Genetic variants within ultraconserved elements and susceptibility to right- and left-sided colorectal adenocarcinoma

We investigated whether single nucleotide polymorphisms within ultraconserved elements (UCEs) are associated with susceptibility to overall colorectal cancer (CRC) and susceptibility to tumor site-specific CRC. The study included 787 CRC patients and 551 healthy controls. The study comprised of a training set (520 cases and 341 controls) and a replication set (267 cases and 210 controls). We observed associations in rs7849 and rs1399685 with CRC risk. For example, a dose-dependent trend (per-allele odds ratio (OR), 0.78; 95% confidence interval (CI), 0.63-1.00; P for trend = 0.05) associated with the variant allele of rs7849 in the training set. The significant trend toward a decrease in CRC risk was confirmed in the replication set (per-allele OR, 0.72; 95% CI, 0.52-0.99; P for trend = 0.044). When stratified by tumor location, for left-sided CRC (LCRC) risk, significant association was observed for the variant-containing genotypes of rs1399685 (OR, 1.77; 95% CI, 1.02-3.06) and the risk was replicated in the replication population (OR, 2.04; 95% CI, 1.02-4.07). The variant genotypes of rs9784100 and rs7849 conferred decreased risk but the associations were not replicated. Three right-sided CRC (RCRC) susceptibility loci were identified in rs6124509, rs4243289 and rs12218935 but none of the loci was replicated. Joint effects and potential higher order gene-gene interactions among significant variants further categorized patients into different risk groups. Our results strongly suggest that several genetic variants in the UCEs may contribute to CRC susceptibility, individually and jointly, and that different genetic etiology may be involved in RCRC and LCRC.     

GWAS-identified colorectal cancer susceptibility loci associated with clinical outcomes

Recent genome-wide association studies (GWAS) have identified several common susceptibility loci associated with the risk of colorectal cancer (CRC). However, whether these loci affect clinical outcomes of CRC is not clear. In this study, we genotyped 26 single nucleotide polymorphisms (SNPs) in 10 GWAS-identified CRC susceptibility regions and evaluated their associations with survival and recurrence in 285 stage II and III patients receiving fluorouracil-based adjuvant chemotherapy. Only one SNP, rs10318 (15q13.3), was significantly associated with recurrence for patients with stage II disease. Three SNPs: rs10749971 (11q23.1), rs961253 (20p12.3) and rs355527 (20p12.3) in two regions were significantly associated with recurrence for patients with stage III disease. Five SNPs: rs961253 (20p12.3), rs355527 (20p12.3), rs4464148 (18q21.1), rs6983267 (8q24.21) and rs10505477 (8q24.21) in three regions were significantly associated with survival for patients with stage III disease. Cumulative effects of multiple unfavorable genotypes were observed for recurrence and survival in patients with stage III CRC. Our results suggest that cancer susceptibility loci may also affect the prognosis of CRC patients receiving fluorouracil-based adjuvant chemotherapy.     

Functional polymorphisms of circadian positive feedback regulation genes and clinical outcome of Chinese patients with resected colorectal cancer

BACKGROUND:

Previous studies have demonstrated that circadian genes play a role in the development and progression of many cancers. This study aims to assess the effects of single nucleotide polymorphisms (SNPs) in circadian genes on recurrence and survival of colorectal cancer (CRC) patients.

METHODS:

Nine functional SNPs in 3 genes (CLOCK, NPAS2, and BMAL1) on the circadian positive feedback loop were selected and genotyped using the Sequenom iPLEX genotyping system in a cohort of 411 resected Chinese CRC patients. Multivariate Cox proportional hazards model and Kaplan‐Meier curve were used for the prognosis analysis.

RESULTS:

The authors identified 2 SNPs in the CLOCK gene to be significantly associated with CRC overall survival. SNP rs3749474 exhibited a significant association with survival of CRC patients in the additive model (hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.37‐0.81; P = .003). In addition, patients carrying the heterozygous variant of rs1801260 had significantly increased overall survival compared with those carrying homozygous wild‐type genotype (HR, 0.31; 95% CI, 0.11‐0.88; P = .03). Findings from functional assay provided further biological support for these significant associations. Stratified analysis found no modifying effect of chemotherapy on the prognostic significance of both SNPs. Moreover, we observed cumulative effects of these 2 SNPs on CRC overall survival (P for trend = .01). Compared with patients carrying no unfavorable genotypes, those carrying 2 unfavorable genotypes had a 2.92‐fold increased risk of death (P = .03).

