Thymidylate synthase expression in hepatic tumors is a predictor of survival and progression in patients with resectable metastatic colorectal cancer

Signaling Pathways Involved in 5-FU Drug Resistance in Cancer

Anti-metabolite drugs prevent the synthesis of essential cell growth compounds. 5-fluorouracil is used as an anti-metabolic drug in various cancers in the first stage of treatment. Unfortunately, in some cancers, 5-fluorouracil has low effectiveness because of its drug resistance. Studies have shown that drug resistance to 5-fluorouracil is due to the activation of specific signaling pathways and increased expressions of enzymes involved in drug metabolites. However, when 5-fluorouracil is used in combination with other drugs, the sensitivity of cancer cells to 5-fluorouracil increases, and the effect of drug resistance is reversed. This study discusses how the function of 5-fluorouracil in JAK/STAT, Wnt, Notch, NF-κB, and hedgehogs in some cancers.

Evening primrose seed extract rich in polyphenols modulates the invasiveness of colon cancer cells by regulating the TYMS expression

Natural polyphenols are plant metabolites exhibiting a broad range of biological activities.

Pharmacogenomics of 5-fluorouracil in colorectal cancer: review and update

BACKGROUND

Colorectal cancer (CRC) is a disease with high morbidity and mortality rates. 5-fluorouracil (5-FU) is the first-line recommended drug for chemotherapy in patients with CRC, and it has a good effect on a variety of other solid tumors as well. Unfortunately, however, due to the emergence of drug resistance the effectiveness of treatment may be greatly reduced. In the past decade, major progress has been made in the field of 5-FU drug resistance in terms of molecular mechanisms, pre-clinical (animal) models and clinical trials.

CONCLUSIONS

In this article we systematically review and update current knowledge on 5-FU pharmacogenomics related to drug uptake and activation, the expression and activity of target enzymes (DPD, TS and MTHFR) and key signaling pathways in CRC. Furthermore, a summary of drug combination strategies aimed at targeting specific genes and/or pathways to reverse 5-FU resistance is provided. Based on this, we suggest that causal relationships between genes, pathways and drug sensitivity should be systematically considered from a multidimensional perspective. In the design of research methods, emerging technologies such as CRISPR-Cas, TALENS and patient-derived xenograft models should be applied as far as possible to improve the accuracy of clinically relevant results.

Cryotherapy for liver metastases

BACKGROUND

The liver is affected by two of the most common groups of malignant tumours: primary liver tumours and liver metastases from colorectal carcinoma. Liver metastases are significantly more common than primary liver cancer and long-term survival rates reported for patients after radical surgical treatment is approximately 50%. However, R0 resection (resection for cure) is not feasible in the majority of patients. Cryotherapy is performed with the use of an image-guided cryoprobe which delivers liquid nitrogen or argon gas to the tumour tissue. The subsequent process of freezing is associated with formation of ice crystals, which directly damage exposed tissue, including cancer cells.

OBJECTIVES

To assess the beneficial and harmful effects of cryotherapy compared with no intervention, other ablation methods, or systemic treatments in people with liver metastases.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE Ovid, Embase Ovid, and six other databases up to June 2018.

SELECTION CRITERIA

Randomised clinical trials assessing beneficial and harmful effects of cryotherapy and its comparators for liver metastases, irrespective of the location of the primary tumour.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We extracted information on participant characteristics, interventions, study outcomes, and data on the outcomes important for our review, as well as information on the design and methodology of the trials. Two review authors independently assessed risk of bias in each study. One review author performed data extraction and a second review author checked entries.

MAIN RESULTS

We found no randomised clinical trials comparing cryotherapy versus no intervention or versus systemic treatments; however, we identified one randomised clinical trial comparing cryotherapy with conventional surgery. The trial was conducted in Ukraine. The trial included 123 participants with solitary, or multiple unilobar or bilobar liver metastases; 63 participants received cryotherapy and 60 received conventional surgery. There were 36 women and 87 men. The primary sites for the metastases were colon and rectum (66.6%), stomach (7.3%), breast (6.5%), skin (4.9%), ovaries (4.1%), uterus (3.3%), kidney (3.3%), intestines (1.6%), pancreas (1.6%), and unknown (0.8%). The trial was not reported sufficiently enough to assess the risk of bias of the randomisation process, allocation concealment, or presence of blinding. It was also not possible to assess incomplete outcome data and selective outcome reporting bias. The certainty of evidence was low because of risk of bias and imprecision.The participants were followed for up to 10 years (minimum five months). The trial reported that the mortality at 10 years was 81% (51/63) in the cryotherapy group and 92% (55/60) in the conventional surgery group. The calculated by us relative risk (RR) with 95% Confidence Interval (CI) was: RR 0.88, 95% CI 0.77 to 1.02. We judged the evidence as low-certainty evidence. Regarding adverse events and complications, separately and in total, our calculation showed no evidence of a difference in recurrence of the malignancy in the liver: 86% (54/63) of the participants in the cryotherapy group and 95% (57/60) of the participants in the conventional surgery group developed a new malignancy (RR 0.90, 95% CI 0.80 to 1.01; low-certainty evidence). The frequency of reported complications was similar between the cryotherapy group and the conventional surgery group, except for postoperative pain. Both insignificant and pronounced pain were reported to be more common in the cryotherapy group while intense pain was reported to be more common in the conventional surgery group. However, the authors did not report whether there was any evidence of a difference. There were no intervention-related mortality or bile leakages.We identified no evidence for health-related quality of life, cancer mortality, or time to progression of liver metastases. The study reported tumour response in terms of the carcinoembryonic antigen level in 69% of participants, and reported results in the form of a graph for 30% of participants. The carcinoembryonic antigen level was lower in the cryotherapy group, and decreased to normal values faster in comparison with the control group (P < 0.05).

FUNDING

the trial did not provide information on funding.

AUTHORS' CONCLUSIONS

The evidence for the effectiveness of cryotherapy versus conventional surgery in people with liver metastases is of low certainty. We are uncertain about our estimate and cannot determine whether cryotherapy compared with conventional surgery is beneficial or harmful. We found no evidence for the benefits or harms of cryotherapy compared with no intervention, or versus systemic treatments.

Immunohistochemical investigation of prognostic biomarkers in resected colorectal liver metastases: a systematic review and meta-analysis

Background

Many studies have investigated the prognostic role of biomarkers in colorectal liver metastases (CRLM). However, no biomarker has been established in routine clinical practice. The aim of this study was to scrutinize the current literature for biomarkers evaluated by immunohistochemistry as prognostic markers in patients with resected CRLM.

Methods

A systematic review was performed according to the PRISMA guidelines. Articles were identified in the PubMed database with selected search terms and by cross-references search. The REMARK quality criteria were applied. Markers were included if they reported the prognostic impact of immunohistochemical markers in a multivariable setting in relation to overall survival (OS). A meta-analysis was conducted when more than one original article provided survival data of a marker.

Results

In total, 26 biomarkers were identified as independent significant markers for OS in resected CRLM. These biomarkers were found to be involved in multiple oncogenic signalling pathways that control cell growth, apoptosis, angiogenesis and evasion of immune detection. Among these biomarker candidates were Ki-67, EGFR, p53, hTERT, CD34, TSP-1, KISS1, Aurora kinase A and CDX2. CD34 and TSP-1 were reported as significantly associated with survival by more than one study and where therefore pooled in a meta-analysis.

Conclusion

A number of independent prognostic biomarkers for resected CRLM were identified. However, most markers were evaluated in a retrospective setting with small patient cohorts, without external validation. Large, prospective, multicentre studies with standardised methods are needed before biomarkers can translated into the clinic.

Phase 2 study of treatment selection based on tumor thymidylate synthase expression in previously untreated patients with metastatic colorectal cancer: A trial of the ECOG-ACRIN Cancer Research Group (E4203)

BACKGROUND

The authors hypothesized that patients with metastatic colorectal cancer (mCRC) who had tumors with low thymidylate synthase (TS-L) expression would have a higher response rate to combined 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) plus bevacizumab (FOLFOX/Bev) than those with high TS (TS-H) expression and that combined irinotecan and oxaliplatin (IROX) plus bevacizumab (IROX/Bev) would be more effective than FOLFOX/Bev in those with TS-H tumors.

