Molecular determinants of folate levels after leucovorin administration in colorectal cancer

Purpose

Oral leucovorin (LV) is used with uracil/tegafur (UFT) in the treatment of colorectal cancer (CRC). In order to find the factors related to the efficacy of LV in enhancing the antitumour effect of UFT, we investigated the relationships between the reduced folate levels in the CRC tissue after LV administration and the gene-expression levels of folate-metabolizing enzymes and folate transporters.

Methods

The subjects were 60 CRC patients, scheduled to undergo surgery. The control group (n = 30) did not receive LV. Three groups (n = 10 for each) received a single dose of oral LV at 25 mg, 4, 12 or 18 h before surgery (LV 4 h, LV 12 h or LV 18 h groups, respectively). The reduced folate levels in plasma and tissues were measured by high-performance liquid chromatography (HPLC) or a thymidylate synthase-FdUMP binding assay, respectively. The intratumoral expression levels of 34 genes were quantitatively evaluated with a real-time polymerase chain reaction (RT-PCR) assay.

Results

The reduced folate levels persisted for a longer period of time in the CRC tissue than in the plasma after LV administration. A multivariate logistic regression analysis revealed that high folylpolyglutamate synthase (FPGS) gene expression, low γ-glutamyl hydrolase (GGH) gene expression and low ATP-binding cassette sub-family C, number 1 (ABCC1) gene expression in CRC tissues were predictive factors for a high reduced folate level after LV administration.

Conclusions

The expression level of FPGS, GGH and ABCC1 in CRC tissues could predict the reduced folate level after LV administration, and these factors may determine the efficacy of LV treatment.     

Gene expression signature and response to the use of leucovorin, fluorouracil and oxaliplatin in colorectal cancer patients

Purpose

FOLFOX (a combination of leucovorin, fluorouracil and oxaliplatin) has achieved substantial success in the treatment of colorectal cancer (CRC) patients. However, about half of all patients show resistance to this regimen and some develop adverse symptoms such as neurotoxicity. In order to select patients who would benefit most from this therapy, we aimed to build a predictor for the response to FOLFOX using microarray gene expression profiles of primary CRC samples.

Patients and methods

Forty patients who underwent surgery for primary lesions were examined. All patients had metastatic or recurrent CRC and received modified FOLFOX6. Responders and nonresponders were determined according to the best observed response at the end of the first-line treatment. Gene-expression profiles of primary CRC were determined using Human Genome GeneChip arrays U133. We identified discriminating genes whose expression differed significantly between responders and nonresponders and then carried out supervised class prediction using the k-nearest-neighbour method.

Results

We identified 27 probes that were differentially expressed between responders and nonresponders at significant levels. Based on the expression of these genes, we constructed a FOLFOX response predictor with an overall accuracy of 92.5%. The sensitivity, specificity, positive and negative predictive values were 78.6%, 100%, 100% and 89.7%, respectively.

Conclusion

The present model suggests the possibility of selecting patients who would benefit from FOLFOX therapy both in the metastatic and the adjuvant setting. To our knowledge, this is the first study to establish a prediction model for the response to FOLFOX chemotherapy based on gene expression by microarray analysis.     

Phase I/II study of irinotecan, UFT and leucovorin with hepatic arterial infusion using 5-FU in colorectal cancer patients with unresectable liver metastases

Purpose

To evaluate the efficacy and tolerability of systemic chemotherapy with irinotecan (CPT-11), UFT and leucovorin (LV) combined with hepatic arterial infusion (HAI) consisting of 5-fluorouracil (5-FU) in colorectal cancer patients with unresectable liver metastases.

Methods

Patients were treated concurrently with escalating doses of intravenous CPT-11 (100, 120, and 140?mg/m²) on day 1 of each 14-day treatment cycle, with oral UFT (300?mg/m² per day) and LV (75?mg/body per day) on days 1?C7 of each cycle, and with HAI 5-FU (2,000?mg/week) on days 8?C14 of each cycle.

