Overview of preoperative and postoperative therapy for colorectal cancer: the European and United States perspectives

Transabdominal Ultrasonography for Preoperative Diagnosis of Lymph Node Metastasis in Colon Cancer: A Retrospective Cohort Study

Background/Aim

Although computed tomography (CT) is the standard modality for diagnosing lymph node metastasis (LNM), transabdominal ultrasonography (US) can be useful due to its high spatial resolution and use of Doppler signals to precisely analyse lymph nodes. This study aimed to evaluate the accuracy of US for lymph node assessment, establish US-based diagnostic criteria for LNM, and compare the capability of US with that of CT for the diagnosis of LNM.

Patients and Methods

This retrospective, single-institution, cohort study included patients who underwent radical surgery for clinical stage 0-III colon cancer, between March 2012 and February 2019.

Results

Overall, 34.9% (66/189) of patients had pathological LNM. The optimal US diagnostic criteria were 1) short axis ≥7 mm and short/long ratio ≥0.75 and 2) at least two of the following: the absence of hilar echoes, expansive appearance, or peripheral/mixed vascularity by the colour Doppler and/or contrast-enhanced method. Compared to CT, US showed a higher diagnostic sensitivity (54.5% vs. 43.9%; p=0.296), higher concordance with the number of pathological LNM (correlation coefficient: US, 0.42; CT, 0.27) and pathological N diagnosis (weighted ĸ: US, 0.35; CT, 0.18), and higher sensitivity for advanced LNM, including multiple LNMs (47.4% vs. 18.4%; p=0.014) and N2 stage (27.8% vs. 5.6%; p=0.177).

Conclusion

US has higher sensitivity than CT for diagnosing LNM in colon cancer, along with a more accurate preoperative diagnosis of the N stage. Additionally, US may be more helpful than CT alone for preoperatively deciding the appropriateness of neoadjuvant treatment in colon cancer with advanced LNM.

Chinese guidelines for the diagnosis and comprehensive treatment of colorectal liver metastases (version 2018)

The liver is the most common anatomical site for hematogenous metastases of colorectal cancer, and colorectal liver metastases is one of the most difficult and challenging points in the treatment of colorectal cancer. To improve the diagnosis and comprehensive treatment in China, the Guidelines have been edited and revised several times since 2008, including the overall evaluation, personalized treatment goals and comprehensive treatments, to prevent the occurrence of liver metastases, improve the resection rate of liver metastases and survival. The revised Guideline includes the diagnosis and follow-up, prevention, MDT effect, surgery and local ablative treatment, neoadjuvant and adjuvant therapy, and comprehensive treatment, and with advanced experience, latest results, detailed content, and strong operability.

Optimal diagnostic method using multidetector-row computed tomography for predicting lymph node metastasis in colorectal cancer

BACKGROUND

Prediction of nodal involvement in colorectal cancer is an important aspect of preoperative workup to determine the necessity of preoperative treatment and the adequate extent of lymphadenectomy during surgery. This study aimed to investigate newer multidetector-row computed tomography (MDCT) findings for better predicting lymph node (LN) metastasis in colorectal cancer.

METHODS

Seventy patients were enrolled in this study; all underwent MDCT prior to surgery and upfront curative resection for colorectal cancer. LNs with a short-axis diameter (SAD) ≥ 4 mm were identified on MDCT images, and the following measures were recorded by two radiologists independently: two-dimensional (2D) SAD, 2D long-axis diameter (LAD), 2D ratio of SAD to LAD, 2D CT attenuation value, three-dimensional (3D) SAD, 3D LAD, 3D SAD to LAD ratio, 3D CT attenuation value, LN volume, and presence of extranodal neoplastic spread (ENS), as defined by indistinct nodal margin, irregular capsular enhancement, or infiltration into adjacent structures.

RESULTS

Forty-six patients presented 173 LNs with a SAD ≥ 4 mm, while 24 patients exhibited pathologically confirmed LN metastases. Receiver operating characteristic analysis revealed that 2D LAD was the most sensitive measure for LN metastases with an area under the curve of 0.752 (cut-off value, 7.05 mm). When combined with CT findings indicating ENS, 2D LAD (> or ≤ 7 mm) showed enhanced predictive power for LN metastases (area under the curve, 0.846; p < 0.001).

CONCLUSIONS

LAD in axial MDCT imaging is the most sensitive measure for predicting colorectal LN metastases, especially when MDCT findings of ENS are observed.

Clinical significance of dual-energy CT-derived iodine quantification in the diagnosis of metastatic LN in colorectal cancer

BACKGROUND

The purpose of this study was to evaluate the diagnostic value of dual-energy computed tomography (DECT) in detecting lymph node (LN) metastasis in patients with colorectal cancer.