METHODS

TS protein expression was determined in mCRC tissue. Patients who had TS-L tumors received FOLFOX/Bev, and those who had TS-H tumors were randomly assigned to receive either FOLFOX/Bev or IROX/Bev. The primary endpoint was the response rate (complete plus partial responses).

RESULTS

In total, 211 of 247 patients (70% TS-H) were registered to the treatment phase. Efficacy analyses included eligible patients who had started treatment (N = 186). The response rates for patients who received IROX/Bev (TS-H), FOLFOX/Bev (TS-H), and FOLFOX/Bev (TS-L) were 33%, 38%, and 49%, respectively (P = nonsignificant). The median progression-free survival (PFS) was 10 months (95% confidence interval [CI], 9-12 months; 10 months in the IROX/Bev TS-H group, 9 months in the FOLFOX/Bev TS-H group, and 13 months in the FOLFOX/Bev TS-L group). The TS-L group had improved PFS compared with the TS-H group that received FOLFOX/Bev (hazard ratio, 1.6; 95% CI, 1.0%-2.4%; P = .04; Cox regression). The median overall survival (OS) was 22 months (95% CI, 20 29 months; 18 months in the IROX/Bev TS-H group, 21 months in the FOLFOX/Bev TS-H group, and 32 months in the TS-L group). OS comparisons for the 2 TS-H arms and for the FOLFOX/Bev TS-H versus TS-L arms were not significantly different.

CONCLUSIONS

TS expression was prognostic: Patients with TS-L tumors who received FOLFOX/Bev had a longer PFS than those with TS-H tumors, along with a trend toward longer OS. Patients with TS-H tumors did not benefit more from IROX/Bev than from FOLFOX/Bev. Cancer 2018;124:688-97. © 2017 American Cancer Society.

Thymidylate synthase: a predictive biomarker in resected colorectal liver metastases receiving 5-FU treatment

AIM

To investigate the role of thymidylate synthase (TS) as a predictive biomarker in patients with resected colorectal liver metastases (CRLM).

MATERIALS & METHODS

PubMed, EMBASE and Cochrane Library were queried up to June 2017. Meta-analysis was performed using random-effects model. Risk of bias was assessed using funnel plots.

RESULTS

Six eligible studies were included, comprising a total of 542 patients. Meta-analysis demonstrated a trend to reduced overall survival in patients with resected CRLM with TS overexpression, with a hazard ratio of 1.13 (95% CI: 0.99-1.29; p = 0.08). In three studies where patients received systemic fluorouracil, the pooled hazard ratio was 2.25 (95% CI: 1.37-3.71; p = 0.001).

CONCLUSION

TS appears to be a clinically relevant predictive biomarker in patients with resected CRLM receiving systemic 5-FU.

Topoisomerase 2α and thymidylate synthase expression in adrenocortical cancer

Topoisomerase II alpha (TOP2A) and thymidylate synthase (TS) are known prognostic parameters in several tumors and also predictors of efficacy of anthracyclines, topoisomerase inhibitors and fluoropirimidines, respectively. Expression of TOP2A and TS mRNA was assessed in 98 patients with adrenocortical carcinoma (ACC) and protein expression was assessed by immunohistochemistry in a subset of 39 tumors. Ninety-two patients were radically resected for stage II-III disease and 38 of them received adjuvant mitotane. Twenty-six patients with metastatic disease received the EDP-M (etoposide, doxorubicin, Adriamycin, cisplatin plus mitotane). TOP2A and TS expression in ACC tissue was directly correlated with the clinical data. Both markers were not associated with either disease free survival (DFS) or overall survival (OS) in multivariate analyses and failed to be associated to mitotane efficacy. Disease response or stabilization to EDP-M treatment was observed in 12/17 (71%) and 1/9 (11%) patients with high and low TOP2A expressing tumors (P = 0.0039) and 9/13 (69%) and 4/13 (31%) patients with high and low TS expressing ACC, respectively (P = 0.049). High TOP2A expression was significantly associated with longer time to progression (TTP) after EDP-M. TOP2A and TS proteins assessed by immunohistochemistry significantly correlated with mRNA expression. Immunohistochemical TOP2A expression was associated with a non-significant better response and longer TTP after EDP-M. TOP2A and TS were neither prognostic nor predictive of mitotane efficacy in ACC patients. The predictive role of TOP2A expression of EDP-M activity suggests a significant contribution of Adriamycin and etoposide for the efficacy of the EDP scheme.

A Study of Thymidylate Synthase Expression as a Biomarker for Resectable Colon Cancer: Alliance (Cancer and Leukemia Group B) 9581 and 89803

Tumor thymidylate synthase (TS) levels were prospectively evaluated in two adjuvant therapy trials for patients with resected stage II or III colon cancer. Results indicated that high tumor TS levels were associated with improved disease‐free survival and overall survival following adjuvant therapy for colon cancer, although tumor TS expression did not predict benefit of 5‐fluorouracil‐based chemotherapy.

Purpose.

Tumor levels of thymidylate synthase (TS), a target of 5‐fluorouracil (5‐FU)‐based chemotherapy for colorectal cancer, have been studied as a predictive or prognostic biomarker with mixed results.

Patients and Methods.

Tumor TS levels were prospectively evaluated in two adjuvant therapy trials for patients with resected stage II or III colon cancer. TS expression was determined by standard immunohistochemistry and by automated quantitative analysis. Tumor mismatch repair deficiency (MMR‐D) and BRAF c.1799T > A (p.V600E) mutation status were also examined. Relationships between tumor TS, MMR‐D, and BRAF mutation status, overall survival (OS), and disease‐free survival (DFS) were investigated in the subset of stage III patients.

Results.

Patients whose tumors demonstrated high TS expression experienced better treatment outcomes, with DFS hazard ratio (HR) = 0.67, 95% confidence interval (CI) = 0.53, 0.84; and OS HR = 0.68, 95% CI = 0.53, 0.88, for high versus low TS expression, respectively. No significant interaction between TS expression and stage was observed (DFS: interaction HR = 0.94; OS: interaction HR = 0.94). Tumors with high TS expression were more likely to demonstrate MMR‐D (22.2% vs. 12.8%; p =  .0003). Patients whose tumors demonstrated both high TS and MMR‐D had a 7‐year DFS of 77%, compared with 58% for those whose tumors had low TS and were non‐MMR‐D (log‐rank p =  .0006). Tumor TS expression did not predict benefit of a particular therapeutic regimen.

Conclusion.

This large prospective analysis showed that high tumor TS levels were associated with improved DFS and OS following adjuvant therapy for colon cancer, although tumor TS expression did not predict benefit of 5‐FU‐based chemotherapy.

Implications for Practice.

This study finds that measurement of tumor levels of thymidylate synthase is not helpful in assigning specific adjuvant treatment for colorectal cancer. It also highlights the importance of using prospective analyses within treatment clinical trials as the optimal method of determining biomarker utility.

Management of patients with colorectal liver metastasis in eleven questions and answers

INTRODUCTION

Colorectal liver metastasis (CRLM) is the most frequent indication for liver resection in many centers. Recent improvements in oncology, surgery, interventional radiology, pathology and anesthesiology allow curative treatment in a larger proportion of patients with CRLM. Areas covered: We illustrate the various aspects of the management of CRLM through 11 questions that summarize the topic, from the current obtained survival to future perspectives such as transplantation. The limits of a curative treatment are also presented from different angles, such as the benefits of pathology, the surgical options for extreme resections, the available chemotherapies and their efficacy, or the non-surgical ablative treatments. Expert commentary: Given the increasing therapeutic possibilities, we strengthen the importance to analyze the situation of each patient with CRLM in a dedicated multidisciplinary team, in order to offer the best individualized treatment combination.