Results

Twelve patients were enrolled in the phase I study. The maximum-tolerated dose was not reached. Consequently, the recommended dose of CPT-11 for the phase II study was determined to be 140?mg/m². Twenty-two patients were evaluated in the phase II study. Five patients experienced grade 3 neutropenia, two experienced grade 3 anorexia, two experienced nausea, and two experienced vomiting. An overall response was observed in 19 out of 22 patients (86.4%). The median progression-free survival period was 11.2?months, and the 3-year survival rate was 50.6%. Fourteen patients (63.6%) were ultimately able to undergo a complete liver resection.

Conclusions

Chemotherapy with CPT-11 and UFT/LV combined with HAI yielded a high response rate and enabled a significant proportion of patients with initially unresectable liver metastases to undergo surgical resection. Further trials are warranted.     

Safety of UFT/LV and S-1 as adjuvant therapy for stage III colon cancer in phase III trial: ACTS-CC trial

Background:

The Adjuvant Chemotherapy Trial of TS-1 for Colon Cancer (ACTS-CC) is a phase III trial designed to validate the non-inferiority of S-1 to UFT/leucovorin (LV) as postoperative adjuvant chemotherapy for stage III colon cancer. We report the results of a planned safety analysis.

Methods:

Patients aged 20–80 years with curatively resected stage III colon cancer were randomly assigned to receive UFT/LV (UFT, 300 mg m⁻² per day as tegafur; LV, 75 mg per day on days 1–28, every 35 days, 5 courses) or S-1 (80, 100, or 120 mg per day on days 1–28, every 42 days, 4 courses). Treatment status and safety were evaluated.

Results:

Of 1535 enrolled patients, a total of 1504 (756 allocated to S-1 and 748 to UFT/LV) were analysed. The completion rate of protocol treatment was 77% in the S-1 group and 73% in the UFT/LV group. The overall incidence of adverse events (AEs) were 80% in S-1 and 74% in UFT/LV. Stomatitis, anorexia, hyperpigmentation, and haematological toxicities were common in S-1, whereas increased alanine aminotransferase and aspartate aminotransferase were common in UFT/LV. The incidences of ⩾grade 3 AEs were 16% and 14%, respectively.

Conclusion:

Although AE profiles differed between the groups, feasibility of the protocol treatment was good. Both S-1 and UFT/LV could be safely used as adjuvant chemotherapy.     

The survivin -31 snp in human colorectal cancer correlates with survivin splice variant expression and improved overall survival

Background

Survivin is involved in the regulation of cell division and survival, two key processes in cancer. The majority of studies on survivin in colorectal cancer (CRC) have focused on protein expression and less is known about the expression of survivin splicing variants or survivin gene polymorphisms in CRC. In the present study, the mRNA levels of the five known isoforms of survivin as well as survivin protein were assessed in matched normal and neoplastic colorectal tissue. Moreover, the 9386 C/T and -31 G/C polymorphisms were investigated.

Methods

Quantitative RT-PCR was used to assess mRNA levels in fresh/frozen tissue samples. Protein levels were immunohistochemically evaluated on formalin-fixed paraffin-embedded tissue sections. Individuals were genotyped using real time PCR

Results

Expression of all 5 survivin splice variants as well as survivin protein was elevated in colorectal carcinomas compared to normal tissue. Specific splice variant expression differentially correlated with clinicopathological parameters. Furthermore, both snps correlated with splice variant levels or their ratios in colorectal carcinomas while the -31 G/C snp may be related to CRC development and improved overall survival.

Conclusion

Our results support a role of survivin in colorectal carcinogenesis while the -31 G/C snp may constitute a marker of survival.     

Lack of Bax expression is associated with irinotecan-based treatment activity in advanced colorectal cancer patients

Background

Currently, first-line chemotherapy in advanced colorectal cancer is not tailored on predictive biomarkers. Bax proapoptotic protein may correlate to chemosensitivity and differential response to irinotecan or oxaliplatin-based combinations.

