The importance of considering competing risks in recurrence analysis of intracranial meningioma

BACKGROUND

The risk of recurrence is overestimated by the Kaplan-Meier method when competing events, such as death without recurrence, are present. Such overestimation can be avoided by using the Aalen-Johansen method, which is a direct extension of Kaplan-Meier that accounts for competing events. Meningiomas commonly occur in older individuals and have slow-growing properties, thereby warranting competing risk analysis. The extent to which competing events are considered in meningioma literature is unknown, and the consequences of using incorrect methodologies in meningioma recurrence risk analysis have not been investigated.

METHODS

We surveyed articles indexed on PubMed since 2020 to assess the usage of competing risk analysis in recent meningioma literature. To compare recurrence risk estimates obtained through Kaplan-Meier and Aalen-Johansen methods, we applied our international database comprising ~ 8,000 patients with a primary meningioma collected from 42 institutions.

RESULTS

Of 513 articles, 169 were eligible for full-text screening. There were 6,537 eligible cases from our PERNS database. The discrepancy between the results obtained by Kaplan-Meier and Aalen-Johansen was negligible among low-grade lesions and younger individuals. The discrepancy increased substantially in the patient groups associated with higher rates of competing events (older patients with high-grade lesions).

CONCLUSION

The importance of considering competing events in recurrence risk analysis is poorly recognized as only 6% of the studies we surveyed employed Aalen-Johansen analyses. Consequently, most of the previous literature has overestimated the risk of recurrence. The overestimation was negligible for studies involving low-grade lesions in younger individuals; however, overestimation might have been substantial for studies on high-grade lesions.

Neuronavigation as a minimally invasive tool in the treatment of intracranial gunshot injuries

Gunshot injury is the most common cause of penetrating brain injury. The in-hospital mortality for civilians with penetrating craniocerebral injury is 52-95%. There are many surgical techniques suitable for the treatment of survivors. We report a surgical technique consisting of neuronavigation guidance for wound treatment with smaller incisions and craniotomies, followed by bullet removal if feasible. We report case of a 15 year old male patient who sustained an accidental firearm injury to the occipital region, submitted to surgical treatment that consisted in a minimally invasive approach guided by neuronavigation. Immediate neurological examination showed inferior homonymous quadrantanopsia alone as a clinical finding. Patient was discharged after one week, and no complications arised in follow-up. We conclude that using neuronavigation as a tool was effective in the reported case and that minimally invasive neurosurgical techniques may be a safe and efficient option for the treatment of traumatic brain injuries caused by firearm projectiles.

Grade I meningiomas with atypical characteristics: a worse prognosis

ABSTRACT The study reviewed the histology of cases of grade I meningiomas with spontaneous necrosis, grade I without necrosis and grade II meningiomas, to evaluate the histological and immunohistochemical factors of the patients’ prognosis, while correlating the clinicopathological features with the clinical follow-up of the patients. A review of 47 cases from the Department of Pathology of UNIFESP was performed and the samples were submitted to immunohistochemical examination with the p53 protein, Ki-67 cell proliferation factor and progesterone receptor markers. A greater expression was found in the progression of several degrees of aggressiveness for p53 and Ki-67, and a higher frequency of progesterone receptors in the lower degrees. The group of grade I meningiomas with spontaneous necrosis showed histological and immunohistochemical indexes that approximate those of the grade II meningioma. This suggests a worse prognosis for grade I meningiomas with necrosis.

Necrosis is a consistent factor to recurrence of meningiomas: should it be a stand-alone grading criterion for grade II meningioma?

The purpose of this study was to evaluate spontaneous necrosis as a possible isolated factor for progression and recurrence in grade I meningiomas classified according to the current World Health Organization (WHO) classification. Meningiomas are the most frequently reported primary intracranial tumours, accounting for more than 35%. The 2016 WHO classification of central nervous system tumors stratifies meningiomas in grades I (benign), II (atypical), and III (malignant), according to histopathological aspects and the risk of progression or recurrence. Among 110 patients with intracranial meningiomas, 70 were WHO grade I meningiomas with no findings of atypia (G1WON), 15 were WHO grade I with necrosis (G1WN), 21 were WHO grade II (G2), and 4 were WHO grade III (G3). The mean follow-up was 5.9 ± 0.2 years. High performance scale (KPS ≥ 80) was different (p < 0.001) between WHO grade I meningiomas without (81.4%) and with (60%) necrosis. The 5-year mortality rate was 1.4, 6.7 and 5.9% for G1WON, G1WN and G2, respectively, with significant difference (p = 0.011) related to the presence of necrosis. The risk of recurrence was 3.7 times higher in G1WN than in G1WON (p = 0.017), and 4.2 times in G2 (p = 0.010). Progression-free survival (PFS) was clearly higher in patients with G1WON compared to G1WN and G2 (p = 0.002 and p < 0.001, respectively). There was no significant difference in PFS between G1WN and G2 (p = 0.692). Retreatment was also superior in meningioma with necrosis. Our findings provide clear statistical data to consider that patients with benign meningiomas and histologic findings of spontaneous necrosis are at increased risk of progression and recurrence compared to those with benign lesion without atypical features. Statistical analysis curves also suggest that these lesions behave more similarly to those currently classified as WHO grade II meningioma.

Knowledge and clinical expertise regarding oral cancer among Brazilian dentists

The aim of the present work was to assess the knowledge and attitudes of Brazilian General Dental Practitioners with regard to aspects of the aetiology, early diagnosis and prevention of oral cancer relevant for general dental practice. A convenience sample of 129 dentists in Brazil was randomly selected and asked to complete a questionnaire. Results of bi-variated analysis revealed that a self-perceived good knowledge regarding relevant aspects of oral cancer was statistically significantly associated with male gender (Chi square=4.59, P<0.05). Simple logistic regression revealed that male professionals were 2.9 times more knowledgeable than their female colleagues (OR=2.9, 1.1-8.1 95% CI, P=0.037), although, this association was not statistically significant when adjusted for age using multiple regression analysis (OR=2.7, 0.9-7.5 95% CI, P=0.059). There were no significant differences in relevant knowledge and attitudes of private compared with public dentists. Importantly, General Dental Practitioners who spent more than half of time of a patient's initial consultation undertaking a clinical examination were the more likely to detect oral cancer (Chi square=4.245, P=0.039) than those who set aside little time examining their patients. It is concluded that the knowledge of dentists in Brazil regarding relevant aspects of oral cancer is suboptimal, and may not be associated with any examined social-demographic variables. Further research is required to clarify the role of continuing professional education in improving the knowledge and attitudes of dentists relevant to oral cancer in Brazil.