Can we improve the clinical risk score? The prognostic value of p53, Ki-67 and thymidylate synthase in patients undergoing radical resection of colorectal liver metastases

OBJECTIVES

The aim of this study was to assess whether biological markers can provide prognostic information additional to that supplied by the clinical risk score (CRS) in patients with colorectal liver metastases.

METHODS

A retrospective review of a prospectively maintained database was conducted. Patients selected for this study were treated between 1996 and 2011 with potentially curative liver surgery. Expressions of p53, Ki-67 and thymidylate synthase were assayed using immunohistochemical techniques on tissue microarrays.

RESULTS

A total of 98 (24%) of 406 patients met the inclusion criteria. The median follow-up was 103 months. Analysis revealed a correlation between p53 protein overexpression and high CRS (P = 0.058). Following multivariate analysis, only high CRS remained as an independent negative prognostic predictor of survival (P = 0.018), as well as an indicator of early recurrence of disease (P = 0.010). Of the biological markers investigated, only Ki-67 overexpression was identified as a positive predictor of survival on multivariate analysis (P = 0.038).

CONCLUSIONS

Ki-67 overexpression was a positive predictor of survival. Only high CRS remained an independent negative prognostic predictor.

Tissue-based biomarkers predicting outcomes in metastatic colorectal cancer: a review

Although there have been recent advances in the treatment of metastatic colorectal cancer, particularly with systemic chemotherapy, new biological agents and surgical metastasectomy, the disease remains difficult to treat. To personalise the management of mCRC and optimise patient outcomes, it is vital to acquire a deeper understanding of its natural history and mechanisms behind disease progression. This may be achieved by extensive study of tumour biomarkers: proteins or genetic alterations within neoplastic cells or their surrounding stroma that may be used to predict patient outcomes, disease trajectory and response to various therapies. The discovery of mutant Kirsten-RAS in determining patients who may be refractory to anti-epidermal growth factor receptor treatments has reinvigorated and reiterated the importance of our attempts to individualise cancer care. While many biomarkers have been studied and shown promise in the setting of mCRC, they are, with the exception of K-ras testing not used currently in a clinical setting due to conflicting results, small patient samples and methodological variations. Larger, multi-centric studies with uniform methods of tumour marker study are required to effectively tailor systemic therapies and select appropriate candidates for surgical metastasectomy.

Surgery for colorectal liver metastases: The evolution of determining prognosis

Despite improvements in the multi-modality treatment of colorectal liver metastasis (CRLM), survival after resection remains varied. Determining prognosis after surgical resection has historically been predicated on preoperative clinicopathological factors such as primary tumor stage, carcinoembryonic antigen levels, number of liver metastases, presence of extrahepatic disease, as well as other factors. While scoring systems have been developed by combining certain preoperative factors, these have been inconsistent in accurately determining prognosis. There has been increasing interest in the use of biologic and molecular markers to predict prognosis following CRLM. The role of markers such as KRAS, BRAF, p53, human telomerase reverse transcriptase, thymidylate synthase, Ki-67, and hypoxia inducible factor-1α and their correlation with accurately predicting survival after surgical resection have been supported by several studies. Furthermore, other elements such as pathological response to chemotherapy and the presence of circulating tumor cells have shown promise in accurately determining prognosis after resection for colorectal liver metastasis. We herein review past, present, and possible future markers of prognosis among colorectal cancer patients with liver metastasis undergoing resection with curative intent.

Prognostic factors after resection of colorectal liver metastases: from morphology to biology

Despite improved overall survival rates after potentially curative liver resection (~50-58% at 5 years), almost half of patients experience disease recurrence highlighting the need for a precise definition of outcomes to stratify patients for clinical trials and to guide treatment decisions. In the past, several factors, such as an advanced primary T stage, the primary N+ status, a large tumor size, multiple tumors, a disease-free interval of <12 months, an elevated carcinoembryonic antigen level, the presence of an extrahepatic disease, and the margin width (<1 cm) and status (positive), have been recognized to predict poor outcomes, but most of them lack the sensitivity for accurate individual prognostication. Thus, in recent years, new factors, such as response to chemotherapy, either clinical or pathological, that more closely reflect tumor biology have been established and adopted in the clinical practice. Similarly, biomarkers of poor prognosis, especially mutations in KRAS and BRAF and the expression of thymidylate synthase, have been studied, yielding promising results. However, robust evidence of their prognostic utility awaits prospective validation.

A combined analysis of mismatch repair status and thymidylate synthase expression in stage II and III colon cancer

This study in 716 colon cancer patients evaluates if a combined instead of a single marker analysis of mismatch repair (MMR) status and thymidylate synthase (TS) expression could individualize the treatment decision. The results indicate that a combined analysis of MMR status and TS expression can improve prediction of response to adjuvant 5-fluorouracil (5-FU)-based chemotherapy in stage III colon cancer.

BACKGROUND

Colon cancer with mismatch repair deficiency and low TS expression has been associated with an improved prognosis. Data also indicate that MMR proficient colon cancer with high TS expression has a better response to adjuvant 5-FU-based chemotherapy. This study evaluates if a combined analysis of MMR status and TS expression in colon cancer can add prognostic value and better predict response to adjuvant 5-FU-based chemotherapy. The potential relationship between MMR status and TS expression is also investigated.

PATIENTS AND METHODS

This study includes a subgroup of 716 patients with colon cancer out of 2224 stage II and stage III colorectal cancer patients enrolled in Nordic trials randomized to surgery alone or surgery plus adjuvant 5-FU-based chemotherapy. After immunohistochemical analysis of tumor MMR status and TS expression the patients were divided into 4 groups.

RESULTS

There was a nonsignificant difference in overall survival between group 1 (patients with deficient MMR tumors with low TS) and group 4 (patients with proficient MMR tumors expressing high TS). When comparing group 1 and group 4 patients treated with surgery alone a trend to better overall survival was found in group 1, P=.06. In group 4, stage III patients had a significantly improved survival when receiving adjuvant 5-FU-based chemotherapy compared with surgery alone, P=.01. No relationship was found between MMR status and TS expression.

CONCLUSIONS

A combined instead of a single marker analysis of MMR status and TS expression can improve the prediction of response to 5-FU-based chemotherapy in stage III colon cancer.

Expression and prognostic significance of thymidylate synthase (TS) in pancreatic head and periampullary cancer

BACKGROUND

Pancreatic cancer has a dismal prognosis. Attempts have been made to improve outcome by several 5-FU based adjuvant treatment regimens. However, the results are conflicting. There seems to be a continental divide with respect to the use of 5-FU based chemoradiotherapy (CRT). Furthermore, evidence has been presented showing a different response of pancreatic head and periampullary cancer to 5-FU based CRT. Expression of thymidylate synthase (TS) has been associated with improved outcome following 5-FU based adjuvant treatment in gastrointestinal cancer. This prompted us to determine the differential expression and prognostic value of TS in pancreatic head and periampullary cancer.

PATIENTS AND METHODS

TS protein expression was studied by immunohistochemistry on original paraffin embedded tissue from 212 patients following microscopic radical resection (R0) of pancreatic head (n = 98) or periampullary cancer (n = 114). Expression was investigated for associations with recurrence free (RFS), cancer specific (CSS) and overall survival (OS), and conventional prognostic factors.

RESULTS

High cytosolic TS expression was present in 26% of pancreatic head tumours and 37% of periampullary tumours (p = .11). Furthermore, TS was an independent factor predicting favourable outcome following curative resection of pancreatic head cancer (p = .003, .001 and .001 for RFS, CSS and OS, respectively). In contrast, in periampullary cancer, TS was not associated with outcome (all p > .10).

CONCLUSION

TS, was found to be poorly expressed in both pancreatic head and periampullary cancer and identified as an independent prognostic factor following curative resection of pancreatic head cancer.