CONCLUSIONS:

The results suggest for the first time that CLOCK gene polymorphisms may serve as an independent prognostic marker for CRC patients. Cancer 2012;. © 2011 American Cancer Society.     

MiR-320e is a novel prognostic biomarker in colorectal cancer

Background:

Advances in early detection and treatment have improved outcomes in patients with colorectal cancer (CRC). However, there remains a need for robust prognostic and predictive biomarkers. We conducted a systematic discovery and validation of microRNA (miRNA) biomarkers in two clinical trial cohorts of CRC patients.

Methods:

We performed an initial ‘discovery'' phase using Affymetrix miRNA expression arrays to profile stage III CRC patients with and without tumour recurrence (n=50 per group) at 3-years of follow-up. All patients received adjuvant 5-fluorouracil (5-FU) plus oxaliplatin, that is, FOLFOX, treatment. During ‘validation'', we analysed miRNAs using qRT–PCR in an independent cohort of 237 stage II–IV CRC patients treated with 5-FU-based chemotherapy, as well as in normal colonic mucosa from 20 healthy subjects. Association with disease recurrence, disease-free survival (DFS) and overall survival (OS) was examined using Cox proportional hazard models.

Results:

In the discovery cohort, miR-320e expression was significantly elevated in stage III colon cancers from patients with vs without recurrence (95% confidence interval (CI)=1.14–1.42; P<0.0001). These results were then independently validated in stage II and III tumours. Specifically, increased miR-320e expression was associated with poorer DFS (hazard ratio (HR)=1.65; 95% CI=1.27–2.13; P=0.0001) and OS (HR=1.78; 95% CI=1.31–2.41; P=0.0003) in stage III CRC patients.

Conclusions:

In two clinical trial cohorts, a systematic biomarker discovery and validation approach identified miR-320e to be a novel prognostic biomarker that is associated with adverse clinical outcome in stage III CRC patients treated with 5-FU-based adjuvant chemotherapy. These findings have important implications for the personalised management of CRC patients.     

Stage-based Variation in the Effect of Primary Tumor Side on All Stages of Colorectal Cancer Recurrence and Survival

Background

Multiple studies have defined the prognostic and potential predictive significance of the primary tumor side in metastatic colorectal cancer (CRC). However, the currently available data for early-stage disease are limited and inconsistent.

Genetic Variations in Stem Cell-Related Genes and Colorectal Cancer Prognosis

Background

Many properties of cancer cells are reminiscent of those in normal stem cells. Genes important to stem cell development have been significantly implicated in the etiology and clinical outcome of colorectal cancer (CRC). However, the associations of genetic variations in these genes with CRC prognosis have not yet been elucidated.

Methods

We analyzed the effects of eight potentially functional single nucleotide polymorphisms (SNPs) in six stem cell-related genes on the prognosis of a well-characterized population of 380 Chinese CRC patients diagnosed from February 2006 to January 2010.

Results

The most significant finding was related to rs879882, a variant in the 5′ region of POU5F1 gene which encodes a protein essential for embryonic stem cell self-renewal and pluripotency, and induced pluripotent stem cell reprogramming. The variant-containing genotypes of rs879882 were associated with an increased risk of recurrence (hazard ratio [HR]?=?2.10, 95 % confidence interval [CI] 1.17–3.76, P?=?0.01). In chemotherapy-stratified analysis, the association remained borderline significant in patients receiving chemotherapy (HR?=?1.97, 95 % CI 0.89–4.34, P?=?0.09). In addition, a nonsynonymous SNP of APC gene was also significantly associated with recurrence risk in chemotherapy-treated patients (HR?=?2.63, 95 % CI 1.14–6.06 P?=?0.02). Further analyses showed a combined effect of the two SNPs in predicting CRC recurrence in patients receiving chemotherapy (P?=?0.04) but not in those without chemotherapy (P?=?0.43). Moreover, an exploratory multivariate assessment model indicated that these two variants enhanced the power to predict recurrence after chemotherapy.

Conclusion

We presented one of the first epidemiologic studies showing that stem cell-related genetic variants may impact CRC clinical outcomes, especially in chemotherapy-treated patients.     

