Expression profiling of colorectal carcinomas using tissue microarrays: cell cycle regulatory proteins p21, p27, and p53 as immunohistochemical prognostic markers in univariate and multivariate analysis

Increased expression of Ki-67 is a poor prognostic marker for colorectal cancer patients: a meta analysis

Background

The prognostic value of Ki-67 expression in colorectal cancer patients was controversial. Therefore, this meta analysis was conducted to ascertain the prognostic value of Ki-67 expression in colorectal cancer patients.

Methods

The electronic databases, including EMBASE, PubMed, Cochrane Library and Web of Knowledge database, were searched from January 1970 to July 2017. The pooled hazard ratios and 95% confidence intervals were calculated to evaluate the prognostic value of Ki-67 expression for colorectal cancer patients.

Results

Totally 34 eligible studies and 6180 colorectal cancer patients were included in the present meta analysis. The pooled hazard ratios were 1.54(95% CI 1.17–2.02, P = 0.005) for overall survival and 1.43(1.12–1.83, P = 0.008) for disease free survival in univariate analysis. After adjustment of other prognostic factors, the pooled HR was 1.50(95% CI 1.02–2.22, P = 0.03) for overall survival in multivariate analysis.

Conclusion

The present meta analysis demonstrated that high Ki-67 expression is significantly correlated with poor overall survival and disease free survival, indicating that high Ki-67 expression may serve as a valuable predictive method for poor prognosis of colorectal cancer patients.

Angiodrastic Chemokines in Colorectal Cancer: Clinicopathological Correlations

Aim

To study the expression of angiodrastic chemokines in colorectal tumors and correlate findings with clinicopathological parameters and survival.

Methods

The proangiogenic factor VEGF, the angiogenic chemokines CXCL8 and CXCL6, and the angiostatic chemokine CXCL4 were measured by ELISA in tumor and normal tissue of 35 stage II and III patients and correlated with the histopathology markers Ki67, p53, p21, bcl2, EGFR, and MLH1 and 5-year survival. The Wilcoxon and chi-square tests were used for statistical comparisons.

Results

There was a significant increase of CXCL6 (p = 0.005) and VEGF (p = 0.003) in cancerous tissue compared to normal. Patients with lower levels of CXCL8 and CXCL4 lived significantly longer. Patients with loss of EGFR expression had higher levels of CXCL8 while p21 loss was associated with higher levels of CXCL6. Chemokine levels were not correlated with TNM or Dukes classification. Strong expression of p53 was accompanied by decreased survival.

Conclusions

(1) The angiogenic factors CXCL6 and VEGF are increased in colorectal cancer tissue with no association with the clinical stage of the disease or survival. (2) However, increased levels of tissue CXCL8 and CXCL4 are associated with poor survival. (3) Strong expression of p53 is found in patients with poor survival.

Clinical significances of p27 in digestive tract cancers: a comprehensive analysis on immunohistochemistry staining, published literatures, microarray and RNA-seq data

In the present study, we conducted a comprehensive analysis on the clinical roles of p27 protein and p27 gene in digestive tract cancers (DTCs). First, we performed immunohistochemistry staining and found that p27 protein was down-regulated in DTCs. Then we collected 62 publications and calculated the combined hazard ratios (HRs), odds ratios (ORs) and 95% confidence intervals (95% CIs) to clarify the relationships of p27 protein expression with prognoses and clinicopathological parameters. The overall HRs indicated that the down-regulated p27 protein was an independent prognostic biomarker for overall survival (HR: 1.58, 95% CI: 1.38-1.81, P < 0.0001) but not for disease-free survival and cancer-specific survival. The combined ORs indicated that a low expression of p27 protein was positively related to lymph node metastasis (OR: 2.15, 95% CI: 1.57-2.96, P < 0.0001), distant metastasis (OR: 2.02, 95% CI: 1.12-3.63, P = 0.019) and pathology grading (OR: 2.14, 95% CI: 1.75-2.62, P < 0.0001). Additionally, 60 DTCs-related microarray and RNA-seq datasets were obtained to investigate the expression level and clinical value of p27 gene in DTCs patients. We found that the expression level of p27 gene in DTCs was similar to that in normal controls. And no significant associations of p27 gene expression with prognoses and clinicopathological factors were observed. In conclusion, according to our results, it was p27 protein, but not p27 gene, that can function as an effective biomarker to predict the clinical outcome in patients with DTCs. The down-regulation of p27 protein in DTCs may not result from the altered expression of p27 gene.

Thymidylate synthase expression and p21(WAF1)/p53 phenotype of colon cancers identify patients who may benefit from 5-fluorouracil based therapy

Background

Studies on the expression of thymidylate synthase (TS) in colorectal cancers (CRCs) have failed to provide unequivocal prognostic or predictive information. Here, we assessed the prognostic significance of TS expression in Astler-Coller stage B2 and C CRCs defined by a p21^WAF1/p53 immunophenotype in patients subjected to 5-fluorouracil (5FU)-based adjuvant therapy.