METHODS

Data from 81 LNs from 28 patients with colorectal adenocarcinoma were retrospectively analyzed. All patients received DECT before surgery without any neoadjuvant therapy. The diagnostic value was assessed using the iodine concentration (IC).

RESULTS

In the pathological findings, 35 (43.2%) LNs from 13 patients were metastatic and 46 (56.8%) LNs from 17 patients were non-metastatic. The mean IC of metastatic LNs in the portal venous phase (PP) was 1.60 mg/ml, which was significantly lower compared with non-metastatic LNs (3.25 mg/ml, p < 0.001). Receiver operating characteristic (ROC) analysis revealed that the IC in PP had the highest ability to discriminate LN metastasis (area under the ROC curve [AUC] 0.932). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of IC in PP (cutoff 2.1 mg/ml) were 87.0%, 88.6%, 85.3%, 90.0%, and 87.9%, respectively. When clinically obvious metastatic LNs in conventional CT findings were excluded, 50 LNs remained (5 metastatic and 45 non-metastatic LNs). In this subgroup analysis, the IC in PP remained the most powerful predictor of metastatic LNs (cutoff: 2.1 mg/ml, AUC 0.933).

CONCLUSIONS

The evaluation of IC in DECT may improve the diagnostic capabilities of discriminating metastatic LNs. This method may be particularly useful when conventional CT findings lead to equivocal results.

The use of molecular markers as a method to predict the response to neoadjuvant therapy for advanced stage rectal adenocarcinoma

AIM

The response to combined neoadjuvant therapy for advanced stage rectal adenocarcinoma is predictive of outcome. In addition to both clinical and pathological features, the expression of a variety of molecules may provide another method of identifying tumour responsiveness to pre-operative therapy. The aim of this study was to evaluate several markers in the apoptotic pathway as well as expression of Cox-2 and vascular endothelial growth factor (VEGF) to determine their ability to predict response to neoadjuvant therapy.

METHOD

In total, 152 patients with advanced rectal adenocarcinoma were treated with neoadjuvant therapy followed by resection. Paraffin-embedded sections obtained before and after therapy were assessed by immunohistochemical staining for Cox-2, VEGF, p53, p21, p27, Bax, BCL-2 and apoptosis protease-activating factor 1 (APAF-1). These stains were correlated with tumour regression grade, complete pathological response and T-downstaging of the surgical specimen. Clinical and pathological data were also collected. Data were analysed using the χ2 and Spearman's correlation tests.

RESULTS

Pathological complete response was seen in 24.5% of patients. Amongst the apoptosis-associated markers, only APAF-1 expression was found to be significantly associated with tumour regression grade (P<0.001), complete pathological response (P<0.031) and T-downstaging (P<0.004). On multivariate analysis, APAF-1 expression was found to be independently associated with good tumour regression grade. In contrast, overexpression of Cox-2 and VEGF in pretreatment biopsies was related to less tumour regression (P<0.003) and less likelihood of T-downstaging (P<0.03).

CONCLUSION

Immunohistochemical evaluation of initial biopsy specimens of rectal cancer with APAF-1, Cox-2 and VEGF may predict tumour response to neoadjuvant therapy in patients with advanced rectal adenocarcinoma. Those with an expected limited response may be considered for other investigational neoadjuvant protocols.

Inhibition of cytosolic chaperonin CCTζ-1 expression depletes proliferation of colorectal carcinoma in vitro

BACKGROUND

It is important to identify the behavior of colorectal cancer (CRC) individually, so more accurate laboratory index is urgently demanded. Chaperonin are key molecules in tumor cell cycle. Our study aims at revealing the expression and correlation of chaperonin containing TCP1 complex 6A (CCTζ-1) in CRC.

METHODS

Fifty-eight patients with CRC admitted from 2005 to 2008 were selected. CCTζ-1 expression in cell, tumor, and non-tumor colorectal tissues was detected by Western blot, and their protein was localized by immunohistochemical stain. After HCT116 cells were transfected with CCTζ-1 siRNA, real-time PCR, and Western blot were used to examine gene expression. Cell multiplication and apoptosis were examined by Cell Counting Kit-8 and Annexin V kit.

RESULTS

CCTζ-1 ptotein expression was detected in 51 of 58 (87.9%) CRC specimens, which was much higher than those in normal mucosa (P < 0.01), and it was correlated with tumor invasion (P < 0.01) and tumor size (P < 0.05). The levels of CCTζ-1 mRNA and protein were inhibited by CCTζ-1 siRNA in HCT116 cells transfected with CCTζ-1 siRNA, which resulted in growth arrest but not apoptosis.