Colorectal obstruction is a potential prognostic factor for stage II colorectal cancer

Background

Obstructive colorectal cancer (CRC) is an emergency situation with high morbidity and mortality, but long-term outcomes of stage II/III obstructive CRC remain unclear. The aim of this study was to evaluate prognostic factors, including colorectal obstruction.

Methods

Data were retrospectively reviewed from consecutive patients with stage II/III CRC who underwent curative surgery between January 2007 and December 2011 at two Japanese institutions. We analyzed overall survival (OS) and relapse-free survival (RFS), according to various prognostic factors including colorectal obstruction.

Results

In total, 979 patients with stage II/III CRC were identified for this study. Among these 979 patients, 94 patients showed colorectal obstruction (9.6%). In both stage II and stage III CRCs, colorectal obstruction showed significantly poorer OS and RFS compared to non-obstruction (5-year OS, obstruction vs. non-obstruction, stage II: 65.9 vs. 86.5%, P?=?0.002; stage III: 55.9 vs. 73.6%, P?=?0.007) (5-year RFS, obstruction vs. non-obstruction, stage II: 59.2 vs. 77.8%, P?=?0.008; stage III 31.3 vs. 56.3%, P?=?0.001). Multivariate analysis demonstrated colorectal obstruction as a significant independent and poor prognostic factor in terms of both OS (hazard ratio (HR) 2.469; 95% CI 1.339–4.545; P?=?0.004) and RFS (HR 1.992; 95% CI 1.160–3.425; P?=?0.012) for stage II CRC, as well as pT4 stage. On multivariate analysis for stage III CRC, colorectal obstruction was a significant predictor of poor RFS (HR 1.626; 95% CI 1.070–2.469; P?=?0.023), but not poor OS.

Conclusions

Colorectal obstruction is an independent poor prognostic factor for stage II CRC. Adjuvant chemotherapy might be feasible for stage II CRC with colorectal obstruction.

     

A molecular signature for the prediction of recurrence in colorectal cancer

Background

Several clinical and pathological factors have an impact on the prognosis of colorectal cancer (CRC), but they are not yet adequate for risk assessment. We aimed to identify a molecular signature that can reliably identify CRC patients at high risk for recurrence.

Results

Two hundred eighty-one CRC samples (stage II/III) were included in this study. A two-step gene expression profiling study was conducted. First, gene expression measurements from 81 fresh frozen CRC samples were obtained using Affymetrix Human Genome U133 Plus 2.0 Arrays. Second, a focused gene expression assay, including prognostic genes and genes of interest from literature reviews, was performed using 200 fresh frozen samples and a Taqman low-density array (TLDA) analysis. An optimal 31-gene expression classifier for the prediction of recurrence among patients with stage II/III CRC was developed using logistic regression analysis. This gene expression signature classified 58.5% of patients as low-risk and 41.5% as high-risk (P < 0.001). The signature was the strongest independent prognostic factor in the multivariate analysis. The five-year relapse-free survival (RFS) rates for the low-risk patients and the high-risk patients were 88.5% and 41.3% (P < 0.001), respectively.

Conclusion

We identified a 31-gene expression signature that is closely associated with the clinical outcome of stage II/III CRC patients.     

GWAS-identified colorectal cancer susceptibility locus associates with disease prognosis

Purpose

Extensive evidence has suggested that risk factors of cancer development may also modulate cancer clinical outcome. Recent genome-wide association (GWA) studies identified several single nucleotide polymorphisms (SNPs) predisposing to colorectal cancer (CRC). Given the pivotal importance of these variants in CRC, we sought to evaluate their associations with clinical outcomes of the disease.

Experimental Design

In a well-characterised cohort including 380 Chinese CRC patients, we genotyped seven SNPs identified in previous multi-stage GWA studies and analysed their associations with patient recurrence and survival.

Results

One SNP on chromosome 15q13, rs4779584 was associated with reduced risk of death with a hazard ratio (HR) of 0.33 (95% confidence interval [CI] 0.15-0.72, P = 0.007). Another SNP in a gene-desert region on chromosome 10p14, rs10795668, was associated with a reduced risk of recurrence with an HR of 0.55 (95% CI 0.30-1.00, P = 0.05). In a stratified analysis, this association was only evident in patients receiving chemotherapy (HR = 0.32, 95% CI 0.14-0.78, P = 0.01, log rank P = 0.004), but not in those without chemotherapy (HR = 1.08, 95% CI 0.43-2.73, P = 0.87, log rank P = 0.66). Moreover, we found that the effects of chemotherapy on CRC recurrence was only evident in patients with the variant-containing genotypes (HR = 0.35, 95% CI 0.13-0.94, P = 0.04) but not in those with the wild-type genotype of rs10795668. Further analyses indicated a borderline significant interaction effect (P interaction = 0.05) between rs10795668 and chemotherapy on patient recurrence.

