Geno- and pheno-typic characterization in ten patients with double-primary gastric and colorectal adenocarcinomas

Circulating Lymphocytes, PD-L1 Expression on Tumor-infiltrating Lymphocytes, and Survival of Colorectal Cancer Patients with Different Mismatch Repair Gene Status

Clinical outcomes of checkpoint blockade immunotherapy on colorectal cancer (CRC) are influenced by mismatch repair (MMR) gene status, which is associated with distinct tumor immune infiltrates and systemic inflammatory response status. However, the prognostic value of PD-L1 expression and the systemic inflammatory response for patients with MMR deficiency has not been fully investigated. In this study, we examined the association of systemic inflammatory markers, PD-1/PD-L1 pathway expression, microsatellite instability (MSI) status, and clinicopathological characteristics of CRC with patient survival between MMR-deficient (dMMR) group (N=168) and MMR-proficient (pMMR) group (N=169). We found a large proportion of dMMR CRC patients displayed increased level of systemic inflammatory markers such as C-reactive protein, Neutrophil/Lymphocyte Ratio (NLR), Glasgow Prognostic Score (GPS), and low expression of PD-L1 in tumor stroma. Several systemic inflammatory markers were associated with AJCC stage only in dMMR patients. Similarly, Tumor infiltrating lymphocyte (TIL) PD-L1 or stroma PD-L1 expression was associated with AJCC stage only in dMMR patients. Circulating serum lymphocytes and TIL PD-L1 expression are both independent prognosis predictors for CRC patients. Overall, we found that dMMR CRC displayed a comprehensively distinct tumor immune microenvironment and systemic inflammatory response makers. PD-L1 expression at different location has different impacts on CRC patient survival, and the TIL PD-L1 expression might be a potential predictor for dMMR CRC patient response to anti-PD-1 therapy.

Clinicopathologic characteristics of colorectal cancer patients with synchronous and metachronous gastric cancer

BACKGROUND

We investigated the characteristics of synchronous and metachronous gastric cancer in patients with colorectal cancer.

METHODS

We reviewed 8,680 patients who underwent operations for primary sporadic colorectal cancer from 1989 to 2008. Synchronous gastric cancer was defined as gastric cancer diagnosed within 6 months of a colorectal cancer diagnosis. Gastric cancer diagnosed more than 6 months before or after colorectal cancer was defined as metachronous.

RESULTS

The incidences of synchronous and metachronous gastric cancer were 0.93 and 1.4%, respectively (combined 2.4%). The standardized incidence ratio was 1.199 (95% confidence interval [CI] = 1.005-1.420) when the patients with premetachronous gastric cancer were excluded. Patients with synchronous and metachronous gastric cancer were 5 years older on average compared to the control population without gastric cancer. In addition, multivariate analysis revealed an odds ratio (OR) of 3.6 for being male, OR = 2 for positive family history of solid tumors, OR = 2.2 for colonic lesion, and OR = 4 for MSH2 expression loss compared to patients without gastric cancer. Patients with postmetachronous gastric cancer (when compared to synchronous and premetachronous gastric cancer), a preoperative CEA level of less than 6 ng/ml, and a relatively early stage of colorectal cancer had significantly higher overall (p = 0.016, 0.007, and 0.004, respectively) and disease-free survival rates (p = 0.046, 0.003, and 0.004, respectively), only on univariate analysis. Lymphovascular invasion of colorectal cancer and an advanced stage of gastric cancer were independent poor prognostic factors for both overall (p = 0.018) and disease-free survival (p = 0.028).

CONCLUSIONS

Gastric cancer surveillance is recommended for patients with colorectal cancer, especially when the patient is old and male, has a positive family history of solid tumors, has a colonic lesion, or lacks MSH2 expression.

Differential Wnt pathway gene expression and E-cadherin truncation in sporadic colorectal cancers with and without microsatellite instability

PURPOSE

Alterations in the Wnt pathway play a major role in colorectal cancer with high (MSI-H) or low microsatellite instability (MSS/MSI-L). However, the differential impact of the Wnt pathway components on these tumors is poorly understood. MMP-3 (stromelysin-1) promoter is a target of the mutator phenotype in sporadic colorectal cancer. Among MMP-3 targets, we investigated E-cadherin integrity status in both groups of tumors. Because beta-catenin is the main effector of the Wnt pathway, we have also investigated the differential cellular status of beta-catenin.

EXPERIMENTAL DESIGN

Expression profiles of 114 genes related to the Wnt pathway were analyzed by oligo microarrays in 48 tumors classified by their MSI status. In addition, we analyzed 48 sporadic colorectal cancers for E-cadherin integrity status. We performed investigation of beta-catenin and cyclin D1 by immunohistochemistry using tissue arrays containing 96 tumors.

RESULTS

Our data show that a group of genes that negatively regulate Wnt signaling are downregulated in MSS/MSI-L as compared with MSI-H colorectal tumors. E-cadherin truncation was significantly higher in MSS/MSI-L as compared with MSI-H tumors. Moreover, MSI-H tumors showed low or null beta-catenin nuclear presence, whereas the group of tumors classified as MSS or MSI-L displayed a high content of the nuclear beta-catenin location.

CONCLUSIONS

Our results suggest that the differential expression of genes that negatively regulate the Wnt pathway, as well as the status of E-cadherin and beta-catenin in MSI-H or MSS/MSI-L colorectal tumors, shed some light on the different clinical behavior showed by the two groups.

Hypermethylation, risk factors, clinical characteristics, and survival in 235 patients with laryngeal and hypopharyngeal cancers

BACKGROUND

It has been established that promoter hypermethylation occurs in several genes during the pathogenesis of head and neck cancer. The authors investigated the role played by the hypermethylation of 4 cancer-related genes in the survival of patients who had laryngeal and hypopharyngeal cancer and in the occurrence of second primary tumors.

METHODS

Archival paraffin-embedded tissue (PET) samples were available from patients who were enrolled in a multicentric European case-control study that was performed between 1979 and 1982 and was followed up to 2000. Genomic DNA extracted from 235 PET samples were analyzed for promoter methylation status of the p16, O(6)-methylguanine-DNA methyltransferase (MGMT), death-associated protein kinase (DAP-K), and E-cadherin genes by using a methylation-specific polymerase chain reaction assay.

RESULTS

Hypermethylation was present in 44% of samples for p16, in 27% of samples for MGMT, in 42% of samples for DAP-K, and in 43% of samples for E-cadherin. Hypermethylation of either individual genes or their combination was not associated with mortality from all causes, mortality from upper aerodigestive tract cancer, or the occurrence of second primary tumors.

CONCLUSIONS

The analysis of a large series of patients with laryngeal and hypopharyngeal cancer suggested that hypermethylation is a frequent event in laryngeal and hypopharyngeal cancer, but it is not a predictor of mortality or second primary cancer.