Improving the clinical risk score: an analysis of molecular biomarkers in the era of modern chemotherapy for resectable hepatic colorectal cancer metastases

BACKGROUND

The prognostic relevance of variations in expression of specific tumor genes in colorectal cancer liver metastases (CRCLMs) in patients treated with resection and modern chemotherapy is not known.

METHODS

Patients submitted to liver resection for CRCLM between January 2000 and October 2007 were studied. A clinical risk score (CRS; range, 0-5) was calculated for each patient. RNA was extracted from histologically confirmed tumor isolates, and using real-time polymerase chain reaction (PCR) studies, we assessed the quantitative expression of 12 genes with potential importance in chemotherapy resistance and tumor progression, including thymidylate synthase (TS; 5-fluorouracil), excision repair cross complementing gene-1, and xeroderma pigmentosum groups A through G (oxaliplatin), topoisomerase-I (irinotecan), c-met, and hepatocyte growth factor. Primary outcomes were recurrence-free survival (RFS) and disease-specific survival (DSS) after hepatic resection.

RESULTS

One-hundred fifty-five patients with good quality tumor mRNA were identified. Median follow-up was 32 months for survivors, and the median CRS was 2. Eighty-seven patients (56%) received preoperative chemotherapy, and 124 (80%) received postoperative chemotherapy. Median RFS for all patients was 13 months, and 3-year DSS was 69%. Median RFS and 3-year DSS for patients with an increased CRS (3-5) was lower (7 vs 18 months [P < .0001] and 50% vs. 80% [P < .0001], respectively). Of the 12 genes studied, only increased TS expression was associated with a lower RFS (hazard ratio, 1.16; 95% confidence interval, 1.0-1.3; P = .03) and DSS (hazard ratio, 1.25; 95% confidence interval, 1.0-1.5; P = .03). Median RFS and 3-year DSS for patients with increased TS expression was decreased (9 vs. 15 months [P = .03] and 48% vs. 82% [P = .001], respectively). TS expression had prognostic value that was independent of CRS on multivariate analysis.

CONCLUSION

In patients with hepatic CRCLM treated with resection and modern chemotherapy, increased expression of TS improves outcome stratification and appears to be a useful biomarker.

Folate receptor-α expression in resectable hepatic colorectal cancer metastases: patterns and significance

Folate receptor alpha (FRα), encoded by folate receptor 1 (adult) gene, has emerged as a cancer biomarker and potential therapeutic target. In addition, its expression in tumors may offer prognostic information. The aim of this study was to assess the prognostic value of FRα expression and other common molecular markers in resected liver metastases from colorectal cancer. To maximize potential biological differences, we selected two groups of patients with markedly different outcomes as study subjects. Immunohistochemical analysis of FRα expression and other common markers (thymidylate synthase, p53, p27, BCL2, ki67, MLH1, MSH2 and MGMT) on tissue microarrays was carried out on samples from 160 patients; 56 patients survived at least 10 years following liver resection, and 104 died within 2 years of surgery. These markers were evaluated and compared with standard clinical predictors of outcome including a previously validated clinical risk score. Our results showed that in addition to known clinical risk factors, FRα positivity was significantly associated with the early death group (32% compared with 13%; P=0.03). None of the other common molecular markers were differentially expressed between the two groups. On multivariate analysis, clinical risk score, margin status and FRα expression were independently associated with outcome. Specific multivariate comparisons confirmed that FRα expression was associated with outcome independent of the clinical risk score and margin. These data demonstrate that FRα expression is present in a subset of resected hepatic colorectal cancer metastases, and this marker is independently associated with survival after hepatic resection. The prognostic value of FRα expression and the utility of FRα-targeted therapies in stage-IV colorectal cancer patients deserve further exploration.

CXCR4 expression predicts patient outcome and recurrence patterns after hepatic resection for colorectal liver metastases

BACKGROUND

The purpose of this study was to determine if the expression of the chemokine receptors, CXCR4 and CCR7, and the chemokine ligand, CXCL12, in completely resected colorectal cancer hepatic metastases are predictive of disease-specific survival, recurrence-free survival and patterns of recurrence.

METHODS

Immunohistochemical analysis of CXCR4, CCR7 and CXCL12 expression within resected hepatic metastases was performed and correlated with clinicopathological variables, disease-specific survival, recurrence-free survival and patterns of recurrence.

RESULTS

Seventy-five patients who underwent partial hepatectomy with curative intent were studied. CXCR4 expression (hazard ratio [HR] 3.6, 95% confidence interval [95% CI] 1.4-9.1) and clinical risk score >2 (HR 2.3, 95% CI 1.1-4.7) were independently associated with disease-specific survival by multivariate analysis. The 5-year estimated disease-specific survival rates for positive and negative CXCR4 tumor expression were 44 and 77%, respectively (P = 0.005). CXCR4 expression (HR 2.2, 95% CI 1.2-4.2) and clinical risk score >2 (HR 1.9, 95% CI 1.1-3.4) were independently associated with recurrence-free survival by multivariate analysis. The five year estimated recurrence-free survival rates for positive and negative CXCR4 tumor expression were 20 and 50%, respectively (P = 0.004). Neither CXCL12 nor CCR7 expression in tumors predicted disease-specific survival or recurrence-free survival. Forty-nine patients (65%) developed recurrent disease after initial hepatectomy. Negative CXCR4 tumor expression was associated with favorable recurrence patterns amenable to salvage resection and/or ablation.

CONCLUSIONS

Negative CXCR4 expression in resected colorectal cancer hepatic metastases is independently associated with improved disease-specific and recurrence-free survival and favorable patterns of recurrence.

Effect of leucovorin on the antitumor efficacy of the 5-FU prodrug, tegafur-uracil, in human colorectal cancer xenografts with various expression levels of thymidylate synthase

The combination of oral tegafur-uracil (UFT) with leucovorin (LV) is used to treat patients with stage II to III colon cancer based on the results of postoperative randomized studies in which UFT/LV treatment showed an equivalent efficacy to intravenous 5-FU plus LV therapy. However, whether the addition of LV to UFT can elevate the antitumor activity of UFT in colorectal tumors with high expression levels of thymidylate synthase (TS), which affects 5-FU efficacy, remains to be clarified. This study investigated the effect of LV on the antitumor activity of UFT and/or 5-FU prodrugs in low folate diet-fed nude mice using human colorectal cancer xenografts with various expression levels of TS. The addition of LV to UFT resulted in a 55-79% inhibition of tumor growth among 11 types of colorectal tumor xenograft, whereas UFT alone showed 23-67% antitumor activity. Although there was an inverse relationship between the antitumor effect of UFT alone and UFT plus LV and tumoral TS activity, UFT plus LV appeared to have a more potent antitumor effect than UFT alone on colorectal tumors such as Co-3 and KM12C/5-FU with high expression levels of TS. This finding was confirmed by the significant positive correlation between the relative inhibition ratio of UFT/LV to UFT alone and TS levels in tumors. To investigate the reason for the higher efficacy of UFT/LV on colorectal cancer xenografts with high TS activity, intratumoral levels of reduced folates and a ternary complex of TS after oral UFT with or without LV were measured using Co-3 xenografts. Elevated levels of reduced folates and an increased ternary complex of TS in LV-treated tumors were noted. Our results indicate that a combined therapy of UFT with LV may contribute to the treatment of colorectal cancer patients with low and high expression levels of tumoral TS by increased formation of the ternary complex of TS leading to potentiated antitumor efficacy of UFT.