Conclusions

Our data suggested that rs10795668, a CRC susceptibility variant identified by GWA studies, might be used as a biomarker to identify CRC patients with high risk of recurrence after chemotherapy.     

Maspin is a marker for early recurrence in primary stage III and IV colorectal cancer

Background:

Little is known about the factors that drive metastasis formation in colorectal cancer (CRC). Here, we set out to identify genes and proteins in patients with colorectal liver metastases that correlate with early disease recurrence. Such factors may predict a propensity for metastasis in earlier stages of CRC.

Methods:

Gene expression profiling and proteomics were used to identify differentially expressed genes/proteins in resected liver metastases that recurred within 6 months following liver surgery vs those that did not recur for >24 months. Expression of the identified genes/proteins in stage II (n=243) and III (n=176) tumours was analysed by immunohistochemistry on tissue microarrays. Correlation of protein levels with stage-specific outcome was assessed by uni- and multivariable analyses.

Results:

Both gene expression profiling and proteomics identified Maspin to be differentially expressed in colorectal liver metastases with early (<6 months) and prolonged (>24 months) time to recurrence. Immunohistochemical analysis of Maspin expression on tumour sections revealed that it was an independent predictor of time to recurrence (log-rank P=0.004) and CRC-specific survival (P=0.000) in stage III CRC. High Maspin expression was also correlated with mucinous differentiation. In stage II CRC patients, high Maspin expression did not correlate with survival but was correlated with a right-sided tumour location.

Conclusion:

High Maspin expression correlates with poor outcome in CRC after spread to the local lymph nodes. Therefore, Maspin may have a stage-specific function possibly related to tumour cell dissemination and/or metastatic outgrowth.     

Growth differentiation factor 15: a prognostic marker for recurrence in colorectal cancer

Background:

Growth differentiation factor 15 (GDF15) belongs to the transforming growth factor beta superfamily and has been associated with activation of the p53 pathway in human cancer. The aim of this study was to assess the prognostic value of GDF15 in patients with colorectal cancer (CRC).

Methods:

Immunohistochemistry and tissue microarrays were used to analyse GDF15 protein expression in 320 patients with CRC. In a subgroup of 60 patients, the level of GDF15 protein in plasma was also measured using a solid-phase proximity ligation assay.

Results:

Patients with CRC with moderate to high intensity of GDF15 immunostaining had a higher recurrence rate compared with patients with no or low intensity in all stages (stages I–III) (HR, 3.9; 95% CI, 1.16–13.15) and in stage III (HR, 10.32; 95% CI, 1.15–92.51). Patients with high plasma levels of GDF15 had statistically shorter time to recurrence (P=0.041) and reduced overall survival (P=0.002).

Conclusion:

Growth differentiation factor 15 serves as a negative prognostic marker in CRC. High expression of GDF15 in tumour tissue and high plasma levels correlate with an increased risk of recurrence and reduced overall survival.     

Incidence of brain metastases as a first site of recurrence among women with triple receptor-negative breast cancer

BACKGROUND:

This retrospective study sought to define the incidence of brain metastases as a first site of recurrence among women with triple receptor–negative breast cancer (TNBC).

METHODS:

A total of 2448 patients with stage I through III TNBC who were diagnosed between 1990 and 2010 were identified. We computed the cumulative incidence of developing brain metastases as a first site of recurrence at 2 and 5 years. Cox proportional hazards models were fitted to determine factors that could predict for the development of brain metastases as a first site of recurrence. The Kaplan‐Meier product limit method was used to compute survival following a diagnosis of brain metastases.

