p53 and Bcl-2 as significant predictors of recurrence and survival in rectal cancer

The role of gut microbiota and probiotics in preventing, treating, and boosting the immune system in colorectal cancer

The gut microbiome plays a significant role in developing colorectal cancer (CRC). The gut microbiome usually acts as a protective barrier against harmful pathogens and infections in the intestine, while also regulating inflammation by affecting the human immune system. The gut microbiota and probiotics play a role not only in intestinal inflammation associated with tumor formation but also in regulating anti-cancer immune response. As a result, they associated with tumor progression and the effectiveness of anti-cancer therapies. Research indicates that gut microbiota and probiotics can be used as biomarkers to predict the impact of immunotherapy and enhance its efficacy in treating CRC by regulating it. This review examines the importance of gut microbiota and probiotics in the development and progression of CRC, as well as their synergistic impact on anti-cancer treatments.

Chitinase 3-Like 2

OBJECTIVES

We aimed to evaluate the expression pattern of chitinase 3-like 2 (CHI3L2) in the tumor core and peritumoral brain zone (PBZ) of newly diagnosed glioblastoma (GBM) in recurrent tumors and its association with patient prognosis.

METHODS

The study was conducted on three sample sets derived from different patient cohorts. Messenger RNA (mRNA) expression of CHI3L2 in the tumor core and PBZ (n = 34) compared with control (n = 20) tissues was studied by quantitative polymerase chain reaction in sample set 1. Sample set 2 included 19 paired, primary-recurrent GBM tissues. Sample set 3 comprised 82 GBM tissues of patients with treatment and follow-up information. Immunohistochemistry (IHC) was performed on all three sample sets.

RESULTS

mRNA expression of CHI3L2 was significantly higher in the tumor core and PBZ compared with control (P < .0001). By IHC, CHI3L2 showed strong cytoplasmic staining in tumor cells. Recurrent tumors had a higher expression of CHI3L2 compared with primary tumors (P = .007). Survival analysis showed CHI3L2 expression was associated with shorter overall survival (P = .034) and progression-free survival (P = .010), which was in line with The Cancer Genome Atlas cohort (P = .043).

CONCLUSIONS

High expression of CHI3L2 in the tumor core and PBZ, as well as its association with tumor recurrence and poor patient prognosis, suggests it might be contributing to tumor spread and recurrence.

Radioresistance and genomic alterations in head and neck squamous cell cancer: Sub-analysis of the ProfiLER protocol

BACKGROUND

Genome analysis could provide tools to assess predictive molecular biomarkers of radioresistance.

METHODS

Head and neck squamous cell carcinoma patients included in ProfiLER study and who underwent a curative radiotherapy were screened. Univariate and Cox multivariate analyses were performed to explore the relationships between molecular abnormalities, infield relapse and complete tumor response after radiation.

RESULTS

One hundred and forty-three patients were analyzed. PIK3CA mutation and genomic instability of MAP kinases pathway were found to be prognostic factors of loco-regional relapse in multivariate analysis with respectively HR 0.33, 95% CI 0.13-0.83, p = 0.005 and HR 0.61, 95% CI 0.38-0.96, p = 0.025. Instability of apoptosis pathway was found to be a prognostic factor of complete response after radiotherapy with HR 0.24, 95% CI 0.07-0.88, p = 0.04.

CONCLUSION

This sub analysis suggests that PIK3CA mutation, variation of copy number of MAP kinases and apoptosis pathways play a significant role in the radioresistance phenomenon.

Intrinsic and extrinsic pathways of apoptosis: Role in cancer development and prognosis

Apoptosis, also named programmed cell death, is a fundament process required for morphogenetic homeostasis during early development and in pathophysiological conditions. It is come into existence in 1972 by work of Kerr, Wyllie and Currie and later on investigated during the research on development of the C. elegans. Trigger by several stimuli, apoptosis is necessary during the embryonic development and aging as homeostatic mechanism to control the cell population and also play a key role as defense mechanism against the immune responses and elimination of damaged cells. Cancer, a genetic disease, is a growing burden on the health and economy of both developing and developed countries. Every year there is tremendously increasing in the number of new cancer cases and mortality rate. Although, there is a significant improvement have been made in biotechnological and bioinformatic fields however, the therapeutic advantages and cancer etiology is still under explored. Several studies determined the deregulation of different apoptotic components during the cancer development and progression. Apoptosis relies on activation of distinct signaling pathways that are often deregulated in cancer. Thus, exploring the single or more than one apoptotic component underlying their expression in carcinogenesis could help to track the disease progression. Current book chapter will provide the several evidences supporting the use of different apoptotic components as prognosis and prediction markers in various human cancer types.

Joint modelling of colorectal cancer recurrence and death after resection using multi-state model with cured fraction

Curing of colorectal cancer (CRC) occurs at the time of resection but it is not immediately observable. If the cancer is not completely eliminated, the patient will not be cured of cancer and will experience recurrence as the tumor has regrown to a detectable size. The main propose of the present study was to assess the effects of different covariates on the probability of being cured as well as the time-to-recurrence, and time-to-death in CRC patients by using multi-state cure model. The information of 283 patients with CRC, who underwent resection, from 2000 to 2015 in Imam Khomeini Hospital of Hamadan, Iran, were analyzed. The results of multi-state cure model reveal that females and who experience metastasis were more likely to be apparently cured. It has been shown that sex has a significant effect on the time-to-recurrence given patient was in the not cured group. The survival time of patients of the not cured group was affected by the stage of disease. However, the survival of the apparently cured patients were affected by age at diagnosis and metastasis status. The multi-state cure model provided a flexible framework to study the effects of prognostic factors simultaneously on the transition between different states and the probability of being apparently cured of CRC.

