Rflp analysis of the L-myc oncogene in head and neck-cancer - relationship study with susceptibility and disease progression

The L-myc DNA restriction fragment length polymorphism (RFLF), revealed by EcoRI digestion, has been evaluated in a case-control study including 161 head and neck cancer (HNSCC) patients and 160 normal healthy individuals with similar smoking and alcohol habits. No significant difference in the distribution of L-myc genotypes (LL, LS or SS) was found between the two populations implying thus no predisposition to head and neck tumour by either allele. There was no significant association between L-myc genotypes and the usual clinicopathological features such as T staging, differentiation status and lymph node involvement. Moreover, follow-up data from 154 patients was obtained and correlated with the L-myc pattern. No significant difference was observed in metastasis occurrence, multiple cancer incidence and survival data in the patients classified according to the L-myc genotypes; only a trend to preferentially develop metastasis in lung for patients with S allele was noted. In conclusion, our data shows that the L-myc typing does not contribute to HNSCC risk or prognosis assessment. A review of L-myc RFLP published studies shows contradictory results even on the same type of tumour and emphasizes the lacunae in understanding the biological role of L-myc for valid interpretation of L-myc allelic associations with cancer susceptibility or prognosis.