Correlation between thymidylate synthase gene variants, RNA and protein levels in primary colorectal adenocarcinomas

This study was designed to compare thymidylate synthase (TS) genotype, mRNA and protein levels in primary colorectal adenocarcinoma, and to examine the correlation between microsatellite instability (MSI) and TS expression. The TS genotype of 68 patients with colorectal cancer was determined by polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis in peripheral blood mononuclear cells and tumour tissue. The TS mRNA levels in tumour tissue were measured by reverse-transcription PCR, and TS protein levels and MSI status were assessed using immunohistochemistry. Significantly higher mRNA and protein levels were observed in patients with the TS 3R/3R versus the 2R/2R and 2R/3R genotypes. There was no correlation between TS single nucleotide polymorphism and TS expression. Individuals homozygous for the six base-pair insertion in the 3'-untranslated region had significantly higher TS mRNA levels than heterozygous and homozygous wild type individuals. The TS mRNA and protein levels were significantly higher in microsatellite unstable tumours compared with microsatellite stable tumours. There was a significant association between the number of TS enhancer region repeats (in blood) and intratumoural TS mRNA and protein levels. A larger case series investigating the role of TS gene polymorphisms as predictors of sensitivity to 5-fluorouracil-based chemotherapy is required.

Role of adjuvant therapy after resection of colorectal cancer liver metastases

Liver resection is the goal of treatment strategies for liver-confined metastatic colorectal cancer. However, after resection the majority of patients will experience recurrence. Chemotherapy seems to improve outcomes compared with surgery alone. We reviewed the data of the role of adjuvant chemotherapy after resection of liver- confined metastatic colorectal cancer. Optimal regimens and sequencing of chemotherapies when liver resection is an option are unclear. Some suggest that resectable liver metastases, in the absence of high-risk features, should begin with surgery and consideration given to adjuvant chemotherapy after surgery. If high-risk features are present, most physicians prefer a short course of systemic preoperative chemotherapy. Perioperative therapy and regional therapy with hepatic arterial infusion (HAI) both increase disease-free survival (DFS) when compared with surgery alone. In unresectable disease, consideration should be given to systemic chemotherapy with or without a biologic agent or HAI with systemic therapy. If the disease becomes resectable, adjuvant treatment should follow surgery. Adjuvant chemotherapy is usually FOLFOX, but HAI combined with systemic chemotherapy is also an option. The role of adjuvant treatment post-liver resection should not be viewed in isolation but rather in the context of prior treatment, surgical preference, and individual patient characteristics. Perioperative therapy and regional therapy have both shown an increase in DFS. Conducting randomized trials examining the role of adjuvant chemotherapy has been difficult because of rapidly changing chemotherapies.

Nuclear thymidylate synthase expression in sporadic colorectal cancer depends on the site of the tumor

Colorectal carcinoma (CRC) is a heterogeneous disease with specific epidemiological, pathological, molecular, and clinical characteristics that depend on the location of the tumor relative to the splenic flexure. Thymidylate synthase (TS) is a major target of 5-fluorouracil-based chemotherapy for CRC and high expression of this enzyme in tumor cells can influence the effect of therapy. We examined differences in TS protein expression in nuclei of tumor cells between CRCs located proximal and distal to the splenic flexure. Nuclear TS was detected by immunohistochemistry with a TS 106 monoclonal antibody on tissue microarrays constructed from 269 CRCs. The median histological score of nuclear TS expression of all proximal tumors was two times higher (p = 0.0003) and in men three times higher (p = 0.00023) than that found in distal tumors. In multivariate analysis which included age, sex, Astler-Coller stage, histological grade, and site, only proximal location of the tumor was identified as an independent factor associated with higher TS expression (odds ratio 2.46, 95% confidence interval = 1.29-4.70, p = 0.0062). These results demonstrate significant differences in nuclear TS expression between proximal and distal cancers and suggest the potential importance of the site of the tumor for proper stratification of patients for chemotherapy.

Correlation Between Thymidylate Synthase Protein Expression and Gene Polymorphism with Clinicopathological Parameters in Colorectal Carcinoma

5-Fluorouracil (5-FU) represents the basis of chemotherapy for colorectal carcinoma, inhibiting thymidylate synthase (TS), an essential enzyme for DNA replication. Previous studies have associated high TS protein expression by tumor cells with poor outcome of patients with colorectal carcinoma, but others have refuted these findings. In view of the potential role of TS as predictive parameter and the lack of consensus in the literature, the present study compared 2 methods: protein expression and gene polymorphism, correlating them with clinicopathological findings. Immunohistochemical detection of TS in tumor cells and detection of gene polymorphism in the blood were performed in 32 patients with colorectal carcinoma treated with 5-FU. No correlation was found between TS protein expression and gene polymorphism. Neither method correlated with survival, tumor staging, and tumor histological grading. This result possibly reflects a complex tumor response to 5-FU therapy, where TS is just one of the involved proteins.

Thymidylate synthase, dihydropyrimidine dehydrogenase, ERCC1, and thymidine phosphorylase gene expression in primary and metastatic gastrointestinal adenocarcinoma tissue in patients treated on a phase I trial of oxaliplatin and capecitabine

Background

Over-expression of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) in tumor tissue is associated with insensitivity to 5-fluorouracil (5-FU). Over-expression of ERCC1 correlates with insensitivity to oxaliplatin (OX) therapy, while high thymidine phosphorylase (TP) levels predict for increased sensitivity to capecitabine (Xel).

Methods

Biopsies of metastatic tumor were taken before OX (130 mg/m² day 1) given with Xel (1200–3000 mg/m² in two divided doses days 1–5 and 8–12) every 3-weeks. Micro-dissected metastatic and primary tumors were analyzed for relative gene expression by real-time quantitative polymerase chain reaction. The clinical protocol prospectively identified the molecular targets of interest that would be tested. Endpoints for the molecular analyses were correlation of median, first and third quartiles for relative gene expression of each target with response, time to treatment failure (TTF), and survival.

Results

Among 91 patients participating in this trial; 97% had colorectal cancer. The median number of prior chemotherapy regimens was 2, and most had prior 5-FU and irinotecan. In paired samples, median mRNA levels were significantly higher in metastatic versus primary tumor (-fold): TS (1.9), DPD (3.8), ERCC1 (2.1) and TP (1.6). A strong positive correlation was noted between DPD and TP mRNA levels in both primary (r = 0.693, p < 0.0005) and metastatic tissue (r = 0.697, p < 0.00001). There was an association between TS gene expression and responsive and stable disease: patients whose intratumoral TS mRNA levels were above the median value had significantly greater risk of early disease progression (43% vs 17%), but this did not translate into a significant difference in TTF. ERCC1 gene expression above the third quartile was associated with a shorter TTF (median 85 vs 162 days, p = 0.046). Patients whose TS mRNA levels in metastatic tumor tissue were below the median had a longer overall survival (median 417 vs 294 days, p = 0.042).

Conclusion

Target gene expression in primary tumor was significantly lower than that in paired metastatic tissue. High ERCC1 mRNA levels in metastatic tumor was associated with a shorter TTF. Lower expression of TS mRNA correlated with a lower chance of early PD with XelOX therapy and improved overall survival.

Thymidylate synthase and microsatellite instability in colorectal cancer: implications for disease free survival, treatment response and survival with metastases

BACKGROUND

Colorectal cancer (CRC) cell lines displaying microsatellite instability (MSI) are resistant to 5-fluorouracil (5-FU) in vitro, which can be overcome by restoring DNA mismatch repair (MMR) competence. Thymidylate synthase (TS) is inhibited by 5-FU, being another potential mediator of therapeutic resistance to 5-FU. The clinical relevance of these observations remains unclear.

OBJECTIVE

We examined the expression of TS and two MMR proteins (hMLH1 and hMSH2) in advanced CRC patients, to determine a) their mutual relationship, b) association to therapeutic response and c) impact on disease outcome.

MATERIAL AND METHODS

Tumour samples from 73 patients CRC who were treated in advanced stage with either irinotecan alone or in combination with 5-FU/leucovorin, were analysed for expression of TS, hMLH1 and hMSH2 using immunohistochemistry (IHC).

RESULTS

TS expression was closely correlated with hMLH1 expression (negative-weak/moderate-strong) (p=0.0001). TS-MMR expression was significantly (p=0.029 for whole series; p=0.004 for the 5-FU treated cases) related to response to treatment; tumours with low levels of both TS and MMR responded better (n=14/27, 51.8%) than those with high TS and MMR (n=3/18, 16.6%). Patients with high TS-MMR expression had a significantly longer DFS (47 months vs. 9 months, n=26) than those with low TS-MMR index (p=0.015), while the reverse was true concerning survival with metastases (WMS) (p=0.018) in all the patients (n=73).