CONCLUSION

CCTζ-1 could be a new prognostic marker for CRC and involve in tumorigenesis. CCTζ-1 inhibition in vivo might therefore become a new therapy for CRC.

Modulated T-complex protein 1 ζ and peptidyl-prolyl cis-trans isomerase B are two novel indicators for evaluating lymph node metastasis in colorectal cancer: Evidence from proteomics and bioinformatics

Lymph node metastasis (LNM) is an important indicator for systematic therapy, which could increase the survival of colorectal cancer (CRC) patients. However, effective clinical evaluation for LNM is still absent to date. In this study, protein expression profiles of CRC tissues were compared between patients with and without LNM. Based on average expression level, 12 proteins were found to be differentially expressed in the CRC tissues with LNM, whose discrimination reliability was confirmed by PCA. With stepwise linear discriminant analysis, T-complex protein 1 ζ subunit and peptidyl-prolyl cis-trans isomerase B (PPIB) were identified as two main contributors for separating CRC tissues with positive LNM from those negative ones in both original-grouped and cross-validated-grouped cases, which was also supported in subsequent linear support vector machine analysis. In addition, the expression alterations of the two proteins were verified by Western blot and immunohistochemistry. Functional studies also confirmed the role of PPIB in migration and invasion of cancer cells. Taken together, the down-regulated T-complex protein 1 ζ subunit and up-regulated PPIB were identified as two promising indicators for the clinical evaluation of LNM in CRC patients.

Radioembolization of colorectal hepatic metastases using yttrium-90 microspheres

BACKGROUND

: The objective of the current study was to determine the safety and efficacy of Yttrium-90 (Y90) microsphere treatment in patients with liver-dominant colorectal metastases.

METHODS

: Seventy-two patients with unresectable hepatic colorectal metastases were treated at a targeted absorbed dose of 120 Gray (Gy). Safety and toxicity were assessed using version 3 of the National Cancer Institute Common Terminology Criteria. Response was assessed by anatomic imaging and positron emission tomography (PET). Survival from the diagnosis of hepatic metastases and first treatment were estimated using the Kaplan-Meier method. Substratification analyses were performed.

RESULTS

: The median dose delivered was 118 Gy. Treatment-related toxicities included fatigue (61%), nausea (21%), and abdominal pain (25%). Grade 3 and 4 bilirubin toxicities were observed in 9 of 72 patients (12.6%). The tumor response rate was 40.3%. The median time to hepatic progression was 15.4 months, and the median response duration was 15 months. The PET response rate was 77%. Overall survival from the first Y90 treatment was 14.5 months. Tumor replacement (< or =25% vs >25%) was associated with significantly greater median survival (18.7 months vs 5.2 months). The presence of extrahepatic disease was associated negatively with overall survival (7.9 months vs 21 months). Overall survival from the date of initial hepatic metastases was 34.6 months. A subset analysis of patients who had an Eastern Cooperative Oncology Group performance status of 0 demonstrated a median survival of 42.8 months and 23.5 months from the time of hepatic metastases and Y90 treatment, respectively.

CONCLUSIONS

: Y90 liver therapy appears to provide sustained disease stabilization with acceptable toxicity. Asymptomatic patients with preserved liver function at the time of Y90 appeared to benefit most from treatment. Cancer 2009. (c) 2009 American Cancer Society.

Correlation of CK-20-positive cells in peripheral venous blood with serum CEA levels in patients with colorectal carcinoma

Tumor cell dissemination appears to be an early event in tumor progression, and tumor cells can be detected in peripheral venous blood at the time of the operation. Although cytokeratin 20 (CK-20) is not specifically expressed by colorectal carcinomas, it represents a widely used marker for the detection of colorectal tumor cells. We used the combination of density centrifugation and CK-20 real-time reverse transcription polymerase chain reaction to detect CK-20-positive cells in the peripheral venous blood of 37 patients with colorectal carcinoma. Detection rates were compared to serum levels of the tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen CA 19-9, and cancer antigen CA 125. The prognostic impact was assessed by the overall survival and by univariate and multivariate analysis. Overall, CK-20-positive cells in peripheral venous blood were detected in 11 of 37 (29.7%) patients. CK-20-positive patients showed a significantly higher mean serum CEA level (90.3 ng/ml) than the 4.1 ng/ml found in the CK-20-negative group (p = 0.03). CEA levels also correlated with CK-20 copy numbers. No significant correlation was observed for CA 19-9 or CA 125. CK-20-negative patients showed a trend toward better survival (p = 0.08). In the univariate analysis, CA 19-9, CEA, tumor size, lymph node status, grading, the presence of distant metastases, and resection status reached significant prognostic levels, whereas the detection of CK-20-positive cells showed only a prognostic trend (p = 0.06). Multivariate analysis failed to identify independent prognostic parameters. Here we report the correlation of CK-20-positive cells in peripheral venous blood with the serum CEA level of patients with colorectal cancer, which may represent a potential marker of the tumor load.