Microbial markers in colorectal cancer detection and/or prognosis

Colorectal cancer (CRC) is the second leading cause of cancer worldwide. CRC is still associated with a poor prognosis among patients with advanced disease. On the contrary, due to its slow progression from detectable precancerous lesions, the prognosis for patients with early stages of CRC is encouraging. While most robust methods are invasive and costly, actual patient-friendly screening methods for CRC suffer of lack of sensitivity and specificity. Therefore, the development of sensitive, non-invasive and cost-effective methods for CRC detection and prognosis are necessary for increasing the chances of a cure. Beyond its beneficial functions for the host, increasing evidence suggests that the intestinal microbiota is a key factor associated with carcinogenesis. Many clinical studies have reported a disruption in the gut microbiota balance and an alteration in the faecal metabolome of CRC patients, suggesting the potential use of a microbial-based test as a non-invasive diagnostic and/or prognostic tool for CRC screening. This review aims to discuss the microbial signatures associated with CRC known to date, including dysbiosis and faecal metabolome alterations, and the potential use of microbial variation markers for non-invasive early diagnosis and/or prognostic assessment of CRC and advanced adenomas. We will finally discuss the possible use of these markers as predicators for treatment response and their limitations.

Histogram analysis of ADC in rectal cancer: associations with different histopathological findings including expression of EGFR, Hif1-alpha, VEGF, p53, PD1, and KI 67. A preliminary study

Functional imaging modalities like Diffusion-weighted imaging are increasingly used to predict tumor behavior like cellularity and vascularity in different tumors. Histogram analysis is an emergent imaging analysis, in which every voxel is used to obtain a histogram and therefore statistically information about tumors can be provided. The purpose of this study was to elucidate possible associations between ADC histogram parameters and several immunhistochemical features in rectal cancer. Overall, 11 patients with histologically proven rectal cancer were included into the study. There were 2 (18.18%) females and 9 males with a mean age of 67.1 years. KI 67-index, expression of p53, EGFR, VEGF, and Hif1-alpha were semiautomatically estimated. The tumors were divided into PD1-positive and PD1-negative lesions. ADC histogram analysis was performed as a whole lesion measurement using an in-house matlab application. Spearman's correlation analysis revealed a strong correlation between EGFR expression and ADCmax (p=0.72, P=0.02). None of the vascular parameters (VEGF, Hif1-alpha) correlated with ADC parameters. Kurtosis and skewness correlated inversely with p53 expression (p=-0.64, P=0.03 and p=-0.81, P=0.002, respectively). ADCmedian and ADCmode correlated with Ki67 (p=-0.62, P=0.04 and p=-0.65, P=0.03, respectively). PD1-positive tumors showed statistically significant lower ADCmax values in comparison to PD1-negative tumors, 1.93 ± 0.36 vs 2.32 ± 0.47×10^-3mm²/s, p=0.04. Several associations were identified between histogram parameter derived from ADC maps and EGFR, KI 67 and p53 expression in rectal cancer. Furthermore, ADCmax was different between PD1 positive and PD1 negative tumors indicating an important role of ADC parameters for possible future treatment prediction.

Disruptive environmental chemicals and cellular mechanisms that confer resistance to cell death

Cell death is a process of dying within biological cells that are ceasing to function. This process is essential in regulating organism development, tissue homeostasis, and to eliminate cells in the body that are irreparably damaged. In general, dysfunction in normal cellular death is tightly linked to cancer progression. Specifically, the up-regulation of pro-survival factors, including oncogenic factors and antiapoptotic signaling pathways, and the down-regulation of pro-apoptotic factors, including tumor suppressive factors, confers resistance to cell death in tumor cells, which supports the emergence of a fully immortalized cellular phenotype. This review considers the potential relevance of ubiquitous environmental chemical exposures that have been shown to disrupt key pathways and mechanisms associated with this sort of dysfunction. Specifically, bisphenol A, chlorothalonil, dibutyl phthalate, dichlorvos, lindane, linuron, methoxychlor and oxyfluorfen are discussed as prototypical chemical disruptors; as their effects relate to resistance to cell death, as constituents within environmental mixtures and as potential contributors to environmental carcinogenesis.

Immunohistochemical detection of p53 expression in patients with preoperative chemoradiation for rectal cancer: association with prognosis

PURPOSE

The expression of p53 in patients with rectal cancer who underwent preoperative chemoradiation and and its potential prognostic significance were evaluated.

MATERIALS AND METHODS

p53 expression was examined using immunohistochemistry in pathologic specimens from 210 rectal cancer patients with preoperative chemoradiotherapy and radical surgery. All patients were classified into two groups according to the p53 expression: low p53 (<50% nuclear staining) and high p53 (≥50%) groups.

RESULTS

p53 expression was significantly associated with tumor location from the anal verge (p=0.036). In univariate analysis, p53 expression was not associated with disease-free survival (p=0.118) or local recurrence-free survival (p=0.089). Multivariate analysis showed that tumor distance from the anal verge (p=0.006), ypN category (p=0.011), and perineural invasion (p=0.048) were independent predictors of disease-free survival; tumor distance from the anal verge was the only independent predictor of local recurrence-free survival. When the p53 groups were subdivided according to ypTNM category, disease-free survival differed significantly in patients with ypN+ disease (p=0.027) only.

CONCLUSION

Expression of p53 in pathologic specimens as measured by immunohistochemical methods may have a significant prognostic impact on survival in patients with ypN+ rectal cancer with preoperative chemoradiotherapy. However, it was not an independent predictor of recurrence or survival.

Predictive markers of response to neoadjuvant therapy in rectal cancer

BACKGROUND

Neoadjuvant therapy followed by radical surgery is the standard treatment in locally advanced rectal cancer. It is important to predict the response because the treatment has side effects and is costly. The aim of this study was to establish the relationship among clinical, pathologic, and molecular biomarkers and the response to neoadjuvant therapy.

METHOD

A total of 130 patients with locally advanced mid and low rectal cancer who underwent long-course radiotherapy with 5-FU based chemotherapy followed by radical surgical resection were included in the study. Clinical and pathologic data were collected. Paraffin-embedded sections obtained in diagnostic biopsies were assessed by immunohistochemical staining for molecular markers and classified using a semiquantitative method. Results were related with T-downstaging and tumor regression grade using Mandard scoring system on surgical specimens.