Methods

Bax expression was assessed by immunohistochemistry in 49 advanced colorectal cancer patients enrolled at our institution from 2002 to 2004 within a multicenter, phase II, randomized trial of first-line UFT/leucovorin/irinotecan (TEGAFIRI) versus UFT/leucovorin/oxaliplatin (TEGAFOX).

Results

Bax-positive and negative samples were 49 and 51 %. Response was significantly lower in Bax positive (25 %) as compared to Bax negative (56 %) (Odds ratio = 0.26; p = 0.03). No significant difference was noted in TEGAFOX subgroup; in TEGAFIRI arm, responses were lower in Bax positive (18 %) than Bax negative (67 %) (Odds ratio = 0.11; p = 0.03). No difference in terms of progression-free and overall survival was observed according to Bax.

Conclusion

Bax-negative colorectal cancer may identify a specific phenotype of patients with significantly higher chance to respond to doublet irinotecan-based chemotherapy.     

Low expression levels of ATM may substitute for CHEK2 /TP53 mutations predicting resistance towards anthracycline and mitomycin chemotherapy in breast cancer

Introduction

Mutations affecting p53 or its upstream activator Chk2 are associated with resistance to DNA-damaging chemotherapy in breast cancer. ATM (Ataxia Telangiectasia Mutated protein) is the key activator of p53 and Chk2 in response to genotoxic stress. Here, we sought to evaluate ATM's potential role in resistance to chemotherapy.

Methods

We sequenced ATM and assessed gene expression levels in pre-treatment biopsies from 71 locally advanced breast cancers treated in the neoadjuvant setting with doxorubicin monotherapy or mitomycin combined with 5-fluorouracil. Findings were confirmed in a separate patient cohort treated with epirubicin monotherapy. Each tumor was previously analyzed for CHEK2 and TP53 mutation status.

Results

While ATM mutations were not associated with chemo-resistance, low ATM expression levels predicted chemo-resistance among patients with tumors wild-type for TP53 and CHEK2 (P = 0.028). Analyzing the ATM-chk2-p53 cascade, low ATM levels (defined as the lower 5 to 50% percentiles) or mutations inactivating TP53 or CHEK2 robustly predicted anthracycline resistance (P-values varying between 0.001 and 0.027 depending on the percentile used to define "low" ATM levels). These results were confirmed in an independent cohort of 109 patients treated with epirubicin monotherapy. In contrast, ATM-levels were not suppressed in resistant tumors harboring TP53 or CHEK2 mutations (P > 0.5).

Conclusions

Our data indicate loss of function of the ATM-Chk2-p53 cascade to be strongly associated with resistance to anthracycline/mitomycin-containing chemotherapy in breast cancer.     

Two consecutive studies using oral UFT-based chemotherapy regimens in elderly patients with advanced colorectal cancer

Background

The continuous oral administration of UFT simulates protracted continuous intravenous infusion of fluorouracil, making this oral therapy a possible substitute for intravenous chemotherapy. Currently, 70% of cases of cancer will occur in patients over 65, and the feasibility of oral administration makes UFT a good drug for the elderly. The main objective of our trials was to evaluate the tolerance and benefits of this oral treatment in elderly patients with advanced colorectal cancer (CRC).

Patients and methods

A total of 214 patients were included in two consecutive trials. Study number 1 included 106 patients treated with a continuous fixed dose of UFT 400 mg/24 hours plus oral folinic acid 45 mg/24 hours. Study number 2 included 108 patients treated with a continuous dose of UFT 400 mg/m²/24 hours without folinic acid. In both trials the main inclusion criterion was age >72 years. Patient characteristics of Study number 1 were: 46 females and 60 males, median age 74, median Karnofsky index 70, and liver metastasis 56%. Those of Study number 2 were: 42 females and 66 males, median age 76, median Karnofsky index 80, and liver metastasis 65%.