Preoperative hepatic and regional arterial chemotherapy in the prevention of liver metastasis after colorectal cancer surgery

OBJECTIVE

To investigate whether preoperative hepatic and regional arterial chemotherapy is able to prevent liver metastasis and improve overall survival in patients receiving curative colorectal cancer resection.

METHODS

Patients with stage II or stage III colorectal cancer (CRC) were randomly assigned to receive preoperative hepatic and regional arterial chemotherapy (PHRAC group, n = 110) or surgery alone (control group, n = 112). The primary endpoint was disease-free survival, whereas the secondary endpoints included liver metastasis-free survival and overall survival.

RESULTS

There were no significant differences in overall morbidity between PHRAC and Control groups. During the follow-up period (median, 36 months), the median liver metastasis time for patients with stage III CRC was significantly longer in the PHRAC group (16 +/- 3 months vs. 8 +/- 1 months, P = 0.01). In stage III patients, there was also significant difference between the 2 groups with regard to the incidence of liver metastasis (20.6% vs. 28.3%, P = 0.03), 3-year disease-free survival (74.6% vs. 58.1%, P = 0.0096), 3-year overall survival (87.7% vs. 75.7%, P = 0.020), and the median survival time (40.1 +/- 4.6 months vs. 36.3 +/- 3.2 months, P = 0.03). In the PHRAC arm, the risk ratio of recurrence was 0.61 (95% CI, 0.51-0.79, P = 0.0002), of death was 0.51 (95% CI, 0.32-0.67; P = 0.009), and of liver metastasis was 0.73 (95% CI, 0.52-0.86; P = 0.02). In contrast, PHRAC seemed to be no benefit for stage II patients. Toxicities, such as hepatic toxicity and leukocyte decreasing, were mild and could be cured with medicine.

CONCLUSIONS

Preoperative hepatic and regional arterial chemotherapy, in combination with surgical resection, could be able to reduce and delay the occurrence of liver metastasis and therefore improve survival rate in patients with stage III colorectal cancer.

90Y microsphere (TheraSphere) treatment for unresectable colorectal cancer metastases of the liver: response to treatment at targeted doses of 135-150 Gy as measured by [18F]fluorodeoxyglucose positron emission tomography and computed tomographic imaging

PURPOSE

The purpose of this phase II study was to determine the safety and efficacy of TheraSphere treatment (90Y microspheres) in patients with liver-dominant colorectal metastases in whom standard therapies had failed or were judged to be inappropriate.

MATERIALS AND METHODS

Twenty-seven patients with unresectable hepatic colorectal metastases were treated at a targeted absorbed dose of 135-150 Gy. Safety and toxicity were assessed according to the National Cancer Institute's Common Toxicity Criteria, version 3.0. Response was assessed with use of computed tomography (CT) and was correlated with response on [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET). Survival from first treatment was estimated with use of the Kaplan-Meier method.

RESULTS

Tumor response measured by FDG PET imaging exceeded that measured by CT imaging for the first (88% vs 35%) and second (73% vs 36%) treated lobes. Tumor replacement of 25% or less (vs >25%) was associated with a statistically significant increase in median survival (339 days vs 162 days; P = .002). Treatment-related toxicities included mild fatigue (n = 13; 48%), nausea (n = 4; 15%), and vague abdominal pain (n = 5; 19%). There was one case of radiation-induced gastritis from inadvertent deposition of microspheres to the gastrointestinal tract (n = 1; 4%). Three patients (11%) experienced ascites/pleural effusion after treatment with TheraSphere as a consequence of liver failure in advanced-stage metastatic disease. With the exception of these three patients whose sequelae were not considered to be related to treatment, all observed toxicities were transient and resolved without medical intervention.

CONCLUSION

TheraSphere administration appears to provide stabilization of liver disease with minimal toxicity in patients in whom standard systemic chemotherapy regimens have failed.