RESULTS

Pathologic complete response was found in 19 patients (14.6%), while in another 18 (13.8%) only minor residual disease was seen in the rectal wall. T-downstaging was observed in 63 (48.5%). The average of lymph node retrieval in the surgical specimens was 9.4. Regarding predictive markers of response, there was significant correlation between the expression of B-cell lymphoma 2 (P = 0.005), β-catenin (P = 0.03), vascular endothelial growth factor (P = 0.048) and apoptotic protease activating factor 1 (P = 0.03), tumor differentiation grade (P < 0.001), and response in the univariate analysis. T-downstaging was associated with vascular endothelial growth factor expression (P = 0.03) and tumor differentiation grade (P < 0.001). Significant parameters found in the multivariate analysis were tumor differentiation grade and Bcl-2 expression.

CONCLUSIONS

Pathologic and molecular biomarkers in the diagnostic biopsies may help us predict tumor response to chemoradiation in rectal cancer patients.

Magnetic poly(glycidyl methacrylate) microspheres for protein capture

The efficient isolation and concentration of protein antigens from complex biological samples is a critical step in several analytical methods, such as mass spectrometry, flow cytometry and immunochemistry. These techniques take advantage of magnetic microspheres as immunosorbents. The focus of this study was on the development of new superparamagnetic polymer microspheres for the specific isolation of the tumor suppressor protein p53. Monodisperse macroporous poly(glycidyl methacrylate) (PGMA) microspheres measuring approximately 5 μm and containing carboxyl groups were prepared by multistep swelling polymerization of glycidyl methacrylate (GMA), 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA) and ethylene dimethylacrylate (EDMA) as a crosslinker in the presence of cyclohexyl acetate as a porogen. To render the microspheres magnetic, iron oxide was precipitated within their pores; the Fe content in the particles received ∼18 wt%. Nonspecific interactions between the magnetic particles and biological media were minimized by coating the microspheres with poly(ethylene glycol) (PEG) terminated by carboxyl groups. The carboxyl groups of the magnetic PGMA microspheres were conjugated with primary amino groups of mouse monoclonal DO-1 antibody using conventional carbodiimide chemistry. The efficiency of protein p53 capture and the degree of nonspecific adsorption on neat and PEG-coated magnetic microspheres were determined by western blot analysis.

The prognostic value of the apoptosis pathway in colorectal cancer: a review of the literature on biomarkers identified by immunohistochemistry

Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients. Evasion of apoptosis, a characteristic feature of tumorigenesis, is known to correlate with patient outcome. We reviewed the literature on immunohistochemistry-based studies between 1998 and 2011 describing biomarkers in this pathway in CRC and identified 26 markers. Most frequently described were p53, Bcl-2, survivin, and the Fas and TRAILR1 receptors and their ligands. None of the studies reviewed provided sufficient support for implementing a single marker into current clinical practice. This is likely due to the complex biology of this pathway. We suggest focusing on the combination of key markers within the apoptosis pathway that together represent an ‘apoptotic tumor profile’, which better reflects the status of this pathway in a tumor.

Locally advanced rectal cancer: from molecular profiling to clinical practice. A literature review: Part 2

Colorectal cancer is the third most common cause of cancer deaths worldwide. The management of rectal cancer has undergone, and continues to undergo, significant evolutions. In the last two decades, new multimodality strategies have been developed. The ability to predict tumor response before treatment could significantly impact the selection of patients for preoperative combined-modality therapy, as well as potentially modify postoperative treatment plans. The present review analyzes the new molecular targets that could be involved in predicting response and prognosis.

Apoptosis signaling proteins as prognostic biomarkers in colorectal cancer: a review

Colorectal cancer is a leading cause of cancer related mortality in the Western world. In recent years, combination 5-fluorouracil based adjuvant chemotherapy as first line treatment of this disease has led to improved disease free and overall survival. However drug resistance, both innate and acquired, remains an obstacle in the effective treatment of this disease. Apoptotic pathways are frequently altered in both tumor progression and drug resistance; therefore proteins associated with this pathway may have potential as prognostic biomarkers for this disease. Identification of clinical biomarkers that are able to identify patients who are more likely to respond to specific chemotherapy will lead to more personalized, effective, and less toxic therapy. This review focuses on the current status of apoptosis related proteins as biomarkers for colorectal cancer and discusses the possible application of systems approaches in this context.

Node-Negative Colorectal Cancer at High Risk of Distant Metastasis Identified by Combined Analysis of Lymph Node Status, Vascular Invasion, and Raf-1 Kinase Inhibitor Protein Expression

Purpose: To identify independent clinicopathologic factors and protein markers leading to the identification of colorectal cancer (CRC) patients with mismatch repair proficiency at risk of developing metastasis and, consequently, more likely to benefit from combined modality therapy.

Experimental Design: Immunohistochemistry for 22 tumor markers was done using a tissue microarray. A subset of 387 CRC patients with complete clinicopathologic data and TNM stage was analyzed. Univariate and multivariate analyses were done to identify independent predictive markers of metastasis. The results were validated on 810 CRC patients.

Results: In univariate analysis, T stage (P &lt; 0.001), N stage (P &lt; 0.001), tumor grade (P = 0.005), vascular invasion (P &lt; 0.001), tumor budding (P &lt; 0.001), positive expression of β-catenin (P = 0.015), overexpression of RHAMM (P = 0.008), negative expression of Raf-1 kinase inhibitor protein (RKIP; P = 0.001), and absence of intraepithelial lymphocytes (P = 0.017) were significantly associated with the presence of distant metastasis. In multivariate analysis, higher N stage (P &lt; 0.001), presence of vascular invasion (P = 0.009), and RKIP loss (P = 0.003) independently predicted distant metastatic disease. A subgroup of node-negative patients was identified as high risk for distant metastasis and showed a similar probability of metastatic risk and nearly identical survival times as node-positive patients with absence of vascular invasion and positive RKIP expression (metastatic risk, 24% and 22%; median survival time, 45.0 and 47.0 months, respectively).

Conclusion: The combined analysis of N stage, vascular invasion, and RKIP expression is highly predictive of distant metastasis in patients with mismatch repair–proficient CRC. Additionally, a subgroup of more aggressive N0 tumors can be identified by evaluating vascular invasion and RKIP expression.

