Long-term survival with pemetrexed-based chemotherapy in a patient with metastatic lung adenocarcinoma of unclear primary origin harboring MTHFR C677T(T/T) mutation: a case report

This case report presents a patient with metastatic adenocarcinoma of unclear primary focus at initial presentation and revealed lung adenocarcinoma in subsequent follow-up. The patient has been surviving for more than 10 years after pemetrexed-based treatment and local radiotherapy. Sequential gene tests showed kirsten rat sarcoma viral oncogene homolog (KRAS) G13D mutation and epidermal growth factor receptor (EGFR) 19ins. To further investigate the correlation between pemetrexed efficacy and genetic polymorphisms, genotyping tests on folate-metabolism-related genes [methylenetetrahydrofolate reductase (MTHFR) (C677T) and MTHFR (A1298C)] were performed, revealing that the patient exhibited the T/T genotype for MTHFR (C677T) and the A/A genotype for MTHFR (A1298C). The clinical data and gene analysis were discussed with literature review to explain the underlying explanation for the long survival.

Correlation between methylene tetrahydrofolate reductase (MTHFR) gene rs1801133 C>T polymorphisms and risk of osteoporosis

Objective

To evaluate the correlation between methylene tetrahydrofolate reductase (MTHFR) gene rs1801133 C>T polymorphisms and risk of osteoporosis.

Methods

We searched the clinical studies related to MTHFR gene rs1801133 C>T polymorphisms and risk of osteoporosis in the electronic databases of PubMed, Web of Science, EMBASE, China National Knowledge Infrastructure (CNKI), Chinese BioMedical Literature Database (CBM) and included the suitable publications in the present meta-analysis according to the inclusion and exclusion criteria. The data of included studies were extracted and pooled by a random or fixed-effect model. The odds ratio (OR) and 95% confidence interval (95% CI) were applied to demonstrate the correlation between MTHFR gene rs1801133 C>T polymorphisms and the risk of osteoporosis. Publication bias was assessed by Begg’s funnel plot and Egger’s line regression test.

Results

Seven case–control clinical studies were included and a data combination was made. The data was pooled by the fixed effect model because of no obvious statistical heterogeneity. The pooled results indicated that people with the T allele had increased risk of developing osteoporosis under the homologous gene model (TT vs CC) (OR = 2.36, 95% CI: 1.81–3.08, p < 0.05), dominant gene model (TT + CT) vs CC (OR = 1.47, 95% CI: 1.21–1.77, p < 0.05) and recessive gene model TT vs (CC + CT) (OR = 2.16, 95% CI: 1.71–2.74, p < 0.05). Egger’s line regression test indicated no significant publication bias for the present meta-analysis in the above homologous, dominant, and recessive gene models.

Conclusion

The MTHFR gene rs1801133 C>T polymorphisms are associated with osteoporosis and subjects with the T allele have an increased risk of developing osteoporosis.