Regional radon concentration impact on glioblastoma patients: Findings from a 10 years monocentric retrospective analysis
Friedrich Bellingrodt Velázquez (Dresden), Tareq Juratli (Dresden), Dietmar Krex (Dresden), Ilker Y. Eyüpoglu (Dresden), Witold H. Polanski (Dresden)
Elevated residential Radon-222 concentration (RRC) is known to influence the incidence of not only lung cancer but also central nervous system tumors. There may be a relationship between a specific range of Radon exposure and the incidence of Glioblastoma (GBM).
To assess whether a particular RRC poses a risk for the development of GBM, we gathered patient demographics, histological findings, gene mutations, survival time, and RRC data (provided by Geoportal from the Federal Office for Radiation Protection).
A total of 4435 patient files were reviewed, and 836 patients with diagnosed IDH-negative GBM WHO-Grade 4 tumors who underwent Tumor Resection or Biopsy between January 2012 and December 2022 were analyzed. The last follow-up was conducted on December 31, 2023. The median age was 66.76 years (Standard Deviation(SD) 13.64 years, range 3.2-92.3 years), with 57.1% being male. The study divided participants into four groups based on their exposure to radiation levels, which was measured in kilobecquerels per cubic meter (kBq/m3). Group 1 (0-40kBq/m3 – 151 participants (pts)), Group 2 (41-75kBq/m3 – 306 pts), Group 3 (76-111kBq/m3 – 200 pts), and Group 4 (>111kBq/m3 – 179 pts). The Pearson chi-square test indicated that gender and MGMT status were equally distributed across all groups (0.833 and 0.939 respectively). The mean age of pts in Group 1 was 63.54 years (SD 14.29 – ranging from 3.2 to 86.3 years), while Group 2 had a mean age of 67.52 years (SD 14.28 – ranging from 9.2 to 87.2 years). Groups 3 and 4 had a mean age of 68.44 years (SD 12.49, range 25.3 to 92.39) and 65.26 years (SD 12.94, range 12.1 to 87.5 years), respectively. Group 1 showed a mean survival time (MST) of 19.37 months in the first 60 months after diagnosis, whereas Group 2 had an MST of 14.87 months. Using Wilcoxon paired comparison, we found that patients in Group 1 had a significantly longer MST than those in Group 2 (p=0.024). Additionally, patients in Group 1 were younger (mean age 63.54 years) compared to the other groups.
Our findings indicates a significant correlation between lower residential Radon-222 concentrations (>40kBq/m3) and reduced mean survival time in GBM patients. The reason for this association remains unclear. It may be that there is a lower threshold for tumor induction of gliomas compared to other known malignancies. Therefore, we suggest further investigations to explore this specific aspect in upcoming studies.