Value of staining intensity in the interpretation of immunohistochemistry for tumor markers in colorectal cancer

The purpose of this study was to determine whether staining intensity in conjunction with the percentage of positive tumor cells should be used as an indicator of protein expression detected by immunohistochemistry. A tissue microarray of 1,197 colorectal cancers was immunostained for p53, Her2/neu, epidermal growth factor receptor (EGFR), adenomatosis polyposis coli (APC), and beta-catenin. Immunoreactivity was described by the percentage of positive tumor cells (percent positivity) and by the staining intensity (weak, moderate, strong). The interobserver reproducibility of both was evaluated by two pathologists. The association of T stage, N stage, tumor grade, vascular invasion, and survival with percent positivity, staining intensity, and the combination of both was assessed. In univariate analysis, protein expression assessed by percent positivity resulted in 11 significant associations between the proteins and clinico-pathological features. Eight of these 11 were also demonstrated using only the degree of staining intensity. However, more than half of the associations identified by percent positivity alone were lost when staining intensity was also analyzed in combination with the percentage of positive tumor cells. A scoring method based on percent positivity, rather than on staining intensity, for p53, Her2/neu, EGFR, APC, and beta-catenin is reproducible and appears to be sufficient for establishing associations of the selected tumor markers with most clinico-pathological features.

Recurrence and survival predictive value of phenotypic expression of Bcl-2 varies with tumor stage of colorectal adenocarcinoma

Although decreased or lack of expression of Bcl-2 has been correlated with advanced tumor stage and shortened patient survival in colorectal cancer (CRC), its value in predicting the recurrence has not been well explored. Therefore, we assessed the usefulness of phenotypic expression of Bcl-2 in non-Hispanic Caucasian patients with CRCs in identifying risk of recurrence. Archival tissues of 92 Stage II and 66 Stage III primary CRCs were evaluated for immunohistochemical expression of Bcl-2. None of these patients received either pre- or post-surgical adjuvant therapies. Kaplan-Meier and Cox proportional hazards methods were used to estimate the rates of recurrence and survival according to Bcl-2 expression. Decreased expression of Bcl-2 was associated with an increased rate of recurrence in patients with Stage II CRCs (5-year log-rank test P=0.0015; Hazard Ratio (HR)=3.90, 95%C.I.:1.55-9.77) but not with Stage III CRCs (5-year log-rank test P=0.6058; HR=1.07, 95%C.I.:0.47-2.45) after adjusting for other demographic and clinicopathological features. Furthermore, decreased expression of Bcl-2 was an indicator of short survival in patients with Stage II CRCs but not with Stage III CRCs. Thus, decreased or lack of Bcl-2 expression in primary CRCs may serve as a molecular biomarker of high risk of recurrence for Caucasian patients with Stage II CRCs. These findings might be useful in identifying biologically aggressive phenotypes of Stage II CRCs, and may aid the oncologist in designing maximally appropriate therapeutic regimens.

Selecting immunohistochemical cut-off scores for novel biomarkers of progression and survival in colorectal cancer

BACKGROUND

Cut-off scores for determining positivity of biomarkers detected by immunohistochemistry are often set arbitrarily and vary between reports.

AIMS

To evaluate the performance of receiver operating characteristic (ROC) curve analysis in determining clinically important cut-off scores for a novel tumour marker, the receptor for hyaluronic acid mediated motility (RHAMM), and show the reproducibility of the selected cut-off scores in 1197 mismatch-repair (MMR) proficient colorectal cancers (CRC).

METHODS

Immunohistochemistry for RHAMM was performed using a tissue microarray of 1197 MMR-proficient CRC. Immunoreactivity was scored using a semi-quantitative scoring method by evaluating the percentage of positive tumour cells. ROC curve analysis was performed for T stage, N stage, tumour grade, vascular invasion and survival. The score with the shortest distance from the curve to the point with both maximum sensitivity and specificity, i.e. the point (0.0, 1.0), was selected as the cut-off score leading to the greatest number of tumours correctly classified as having or not having the clinical outcome. In order to determine the reliability of the selected cut-off scores, 100 bootstrapped replications were performed to resample the data.

RESULTS

The cut-off score for T stage, N stage, tumour grade and vascular invasion was 100% and that for survival 90%. The most frequently selected cut-off score from the 100 resamples was also 100% for T stage, N stage, tumour grade, and vascular invasion and 90% for survival.

CONCLUSIONS

ROC curve analysis can be used as an alternative method in the selection and validation of cut-off scores for determining the clinically relevant threshold for immunohistochemical tumour positivity.

Bcl-2 expression in rectal cancer

BACKGROUD: Proteins involved in apoptosis process seem to play an important role in colorectal carcinogenesis AIM: To determine the prevalence of bcl-2 protein immunohistochemical expression and its relation with clinical and histopathological variables of rectal adenocarcinoma. PATIENTS AND METHODS: One hundred and thirty-two patients operated at "Hospital de Clínicas de Porto Alegre", Porto Alegre, RS, Brazil, between 1988 and 1999 were studied through immunohistochemical reaction using a monoclonal antibody anti-bcl-2 on formalin-fixed, paraffin-embedded tissue samples RESULTS: The prevalence of bcl-2 protein was 29.5%. There was a significant increased number of positive bcl-2 cases among women as compared to men. There was no significant association between bcl-2 and age, tumour site, histological grade, mucin production, depth of invasion, lymphatic involvement, distant metastasis or stage, despite a trend showing decreased immunoreactivity to bcl-2 among poorly and moderately differentiated tumours, as well as disseminated disease CONCLUSIONS: Analysis of bcl-2 protein expression in tumour tissues, as well as other oncoproteins, may have a role in predict therapeutic response and prognosis of colorectal cancer. However, the potential use of bcl-2 protein assessment in the clinical set for management of rectal cancer remains to be determined.

Does Biomolecular Characterization of Stage II/III Colorectal Cancer Have Any Prognostic Value?

As new improvements in the treatment of colorectal cancer have become available, it has become important to understand the benefits of new therapies or the deleterious effects stemming from the increased risk of toxicity. In particular, a more rational approach to adjuvant chemotherapy for patients with stage II/III disease should be defined by understanding which patients have a higher recurrence risk. Many studies have investigated several molecular markers, but none has been definitively associated with patient outcome. We present a review of studies that have evaluated the immunohistochemical correlation between expression of some biomarkers, such as thymidylate synthase, p53, Ki-67, Bcl-2, and microsatellite instability status expressed by Mut-L homologue 1 and Mut-S homologue 2 proteins, and the prognosis of patients with stage II/III colorectal cancer. We have evaluated studies in which > or = 100 patients were involved in an effort to ensure a representative study group. The only biomarker likely to have a prognostic value is microsatellite instability status, which correlated with a better prognosis.

