Medulloblastoma: Does the Isochromosome 17q Influence on the Long Term Survival?.

Nam, Do Hyun; Wang, Kyu Chang; Kim, Seung Ki; Chi, Je G; Kim, Youn Mi; Cho, Byung Kyu

Original Article

Journal of Korean Neurosurgical Society 1999;28(9): 1312-1315.

Do Hyun Nam, Kyu Chang Wang, Seung Ki Kim, Je G Chi, Youn Mi Kim, Byung Kyu Cho

¹Department of Neurosurgery, Seoul National University College of Medicine, Seoul, Korea.
²Department of Pathology, Seoul National University College of Medicine, Seoul, Korea.

ABSTRACT

OBJECTIVE
An isochromosome for the long arm of 17, i(17q), is the most frequent chromosomal abnormality in medulloblastoma, occurring in 30-60% of cases by karyotype analysis and this abnormality has been reported to be present in cases with a shorter survival time by some authors. Moleculogenetic analysis for i(17q) was performed to identify its influence on the long term survival. PATIENTS AND METHODS:The authors reviewed 17 children and divided them into two groups(favorable and poor outcomes) to elucidate the influence of the i(17q) on the long term survival. Eight children with favorable outcome are in disease-free status during the follow-up period (range: 52-87 months, median: 66 months). The other nine children with poor outcome died of disease progression or recurrence and their median survival time was 13 months (range: 1-28 months). Fluorescent in situ hybridization(FISH) was used for the detection of i(17q) in 17 children.
RESULTS
The i(17q) was detected in nine of 17 children. There was no difference in the positive rates of i(17q) between two groups.
CONCLUSION
The i(17q) was detected by FISH in 53% of medulloblastoma patients. Presence of the i(17q) was not a prognostic factor on the long term survival.

Key Words: Medulloblastoma; Isochromosome 17q; Prognosis