CONCLUSIONS

The present data suggest that MSI patients with low TS and deficient MMR demonstrate a significantly shorter DFS and longer WMS than patients with high expression of both markers, and they are also more likely to obtain the greatest benefit from 5-FU based chemotherapy.

Bcl-2 expression significantly correlates with thymidylate synthase expression in colorectal cancer patients

AIM: To examine the expression of thymidylate synthase (TS) and oncoprotein Bcl-2 in advanced colorectal cancer (CRC) patients, and to determine their mutual relationship, association to therapeutic response and impact on disease outcome.

METHODS: Tumor samples from 67 patients with CRC, who were treated at advanced stage with either irinotecan alone or in combination with 5-fluorouracil/leucovorin, were analyzed for expression of TS and Bcl-2 using immunohistochemistry.

RESULTS: A significant linear correlation between lower expression levels of Bcl-2 and lower levels of TS expression was found (P = 0.033). Patients with high levels of both TS and Bcl-2 expression had a significantly longer disease-free survival (DFS) (42.6 mo vs 5.4 mo, n = 25) than those with low TS/Bcl-2 index (P = 0.001). Tumors with low levels of both TS and Bcl-2 were associated with a longer survival with metastasis (WMS) interval in the whole patients group (n = 67, P = 0.035). TS/Bcl-2 index was not significantly related to disease-specific survival.

CONCLUSION: The present data suggest that CRC patients with low TS/Bcl-2 demonstrate a significantly shorter DFS and longer WMS.

Predictive molecular markers for colorectal cancer patients with resected liver metastasis and adjuvant chemotherapy

BACKGROUND & AIMS

The aims of the study were to evaluate the predictive value of 8 candidate molecular markers for colorectal cancer (CRC) patients receiving hepatic arterial infusion (floxuridine [FUDR] and dexamethasone) and systemic irinotecan (CPT11) post resection of liver metastasis.

METHODS

RNA was extracted from microdissected tumor cells of fixed and embedded specimens of resected liver metastases (94 cases) and analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) for thymidine phosphorylase, dihydropyrimidine dehydrogenase, thymidylate synthase, uridine phosphorylase, uridine/cytidine (monophospho)kinase, Bcl-2 related protein, Cyclin-D1, and Survivin expression. Uni- and multivariate statistical analyses and an explorative hierarchical clustering analysis of quantitative RT-PCR data were performed for overall survival and recurrent disease.

RESULTS

After adjustment for multiple clinicopathologic parameters, none of the markers were significantly associated with overall survival (except, marginally, Cyclin-D1; P = .06) or extrahepatic recurrence. However, high Survivin (P = .03) and Cyclin-D1 (P = .05) levels were predictive for hepatic recurrence. Hierarchical cluster analysis identified 7 of 94 patients associated with lower hepatic recurrence (P < .001). This patient group was characterized by low Cyclin-D1 and Survivin messenger RNA levels, both genes also clustering together.

CONCLUSIONS

Cyclin-D1 and Survivin messenger RNA analyzed by standardized, quantitative RT-PCR are predictive markers for CRC patients receiving hepatic arterial infusion (FUDR/dexamethasone) and systemic CPT11 post resection of liver metastasis. Moreover, our exploratory hierarchical cluster analysis of quantitative RT-PCR data supports its potential as an application to define clinically relevant patient subgroups.

Surgical therapy for colorectal metastases to the liver

Colorectal cancer is the fourth most common type of cancer in the West and the second leading cause of cancer-related deaths in the United States. Approximately 35 to 55% of patients with colorectal cancer develop hepatic metastases during the course of their disease. Surgical resection of colorectal liver metastases represents the only chance at potential cure, and long-term survival can be achieved in 35 to 58% of patients after resection. The goal of hepatic resection should be to resect all metastases with negative histologic margins while preserving sufficient functional hepatic parenchyma. In patients with extensive metastatic disease who would otherwise be unresectable, ablative approaches can be used instead of or combined with hepatic resection. The use of portal vein embolization and preoperative chemotherapy may also expand the population of patients who are candidates for surgical treatment. Despite these advances, many patients still experience a recurrence after hepatic resection. More active systemic chemotherapy agents are now available and are being increasingly employed as adjuvant therapy either before or after surgery. Modern treatment of colorectal liver metastasis requires a multidisciplinary approach in an effort to increase the number of patients who may benefit from surgical treatment of colorectal cancer liver metastasis.

Neoadjuvant chemotherapy for patients with liver metastases from colorectal cancer

Colorectal cancer is the second most common type of cancer in industrialized countries. Despite improved resection procedures and optimized adjuvant chemotherapy, local or distant recurrences occur in 22-25% of patients with stage II/III colon cancer. Approximately 30% of patients have advanced disease at presentation. The liver is the most common site of colorectal metastases and, interestingly, 20-30% of patients with colorectal cancer have liver-only metastases. The combined modality of chemotherapy and surgery increases overall survival and the chance of cure for metastatic patients, even if there is no agreement in terms of the best schedule and how long the treatment must last. In this paper, we review the role and the rationale of neoadjuvant chemotherapy within a multimodal approach, and discuss remaining questions and future directions.

Shifting from clinical to biologic indicators of prognosis after resection of hepatic colorectal metastases

Following resection of hepatic colorectal metastases, there are few criteria for predicting which patients have more aggressive disease and are, therefore, more likely to experience recurrence and reduced survival. Traditionally, primary tumor stage, preoperative carcinoembryonic antigen level, time from primary tumor treatment to diagnosis of hepatic metastases (disease-free interval), hepatic tumor size, number of hepatic metastases, and presence of extrahepatic disease have been reported to be predictors of survival after resection. However, the data regarding the prognostic importance of these clinicopathologic factors are inconsistent and conflicting. Therefore, conventional clinicopathologic factors may be inadequate for the purposes of prognostication. More recently, there has been increased interest in identifying biologic indicators that may help better define patients at risk for recurrence after hepatic resection for colorectal metastases. Recent studies have shown that proliferation markers such as p53 expression, tritiated thymidine uptake, thymidylate synthase, Ki-67, and human telomerase reverse transcriptase may be better predictors of outcome after resection of hepatic colorectal metastases. Moreover, tumor response to preoperative chemotherapy may also prove to be a useful predictor of outcome following liver resection for colorectal metastases.

Thymidylate synthase expression in primary colorectal tumours is correlated with its expression in metastases

OBJECTIVE

Thymidylate synthase (TS) is the rate-limiting enzyme in the synthesis of pyrimidine nucleotides and as such a critical target for fluoropyrimidines, which are widely used in the treatment of colorectal cancer (CRC). The purpose of this study was to investigate TS expression in the primary tumours (PTs) and their metastases (M) in advanced CRC.

MATERIAL AND METHODS

TS expression was determined immunohistochemically in paraffin-embedded biopsies of PT-M pairs in 39 CRC patients, as related to the clinical data.

RESULTS

There was no difference in the mean TS index of PTs compared with that of M, 1.25 and 1.14, respectively (p=0.12). TS expression of PTs was above the mean more often than that of M (61.5% and 41.0%, respectively, p=0.035). High TS expression in PTs was significantly related to high expression in M (the Fisher exact test, p=0.001). Using the absolute index values, TS expression in PT and M was significantly correlated (Pearson R=0.501, p=0.001). In 29/39 (74.3%) pairs, PT and M had concordant expression levels (Cohen's kappa 0.508, 95% CI 0.260-0.756, p=0.001; intraclass correlation coefficient (ICC) = 0.679, 95% CI 0.358-0.836, p=0.0001). No significant association was found between TS expression and any of the clinicopathological variables, disease outcome (DFS, DSS) or its response to treatment in univariate or multivariate analysis.