RESULTS:

At a median follow‐up of 39 months, 115 (4.7%) patients had developed brain metastases as a first site of recurrence. The cumulative incidence at 2 and 5 years was 3.7% (95% confidence interval [CI] = 2.9%‐4.5%) and 5.4% (95% CI = 4.4%‐6.5%), respectively. Among patients with stage I, II, and III disease, the 2‐year cumulative incidence of brain metastases was 0.8%, 3.1%, and 8%, respectively (P < .0001). The 5‐year cumulative incidence was 2.8%, 4.6%, and 9.6% among patients with stage I, II, and III disease, respectively (P < .0001). In the multivariable model, patients with stage III disease had a significant increase in the risk of developing brain metastases as a first site of recurrence (hazards ratio = 3.51; 95% CI = 1.85‐6.67; P = .0001) compared to patients with stage I disease. Those with stage II disease had a nonsignificant increased risk of developing brain metastases as a first site of recurrence (hazards ratio = 1.61; 95% CI = 0.92‐2.81; P = .10) compared with patients with stage I disease. Median survival following a diagnosis of brain metastases was 7.2 months (range, 5.7‐9.4 months).

CONCLUSIONS:

Patients with nonmetastatic TNBC have a high early incidence of developing brain metastases as a first site of recurrence, which is associated with subsequent poor survival. Patients with stage III TNBC in particular would be an ideal cohort in which to research preventive strategies. Cancer 2012. © 2012 American Cancer Society.     

Genetic variations in regulator of G‐protein signaling (RGS) confer risk of bladder cancer

BACKGROUND:

Alterations in the regulator of G‐protein signaling (RGS) pathway have been implicated in several cancers; therefore, the authors investigated the role of such alterations in overall bladder cancer risk, recurrence, progression, and survival.

METHODS:

In this case‐control series, 803 patients with bladder cancer were frequency‐matched with a control cohort of 803 healthy individuals. Ninety‐five single‐nucleotide polymorphisms (SNPs) in 17 RGS genes were investigated for an association with overall bladder cancer risk, recurrence, and progression in patients who had nonmuscle‐invasive bladder cancer (NMIBC) and for an association with death in patients who had muscle‐invasive bladder cancer (MIBC). Cumulative effects and classification and regression tree analyses were performed for SNPs that were associated with overall bladder cancer risk. Kaplan‐Meier plots were created to evaluate differences in the survival of patients with MIBC.

RESULTS:

Reference SNP 10759 (rs10759) on the RGS4 gene demonstrated the greatest association with overall bladder cancer risk, conferring a 0.77‐fold reduced risk with an increasing number of variant alleles (P < .001). A cumulative effects analysis that included all 5 significant SNPs demonstrated an increasing risk with the number of unfavorable genotypes (odds ratio, 4.13; 95% confidence interval, 2.14‐7.98). In patients with NMIBC, 11 SNPs were identified that had an association with disease recurrence, and 13 SNPs were associated with disease progression. Of the 10 SNPs that were associated with death in patients with MIBC, rs2344673 in an additive model was the most significant and was associated with a decreased median survival of 13.3 months compared with 81.9 months in individuals without a variant allele.

CONCLUSIONS:

Genetic variations in the RGS pathway were associated with the overall risk of bladder cancer, recurrence, and progression in patients with NMIBC and with the risk of death in patients with MIBC. Cancer 2013. © 2013 American Cancer Society.     

Colorectal cancer risk and patients’ survival: influence of polymorphisms in genes somatically mutated in colorectal tumors

Purpose

The first two studies aiming for the high-throughput identification of the somatic mutation spectrum of colorectal cancer (CRC) tumors were published in 2006 and 2007. Using exome sequencing, they described 69 and 140 candidate cancer genes (CAN genes), respectively. We hypothesized that germline variants in these genes may influence CRC risk, similar to APC, which is causing CRC through germline and somatic mutations.

Methods

After excluding the well-established CRC genes APC, KRAS, TP53, and ABCA1, we analyzed 35 potentially functional single-nucleotide polymorphisms (SNPs) in 10 CAN genes (OBSCN, MLL3, PKHD1, SYNE1, ERCC6, FBXW7, EPHB6/TRPV6, ELAC1/SMAD4, EPHA3, and ADAMTSL3) using KBiosciences Competitive Allele‐Specific PCR? genotyping assays. In addition to CRC risk (1,399 CRC cases, 838 controls), we also considered the influence of the SNPs on patients’ survival (406 cases).