The diagnostic value of multiplanar reconstruction on MDCT colonography for the preoperative staging of colorectal cancer

The purpose of this study was to determine whether multiplanar reconstruction (MPR) images can improve the accuracy of MDCT-based colorectal cancer preoperative staging by receiver-operating characteristic (ROC) analysis. Fifty-five patients with colorectal cancer underwent contrast-enhanced CT colonography using an 8- or 16-row scanner. Two separate interval reviews of the axial MDCT datasets with/without MPR images (coronal and sagittal) were performed independently by two radiologists blinded to both the colonoscopic and histopathologic results. At each review session, the radiologists were asked to determine the colorectal cancer TNM stage within the context of differentiating < or =T3 from T4, N0 from > or =N1 and M0 from M1 using a five-point confidence scale. The radiologists' performance for staging the colorectal cancer using axial CT datasets with/without MPR images was evaluated using ROC analysis. Sensitivities, specificities and interobserver agreement were assessed. When MPR images were added, significant improvement was achieved by both radiologists for differentiating N0 from > or =N1 in terms of both A(Z) (0.651 to 0.769; 0.573 to 0.713) and specificity (26.7 to 69.2%; 23.1 to 76.9%) (P<0.05). For T staging, ROC analysis failed to show a significant improvement in terms of differentiating < or =T3 from T4 for either radiologist (P>0.05), but a significant improvement in the specificity (70 to 90%; 80 to 92%) was achieved by one radiologist (P<0.05). In terms of the M staging, a significant improvement in the Az (0.844 to 0.996) was observed for the combined interpretation of the axial and MPR images by one radiologist (P<0.05). Furthermore, substantial or almost perfect interobserver agreement was achieved for all TNM stagings for the combined interpretations (kappa=0.641-0.866), whereas only fair to substantial agreement was achieved for the axial images alone (kappa=0.337-0.707). In conclusion, the combined interpretation of the axial and MPR MDCT images significantly improved the local staging of colorectal cancer compared with assessments based on axial images alone.

[Improvements in detection of rectal cancer recurrence by multiplanar reconstruction]

PURPOSE

To evaluate the advantages of multiplanar reconstruction and different axial slice thickness in diagnostic of rectal cancer recurrence after operation and radiotherapy.

METHOD

We included 83 patients after operation and radiotherapy of rectal cancer in this study. All patients got a minimum of three CT-examinations in their follow-up program. A total of 294 CT-scans were evaluated. Each examination was reviewed by two experienced radiologists in respect to recurrence. Each examination was presented in axial reconstruction with a slice sickness of 8, 5, and 1.25 mm and in multiplanar reconstruction. The sensitivity, specificity, positive predictive value and accuracy were calculated.

RESULTS

Multiplanar reconstructions showed better results for the detection of recurrence than axial reconstruction. A reduced slice thickness did not lead to better results in axial reconstruction. Multiplanar reconstruction showed a sensitivity of 0.88, a specificity of 0.98, an accuracy of 0.96 and a positive predictive value of 0,94, for axial reconstruction we calculated: 0.82, 0.97, 0.94 and 0.88, respectively. Sensitivity and accuracy showed a significant increase after the first and second examination.

CONCLUSION

Multiplanar reconstructions allow a significant better detection of rectal cancer recurrence when compared to axial reconstructions. Thinner axial slice thickness shows no diagnostic advantage.

Lokalrezidivdiagnostik des Rektumkarzinoms mittels Kontrastmittelanreicherungsverhalten im Mehrzeilen-Spiral-CT

PURPOSE

The purpose of this study was to evaluate whether the recurrence of rectal cancer could by diagnosed reliably by contrast enhancement.

METHOD

A total of 83 patients were included after surgery and radiotherapy for rectal cancer. All patients received a minimum of three CT-examinations in their follow-up program. The contrast enhancement between the native scan and after admission of 75 ml Iopromid 370 mg/ml was calculated, as was the correlation between muscle enhancement and the enhancement of the suspicious lesion.

RESULTS

The only acceptable results for the diagnosis of recurrence were established by using the difference in the density of the suspicious lesion before and after admission of contrast media. No statistically significant difference was found for any of the enhancement parameters examined.

CONCLUSION

Static contrast enhancement of a suspicious lesion in MD-CT cannot confirm the diagnosis of a recurrence.

Polo-like kinase 1 expression is a prognostic factor in human colon cancer

AIM

To clarify the expression patterns and prognostic implications of the mitotic regulator Polo-like kinase 1 (PLK1) in colon cancer.

METHODS

Expression of PLK1 was investigated by immunohistochemistry (158 cases) and immunoblotting in tissue of colon adenomas and adenocarcinomas. PLK1 expression patterns were correlated with clinicopathological parameters and patient prognosis. In addition, expression of PLK1 was evaluated by immunoblot and PCR in colon carcinoma cell lines, and coexpression of PLK1 with the proliferation marker Ki-67 was investigated.