CONCLUSIONS

Albeit usually higher, TS expression in PT was closely correlated with TS expression in M. This suggests that measurement of TS in primary CRC accurately predicts TS expression in subsequent metastases, which may help in selecting those patients most likely to respond to 5-FU-based regimens.

Molecular-based choice of cancer therapy: realities and expectations

Current choice of cancer therapy is usually empirical and relies mainly on the statistical prediction of the treatment success. Molecular research provides some opportunities to personalize antitumor treatment. For example, life-threatening toxic reactions can be avoided by the identification of subjects, who carry susceptible genotypes of drug-metabolizing genes (e.g. TPMT, UGT1A1, MTHFR, DPYD). Tumor sensitivity can be predicted by molecular portraying of targets and other molecules associated with drug response. Tailoring of antiestrogen and trastuzumab therapy based on hormone and HER2 receptor status has already become a classical example of customized medicine. Other predictive markers have been identified both for cytotoxic and for targeted therapies, and include, for example, expression of TS, TP, DPD, OPRT, ERCC1, MGMT, TOP2A, class III beta-tubulin molecules as well as genomic alterations of EGFR, KIT, ABL oncogenes.

Thymidylate synthase expression in colon carcinomas with microsatellite instability

PURPOSE

Colon cancer cells with high-frequency microsatellite instability (MSI-H) display resistance to 5-fluorouracil (5-FU) that can be reversed by restoring DNA mismatch repair (MMR) proficiency. Given that thymidylate synthase (TS) is inhibited by 5-FU, we studied the relationship between MSI and TS expression, and the prognostic effect of these and other markers (i.e., p53 and 17p allelic imbalance).

EXPERIMENTAL DESIGN

Dukes' stage B2 and C colon carcinomas (n = 320) from participants in 5-FU-based adjuvant therapy trials were analyzed for MSI and 17p allelic imbalance. Expression of MMR (hMLH1, hMSH2), TS, and p53 proteins were analyzed by immunohistochemistry. Correlations between markers and associations with overall survival were determined.

RESULTS

Of 320 cancers studied, 60 (19%) were MSI-H. TS expression variables were similar in MSI-H and microsatellite stable/low-frequency MSI (MSS/MSI-L) cancers, and unrelated to MMR proteins. MSI-H tumors had lower stage (P = 0.0007), fewer metastatic lymph nodes (P = 0.004), and improved overall survival (P = 0.01). Loss of MMR proteins was also associated with better overall survival (P = 0.006). None of the TS variables were prognostic. Histologic grade (P = 0.0008) and nodal status (P = 0.0002) were associated with overall survival, in contrast to 17p allelic imbalance or p53. Only MSI status or loss of MMR proteins, histologic grade, and tumor stage were independent markers for overall survival.

CONCLUSIONS

MSI-H tumors show earlier stage at presentation and better stage-adjusted survival rates. MSI status and TS expression were unrelated and TS was not prognostic, suggesting that TS levels cannot explain therapeutic resistance to 5-FU reported in MSI-H colon cancers.

Molecular prognostic markers in resectable colorectal liver metastases: A systematic review

BACKGROUND

Determination of prognosis in patients with resectable colorectal liver metastases (CLM) is desirable in order to improve case selection for surgery and tailor adjuvant treatment according to individual recurrence risk. Conventional clinicopathological factors lack the sensitivity to accurately achieve this goal. Consideration of tumour biology and the identification of molecular prognostic markers may allow more accurate risk stratification.

METHOD

This systematic review examines evidence from published manuscripts looking at molecular markers in resectable colorectal liver metastases and their correlation with disease recurrence and survival following hepatectomy.

RESULTS

Studies have yielded promising results in the search for prognostic molecular markers of CLM. Molecular biomarkers from varied aspects of tumour biology have been examined and a number of these, including proliferation indices, telomerase, thymidylate synthase, microvessel density and thrombospondin-1 appear to have prognostic utility in this context. Validation of other markers, notably p53, has been limited by a failure of methodologies to account for their biological complexity.

CONCLUSIONS

A biomarker-based approach may yield significant benefits through informed treatment of resectable metastatic colorectal malignancy. Standardised retrospective analyses are necessary to confirm preliminary findings and identify existing and novel markers for inclusion into prospective studies. Assessment and verification of multiple molecular markers in this manner may allow molecular profiling of metastases and tailoring of therapy according to the biological aggressiveness of individual tumours. The advent of genomic- and proteomic-based technologies will allow the simultaneous analysis of multiple molecular markers and the derivation of disease profiles associated with disease recurrence and poor survival.

The Treatment of Hepatic Metastases in Colorectal Carcinoma

Colorectal carcinoma is the third most common cause of cancer death in the United States, with 135,000 new cases and 55,000 deaths annually. Ultimately, two-thirds (99,000) of all patients with colorectal cancer will develop metastasis to the liver and other organs in their life span, making metastatic colorectal cancer the second leading cause of cancer-related death in North America. The optimal management of these patients has become increasingly complex with the myriad of treatment options that are available. Because the timing of any therapy (surgery, chemotherapy, or others) has become integral to the success of the treatment, a collaborative approach involving multiple specialties is needed for the best patient outcome. Defined clinical and pathologic determinants of outcome have been demonstrated to effect the overall and disease-free survival of patients with metastatic colorectal cancer. Understanding of these determinants remains essential to any treating physician and has lead to significant paradigm shifts in the management of patients with metastatic colorectal cancer.

Hepatic arterial infusion alternating with systemic chemotherapy in patients with non-resectable hepatic metastases from colorectal cancer

BACKGROUND AND AIM

Hepatic arterial infusion (HAI) chemotherapy has a number of limitations, including a low rate of complete response and frequent extrahepatic recurrence, in colorectal cancer patients with non-resectable hepatic metastases.

METHODS

Twenty-nine colorectal cancer patients with non-resectable hepatic metastases were consecutively enrolled for HAI alternating with systemic chemotherapy (HA + SC group). The protocol comprised six cycles of alternating HAI (5-FU + leucovorin for 14 days, and mitomycin C on the first day) and systemic chemotherapy (5-FU + leucovorin). Colorectal cancer patients with two or more hepatic metastases treated using hepatic resection and systemic chemotherapy (HR + SC group) were selected as a comparative group.

RESULTS

Within the HA + SC group, complete response was achieved in eight patients (28%), whereas 13 patients (45%) showed progressive disease. Six of the eight patients with complete response lived for more than 38 months. Extrahepatic recurrences were more frequent in the HR + SC group than the HA + SC group (47 vs 21%, P = 0.024). The two groups did not differ with respect to overall and hepatic progression-free survival (P = 0.947 and 0.444, respectively), displaying median +/- SE values of 38 +/- 7 and 20 +/- 3 months in the HA + SC group, and 39 +/- 9 and 33 +/- 14 months in the HR + SC group, respectively. One patient in each group experienced toxic hepatitis, and sclerosing cholangitis occurred in one patient of the HA + SC group. Other complications were mostly grade 1 or 2.

CONCLUSIONS

HAI alternating with systemic chemotherapy led to a promising response and hepatic progression-free survival, possibly reducing extrahepatic recurrence in colorectal cancer patients with non-resectable liver metastases.

Hepatic arterial infusion versus systemic therapy for hepatic metastases from colorectal cancer: a randomized trial of efficacy, quality of life, and molecular markers (CALGB 9481)

PURPOSE

Hepatic metastases derive most of their blood supply from the hepatic artery; therefore, for patients with hepatic metastases from colorectal cancer, hepatic arterial infusion (HAI) of chemotherapy may improve outcome.

METHODS

In a multi-institutional trial, 135 patients were randomly assigned to receive HAI versus systemic bolus fluorouracil and leucovorin. The primary end point was survival; secondary end points were response, recurrence, toxicity, quality of life, cost, and the influence of molecular markers.