Outcome after curative resection for locally recurrent rectal cancer

PURPOSE

Few biologic markers have been studied as prognostic factors in recurrent rectal carcinoma patients. We sought to determine the influence of clinical, pathologic, and biologic (p53, bcl-2, and ki-67) variables on survival after curative resection of locally recurrent rectal cancer.

METHODS

Retrospective review of patients with locally recurrent rectal cancer who received surgery with curative intent.

RESULTS

From 1988 to 1998, 134 patients with locally recurrent rectal cancer underwent operative exploration. Curative resection was performed in 85 patients. Median follow-up was 43 (range, 1.3-149) months. On multivariate analysis, negative predictors of overall survival included an elevated carcinoembryonic antigen level (P=0.02; hazard ratio 2.41; 95 percent confidence interval, 1.19-4.89) and an R1 resection margin (P = 0.01; hazard ratio, 2.81; 95 percent confidence interval, 1.27-6.21). In 26 patients for whom biologic variables were available, p53, bcl-2, and ki-67 did not significantly impact disease-specific survival or overall survival. Five-year disease-specific survival, overall survival, and pelvic control rates were 46, 36, and 51 percent respectively. Of the 50 patients who relapsed, time to second local recurrence was longer than time to development of metastasis (median, 16.5 vs. 9 months). Median survival for patients with metastatic recurrence was 26.l vs. 41.5 months for those with a subsequent local recurrence alone.

CONCLUSIONS

Approximately two-thirds of patients with locally recurrent rectal cancer can be resected for cure. Preoperative carcinoembryonic antigen and an R0 resection margin were the only significant predictors of overall survival. p53, bcl-2, and ki-67 did not impact survival outcomes.

Modelling intervention effects after cancer relapses

This article addresses the problem of incorporating information regarding the effects of treatments or interventions into models for repeated cancer relapses. In contrast to many existing models, our approach permits the impact of interventions to differ after each relapse. We adopt the general model for recurrent events proposed by Peña and Hollander, in which the effect of interventions is represented by an effective age process acting on the baseline hazard rate function. To accommodate the situation of cancer relapse, we propose an effective age function that encodes three possible therapeutic responses: complete remission, partial remission, and null response. The proposed model also incorporates the effect of covariates, the impact of previous relapses, and heterogeneity among individuals. We use our model to analyse the times to relapse for 63 patients with a particular subtype of indolent lymphoma and compare the results to those obtained using existing methods.

Analysis of the correlation between p53 and bcl-2 expression with staging and prognosis of the colorectal adenocarcinoma

PURPOSE

To analyze the correlation between p53 and bcl-2 expression and colorectal adenocarcinoma staging and prognosis.

METHODS

This was a retrospective series of 125 colorectal adenocarcinoma patients (67 women and 58 men; ages 30-87 years) who underwent surgery with curative intent. The mean follow-up was 28.5 months (range: 2-96 months). TNM staging, tumor recurrence, survival and cancer-related mortality were analyzed. Immunoreactivity was evaluated using DO7 (Dako) for p53 and K492 (Dako) for bcl-2. Tumors with accumulation of staining for cytoplasmic bcl-2 or nuclear p53 in more than 10% of cells were considered positive. Statistical analysis utilized Pearson chi-squared, log-rank and Wilcoxon tests, and Kaplan-Meier survival estimation (significance level: p<0.05).

RESULTS

p53+ was found in 11.8% (14/118), bcl-2+ in 50% (58/116) and associated p53+/bcl-2+ in 6.4% (7/109) of the tumors. There was no significant correlation between expression of these biomarkers and TNM I, II, III and IV staging (p=0.385 for p53; p=0.461 for bcl-2). For tumor recurrence, p53+ was found in 9.5% (2/21), bcl-2+ in 50% (11/22), and associated p53+/bcl-2+ in 5.2% (1/19) of the tumors (p=0.714, p=1.000 and p=0.960, respectively). For survival analysis, p53+: 57 months (45.0-68.0), bcl-2+: 78 (37.0-89.0), and p53+/bcl-2+: 62 (56.0-68.0) (p=0.319). For cancer-related mortality, p53+: 8.3% (3/36), bcl-2+: 47.2% (17/36), and p53+/bcl-2+: 5.9% (2/36) of the patients (p=0.432, p=0.688 and p=0.907, respectively).

CONCLUSION

No correlation was found between tumor expression of p53 and bcl-2 and the TNM staging, recurrence, survival and cancer-related mortality in colorectal adenocarcinoma.

Evidence that the p53 negative / Bcl-2 positive phenotype is an independent indicator of good prognosis in colorectal cancer: a tissue microarray study of 460 patients

BACKGROUND

Advances in our understanding of the molecular biology of colorectal cancer have fuelled the search for novel molecular prognostic markers to complement existing staging systems. Markers assessed in combination may perform better than those considered individually. Using high-throughput tissue microarray technology, we describe the prognostic value of combined p53 / Bcl-2 status in colorectal cancer.

PATIENTS AND METHODS

Tumour samples from 462 patients who underwent elective surgery to resect a primary colorectal cancer between 1994 and 2000 (mean follow-up of 75 months) were assembled in tissue microarray format. Clinico-pathological data including tumour grade, stage, vascular invasion status along with disease specific survival data has been collected prospectively. Immunohistochemical analysis of p53 and Bcl-2 expression was performed using antibodies DO-7 (p53) and 124 (Bcl-2), and results correlated with known clinico-pathological variables and outcomes.

