Advances in our understanding of postoperative adjuvant chemotherapy in resectable non-small-cell lung cancer

The effect of locoregional transarterial infusion chemotherapy on liver metastasis after gastric cancer resection

OBJECTIVE

A retrospective clinical study to evaluate the effect of transarterial infusion (TAI) chemotherapy and transarterial chemoembolization (TACE) on liver metastasis after gastric cancer resection.

METHODS

The study recruited patients who underwent surgical resection for stage T(2)N(2)M(0) gastric adenocarcinoma without liver metastasis. Patients chose to receive either TAI or systemic chemotherapy, based on the advantages and disadvantages of each regimen as explained by physicians. Both regimens comprised 100 mg/m2 oxaliplatin and 500 mg/m2 fluorodeoxy uridine, administered via TAI or a peripheral vein, commencing 30 days postsurgery. Patients who developed liver metastasis during the 3-year follow-up period were offered TACE.

RESULTS

Mean time from gastric cancer diagnosis to liver metastasis was significantly longer in the TAI group (n = 13) than in the systemic chemotherapy group (n = 29); 944 ± 231 days versus 506 ± 77 days. Patients who received TACE (n = 32) had a partial remission rate of 46.9% and a median survival of 14.7 months after diagnosis of liver metastasis.

CONCLUSIONS

Locoregional TAI chemotherapy was more effective in reducing liver metastasis after gastric cancer resection than conventional systemic chemotherapy. TACE is an effective treatment for liver metastasis.

Ethnic disparities in Americans of European descent versus Americans of African descent related to polymorphic ERCC1, ERCC2, XRCC1, and PARP1

Nucleotide excision repair (NER) and base excision repair (BER) pathways are DNA repair pathways that are important in carcinogenesis and in response to DNA-damaging chemotherapy. ERCC1 and ERCC2 are important molecular markers for NER; XRCC1 and PARP1 are important molecular markers for BER. Functional polymorphisms have been described that are associated with altered expression levels of these genes and with altered DNA repair capability. We assayed genomic DNA from 156 Americans of European descent and 164 Americans of African descent for the allelic frequencies of specific polymorphisms of ERCC1 N118N (500C>T), ERCC1 C8092A, ERCC2 K751Q (2282A>C), XRCC1 R399Q (1301G>A), XRCC1 R194W (685C>T), and PARP1 V762A (2446T>C). Differences were observed between Americans of European descent and Americans of African descent in the allelic frequencies of the ERCC1 N118N polymorphism (P < 0.000001). Differences were also observed between these two ethnic groups for ERCC2 K751Q (P = < 0.006675), XRCC1 R399Q (P < 0.000001), and PARP1 V762A (P = 0.000001). The ERCC1 N118N polymorphic variant that is seen most commonly in Americans of European descent is associated with a measurable reduction in NER function. ERCC1-mediated reduction in NER functionality affects the repair of cisplatin-DNA lesions.

Lung cancer staging in the genomics era

The search for clinically applicable biologic markers or tumor signatures sufficiently powered as prognosticators of tumor behaviors or responses to therapeutic interventions has significantly advanced in scope and sophistication in the last 10 years. The TNM system, examining of tumor tissues to identify histopathologic features that could be correlated with tumor biology and outcome, could be improved by the immunohistochemical assessment of individual marker proteins or painstaking sequencing of candidate genes (one at a time) from tumor tissues. Large-scale investigation of the gene or protein expression profiles using genomics or proteomics technology may further improve risk stratification and assessment of therapeutic response. Although the gene expression profiling studies summarized in this article are exciting and initially serve as proofs of concept that large-scale mining of the genome and the transcriptome yields clinically useful data, the technology is still evolving and standardization is still needed for large-scale studies and data validation. As a proof of principle, studies have been performed to demonstrate that it is feasible to perform complete tumor microarray analysis, from tissue processing to hybridization and scanning, at multiple independent laboratories for a single study, and to demonstrate significant, albeit incomplete, agreement of gene expression patterns related to lung cancer biology and predictive of treatment outcomes via cross-study comparative analysis. Leading the concerted efforts of molecular characterization of lung cancer is the National Cancer Institute Director's Challenge Program: Toward A Molecular Classification of Cancer. The ultimate goal of molecular staging, envisioned as a combination of traditional TNM classification bolstered with gene/protein unique expression signatures, is to classify patients who have lung cancer on the basis of tumor biology, for better risk stratification and treatment using targeted patient-tailored therapeutics based on unique genotypes of individual tumors.