RESULTS

Overall survival was significantly longer for HAI versus systemic treatment (median, 24.4 v 20 months; P = .0034), as were response rates (47% and 24%; P = .012) and time to hepatic progression (THP; 9.8 v 7.3 months; P = .034). Time to extrahepatic progression (7.7 v 14.8 months; P = .029) was significantly shorter in the HAI group. Quality-of-life measurements showed improved physical functioning in the HAI group at the 3- and 6-month follow-up assessments. Toxicity included grade > or = 3 neutropenia (2% and 45%; P < .01), stomatitis (0% and 24%; P < .01), and bilirubin elevation (18.6% and 0; P < .01) in the HAI and systemic treatment groups, respectively. A greater proportion of men versus women receiving HAI experienced biliary toxicity (37% and 15%, respectively; P = .05). For HAI patients with thymidylate synthase levels in tumor less than or > or = 4, the median survival was 24 and 14 months, respectively (P = .17).

CONCLUSION

HAI therapy increased overall survival, response rate, THP, and was associated with better physical functioning compared with systemic therapy. Additional studies need to address the overall benefit and cost of new chemotherapy agents versus HAI alone or the combination of HAI with new agents.

Detection of Thymidylate Synthase Expression in Lymph Node Metastases of Colorectal Cancer Can Improve the Prognostic Information

Purpose

The level of thymidylate synthase (TS) in primary colorectal cancer (CRC) has been reported as a prognostic marker. The purpose of this study was to determine whether TS expression in lymph node metastases of Dukes' C CRC is a prognostic marker.

Patients and Methods

TS expression in the primary tumor and lymph node metastases from 348 patients with Dukes' C CRC was retrospectively assessed using immunohistochemistry and the monoclonal antibody TS 106. The patients had all been enrolled onto our previous study of 862 CRC patients who were included in Nordic trials that randomly assigned the patients to either surgery alone or surgery plus adjuvant chemotherapy.

Results

TS expression in lymph node metastases was a distinct prognostic marker in the entire study group for overall survival (OS; P = .02) and disease-free survival (DFS; P = .04). A low TS expression in the lymph node metastases correlated with a better clinical outcome. In the subgroup of patients treated with surgery alone, the expression of TS in lymph node metastases also had a prognostic value for OS (P = .04) and DFS (P = .03), but this was not the case for the other subgroup who received adjuvant fluorouracil-based chemotherapy (OS, P = .5; DFS, P = .2). The expression of TS in the primary tumor only had a significant prognostic value among patients who were treated with surgery alone (OS, P = .03; DFS, P = .03) and not among the entire patient population.

Conclusion

These data show that TS expression in lymph node metastases is a prognostic marker for patients with Dukes' C CRC.

Drg1 expression in 131 colorectal liver metastases: correlation with clinical variables and patient outcomes

PURPOSE

The differentiation-related gene-1 (Drg1) is a recently identified gene down-regulated in malignancy and a putative suppressor of colorectal cancer metastases. Its expression is associated with improved survival in patients with prostate or breast cancer. Drg1 expression is also associated with resistance to irinotecan therapy in preclinical colorectal cancer models. The clinical evaluation of Drg1 in colorectal cancer has been limited. We performed this study to evaluate the role of Drg1 in a large cohort of patients with metastatic colorectal cancer who were irinotecan naive.

EXPERIMENTAL DESIGN

We examined Drg1 expression by immunohistochemistry in 131 patients with metastatic colorectal cancer enrolled in a clinical trial of adjuvant fluorouracil-based therapy from 1991 to 1995. We correlated expression of Drg1 to numerous clinical and tumor related variables and to patient outcomes, including a subset of patients who recurred and received irinotecan-based therapy.

RESULTS

Drg1 expression was identified in all metastatic tissue samples. There was a trend for unilobar metastases with high Drg1 expression (P = 0.07) and a suggestion of improved 2-year survival (82.4% versus 69.6%, P = 0.148). High Drg1 expression suggested irinotecan resistance (P = 0.07).

CONCLUSIONS

In colorectal cancer, Drg1 expression may be associated with a less aggressive, indolent colorectal cancer. High Drg1 may also be associated with relative resistance to irinotecan. The role of Drg1 in malignancy continues to be defined.

Pharmacogenomics of fluorouracil, irinotecan, and oxaliplatin in hepatic metastases of colorectal cancer: clinical implications

Hepatic metastases occur in about half of patients with colorectal cancer. Since hepatic metastases are often not accessible for surgery, chemotherapy of metastases is important. The most commonly used chemotherapy drugs for hepatic metastases are fluorouracil, irinotecan, and oxaliplatin. Several enzymes are known to be involved in the catabolism and anabolism of these drugs, and the activity of these enzymes varies greatly between individuals. The causes of this variation include genetic polymorphisms, different regulation between normal and cancer tissue, and the influence of chemotherapy on enzyme expression. The varying enzyme activity may have an important effect on the outcome of chemotherapy. Several studies confirm the influence of the activity of thymidylate synthase, thymidine phosphorylase and dihydropyrimidine dehydrogenase on the outcome of fluorouracil therapy for colorectal cancer, with higher enzyme activities predicting lower treatment efficacy. Although fewer studies are available regarding therapy of hepatic metastases, the same relationship between thymidylate synthase activity and outcome of fluorouracil therapy observed for primary colorectal cancer was found. For the other two enzymes, only a few studies are available, but the results indicate similarly that higher enzyme activity seems to be disadvantageous. The enzymes responsible for the activation, metabolism and mechanism of action of irinotecan, namely carboxylesterase 2, cytochrome P450 (CYP) 3A4, uridine diphosphate glucuronosyltransferase isoform 1A1 (UGT1A1), and topoisomerase-I, also exhibit variable interindividual activity. Thus, there may be an association between enzyme activity and response to therapy. For instance, in patients with colorectal cancer, higher enzyme activity of topoisomerase-I seems to be predictive of a better response to irinotecan. CYP3A4 and UGT1A1 activity levels might be predictive of irinotecan toxicity rather than efficacy. The degradation of oxaliplatin is independent of potentially varying enzyme activity, but for this drug, the DNA repair enzyme ERCC1 may influence the survival time after chemotherapy. Taken together, the available data indicate the importance of the different enzyme activities on the outcome of chemotherapy of hepatic metastases in colorectal cancer. More information is needed, especially for the newer drugs irinotecan and oxaliplatin. However, the existing data are very promising in respect to the potential to guide dose and drug selection for more efficient and less toxic chemotherapy of hepatic metastases.

Catalytic Subunit of Human Telomerase Reverse Transcriptase Is an Independent Predictor of Survival in Patients Undergoing Curative Resection of Hepatic Colorectal Metastases: A Multicenter Analysis

Purpose

To determine the role of the catalytic subunit of human telomerase reverse transcriptase (hTERT) in predicting survival after resection of hepatic colorectal metastases (CRM).

Patients and Methods

Two hundred one patients who underwent curative resection of hepatic CRM between 1990 and 2000 were identified from a multicenter database. The CRM were analyzed for hTERT nucleolar expression by standard immunohistochemical techniques. hTERT expression and known clinicopathologic factors of survival were examined.

Results

With a median follow-up of 80 months, 152 patients (75.6%) had died; the 5-year overall survival was 30.7%. On univariate analysis, number of metastases greater than two (P = .0005), extrahepatic disease (P = .0054), disease-free interval less than 12 months (P = .006), carcinoembryonic antigen level greater than 200 ng/mL (P = .0071), and positive hTERT nucleolar staining (P < .0001) were associated with decreased survival. On multivariate analysis, three factors independently predicted survival: number of metastases (relative risk [RR] = 1.74; P = .0011); disease-free interval (RR = 1.70; P = .0035); and positive hTERT nucleolar staining (RR = 2.03; P < .0001). Patients with none or one of these factors had a 5-year survival rate of 48%, whereas those with two or three of these factors had a 5-year survival of 15% (P < .0001).

Conclusion

hTERT nucleolar expression is associated with worse survival after resection of hepatic CRM. hTERT expression in conjunction with number of hepatic metastases and disease-free interval may permit more accurate prediction of survival after resection of hepatic CRM.