RESULTS

Weak PLK1 expression was observed in normal colon mucosa and adenomas. In contrast, 66.7% of carcinomas showed strong expression of PLK1. Overexpression of PLK1 correlated positively with Dukes stage (P<0.001), tumor stage (P = 0.001) and nodal status (P<0.05). Additionally, PLK1 expression was a prognostic marker in univariate survival analysis (P<0.01) and had independent prognostic significance (RR = 3.3, P = 0.02) in patients with locoregional disease. Expression of PLK1 mRNA and protein was detected in all cell lines investigated. Coexpression of PLK1 and Ki-67 was observed in the majority of colon cancer cells, but a considerable proportion of cells showed PLK1 positivity without Ki-67 expression.

CONCLUSION

PLK1 is a new prognostic marker for colon carcinoma patients and may be involved in tumorigenesis and progression of colon cancer. Strategies focusing on PLK1 inhibition in vivo might therefore represent a promising new therapeutic approach for this tumor entity.

Adjuvant therapy with edrecolomab versus observation in stage II colon cancer: a multicenter randomized phase III study

BACKGROUND

In a phase III study recruiting patients with stage II colon cancer the effect of adjuvant therapy with edrecolomab, a murine monoclonal antibody to the cell-surface glycoprotein 17-1A, was compared to observation alone.

PATIENTS AND METHODS

From January 1997 until July 2000 a total of 377 patients were postoperatively stratified according to tumor stage (T3 vs. T4) and center, and randomly allocated to either treatment with edrecolomab (cohort A, n = 183) or observation (cohort B, n = 194). Patients in cohort A received a total of 900 mg edrecolomab. The study was terminated prematurely because of discontinuation of drug supply in Germany.

RESULTS

305 patients were eligible for the primary endpoint of overall survival and 282 patients for disease-free survival. After a median follow-up of 42 months overall survival and disease-free survival were not significantly different. Toxicity was mild.

CONCLUSIONS

In the present study, postoperative adjuvant treatment with edrecolomab in patients with resected stage II colon cancer did not improve overall or disease-free survival.

CF101, an agonist to the A3 adenosine receptor, enhances the chemotherapeutic effect of 5-fluorouracil in a colon carcinoma murine model

NF-kappaB and the upstream kinase PKB/Akt are highly expressed in chemoresistance tumor cells and may hamper the apoptotic pathway. CF101, a specific agonist to the A3 adenosine receptor (A3AR), inhibits the development of colon carcinoma growth in cell cultures and xenograft murine models. Because CF101 has been shown to downregulate PKB/Akt and NF-kappaB protein expression level, we presumed that its combination with chemotherapy will enhance the antitumor effect of the cytotoxic drug. In this study, we utilized 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays and a colon carcinoma xenograft model. It has been shown that a combined treatment of CF101 and 5-fluorouracil (5-FU) enhanced the cytotoxic effect of the latter on HCT-116 human colon carcinoma cell proliferation and tumor growth. Downregulation of PKB/Akt, NF-kappaB, and cyclin D1, and upregulation of caspase-3 protein expression level were observed in cells and tumor lesions on treatment with a combination of CF101 and 5-FU. Moreover, in mice treated with the combined therapy, myelotoxicity was prevented as was evidenced by normal white blood cell and neutrophil counts. These results show that CF101 potentiates the cytotoxic effect of 5-FU, thus preventing drug resistance. The myeloprotective effect of CF101 suggests its development as an add-on treatment to 5-FU.

The current clinical value of genomic instability

Clinical Oncologists have largely ignored the debate over genetic instability in human cancers. It is clear that genetic lesions themselves provide valuable information in the treatment of patients with cancer and those genetic lesions can be exploited successfully as therapeutic targets. Whether the mechanisms resulting in the accumulation of genetic lesions can be translated and used clinically remains to be seen.

Converging patterns of colorectal cancer mortality in Europe

Trends in mortality rates from colorectal cancer during the second half of the 20th century were analysed for 21 European countries and grouped in three broad European regions. For each gender, age-standardised (world standard population) mortality rates were computed by the direct method, and joinpoint analysis was used to identify significant changes in rates. A favourable pattern in colorectal cancer mortality for both genders was observed in most European countries from the 1990s onwards. Colorectal cancer mortality rates were still in the upward direction in some Eastern European countries, as well as in some Mediterranean countries. Mortality rates tended to converge at around 20/100000 in men and around 11/100000 in women. This converging pattern is even clearer when colorectal mortality rates are examined in three broad European regions. Similar mortality rates over recent calendar years have been reached by countries where mortality has been decreasing in recent decades and in those countries (mainly Eastern European and Mediterranean countries) which have experienced a recent levelling-off and decrease. If recent trends are maintained, colorectal cancer mortality is likely to decline further in Europe in the current decade.

The consistency of panelists’ appropriateness ratings: do experts produce clinically logical scores for rectal cancer treatment?

