Long-term treatment outcomes of temozolomide-based chemoradiation in patients with adult-type diffuse IDH-mutant
grade 2 astrocytoma.
J Neurooncol 2023;
164:331-339. [PMID:
37665475 PMCID:
PMC10522719 DOI:
10.1007/s11060-023-04418-z]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 08/07/2023] [Indexed: 09/05/2023]
Abstract
PURPOSE
To report the long-term outcomes in adult patients with grade 2 IDH-mutant astrocytoma treated with temozolomide (TMZ)-based chemoradiation.
METHODS
One hundred and three patients with histologically proven grade 2 astrocytoma received radiation therapy (RT), 50.4-54 Gy in 1.8 Gy fractions, and adjuvant TMZ up to 12 cycles. Fifty-two patients received RT at the time of tumor progression and 51 in the early postoperative period for the presence of at least one high-risk feature (age > 40 years, preoperative tumor size > 5 cm, large postoperative residual tumor, tumor crossing the midline, or presence of neurological symptoms). Overall survival (OS) and progression-free survival (PFS) were calculated from the time of diagnosis.
RESULTS
With a median follow-up time of 9.0 years (range, 1.3-15 years), median PFS and OS times were 9 years (95%CI, 6.6-10.3) and 11.8 years (95%CI, 9.3-13.4), respectively. Median PFS was 10.6 years in the early treatment group and 6 years in delayed treatment group (hazard ratio (HR) 0.30; 95%CI 0.16-0.59; p = 0.0005); however, OS was not significantly different between groups (12.8 vs. 10.4 years; HR 0.64; 95%CI 0.33-1.25; p = 0.23). Extent of resection, KPS, and small residual disease were associated with OS, with postoperative tumor ≤ 1 cc that emerged as the strongest independent predictor (HR: 0.27; 95%CI 0.08-0.87; p = 0.01).
CONCLUSIONS
TMZ-based chemoradiation is associated with survival benefit in patients with grade 2 IDH-mutant astrocytoma. For this group of patients, chemoradiation can be deferred until time of progression in younger patients receiving extensive resection, while early treatment should be recommended in high-risk patients.
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