Results

Study number 1: Ninety-six patients were evaluable for response and 98 for toxicity. The overall response rate (RR) was 18% (95% CI, 10–27%). Toxicity was mild with only one case of grade 3 thrombocytopenia, one case of grade 3 mucositis and 11 cases of grade 3–4 diarrhea. Overall median survival was 13.7 months. Study number 2: Ninety-two patients were evaluable for response and 108 for toxicity. The overall RR was 13% (95% CI, 6–20%). Toxicity was also mild without hematological toxicity and only nine cases of grade 3–4 diarrhea. Overall median survival was 11.8 months.

Conclusion

UFT with or without modulation with folinic acid is an effective and comfortable treatment for elderly CRC patients.     

Synergistic killing of colorectal cancer cells by oxaliplatin and ABT-737

Background

Oxaliplatin is frequently used in the treatment of metastatic colorectal cancer (CRC). Our previous work shows that oxaliplatin induces the pro-apoptotic protein Noxa in CRC cells. The Bcl2-inhibitor ABT-737 is particularly effective in cells with high Noxa levels. Therefore, we tested whether oxaliplatin and ABT-737 display synergy in killing CRC cells.

Methods

A panel of CRC cell lines was treated with oxaliplatin and ABT-737, either alone or in combination. Apoptosis was measured by FACS analysis of sub-G1 DNA content and by Western blot analysis of caspase-3 processing. Noxa expression was suppressed by lentiviral RNA interference.

Results

Oxaliplatin and ABT-737 displayed a strong synergistic apoptotic response, which was dependent on wildtype TP53 and oncogenic KRAS. TP53 and KRAS were required for drug-induced Noxa expression and this was essential for tumor cell apoptosis. Oxaliplatin, but not ABT-737, induced p53 accumulation, but both drugs stimulated Noxa expression. Combination treatment of mice with subcutaneous tumor xenografts drastically reduced tumor volume, while single drug treatment had no effect.

Conclusion

ABT-737 synergizes with oxaliplatin to kill colorectal cancer cells. This requires induction of Noxa by wildtype TP53 and oncogenic KRAS. Future studies should explore the anti-tumor efficacy of this drug combination in mouse models for spontaneous CRC development and in patient-derived tumor cell cultures and xenografts.     

Epidermal growth factor receptor (EGFR) mRNA levels and protein expression levels in primary colorectal cancer and corresponding liver metastases

Purpose

High expression levels of EGFR mRNA are reported to be associated with a higher response probability in epidermal growth factor receptor (EGFR) targeted drugs. Our aim was to determine how EGFR gene expression levels in primary colorectal cancer (CRC) were related to those in liver metastases.

Methods

31 pairs of primary CRC and corresponding liver metastases were analyzed. Gene expression level was measured using real-time RT-PCR.

Results

No significant difference was observed between median mRNA expression levels of EGFR in primary cancer and those in corresponding liver metastases (P = 0.99). When matched tissue sets were compared on an individual basis, there was a significant correlation for EGFR mRNA expression between primary cancer and corresponding liver metastases (r _s = 0.78, P < 0.0001).

Conclusions

A good prediction of EGFR mRNA levels in liver metastases can be obtained by measuring those in the primary CRC.     

Effects of a low-fat meal on the oral bioavailability of UFT and leucovorin in patients with colorectal cancer

Background

UFT is composed of tegafur, a prodrug of 5-fluorouracil, and uracil, at a fixed ratio of 1: 4. UFT is widely used with leucovorin as adjuvant chemotherapy in patients with colon cancer. As reported, UFT/leucovorin should not be taken simultaneously with food because a high fat content will reduce the systemic exposure to the active cytotoxic moiety of UFT. In this single-dose, randomized, two-way crossover study, we investigated the effects of a low-fat Japanese meal on the pharmacokinetics and oral bioavailability of UFT (2 × 100-mg capsules; dose in terms of tegafur) and leucovorin (1 × 25-mg tablet).