RESULTS

Abnormal nuclear p53 accumulation and Bcl-2 overexpression were detected in 221/445 (49.6%) and199/437 (45.5%) tumours respectively, with a significant inverse correlation between the two markers (p = 0.023). On univariate analysis no correlations were found between either marker and standard clinico-pathological variables, however nuclear p53 expression was associated with a significantly reduced survival (p = 0.024). Combined analysis of the two markers indicated that 112/432 (24.2%) cases displayed a p53(-)/Bcl-2(+) phenotype, this occurring more frequently in earlier stage tumours. Kaplan-Meier analysis revealed a significant survival advantage in these p53(-)/Bcl-2(+) tumours compared with the remaining cases (p = 0.0032). On multivariate analysis using the Cox proportional hazards model, neither p53 expression nor Bcl-2 expression alone were of independent prognostic significance, however the combined p53(-)/Bcl-2(+) phenotype was significantly associated with a good prognosis in this series (HR 0.659, 95%CI 0.452-0.959, p = 0.029).

CONCLUSION

Patient stratification by combined p53 / Bcl-2 phenotype provides stage-independent prognostic information in colorectal cancer. Specifically, that up to a quarter of patients display a good prognosis p53(-)/Bcl-2(+) phenotype. This may indicate a more clinically indolent phenotype and a subset of patients for whom less aggressive adjuvant treatment appropriate.

Immunohistochemical patterns in rectal cancer: application of tissue microarray with prognostic correlations

We utilized the high-throughput tissue microarray method to characterize immunohistochemical expression patterns with correlations to prognosis in rectal cancer. Immunostaining for the markers Ki-67, Bcl-2, p53, EGFR, E-cadherin, beta-catenin, MLH1 and MSH2 was performed in 269 rectal cancers. Expression profiles were correlated to metastasis-free survival. Immunostaining revealed frequent upregulation and/or aberrant staining patterns for several of the markers, but Ki-67, p53, Bcl-2 and EGFR did not show any correlation to prognosis. However, reduced membranous staining for beta-catenin (p = 0.04), lack of cytoplasmic staining for beta-catenin (p = 0.04), reduced membranous staining for E-cadherin (p = 0.02) and lack of cytoplasmic staining for E-cadherin (p = 0.02) correlated with metastatic disease. Multivariate analysis including the factors Dukes' stage and tumor differentiation grade demonstrated increased risk of metastatic disease in tumors with lack of cytoplasmic staining for beta-catenin (HR = 3.1, p = 0.02), reduced membranous staining for beta-catenin (HR = 1.7, p = 0.06) and reduced membranous staining for E-cadherin (HR = 2.1, p = 0.06). Loss of MMR protein expression was confirmed to be a rare event in rectal cancer with loss of MLH1 staining in 3% and MSH2 in 1% of the tumors. The lack of prognostic information contributed by most of these markers suggests that single markers for prognosis may be of limited value in rectal cancer. However, altered expression of beta-catenin and E-cadherin correlated with metastatic disease, and these markers may have prognostic importance in rectal cancer.

Paradoxes of Non-Trivial Gene Networks: How Cancer-Causing Mutations Can Appear to Be Cancer-Protective

Abnormalities of gene structure or expression are commonly found in cancers, where they are used as prognostic markers, predicting the likely severity of disease or chances of response to therapy. An odds ratio (OR) of <1 indicates that a marker's presence is correlated with better outcome. An OR of <1 is also often taken to mean that the gene concerned has a protective effect in the mechanism of cancer. I show that this is not necessarily so. Modeling of the genes involved in the causation of cancer as a network of weak, failure-prone elements shows that "cancer-causing" genes (i.e., genes whose abnormality is causal in driving cancer) can nevertheless appear as "protective" markers in later stage cancers. This implies that results suggesting that well-known oncogenes have an OR of <1 are quite valid, and that predicting a "protective" role from an apparently protective prognostic value is not valid. I identify mdm-2 and bax as candidates for genes with an apparently protective role through this mechanism.

Modeling recurrence in colorectal cancer

OBJECTIVE

To assess the role of recurrence in prognosis of colon cancer, we investigated several methodologic issues, including application of classic survival analysis and Markov model.

STUDY DESIGN AND SETTING

The data were recorded by the Registry of Digestive Tumors of Côte d'Or, France, for 874 patients who had been treated by surgery between 1976 and 1984 and followed for up to 11 years. Survival analyses included the Cox proportional hazards model and its two generalizations that allow recurrence to be taken into account as a time-dependent covariate or as a competing outcome. The Markov model was used to analyze simultaneously recurrence and death.

RESULTS

The competing risks approach is not appropriate because censoring is indisputably informative. The Markov model and the Cox model, with recurrence as a time-dependent covariate, provided similar results, demonstrating the impact of age and gender on recurrence and revealing a reduction in the effect of site and stage on mortality.

CONCLUSION

A Markov multistate model seems to give new insights about the course of digestive cancer progression and into the role of recurrence in this process.

Histopathological study of intraductal papillary mucinous tumor of the pancreas: special reference to the roles of Survivin and p53 in tumorigenesis of IPMT

AIM

In this study, we investigated the tissue expression of Survivin, p53, and Bcl-2 in intraductal papillary-mucinous tumor (IPMT) of the pancreas to identify their roles in tumorigenesis of IPMT, and examined their correlations with tumor cell apoptosis and proliferation in IPMT. The diagnostic values of the expression of Survivin, p53, and Bcl-2 and the apoptotic index (AI) and Ki-67 labeling index (Ki-67 LI) in IPMT were also examined.

METHODS

Twenty-two lesions from 17 patients with IPMT, including 12 benign (IPMT Adenoma) and 10 malignant (IPMT Carcinoma In Situ [CIS] (n = 4) and Invasive IPMT (n = 6) lesions, were immunostained for Survivin, p53, Bcl-2 and Ki-67. The apoptotic cells were detected by the Apop Tag(R) In Situ Oligo Ligation (ISOL) method.

RESULTS

The immunoreactivities for Survivin and p53 significantly increased in the transition from IPMT Adenoma to IPMT CIS (p < 0.05 for both). This transition was associated with a significant decrease in tumor cell apoptosis ( p < 0.001). The expression of Survivin was significantly associated with AI in IPMT ( p < 0.01), but not with Ki-67 LI. The expressions of Survivin and p53, and AI and Ki-67 LI were also significantly different between benign IPMT and malignant IPMT. Bcl-2 was not expressed in IPMT.

