MOLECULAR BIOLOGY OF NEUROBLASTOMA IN A
MULTIRACIAL ASIAN POPULATION
Rajalingam, V, Yong M H, Joseph
V T
KK Women’s & Children’s
Hospital, Singapore
Objective: Neuroblastoma is
well known for its genetic heterogeneity which results in diverse clinical
behaviour and outcome. While
N-myc amplification and 1p deletion are well documented there are unknown
genetic changes that may have an adverse effect on outcome.
Methods: Tumours from sixteen prospective patients were analyzed by
Fluorescence In-situ Hybridisation (FISH) on tumour touch preparations for
1p deletion and N-myc amplification using commercially available DNA
probes. In addition,
Comparative Genomic Hybridisation (CGH) was performed if there was
sufficient DNA available. All
but three patients had Stage 4 disease.
Results: 17q amplification was identified in two Stage 4 and three Stage
3 patients who were negative for both 1p deletion and N-myc
amplification. Only two Stage
4 patient had 1p deletion with N-myc amplification. None of the other patients had
identified adverse biological markers. Our preliminary results indicate that 1p deletion and
N-myc amplification may not be as common in our local population as in the
West. It appears that 17q
amplification occurs as frequently as 1p deletion and Nmyc amplification in
our series.
Conclusion: We conclude that
CGH may prove valuable for the genetic characterisation of neuroblastoma;
both for the detection of frequently occurring genomic imbalances and for
the identification of previously unnoticed genetic changes. Such information may prove useful
to better define a group of high-risk patients who are not N-myc amplified
and or 1p deleted yet who require more intensive treatment because of
aggressive disease and poor outcome.