Methods

Patients (n = 12) were randomly assigned to receive both drugs after an overnight fast or 5 min after eating a standard Japanese breakfast (641 kcal), with a 3-day washout period between treatments. Pharmacokinetics (n = 12) were determined for tegafur, 5-fluorouracil, uracil, leucovorin, and 5-methyltetrahydrofolate (an active metabolite of leucovorin).

Results

For 5-fluorouracil pharmacokinetics, the maximum plasma concentration and the area under the curve were reduced by 73.7% and 47.4%, respectively, when UFT was taken postprandially, and the maximum plasma concentration and the area under the curve for uracil were reduced by 84.1% and 68.9%, respectively, compared with dosing on an empty stomach. These decreases in the systemic exposure to 5-fluorouracil were quite marked and may have an impact on its antitumor effect.

Conclusion

A low-fat meal affects the pharmacokinetics of UFT similarly to a high-fat meal.     

Final results of randomized trials by the National Surgical Adjuvant Study of Colorectal Cancer (NSAS-CC)

Objective

In the latter 1990s, adjuvant chemotherapy for completely resected Stage III colorectal cancer remained controversial in Japan. We conducted two independent randomized controlled trials in patients with Stage III colon and rectal cancer.

Methods

Patients were randomly assigned to receive surgery alone or surgery followed by treatment with UFT (400?mg/m²/day), given for five consecutive days per week for 1?year. The primary endpoint was relapse-free survival (RFS), and the secondary endpoint was overall survival (OS).

Results

A total of 334 patients with colon cancer and 276 with rectal cancer were enrolled. The patients?? characteristics were similar between the UFT group and the Surgery-alone group. There was no significant difference in RFS or OS in colon cancer. In rectal cancer, however, RFS and OS were significantly better in the UFT group than in the Surgery-alone group. The only grade 4 toxicity in the UFT group was diarrhea, occurring in one patient with colon cancer and one patient with rectal cancer.

Conclusions

Postoperative adjuvant chemotherapy with UFT is successfully tolerated and improves RFS and OS in patients with Stage III rectal cancer. In colon cancer, the expected benefits were not obtained (hazard ratio?=?0.89).     

Apoptosis and KI 67 index correlate with preoperative chemotherapy efficacy and better predict the survival of gastric cancer patients with combined therapy

Purpose

The correlation of apoptotic and proliferation index with preoperative chemotherapy efficacy was investigated. Their prognostic value was also explored.

Methods

167 patients were enrolled, curative gastrectomy and D2 lymphadenectomy were performed, and a total of 12 cycles of perioperative mFOLFOX7 chemotherapy was recommended. Apoptosis index (AI) and Ki67 index (KI) in surgical specimens were detected.

Results

Apoptosis index, KI and AI/KI were significantly different between patients received perioperative chemotherapy and surgery (CS group, n = 84) and those who received only surgery and postoperative chemotherapy (S group, n = 83). In the CS group, number of patients who received 2, 4, 6 cycles of preoperative chemotherapy were, respectively, 28, 53 and 3. AI, KI and AI/KI were closely related to pathological response. Cutoff value of AI and AI/KI for response separated CS group patients into two subgroups with significant different prognosis and picked up more potential responders than pathological evaluation, especially in pathological response evaluation grade 1a–b.

Conclusions

Apoptosis index, KI and AI/KI are significantly related to chemotherapy efficacy and prognosis of gastric cancer patients who received perioperative chemotherapy and radical gastrectomy. They could be used in combination with pathological response evaluation to distinguish more potential responders.     

Biweekly vinorelbine and tegafur/uracil in patients with metastatic breast cancer previously treated with anthracyclines and taxanes: GEICAM 2000–02 phase II study

Introduction

To assess the efficacy and safety profile of biweekly vinorelbine and tegafur/uracil (UFT) as treatment in patients with metastatic breast cancer previously treated with anthracyclines and taxanes.

