L-myc genotype is associated with different susceptibility to lung cancer in smokers

Association of MYC gene polymorphisms with neuroblastoma risk in Chinese children: A four-center case-control study

BACKGROUND

Neuroblastoma is one of the most common malignant tumors in childhood. Polymorphisms in proto-oncogene MYC are implicated in many cancers, although their role in neuroblastoma remains unclear. In the present study, we attempted to investigate the association between MYC gene polymorphisms and neuroblastoma susceptibility in Chinese children.

METHODS

We included two MYC polymorphisms (rs4645943 and rs2070583) and assessed their effects on neuroblastoma risk in 505 cases and 1070 controls via the Taqman method.

RESULTS

In single and combined locus analysis, no significant association was found between the two selected polymorphisms and neuroblastoma susceptibility. In stratification analysis, the rs4645943 CT/TT genotypes were significantly associated with a decreased neuroblastoma risk in subjects with tumors originating from other sites [adjusted odds ratio (OR) = 0.42, 95% confidence interval (CI) = 0.21-0.84, p = 0.013]. Meanwhile, the presence of one or two protective genotypes was significantly associated with a decreased neuroblastoma risk in subjects with tumors arising from other sites (adjusted OR = 0.50, 95% CI = 0.26-0.96, p = 0.036).

CONCLUSIONS

The present study indicates that MYC gene polymorphisms may have a weak effect on the neuroblastoma risk, which neeeds to be verified further.

An intervention study of smoking cessation with feedback on genetic cancer susceptibility in Japan

BACKGROUND

To evaluate whether feedback of genetic information regarding an L-myc polymorphism, identified as impacting on tobacco-related cancer risk, has an influence on smoking cessation, an intervention study was conducted.

METHODS

We recruited smokers from first-visit outpatients at Aichi Cancer Center Hospital. Six hundred and seventeen participated and were allocated into two groups: the biomarker feedback group (BF) and the follow-up smoking status group (FS). The subjects were asked for their smoking status at enrolment and at 3- and 9-month follow-ups. BF subjects were notified about their L-myc genotype.

RESULTS

The smoking cessation rate at 9-month follow-up was essentially the same for both BF and FS cases, at 18.8% and 17.0%, respectively (P = 0.798). However, a difference in the rate was evident with non-cancer subjects (12.7% and 8.4%, respectively, P = 0.237), especially in females (15.0% and 4.2%, respectively, P = 0.024). The non-cancer subjects informed of their genotype were more likely to quit smoking than the FS patients; particularly in those having a risky genotype, this was significant (odds ratio: 2.87, P = 0.003). Again it was most prominent in females.

CONCLUSION

Feedback regarding an L-myc polymorphism did not impact on smoking cessation overall but appeared to benefit smokers without cancer. In addition, gender could affect the response to the feedback.

Meta-Analysis Suggests Association of L-myc EcoRI Polymorphism with Cancer Prognosis

The L-myc EcoRI polymorphism is a noncoding variation in the second intron of the L-myc gene, resulting in S and L alleles. Individuals carrying the S allele tend to have poor prognosis and increased risk of several tumor types, although controversial results have been reported. A meta-analysis of 36 studies on L-myc EcoRI genotyping, including 3563 patients with different types of cancer and 2953 controls, was performed. In lung cancer patients the S/S genotype was significantly associated with lymph node metastasis [odds ratio (OR), 2.8; 95% confidence interval (CI), 1.8-4.3], distant metastasis (OR, 4.7; 95% CI, 2.4-9.2), and stage (OR, 2.3; 95% CI, 1.2-4.4). No association was observed between the S/S genotype and cancer (OR, 1.1; 95% CI, 0.8-1.4). In patients with other cancers, the S/S genotype was significantly associated with tumor recurrence (OR, 2.8; 95% CI, 1.4-6.0), whereas no significant association was seen for the other prognostic parameters. When all types of cancer were examined together, the S/S genotype was associated with lymph node metastasis (OR, 2.3; 95% CI, 1.6-3.3), distant metastasis (OR, 2.9; 95% CI, 1.8-4.6), clinical stage (OR, 1.8; 95% CI, 1.2-2.9), and cancer risk (OR, 1.25; 95% CI, 1.07-1.45). The meta-analysis suggests that the L-myc EcoRI polymorphism is a marker of tumor prognosis in lung cancer and possibly in other types of cancer.