Long-term impact of temozolomide on 1p/19q-codeleted low-grade glioma growth kinetics

• Published in: Journal of neuro-oncology Vol. 136; no. 3; pp. 533 - 539
• Main Authors: Izquierdo, C., Alentorn, A., Idbaih, A., Simó, M., Kaloshi, G., Ricard, D., Barritault, M., Meyronet, D., Bruna, J., Honnorat, J., Delattre, J. Y., Ducray, F.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-02-2018; Springer Nature B.V
• Subjects: Adult; Aged; Antineoplastic Agents, Alkylating - therapeutic use; Brain - diagnostic imaging; Brain - drug effects; Brain - physiopathology; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - drug therapy; Brain Neoplasms - genetics; Brain Neoplasms - physiopathology; Brain tumors; Chemotherapy; Chromosome Deletion; Chromosomes, Human, Pair 1; Chromosomes, Human, Pair 19; Clinical Study; Disease Progression; Female; Glioma; Glioma - diagnostic imaging; Glioma - drug therapy; Glioma - genetics; Glioma - physiopathology; Humans; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Grading; Neurology; Oncology; Retrospective Studies; Temozolomide; Temozolomide - therapeutic use; Time Factors; Treatment Outcome; Tumor Burden - drug effects; Tumors; Volumetric analysis; Oligodendroglioma grade II; Temozolomide; Growth kinetics; Low-grade glioma
• ISSN: 0167-594X; 1573-7373
• DOI: 10.1007/s11060-017-2677-4

Although upfront temozolomide (TMZ) has been widely-used to treat 1p/19q-codeleted diffuse low-grade gliomas (LGG), its long-term impact on the growth kinetics of these tumors has not been determined. Based on serial magnetic resonance images we retrospectively evaluated the evolution of the mean tumor diameter (MTD) in 36 progressive 1p/19q-codeleted LGG treated with upfront TMZ. After TMZ onset, all but two patients (94.4%) presented a progressive MTD decrease that lasted for a median duration of 23 months (range 3–114). In 10 patients (27%) MTD regrowth occurred during TMZ treatment and in 22 patients (66%) after TMZ discontinuation. In these patients, median time to MTD regrowth after TMZ discontinuation was 12 months (range 1–88). The rate of MTD regrowth at 3 and 5 years after TMZ onset was 77 and 94%, respectively. Time to tumor progression (TTP) based on volumetric analysis was shorter than TTP based on Response Assessment in Neuro-Oncology (RANO) bidimensional criteria (23 vs. 35 months, p = 0.05) and shorter than time to next oncological treatment (23 vs. 46 months, p = 0.001). In 10 patients (27%), absence of volumetric analysis led to continue TMZ for a median of 10 cycles after MTD had started to regrow. Volumetric analysis is important to precisely assess chemotherapy efficacy in 1p/19q-codeleted LGG, identify early tumor progression and avoid futile chemotherapy continuation. In the present series, although some long-lasting volumetric responses were observed, most tumors resumed their growth within 3 years after TMZ onset.