The 70-year-old newly diagnosed glioblastoma patients are older than the 65-year-old? Outcome evaluation of the two categories in a matched case control study with propensity score balancing.

Background: The standard of care for elderly, newly-diagnosed glioblastoma patients consists, if feasible, of surgical resection followed by a short course of radiation therapy (RT) with concomitant and adjuvant temozolomide chemotherapy (TMZCHT). To date, the literature lacks of consistence in the definition of elderly, if older than 65 years, or 70 years. Aim of this study was to explore whether differences exist between these two cohorts, comparing outcomes using a propensity score matched analysis (PSM).

Materials And Methods: Two hundred twenty-one elderly newly diagnosed glioblastoma patients were included. All patients received surgery followed by RT with concurrent and adjuvant TMZCHT. The RT dose prescribed was 60 Gy/30 fractions for patients 65-69-year-old or 40.5 Gy/15 fractions for ≥70-year-old. After 1:1 matching there were 86 patients in each group. Distribution of covariates was adequately balanced in the matched data set.

Results: After PSM median PFS time, 1,2,3-year PFS rates were 10 months, 33.3%, 13.1%, and 6.6% for the 65-69-year group, 9 months, 34.7%, 11% and 4.8% for the ≥70-year group (p = 0.530). Median OS time, and 1,2,3-year OS rates were 14 months, 54.1%, 23.4%, 13.9% for the 65-69-year old group, and 12 months, 49.3%, 21.5%, 10% for the ≥70-year group (p = 0.357). No differences were recorded in relation to different groups of age.

Conclusions: The PSM analyses showed a similar outcome in 65-69-year old patients compared to older ones notwithstanding a more burdensome RT schedule. Hypofractionated RT treatment has to be considered also in this group of younger elderly, newly-diagnosed GBM patients.