CONCLUSION

These results suggest that Survivin and p53 may play important roles in the transition from IPMT Adenoma to IPMT CIS. This transition is accompanied by a significant decrease in tumor cell apoptosis. Survivin is significantly associated with the change in AI in IPMT. The immunohistochemical detection of Survivin and p53 as well as the determination of the AI and Ki-67 LI have useful roles in the diagnosis of IPMT.

Prognostic molecular markers for planning adjuvant chemotherapy trials in Dukes' B colorectal cancer patients: how much evidence is enough?

The benefit of postoperative adjuvant chemotherapy in patients with Dukes' B colorectal cancer is still uncertain and its routine use is not recommended. Prognostic biomarkers may be useful for identifying high-risk patients with resected, node-negative disease, and this stratification may represent an innovative strategy for designing adjuvant chemotherapy trials. Featured prognostic molecular markers can be divided into the following categories: cell proliferation indices (Ki-67, Mib-1, proliferating cell nuclear antigen); oncogenes/tumor suppressor genes [p53, K-ras, Deleted in Colorectal Cancer (DCC), Bcl-2, c-erbB2]; DNA repair (microsatellite instability); markers of angiogenesis (vascular count, vascular endothelial growth factor); markers of invasion/metastasis (plasminogen-related molecules, matrix metalloproteinases); and biochemical markers (thymidylate synthase). Studies that have investigated their prognostic role in Dukes' B colorectal cancer patients are reviewed here. Current data do not provide sufficient evidence for the incorporation of available prognostic biomarkers into clinical practice. However, a biomarker-based approach could be an effective strategy for improving results of postoperative adjuvant treatments in high-risk Dukes' B colorectal cancer patients. Markers of altered DCC function have shown promising prognostic role and sufficient prevalence in retrospective investigations and they deserve further assessment in prospective studies.

Conventional approach x laparoscopic abdominoperineal resection for rectal cancer treatment after neoadjuvant chemoradiation: results of a prospective randomized trial

OBJECTIVE

The aims of this study were to evaluate the safety and efficacy of laparoscopic abdominoperineal resection compared to conventional approach for surgical treatment of patients with distal rectal cancer presenting with incomplete response after chemoradiation.

METHOD

Twenty eight patients with distal rectal adenocarcinoma were randomized to undergo surgical treatment by laparoscopic abdominoperineal resection or conventional approach and evaluated prospectively. Thirteen underwent laparoscopic abdominoperineal resection and 15 conventional approach.

RESULTS

There was no significant difference (p<0,05) between the two studied groups regarding: gender, age, body mass index, patients with previous abdominal surgeries, intra and post operative complications, need for blood transfusion, hospital stay after surgery, length of resected segment and pathological staging. Mean operation time was 228 minutes for the laparoscopic abdominoperineal resection versus 284 minutes for the conventional approach (p=0.04). Mean anesthesia duration was shorter (p=0.03) for laparoscopic abdominoperineal resection when compared to conventional approach : 304 and 362 minutes, respectively. There was no need for conversion to open approach in this series. After a mean follow-up of 47.2 months and with the exclusion of two patients in the conventional abdominoperineal resection who presented with unsuspected synchronic metastasis during surgery, local recurrence was observed in two patients in the conventional group and in none in the laparoscopic group.

CONCLUSIONS

We conclude that laparoscopic abdominoperineal resection is feasible, similar to conventional approach concerning surgery duration, intra operative morbidity, blood requirements and post operative morbidity. Larger number of cases and an extended follow-up are required to adequate evaluation of oncological results for patients undergoing laparoscopic abdominoperineal resection after chemoradiation for radical treatment of distal rectal cancer.

Prognostic value of P53 mutations in rectal carcinoma

The influence of p53 mutations on the response to ionizing radiation and survival was retrospectively evaluated in patients treated with preoperative radiotherapy for rectal carcinoma. From 1989 to 1991, 86 rectal cancer patients treated by preoperative radiotherapy were included in this series. For all patients, endorectal sonography (to define ultrasonography TNM [uTNM]) was performed before treatment; 19 patients were classified as stage 1, 27 as stage 2 and 40 as stage 3. Response to radiotherapy (39 Gy in 13 fractions delivered in 17 days) was assessed by comparing the uT and the T obtained by histologic examination of the resected specimen (TNM classification). A rectal cancer biopsy was performed before treatment and enabled the search for p53 mutations by denaturing gradient gel electrophoresis (DGGE) and sequencing. The status of the p53 gene was correlated with the response to radiotherapy and survival. Forty-nine percent of the tumors presented abnormal DGGE profiles. The prevalence of p53 mutations was significantly higher in patients who did not respond to radiotherapy (63%) than in those who did respond (34%) (p < 0.01). Presence of a p53 mutation was associated with significantly shorter 5-year survival compared to patients without mutations (p < 0.02). In a multivariate analysis, p53 mutation status remained a prognostic factor independent of tumor posttreatment staging (p < 0.05). p53 status is an independent prognostic factor of response to radiotherapy and survival in rectal carcinoma.

Evaluation of the tissue microarray technique for immunohistochemical analysis in rectal cancer

BACKGROUND

Immunohistochemical staining for tumor-associated proteins is widely used for the identification of novel prognostic markers. Recently, a tissue-conserving, high-throughput technique, tissue microarray, has been introduced. This technique uses 0.6-mm tissue core biopsy specimens, 500 to 1000 of which are brought into a new paraffin array block, which can be sectioned up to 100 times.

METHODS

We evaluated the tissue microarray technique for immunohistochemical analysis in 20 rectal cancers. Immunohistochemical staining was performed for the proliferation marker Ki-67 and the tumor suppressor protein p53 in whole tissue sections and in tissue core biopsy specimens.

RESULTS

The whole tissue sections were assessed by counting all cells in 10 high-power fields (x40), which resulted in a mean fraction of Ki-67-expressing tumor cells of 0.81 (range, 0.54-1.0). p53 expression assessed in whole tissue sections showed nuclear staining in 15 (75%) of 20 rectal carcinomas. For the tissue microarray technique, a median of 3 (range, 3-5) 0.6-mm tissue core biopsy specimens were studied from each of the 20 tumor specimens. The tissue microarray method gave a mean Ki-67 expression of 0.85 (range, 0.50-1.0) in tumor cell nuclei and showed p53 protein expression in the same 15 of 20 tumors as in the whole tissue sections.

