Gliomas Infiltrating the Corpus Callosum: A Systematic Review of the Literature

SIMPLE SUMMARY: Gliomas infiltrating the corpus callosum (G-I-CC) may carry significant tumor burden by causing severe neurocognitive and functional impairments. The role of surgical resection has been widely debated over the years, as it has been correlated with significant survival improvement but may also predispose the patient to major post-operative complication risks. The aim of our systematic review was to comprehensively analyze the current literature on G-I-CC, describing clinical presentations, management strategies, outcomes, and prognoses. We found that most G-I-CC are IDH-wildtype grade-4 glioblastomas involving the corpus callosum genu and with bilateral lobe infiltration. In patients with high-grade G-I-CC, surgical resection, especially gross-total, led to significantly longer survival when coupled with post-surgery radiation and temozolomide. Rates of symptom improvement and complications did not significantly differ in preservation versus resection of tumor-infiltrated corpus callosum. Overall, maximally safe resection should be considered in patients with G-I-CC, co-adjuvated with intraoperative neuromonitoring and cortical mapping to further reduce complication risks. ABSTRACT: Background: Gliomas infiltrating the corpus callosum (G-I-CC) majorly impact patient quality-of-life, but maximally safe tumor resection is challenging. We systematically reviewed the literature on G-I-CC. Methods: PubMed, EMBASE, Scopus, Web of Science, and Cochrane were searched following the PRISMA guidelines to include studies of patients with G-I-CC. Clinicopathological features, treatments, and outcomes were analyzed. Results: We included 52 studies comprising 683 patients. Most patients experienced headache (33%), cognitive decline (18.7%), and seizures (17.7%). Tumors mostly infiltrated the corpus callosum genu (44.2%) with bilateral extension (85.4%) into frontal (68.3%) or parietal (8.9%) lobes. Most G-I-CC were glioblastomas (84.5%) with IDH-wildtype (84.9%) and unmethylated MGMT promoter (53.5%). Resection (76.7%) was preferred over biopsy (23.3%), mostly gross-total (33.8%) and subtotal (32.5%). The tumor-infiltrated corpus callosum was resected in 57.8% of cases. Radiation was delivered in 65.8% of patients and temozolomide in 68.3%. Median follow-up was 12 months (range, 0.1–116). In total, 142 patients (31.8%) experienced post-surgical complications, including transient supplementary motor area syndrome (5.1%) and persistent motor deficits (4.3%) or abulia (2.5%). Post-treatment symptom improvement was reported in 42.9% of patients. No differences in rates of complications (p = 0.231) and symptom improvement (p = 0.375) were found in cases with resected versus preserved corpus callosum. Recurrences occurred in 40.9% of cases, with median progression-free survival of 9 months (0.1–72). Median overall survival was 10.7 months (range, 0.1–116), significantly longer in low-grade tumors (p = 0.013) and after resection (p < 0.001), especially gross-total (p = 0.041) in patients with high-grade tumors. Conclusions: G-I-CC show clinicopathological patterns comparable to other more frequent gliomas. Maximally safe resection significantly improves survival with low rates of persistent complications.