Patients and methods

Patients with histologically confirmed breast cancer, measurable disease, no more than one prior chemotherapy regimen for metastatic disease, an Eastern Cooperative Oncology Group (ECOG) performance status ≤2, and adequate bone marrow, renal and liver function were eligible. Patients received vinorelbine (30 mg/m² on day 1) and UFT (250 mg/m² daily) every two weeks for 12 cycles unless progression or unacceptable toxicity was observed.

Results

Thirty-seven patients were included and received 311 cycles of chemotherapy. Efficacy and toxicity analyses were carried out on an intention-to-treat basis. The overall response rate was 35% (95% CI: 20–53). With a median follow-up of 18.6 months (95% CI: 1.0–74.3), the median time to progression was 7.0 months (96% CI: 5.2–8.9) and the median overall survival was 19.4 months (95% CI: 11.1–27.8). The most common severe toxicities were neutropenia (38% of patients) and asthenia (11% of patients).

Conclusion

The combination of biweekly vinorelbine and UFT in patients with metastatic breast cancer pretreated with anthracyclines and taxanes is a well tolerated and effective regimen. AEMPS Trial Registration No.: 00-0534.     

Thrombocytosis and immunohistochemical expression of connexin 43 at diagnosis predict survival in advanced non-small-cell lung cancer treated with cisplatin-based chemotherapy

Purpose

Patients with advanced non-small-cell lung cancer (NSCLC) have poor survival, and platinum-based chemotherapy agents are the standard first-line chemotherapy agents for advanced NSCLC. This study aimed to identify predictive factors associated with the response to chemotherapy and survival in 258 patients with advanced NSCLC treated with platinum-based chemotherapy.

Methods

Stage IIIA–IV NSCLC patients diagnosed in Kaifeng second people’s hospital (Henan, China) between March 2002 and September 2011 were retrospectively reviewed. All of the patients had received platinum-based chemotherapy, and patients were followed up to date of death or last follow-up to obtain data of response to chemotherapy and survival. Potential prognostic factors such as gender, age, tumor size, tumor type, histologic stage, anemia, calcium levels, ECOG performance status (PS), thrombocytosis, TTF-1, p63, and connexin 43 were analyzed. Response to chemotherapy, overall survival (OS) and progression-free survival (PFS) were calculated by the Kaplan–Meier method and Cox regression model.

Results

A univariate analysis indicated that thrombocytosis and connexin 43 were found to be significant prognostic factors (p < 0.001) and ECOG PS, Hb levels, and p63 presented a tendency toward association with survival. Kaplan–Meier survival showed that the mean OS and PFS in chemotherapy responders with connexin 43 ≥+2 were significantly longer than in chemotherapy responders with connexin 43 ≤1+. In contrast, thrombocytosis was associated with increased mortality and resistance to chemotherapy in chemotherapy responders. In addition, all 21 patients of the 5-year OS were from chemotherapy responders with connexin 43 ≥+2 or non-thrombocytosis.

Conclusions

Thrombocytosis and connexin 43 absence may be reliable surrogate markers for the prediction of chemotherapy response and prognosis for patients with advanced NSCLC, and assessment of these factors may identify a population of patients with advanced NSCLC that is likely to have a prolonged life expectancy.     

A phase II study of uracil-tegafur plus doxorubicin and prognostic factors in patients with unresectable biliary tract cancer

Purpose

The purpose of this study was to clarify the safety and efficacy of combination chemotherapy of uracil-tegafur (UFT) and doxorubicin (UFD regimen), and to identify the prognostic factors in patients with unresectable advanced biliary tract cancer who received systemic chemotherapy.

Methods

Patients with histologically or cytologically confirmed, measurable biliary tract cancer, including intrahepatic or extrahepatic cholangiocarcinoma, gallbladder cancer, and ampullary cancer, who were not suitable candidates for surgery, were eligible for the study. Patients received oral UFT at 300 mg/m² per day divided into two doses on days 1–14 and intravenous doxorubicin at 30 mg/m² on day 1. This cycle was repeated every 21 days. The relationship between the patient characteristics and the prognosis was examined. Univariate and multivariate analyses were conducted to identify the prognostic factors associated with survival.