OBJECTIVE

To quantify the clinical consistency of expert panelists' ratings of appropriateness of pre-operative and post-operative chemotherapy plus radiation for rectal cancer.

METHODS

A panel of nine physicians (two surgeons, four medical oncologists, three radiation oncologists) rated the appropriateness of providing pre-operative and post-operative treatments for rectal cancer, utilizing a modified-Delphi (RAND/UCLA) approach. Clinical scenarios were paired so that each component of a pair differed by only one clinical feature (e.g. tumor stage). A pair of appropriateness ratings was defined as inconsistent when the clinical scenario that should have had the higher (or at least equal) appropriateness rating was given a lower rating. The rate of inconsistency was analyzed for panelists' ratings of pre- and post-operative chemotherapy plus radiation.

RESULTS

The final panel rating was inconsistent for 1.19% of pre-operative scenario pairs, and 0.77% of post-operative scenario pairs. Using the conventional RAND/UCLA definition of appropriateness, the magnitude of the inconsistency would produce inconsistent appropriateness ratings in 0.43% of pre-operative and 0.11% of post-operative scenario pairs. There was significant variation in the rate of inconsistency among individual panelists' final ratings of both pre-operative (range: 0.43-5.17%, P < 0.001) and post-operative (range: 0.51-2.34%, P < 0.001) scenarios. Panelists' overall average rate of inconsistency improved significantly after the panel meeting and discussion (from 5.62 to 2.25% for pre-operative scenarios, and from 1.47 to 1.24% for post-operative scenarios, both P < 0.05). There was no clear difference between specialty groups. Inconsistency was related to the structure of the rating manual: in the second round there were no inconsistent ratings when scenario pairs occurred on the same page of the manual.

CONCLUSIONS

The RAND/UCLA appropriateness method can produce ratings for cancer treatment that are highly clinically consistent. Modifications to the structure of rating manuals to facilitate direct assessment of consistency at the time of rating may reduce inconsistency further.

Prognostic value of p27, p53, and vascular endothelial growth factor in Dukes A and B colon cancer patients undergoing potentially curative surgery

PURPOSE

Early-stage colon cancer patients (Dukes A or B; pT1-T3 pNO pMO) are excluded from adjuvant chemotherapy following potentially curative surgery because they are expected to have good long-term survival. However, 20 percent to 30 percent of these patients ultimately succumb from recurrent disease. This indicates that the conventional staging procedures may be unable to precisely predict cancer prognosis.

METHODS

In 65 early-stage colon cancers, we investigated by immunohistochemistry the role of molecular markers such as p27, p53, and vascular endothelial growth factor in identifying high-risk patients who may benefit from adjuvant treatments.

RESULTS

No clinicopathologic factor, namely Dukes stage, t parameter, number of resected nodes, and vascular or lymphatic invasion, was found be an independent significant predictor of disease-specific and disease-free survival. In contrast, each molecular marker predicted survival and recurrence rates much better than the conventional Dukes staging system. The best combination of variables for prediction of long-term outcome and recurrence rate included p27, p53, and vascular endothelial growth factor. Interestingly, the greater the number of molecular alterations, the lower the five-year estimated survival function. Nearly all cancer-related deaths were observed among patients whose colon cancers expressed all three molecular alterations. Regardless of Dukes stage, the recurrence rate was found to increase with the increase in the number of molecular alterations. Early-stage colon cancers expressing p27 down-regulation and high p53 and vascular endothelial growth factor immunoreactivity showed a 100 percent actuarial four-year recurrence rate.

CONCLUSIONS

Assessment of molecular alterations may be useful to identify a higher-risk group of early-stage colon cancer patients who may benefit from adjuvant chemotherapy.

Antiangiogenic and antitumoral activity of phenyl-3-(2-chloroethyl)ureas: a class of soft alkylating agents disrupting microtubules that are unaffected by cell adhesion-mediated drug resistance