CONCLUSION

We conclude that the tissue microarray technique for immunohistochemical staining in rectal cancer yields staining of good quality and expression data for Ki-67 and p53 comparable to those obtained with whole tissue staining. The feasibility of tissue microarray thus enables time- and tissue-preserving studies of multiple markers in large tumor series.

An analysis of p53, BAX and vascular endothelial growth factor expression in node-positive rectal cancer. Relationships with tumour recurrence and event-free survival of patients treated with adjuvant chemoradiation

Tumours of patients with node-positive rectal cancer were studied by immunohistochemistry for p53, BAX and vascular endothelial growth factor expressions. Results were correlated to the relapse rate, the pattern of relapse and the event-free survival after radical surgery and adjuvant chemoradiation. After a median follow-up of 60 months, 39 patients remained disease-free and 40 patients relapsed (18 local relapses and 22 distant metastases). The majority of disease-free patients showed p53 negative and vascular endothelial growth factor negative tumours. Local relapses occurred more frequently in patients with p53 overexpressing tumours (P<0.01), while distant metastases were in patients with vascular endothelial growth factor positive tumours (P<0.003). Patients with p53 negative or vascular endothelial growth factor negative tumours showed better event-free survival than patients with p53 positive or vascular endothelial growth factor positive tumours. BAX analysis did not show any association with patients' outcome and it was unrelated to the p53 status. Adjuvant treatment strategies for node-positive rectal cancer may be improved by identifying categories of high-risk patients. In this study, vascular endothelial growth factor and p53 expressions correlated with recurrent disease, pattern of relapse and poor event-free survival.

Prediction of distant metastases after curative surgery for rectal cancer

BACKGROUND

This study was performed to define selection criteria for adjuvant therapy in rectal cancer.

MATERIALS AND METHODS

An immunohistochemical analysis using nine monoclonal antibodies against CEA, CD15s, CD44v6, DCC, E-cadherin, EGF-R, NM23, PAI-1, and P53 was performed on paraffin sections of two matched (age, gender, UICC stage [I-III], year of operation [1982-1991]) groups of patients (n = 2 x 64) with rectal carcinoma curatively treated by surgery alone. The two groups differed only with regard to metachronous distant metastatic spread. In order to exclude the influence of surgery, all patients had to meet the selection criterion "free of locoregional disease." Follow-up was prospective (median 80 months). Conventional staining procedures and immunohistochemical evaluation were used. Tumor grading and lymphatic and extramural venous invasion were also investigated. Analysis was performed with Fisher's exact test and Kaplan-Meier estimates of disease-free survival (log rank). The Cox model was used for multivariate analysis.

RESULTS

In univariate analysis only grading (P < 0.001) and extramural venous invasion (P < 0.001) correlated significantly with metachronous metastases. In multivariate analysis, beside grading (P = 0.010) and extramural venous invasion (P = 0.011), CD15s (P = 0.042) was also of significance. All other immunohistochemical markers failed.

CONCLUSIONS

The histopathological parameters grading and extramural venous invasion appear to be acceptable predictors of metachronous distant spread in curatively resected rectal cancer. In contrast to the immunohistochemical markers, grading seems to better reflect the individual tumor phenotype and its behavior.

Clinical significance of molecular expression profiles of Hürthle cell tumors of the thyroid gland analyzed via tissue microarrays

Hürthle cell tumors are rare thyroid neoplasms for which disease biology is poorly understood and diagnosis of carcinoma can be challenging. The aim of the study was to characterize molecular expression profiles of Hürthle cell tumors and to determine the clinical significance of identified phenotypes. Paraffin-embedded tissue cores of normal thyroid (n = 18), and histopathologically well-defined Hürthle cell adenomas (n = 27), Hürthle cell tumors of unknown malignant behavior (n = 7), and minimally (n = 14) and widely (n = 21) invasive Hürthle cell carcinomas were arrayed in triplicate on tissue microarrays. Expression profiles of p53, mdm-2, p21, Bcl-2, cyclin D1, and Ki-67 were detected by immunohistochemistry and correlated with clinicopathological data and patient outcome using standard statistical methodology. Median follow-up time was 8 years. High Ki-67 proliferative index was evident only in the clinically aggressive widely invasive Hürthle cell carcinomas and was associated with significantly reduced relapse-free (P = 0.001) and disease-specific (P < 0.001) survival. The molecular phenotype of Hürthle cell tumors, independent of histopathological subtype diagnosis, was characterized by p53(-), mdm-2(+), p21(+/-), cyclin D1(-), and Bcl-2(+/-). Normal thyroid tissue demonstrated a p53(-), mdm-2(-), p21(-), cyclin D1(-), and Bcl-2(+) phenotype. The Bcl-2(+) phenotype was associated with improved relapse-free survival (P = 0.04) and disease-specific survival (P = 0.01) in widely invasive carcinomas and the Ki-67(+)/Bcl-2(-) phenotype was associated with the diagnosis of widely invasive Hürthle cell carcinoma (P < 0.001). This study demonstrates that tissue microarray-based profiling allows identification of molecular markers that are associated with patient prognosis. High Ki-67 proliferative index was associated with adverse outcome in Hürthle cell neoplasms. Together with down-regulation of Bcl-2, high Ki-67 proliferative index may be useful for diagnosing widely invasive Hürthle cell carcinomas. Molecular alterations in the p53 pathway play a role in Hürthle cell tumorigenesis, but other unidentified molecular changes seem to be required to induce the malignant phenotype.

Adjuvant therapy for resectable rectal adenocarcinoma

The mainstay of treatment for rectal cancer over the past 100 years has been surgical resection. However, for the majority of rectal cancers treated conventionally by resection alone, locoregional recurrence is the major mode of failure. Over the past several decades, significant progress has been made in developing effective adjuvant regimens. In the United States, postoperative chemoradiation is standard treatment for T3 or node-positive patients. However, preoperative radiation with or without chemotherapy decreases local recurrence, increases sphincter preservation, and may improve survival. The purpose of this article is to review the role of adjuvant therapy in resectable rectal cancers and to update the status of ongoing randomized trials.