Open AccessThe effects of tumor size and postoperative radiotherapy for patients with adult low‐grade (WHO grade II) infiltrative supratentorial astrocytoma/oligodendroglioma: A population‐based and propensity score matched study
Author(s) -
Lin DongDong,
Deng XiangYang,
Zheng DongDong,
Gu ChengHui,
Yu LiSheng,
Xu ShangYu,
Li DanDong,
Fang JunHao,
Yin Bo,
Sheng HanSong,
Lin Jian,
Zhang XiaoLei,
Zhang Nu
Publication year - 2018
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.1853
Subject(s) - medicine , propensity score matching , multivariate analysis , astrocytoma , radiation therapy , confounding , oligodendroglioma , statistical significance , surgery , nomogram , retrospective cohort study , glioma , oncology , cancer research
Background The update of 2018 NCCN guidelines (central nervous system cancers) recommended the risk classification of postoperative patients diagnosed as adult low‐grade (WHO grade II) infiltrative supratentorial astrocytoma/oligodendroglioma (ALISA/O) should take tumor size into consideration. Moreover, the guidelines removed postoperative radiotherapy (PORT) for low risk patients. Our study aimed to explore the specific tumor size to divide postoperative patients into relatively low‐ or high risk subgroups and the effect of PORT for ALISA/O patients. Methods We conducted a retrospective study choosing 1277 postoperative ALISA/O patients from the Surveillance, Epidemiology, and End Results database. The X‐tile analysis provided the optimal cutoff point based on tumor size. The differences between surgery alone and surgery +RT groups were balanced by propensity score‐matched analysis. The multivariable analysis and the nomogram evaluated multiple prognostic factors based on cancer‐specific survival (CSS) and overall survival (OS). Results X‐tile plots defined 59 mm ( P < 0.001) as the optimal cutoff tumor size value in terms of CSS, which was verified in multivariate analysis ( P < 0.001). The Kaplan‐Meier analysis showed that the surgery alone had higher CSS and OS than surgery +RT, while the low risk group had no statistical significance after propensity score match. Multivariable analysis showed that surgery +RT was independently associated with diminished OS and CSS for high risk group, which had no statistical significance for low‐risk group. Conclusions Our study suggested that tumor size of 59 mm was an optimal cutoff point to divide postoperative patients into relatively low‐ or high risk subgroups. PORT may not benefit patients, while the effects of PORT for low risk patients need further research.