Exploring the Impact of Extent of Resection MRI Findings and Genetic Markers on Overall Survival in Low Grade Glioma Patients: Evaluation at the End of 1 Year

Background Diffuse low-grade glioma (LGG), i.e WHO grade II glioma, is a rare brain cancer, whose etiopathogenesis is poorly understood, making difficult the prediction of its natural course, especially at an individual level. LGG spontaneously exhibits different stages in its evolution, namely (i) a pre- symptomatic period in which the tumor is usually slow growing, as demonstrated in cases of incidental discovery (ii) a symptomatic period in which the glioma induces clinical consequences, usually seizures and/or mild cognitive impairments visible on neuropsychological assessment , while continuing to progress slowly but constantly (about 3-4 mm mean diameter per year) and (iii) a period of malignant transformation (MT) with acceleration of the growth rate, resulting in more severe neurological deficits and ultimately death . Aims and Objectives To evaluate the surgical effect on survival in patients with low-grade glioma (LGG). To identify factors that influence survival for patients that underwent surgical resection of LGGs. Materials and Methods Data of patients who underwent surgery for excision of LGGs during the years 2019 2023 in Koikilaben Dhirubhai Ambani Hospital & Research Institute will be collected from the Department of Neurosurgery database. Data of operated patient would be thoroughly examined, pre- and post- operative neurological status, size of the lesion would be measured volumetrically comparing the pre- and post-operative MRI imaging along with other features of lesion at interval of 1week, 3months, 6months and 1 year. The neurological deficits and progression free survival will be closely monitored. Results In this study, we evaluated the impact of extent of resection, MRI findings, and 1p/19q status on tumor progression in 78 patients with low-grade glioma (LGG) over a 12-month follow- up period. Our findings indicate that age under 40 years, IDH-mutant status, safe maximal surgical resection, and early initiation of chemotherapy and/or radiotherapy (CT/RT) for residual lesions were associated with better clinical outcomes. Among the 57 patients with IDH-mutant tumours, the lesion size remained stable over the 1-year follow-up period. In contrast, of the 21 patients with IDH-wildtype tumours, 6 showed an increase in residual lesion size, and 9 experienced tumour recurrence. Patients with 1p/19q codeletion responded more favourably to CT/RT compared to those with 1p/19q retention. Specifically, 56 patients with the 1p/19q codeleted status demonstrated stable residual lesions or no recurrence, indicating a better response to chemotherapy. On the other hand, in the 22 patients with 1p/19q retention, tumour progression or recurrence was observed despite early initiation of CT/RT. These findings underscore the importance of molecular markers (IDH and 1p/19q status) and extent of surgical resection in guiding treatment strategies and improving outcomes in LGG patients. Conclusion Our single-institution cohort of 78 patients confirmed that in lower-grade gliomas, the IDH mutation is the most significant predictor of clinical outcomes. Patients with IDH-wildtype tumors demonstrated significantly shorter progression-free survival compared to those with IDH-mutant tumors. Importantly, IDH mutation status appeared to outweigh traditional histological grading, as there was no significant difference in median overall or progression- free survival between IDH-mutant grade II and grade III tumours. The integration of molecular biomarkers particularly IDH mutation and 1p/19q codeletion into routine diagnostic workflows represents a major advancement in the field. This molecularly integrated approach is essential not only for accurate prognosis but also for the development of personalized treatment strategies. For example, identification of 1p/19q codeletion may guide clinicians toward more intensive chemotherapy regimens, whereas IDH-mutant, 1p/19q-retained tumours may benefit from alternative therapeutic approaches. Our findings reinforce the growing importance of incorporating molecular diagnostics into glioma classification and treatment planning. This personalized, biomarker-driven strategy enhances our understanding of glioma biology and supports more precise, patient-centred care. Additionally, the study underscores the critical need for continued research into the molecular underpinnings of gliomas, as ongoing discoveries in tumour genetics will further refine how we classify, treat, and ultimately improve outcomes for patients with these tumours.