Article
Is less more? Comparison of wait and scan with primary adjuvant treatments in IDH mutant low grade gliomas
Ist weniger machmal mehr? Vergleich von ‘wait and scan’ nach primärer Operation mit direkter adjuvanter Therapie in einer Serie von IDH mutierten niedriggradigen Gliomen
Search Medline for
Authors
Published: | May 8, 2019 |
---|
Outline
Text
Objective: Based on the limited evidence for adjuvant treatment counselling patients with diffuse WHO°II glioma (LGG) is challenging. In so-called “high-risk” patients most centers nowadays apply an early aggressive adjuvant treatment after surgery. Aim of the retrospective assessment was to compare progression-free survival (PFS) and overall survival (OS) of patients receiving a stand-alone radiotherapy (RT) or chemotherapy (CT) or a concomittant/sequential RT+CT with patients without primary adjuvant treatment after surgery.
Methods: A sub-group analysis of patients with a confirmed IDH mutation was performed based on a retrospective multi-center cohort of 288 patients (≥18a) with LGG. Influence of primary adjuvant treatment after initial surgical resection on PFS and OS was assessed using Kaplan-Meier estimates and multivariate Cox-regression models including age ≥40, complete tumor resection (CTR), recurrent surgery and histology (astrocytoma vs. oligodendroglioma).
Results: 144 patients matched the inclusion criteria. 40 (27.8%) patients received adjuvant treatment. Median follow up was 6 years (CI95%4.8–6.3). Median PFS was 3.9 years and median OS was 16.1 years. PFS and OS were significantly longer without adjuvant treatment (p=0.003). A significant difference in favor of no adjuvant therapy was achieved even in high-risk patients (age ≥40a or residual tumor, 3.9 vs. 3.1 years, p=0.025). In the multivariate model (controlled for age, CTR, oligodendroglial diagnosis and recurrent surgery) adjuvant therapy showed a significant negative influence on PFS (p=0.030) and OS (p=0.009). This effect was most pronounced, if RT+CT was used (p=0.004, HR 2.3 for PFS and p=0.001, HR 20 for OS).
Conclusion: In our series of IDH-mutant LGGs, adjuvant treatment with RT, CT or both showed no significant advantage for PFS and OS. Even high-risk patients with LGG showed a similar significant negative impact of adjuvant treatment on PFS and OS. Our results underscore the importance of a complete tumor resection in LGG. Whether patients ≥40 years should receive adjuvant treatment despite a complete tumor resection should be a matter of debate. A potential tumor de-differentiation by early administration of TMZ, RT or CRT in IDH mutated LGG should be considered. However, our data is limited by the retrospective study design and the potentially heterogeneous indication for adjuvant treatment.