Results

In spite of the fact that our in silico analyses suggested functional relevance for the studied genes and SNPs, our data did not support a strong influence of the studied germline variants on CRC risk and survival. The strongest association with CRC risk and survival was found for MLL3 (rs6464211, OR 1.50, p = 0.002, dominant model; HR 2.12, p = 0.020, recessive model). Two SNPs in EPHB6/TRPV6 (dominant model) showed marginal associations with survival (rs4987622 HR 0.58 p = 0.028 and rs6947538 HR 0.64, p = 0.036, respectively).

Conclusion

Although somatic mutations in the CAN genes have been related to the development and progression of various types of cancers in several next-generation sequencing or expression analyses, our study suggests that the studied potentially functional germline variants are not likely to affect CRC risk or survival.     

Racial disparities and survival for nonsmall‐cell lung cancer in a large cohort of black and white elderly patients

BACKGROUND:

This study aimed to examine disparities in survival and associated factors for patients with nonsmall‐cell lung cancer (NSCLC) and to determine whether racial disparities varied over time (1991‐1995, 1996‐1999, and 2000‐2002).

METHODS:

The authors studied 70,901 patients aged ≥65 years with stage I‐IV NSCLC identified from Surveillance, Epidemiology, and End Results/Medicare data. Multivariate time‐to‐event survival analyses were completed using Cox proportional regression modeling.

RESULTS:

The 5‐year observed lung cancer‐specific survival rates were 52.7% for whites and 47.5% for blacks with stage I‐II disease, and 17.7% and 19.6% for whites and blacks, respectively at stages III‐IV. After controlling for standard treatment, socioeconomic status (SES), and other factors, there were no significant differences in all‐cause mortality, or lung cancer‐specific mortality between black and white patients with stage I‐II or III‐IV lung cancer. However, blacks had an increased risk for overall all‐cause mortality at stage I‐IV (hazard ratio [HR], 1.24; 95% confidence interval, 1.13‐1.35), and during 2000‐2002 at stage III‐IV for all‐cause mortality (HR, 1.22; 95% CI, 1.02‐1.47) and lung cancer‐specific mortality (HR, 1.24; 95% CI,1.01‐1.53). Standard treatment was significantly associated with increased survival, whereas poor SES was associated with increased mortality.

CONCLUSIONS:

There were no significant differences in survival between blacks and whites with NSCLC within stage stratifications after adjusting for covariates, except for black patients at overall stage for all‐cause mortality and at stage III‐IV diagnosed in 2000‐2002. Receiving stage‐specific evidence‐based standard therapy was associated with significantly increased survival. Cancer 2009. © 2009 American Cancer Society.     

Local recurrence after surgery for early stage lung cancer

BACKGROUND:

The objective of the current study was to evaluate the actuarial risk of local failure (LF) after surgery for stage I to II nonsmall cell lung cancer (NSCLC) and assess surgical and pathologic factors affecting this risk.

METHODS:

The records, including pertinent radiologic studies, of all patients who underwent surgery for T1 to T2, N0 to N1 NSCLC at Duke University between 1995 and 2005 were reviewed. Risks of disease recurrence were estimated using the Kaplan‐Meier method. A multivariate Cox regression analysis assessed factors associated with LF in the entire cohort and a subgroup undergoing optimal surgery for stage IB to II disease.

RESULTS:

For all 975 consecutive patients, the 5‐year actuarial risk of local and/or distant disease recurrence was 36%. First sites of failure were local only (25%), local and distant (29%), and distant only (46%). The 5‐year actuarial risk of LF was 23%. On multivariate analysis, squamous/large cell histology (hazards ratio [HR], 1.98), stage > IA (HR, 2.02), and sublobar resections (HR, 1.99) were found to be independently associated with a higher risk of LF. For the subset of patients (n = 445) undergoing at least a lobectomy with negative surgical margins and currently considered for adjuvant chemotherapy (stage IB‐II disease), the 5‐year actuarial risk of LF was 27%. Within this subgroup, squamous/large cell histology (HR, 2.5) and lymphovascular space invasion (HR, 1.74) were associated with a higher risk of LF. The 5‐year rate of LF was 13%, 32%, and 47%, respectively, with 0, 1, or 2 risk factors.

CONCLUSIONS:

Greater than half of disease recurrences after surgery for early stage NSCLC involved local sites. Pathologic factors may help to distinguish those patients at highest risk. Cancer 2009. © 2009 American Cancer Society.     

