective studies examining the association of COX-2 expression with tumor recurrence and interventional studies examining the role of COX-2 inhibitors anticancer therapy of meningioma are warranted.

Tumor-associated edema in brain cancer patients: pathogenesis and management

The long-term treatment of peritumoral edema remains a major challenge in clinical neuro-oncology. Steroids have been and will remain the backbone of any anti-edematous therapy because of their striking activity, convenient oral administration and also because of their cost-effectiveness. Their side effects, however, can compromise quality of life, particularly upon continuous administration. Therapeutic alternatives which may replace or - at least - help to reduce the steroid dose are limited. However, with the development of new agents such as corticorelin acetate, there is a hope that steroid-induced side effects can be delayed and reduced. The administration of anti-angiogenic agents with steroid-sparing effects, for example, bevacizumab, is limited due to their costs. Increased knowledge on boswellic acids and cyclooxygenase-2 inhibitors which are available for clinical application may help to exploit their anti-edema activity more efficiently in the future.

Non-steroidal anti-inflammatory drug use and brain tumour risk: a case-control study within the Clinical Practice Research Datalink

PURPOSE

The aetiology of primary brain tumours is largely unknown; the role of non-steroidal anti-inflammatory drugs (NSAIDs) or aspirin use and glioma risk has been inconclusive, but few population-based studies with reliable prescribing data have been conducted, and the association with meningioma risk has yet to be assessed.

METHODS

The UK Clinical Practice Research Datalink was used to assess the association between aspirin and non-aspirin NSAID use and primary brain tumour risk using a nested case-control study design. Conditional logistic regression analysis was performed on 5,052 brain tumour patients aged 16 years and over, diagnosed between 1987 and 2009 and 42,678 controls matched on year of birth, gender and general practice, adjusting for history of allergy and hormone replacement therapy use in the glioma and meningioma models, respectively.

RESULTS

In conditional logistic regression analysis, excluding drug use in the year preceding the index date, there was no association with non-aspirin NSAID use (OR 0.96, 95 % CI 0.81-1.13) or glioma risk comparing the highest category of daily defined dose to non-users; however, non-aspirin NSAID use was positively associated with meningioma risk (OR 1.35, 95 % CI 1.06-1.71). No association was seen with high- or low-dose aspirin use irrespective of histology.

CONCLUSIONS

This large nested case-control study finds no association between aspirin or non-aspirin NSAID use and risk of glioma but a slight increased risk with non-aspirin NSAIDs and meningioma.

Cyclooxygenase-2 supports tumor proliferation in vestibular schwannomas

BACKGROUND

Recent studies have shown that cyclooxygenase-2 (COX-2) plays an important role in tumor growth and neovascularization. However, COX-2 expression in vestibular schwannomas (VSs) has not been investigated.

OBJECTIVE

To analyze the pattern of COX-2 expression in sporadic and neurofibromatosis type 2 (NF2)-associated VSs and its relationship with tumor proliferation and microvessel density.

METHODS

Fifteen sporadic and 15 NF2-associated VSs were examined for COX-2 expression, microvessel density, and proliferation rate by immunohistochemical methods. Immunohistochemical scores were used to interpret the extent and intensity of COX-2 staining. Microvessel density (MVD) was determined using von Willebrand factor (vWf). Proliferation rate was quantified using Ki-67. The relationship among COX-2 expression, MVD, and proliferation rate was statistically analyzed.

RESULTS

COX-2 expression was detected in 29 (96.67%) of 30 VSs, with no significant difference between sporadic and NF2-associated VSs (P = .722). In 6 (20%) VSs, COX-2 expression was graded as strong, in 12 (40%) as moderate, and in 11 (36.7%) as weak. VSs with high proliferation showed significantly higher COX-2 expression (P = .015) than VSs with low proliferation. COX-2 expression and MVD did not show specific biological correlations (P = .035).

CONCLUSION

Our data demonstrate that COX-2 is expressed in VSs. High COX-2 expression in VSs with high proliferation rates suggests that the COX-2 pathway may be involved in the development and growth of VSs.