The development of new anticancer agents with lower toxicity, higher therapeutic index, and weaker tendency to induce resistant phenotypes in tumor cells is a continuous challenge for the scientific community. Toward that end, we showed previously that a new class of soft alkylating agents designed as phenyl-3-(2-chloroethyl)ureas (CEUs) inhibits tumor cell growth in vitro and that their efficiency is not altered by clinically relevant mechanisms of resistance such as overexpression of multidrug resistance proteins, increase in intracellular concentration of glutathione and/or glutathione S-transferase activity, alteration of topoisomerase II, and increased DNA repair. Mechanistic studies have showed recently that the cytotoxic activity of several CEUs was mainly related to the disruption of microtubules. Here, we present results supporting our assumption that 4-tert-butyl-[3-(2-chloroethyl)ureido]phenyl (tBCEU) (and its bioisosteric derivative 4-iodo-[3-(2-chloroethyl)ureido]phenyl (ICEU) are potent antimicrotubule agents both in vitro and in vivo. They covalently bind to beta-tubulin, leading to a microtubule depolymerization phenotype, consequently disrupting the actin cytoskeleton and altering the nuclear morphology. Accordingly, tBCEU and ICEU also inhibited the migration and proliferation of endothelial and tumor cells in vitro in a dose-dependent manner. It is noteworthy that ICEU efficiently blocked angiogenesis and tumor growth in three distinct animal models: (a) the Matrigel plug angiogenesis assay; (b) the CT-26 tumor growth assay in mice; and (c) the chick chorioallantoic membrane tumor assay. In addition, we present evidence that CEU cytotoxicity is unaffected by additional resistance mechanisms impeding tumor response to DNA alkylating agents such as cisplatin, namely the cell adhesion mediated-drug resistance mechanism, which failed to influence the cytocidal activity of CEUs. On the basis of the apparent innocuousness of CEUs, on their ability to circumvent many classical and recently described tumor cell resistance mechanisms, and on their specific biodistribution to organs of the gastrointestinal tract, our results suggest that CEUs represent a promising new class of anticancer agents.

A novel mouse model of rectal cancer established by orthotopic implantation of colon cancer cells

A novel intraluminal colon tumor model was established in mice by intrarectal instillation of colon cancer cells followed by short-term induction of colitis by an irritant agent. Male BALB/c mice were fed a diet containing 3% (w/w) dextran sulfate sodium (DSS) for 7 days to induce colitis, and colon 26 cells (1-2 x 10(6) cells/mouse) were infused intrarectally after the mice had been deprived of food for the last 18 h of DSS treatment. The tumor incidence (%) and size (mean volume +/- SD, mm(3)) at the rectal mucosa were 35% (2 +/- 3), 95% (96 +/- 79), 95% (141 +/- 137) and 94% (325 +/- 270) at 1, 2, 3 and 4 weeks after instillation of tumor cells, respectively. Histopathological analyses revealed that a solid tumor was formed initially at the rectal mucosa at 1 week after instillation, then became invasive into the submucosal and muscular tissues at 3 weeks after implantation. Intrarectal instillation of human colon cancer cells, LS174T (1 x 10(7) cells/mouse), mixed with "Matrigel" (0.5 mg/mouse), an extracellular matrix solution, in SCID mice led to formation of rectal tumors at 4 weeks after instillation, and immunohistochemical analysis revealed that the tumor cells expressed human carcinoembryonic antigen, suggesting that the tumor nodule was derived from the instilled LS174T cells. Oral or intravenous administration of a camptothecin (CPT) derivative, CPT-11, resulted in a significant reduction in tumor incidence and tumor volume in the colon 26-intraluminal implantation system. In conclusion, it was suggested that the present intraluminal colon tumor model is useful for examination of chemotherapeutic agents and also intraluminal factors (dietary compounds, intestinal microflora, etc.) that might function to suppress or enhance the growth of colorectal cancer in situ.

Circadian rhythm of dihydrouracil/uracil ratios in biological fluids: a potential biomarker for dihydropyrimidine dehydrogenase levels

1. In many cancer patients, 5-fluorouracil (5-FUra) treatment is toxic and even causes death. Nevertheless, all patients are subjected to a standard therapy regimen because there is no reliable way to identify beforehand those patients who are predisposed to 5-FUra-induced toxicity. In this study, we identified the dihydrouracil/uracil (UH2/Ura) ratio in plasma or urine as a potential biomarker reflecting the activity of dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme in 5-FUra metabolism. 2. UH2/Ura ratios were measured by high-performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC-MS/MS) in both healthy subjects (n=55) and in patients (n=20) diagnosed with grade I/II gestational trophoblastic tumours. In addition, rats (n=18) were used as an animal model to verify a correlation between UH2/Ura ratios and DPD levels in the liver. 3. A significant circadian rhythm was observed in UH2/Ura ratios in healthy subjects, whereas a disrupted rhythm occurred in cancer patients who were continuously infused with a high dose of 5-FUra. In rats, UH2/Ura ratios, liver DPD levels and PBMC DPD levels showed a definite circadian rhythm. Significant linear correlations with liver DPD levels were demonstrated for plasma UH2/Ura ratios (r=0.883, P<0.01), urine UH2/Ura ratios (r=0.832, P<0.01) and PBMC DPD levels (r=0.859, P<0.01). 4. The UH2/Ura ratio in biological fluid was significantly correlated with liver DPD levels; hence, this ratio could be a potential biomarker to identify patients with a deficiency in DPD.