KRAS as a predictor of poor prognosis and benefit from postoperative FOLFOX chemotherapy in patients with stage II and III colorectal cancer

Purpose

The KRAS gene frequently mutates in colorectal cancer (CRC). Here we investigated the prognostic and predictive role of KRAS mutation in patients with stage II or III CRC.

Experimental design

A consecutive cohort of patients with stage II or III CRC from a single center database was studied. The association between KRAS status, adjuvant FOLFOX therapy, and 3‐year disease‐free survival (3‐y DFS) was analyzed.

Results

Of our 433 patients, 166 (38.3%) exhibited the KRAS mutation. Among the 190 patients who did not receive adjuvant therapy, those with KRAS mutation tumors had a worse 3‐y DFS (hazard ratio [HR], 1.924; 95% confidence interval [CI], 1.078–3.435; P = 0.027). Among patients who received adjuvant chemotherapy, KRAS mutation was not correlated with worse 3‐y DFS (HR, 1.083; 95% CI, 0.618–1.899; P = 0.781). Adjuvant chemotherapy improved 3‐y DFS only among patients with KRAS mutant tumors (78.0% vs 69.2%) on multivariate analysis adjusted for age, stage, grade, site, vessel invasion, and carcinoembryonic antigen level (HR, 0.454; 95% CI, 0.229–0.901; P = 0.024). In contrast, there was no benefit of adjuvant chemotherapy in the KRAS wild‐type group (84.3% vs 82.0%).

Conclusions

KRAS mutation indicates poor prognosis. FOLFOX adjuvant chemotherapy benefits patients with stage II or III colorectal cancer with KRAS mutant tumors and is worth further investigation.     

Association between polymorphisms in long non-coding RNA PRNCR1 in 8q24 and risk of colorectal cancer

Background

Genome-wide association studies have identified that genetic variants in 8q24 confer susceptibility to colorectal cancer (CRC). Recently, a novel lncRNA (PRNCR1) that located in the 8q24 was discovered. Single nucleotide polymorphisms (SNPs) in the lncRNAs may influence the process of splicing and stability of mRNA conformation, resulting in the modification of its interacting partners. We hypothesized that SNPs in the lncRNA PRNCR1 may be related to the risk of CRC.

Methods

We conducted a case–control study and genotyped five tag SNPs in the lncRNA PRNCR1 in 908 subjects including 313 cases with CRC and 595 control subjects using polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) assay.

Results

In overall analyses, we found that the rs13252298 and rs1456315 were associated with significantly decreased risks of CRC. In stratification analyses, we found that CRC patients carrying the rs1456315G were likely to have a tumor size of greater than 5 cm (G vs. A: adjusted OR = 1.56, 95% CI: 1.10-2.23). Additionally, patients with the rs7007694C and rs16901946G had decreased risks to develop poorly differentiated CRC, whereas patients with the rs1456315G had an increased risk to develop poorly differentiated CRC.

Conclusion

These findings suggest that SNPs in the lncRNA PRNCR1 may contribute to susceptibility to CRC.     

The association between neutropenia and prognosis in stage III colorectal cancer patients receiving adjuvant chemotherapy

Neutropenia during chemotherapy has been reported to be a predictor of better survival in patients with several types of cancer, although there are no reports on stage III colorectal cancer (CRC). The purpose of this study was to examine the association between neutropenia and prognosis in stage III CRC patients receiving adjuvant chemotherapy consisting of oral uracil and tegafur (UFT) plus leucovorin (LV). We retrospectively analysed 123 patients with stage III CRC who received UFT/LV as adjuvant chemotherapy. The end‐point was disease‐free survival (DFS). Survival curves of the two categories (neutropenia absent vs. present) were estimated using the Kaplan‐Meier method and compared by the log‐rank test. We estimated the hazard ratio (HR) for DFS according to neutropenia after adjustment for covariates by multivariate analyses using Cox's regression analysis. A total of 33 (26.8%) patients experienced neutropenia. Patients without neutropenia showed a significantly lower DFS than those with neutropenia (3‐year DFS 57.3% vs. 81.2%, P = 0.0213). By multivariate analysis, neutropenia and histological type were independent prognostic factors, with HR of 0.410 (neutropenia absent vs. present, P = 0.045) and 4.793 (well to moderately differentiated vs. poorly differentiated, P = 0.004) respectively. We demonstrated that neutropenia occurring during adjuvant chemotherapy consisting of UFT/LV may be a prognostic factor of recurrence in stage III CRC patients.