Table 1.
Clinical Characteristics of the Oligodendroglioma Cohort
| Parameter | Grade II oligodendroglioma | Grade III oligodendroglioma |
|---|---|---|
| No. male (%) | 41 (51.9) | 22 (68.8) |
| Median age (range) | 42 y (19—79 y) | 49 y (25—80 y) |
| No. biopsy only (%) | 21 (29.2) | 7 (26.9) |
| No. GTR (%) | 22 (30.6) | 6 (23.1) |
| No. STR (%) | 29 (40.3) | 13 (50.0) |
| No. temporal lobe (%) | 14 (23.7) | 3 (15.8) |
| No. non-temporal lobe (%) | 45 (76.3) | 16 (84.2) |
| No. with no adjuvant therapy (%) | 26 (36.6) | 8 (30.8) |
| No. with radiation only (%) | 13 (18.3) | 4 (15.4) |
| No. with chemo only (%) | 24 (33.8) | 3 (11.5) |
| No. with radiochemotherapy (%) | 8 (11.3) | 11 (42.3) |
| Mean follow-up interval | 3.4 y | 3.4 y |
| Median follow-up interval | 2.9 y | 1.9 y |
| Follow-up range | 0.3—17.5 y | 0.1—18.9 y |
| No. died (%) | 11 (15.5) | 19 (59.4) |
| No. 1p/19q intact by FISH and LOH (%) | 22 (27.8) | 4 (12.5) |
| No. 1p/19q codeleted by FISH and LOH (%) | 43 (54.4) | 22 (68.8) |
| No. codeleted by FISH not LOH (%) | 14 (17.7) | 6 (18.8) |
| No. codeleted by LOH not FISH (%) | 0 (0) | 0 (0) |
| No. with 10q LOH (%) | 17/72 (23.6) | 9/26 (34.6) |
Seventy-nine grade II oligodendrogliomas and 32 grade III oligodendrogliomas were subjected to prospective molecular testing at the time of diagnosis. The type of surgery was known in 72 grade II and 26 grade III tumors; postoperative treatment information was available for 71 grade II and 26 grade III tumors; precise tumor location was retrievable for 59 grade II and 19 grade III tumors. Overall 1p/19q concordance between FISH and LOH was 81.1%. FISH = fluorescence in situ hybridization; GTR = gross total resection; STR = subtotal resection; LOH = loss of heterozygosity.