Results

Sixty-one patients from 12 institutions were enrolled in the late phase II study between April 2005 and March 2006. Of the 61 patients, 4 patients had partial responses, for an objective response rate of 6.6% (95% CI: 1.8–15.9%); 28 patients had stable disease, 27 had progressive diseases, and 2 patients were not evaluated. The median progression-free survival was 1.6 months, and the overall median survival time was 6.5 months. In the 85 patients who received this UFD chemotherapy in previous and late phase II studies, multivariate analysis revealed the ECOG performance status 1 (P = 0.001), gallbladder as the primary cancer site (P = 0.014), T-factor 4 of the TNM classification (P = 0.035), and elevated serum lactate dehydrogenase levels (P = 0.043) as being associated with a significantly shorter survival.

Conclusions

Combination chemotherapy of UFT and doxorubicin had minimum activity against advanced biliary tract cancer. Performance status was identified as the most important prognostic factor in patients who received systemic chemotherapy.     

Over-expression of Her-2 in colorectal cancer tissue, but not in serum, constitutes an independent worse prognostic factor

Background

Currently, conflicting information exists regarding Her-2 over-expression and its clinicopathological implications in colorectal cancer (CRC). This study was undertaken to determine Her-2 over-expression in both serum and tumor tissue of CRC patients, and to assess its clinicopathological and targeted therapeutic implications.

Methods

Ninety five CRC patients and sixty healthy controls were prospectively enrolled. Her-2 expression status in serum and CRC tissue were examined by chemiluminescent immunoassay and immunohistochemical staining, respectively. The results were confirmed using fluorescent in situ hybridization. Clinicopathological parameters were analyzed according to Her-2 expression status.

Results

Serum Her-2 levels were found to be increased in CRC patients as compared to those of healthy controls. However, serum Her-2 levels were not found to be significantly associated with prognostic parameters. Her-2 expression analysis of CRC tissues revealed Her-2 over-expression in 23 patients (25%), i.e., 13 patients (14%) showed moderate over-expression and 10 patients (11%) showed strong over-expression. The overall survival of patients negative for Her-2 expression was significantly better than that of patients positive for Her-2 expression (P?=?0.018). The disease-free survival of patients with Her-2 over-expression was significantly shorter than that of patients with no Her-2 expression (P?=?0.021).

Conclusions

Her-2 over-expression in CRC tissue, but not in serum, acts as a significant independent worse prognostic factor. Assessment of Her-2 expression status may be valuable for the targeted therapeutic management of CRC.     

Variation in the Vitamin D Receptor Gene is not Associated with Risk of Colorectal Cancer in the Czech Republic

Purpose

Increased levels of vitamin D may protect against colorectal cancer (CRC) development and recurrence. Accumulating epidemiologic evidence suggests these effects may be partly mediated by genetic variants of the vitamin D receptor (VDR) proposed to be associated with altered risk of CRC. We wished to determine if common VDR polymorphisms affected CRC risk in the Czech Republic, a homogenous European population with a high CRC incidence rate.

Methods

Frequencies of the common VDR gene polymorphisms rs2238136, rs1544410 (BsmI), rs7975232 (ApaI), and rs731236 (TaqI) were determined using allele-specific PCR in a case control analysis of a series of 754 CRC patients and 627 patients without malignant disease recruited from centers throughout the Czech Republic. Unconditional logistic regression was used to calculate odds ratios and 95% confidence intervals for the association between these variants and risk of CRC.

Results

None of the four polymorphisms tested had any significant effect on CRC risk. No significant differences were observed in susceptibility when the population was stratified by anatomical sub-site, sex, BMI, smoking, alcohol, or presence of polyps.

Conclusions

We conclude that common variation in the VDR gene had little effect on its own on predisposition to sporadic CRC in the Czech population.     

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.