Methods

A cohort of 189 CRCs was asssessed for TS, p21^WAF1 and p53 expression on tissue microarrays using immunohistochemistry, and associations with disease-free survival (DFS) and overall survival (OS) of the patients were assessed using univariate and multivariate analyses.

Results

TS expression led to the stratification of patients with colon cancer, but not rectal cancer, with immunophenotypes other than p21^WAF1+/p53- (referred to as P&P) into subgroups characterized by a worse (P&P TS+) and a better (P&P TS-) DFS and OS, in univariate (P = 0.006 and P = 0.005, respectively) and multivariate (P = 0.0004 and P = 0.002, respectively) analyses. The p21^WAF1+/p53- immunophenotype was associated with a favorable prognosis, irrespective of TS expression.

Conclusions

The strong association observed between the P&P TS+ immunophenotype and a worse DFS and OS suggests a predictive significance of TS expression for 5FU-based adjuvant therapy in patients with colon cancers exhibiting the P&P immunophenotype. In addition, our findings suggest that the appropriate target for assessment of TS expression as a prognostic/predictive marker is a subgroup of colon cancers with an immunophenotype other than p21^WAF1+/p53-, and that only in this subgroup high TS expression is associated with an unfavorable DFS and OS. Therefore, we suggest that assessing TS expression in conjunction with p21^WAF1/p53 immunophenotyping of colon cancers may improve the selection of patients suitable for 5FU-based adjuvant chemotherapy.

Microdensitometry of osteopontin as an immunohistochemical prognostic biomarker in colorectal carcinoma tissue microarrays: potential and limitations of the method in 'biomarker pathology'

AIMS

To explore the potential and limitations of 'biomarker pathology' with quantitative immunohistochemistry on tissue microarrays, taking osteopontin and colorectal carcinoma as a model system.

METHODS AND RESULTS

Microdensitometry for quantitative evaluation of osteopontin immunohistochemistry (clone OP3N) on digital microphotographs using the public domain software ImageJ was observed to be straightforward to perform and reliable. However, using colorectal carcinoma cell lines (n = 11) the correlation between densitometric evaluations of Western blots and microdensitometry of immunocytochemistry of slide cultures was only moderate. A virtual resampling method to simulate tissue microarrays showed that, due to heterogeneity of immunostaining, tumours were misclassified in nearly 20% of the arrays, even if four punches were used. With regard to prognosis, microdensitometric evaluation of a tissue microarray made of a clinicopathologically well-characterized series of colorectal carcinomas with long-term follow-up (222 cases evaluable in the tissue microarray, UICC Stages I-III/R0) showed a moderate survival advantage of patients with high osteopontin expression by microdensitometry.

CONCLUSIONS

These results challenge the basic assumption that microdensitometry is a precise technique for the quantification of proteins detected by immunohistochemistry and delineate drawbacks encountered when working with tissue microarrays in clinicopathological studies.

Pretreatment CD133 and cyclooxygenase-2 expression as the predictive markers of the pathological effect of chemoradiotherapy in rectal cancer patients

BACKGROUND

CD133 confers chemoradioresistance properties to cells and has recently been used to identify cancer-initiating cells.

OBJECTIVE

We investigated whether the overexpression of CD133 and cyclooxygenase-2 can be used as predictive markers of tumor response to preoperative chemoradiotherapy in patients with rectal cancer.

SETTING

The study was conducted at the National Defense Medical College Hospital in Japan.

PATIENTS

We recruited 96 patients who underwent a single regimen of preoperative short-term chemoradiotherapy (20 Gy in 5 fractions with 400 mg/day Tegafur/Uracil for 1 week) and radical resection.

DESIGN

This was a retrospective study. We obtained pretreatment biopsy specimens of these patients and immunostained these specimens with antibodies for CD133, cyclooxygenase-2, p53, p27, p21, and epidermal growth factor receptor. The resected primary tumor was evaluated according to 2 different tumor regression grading systems that were based on the degrees of fibrosis and cytological alterations.

RESULTS

Positivity for CD133 or cyclooxygenase-2 expression was associated with chemoradioresistance, which was determined by the degree of fibrosis, in both univariate (P = .02 and P = .0003) and multivariate (P = .03 and P = .001) analyses. Univariate and multivariate analyses of the degree of cytological alterations also revealed a significant association between chemoradioresistance and the expression of CD133 (P = .005 and P = .003) and cyclooxygenase-2 (P = .005 and P = .03), whereas other markers failed to associate.

LIMITATIONS

The information on patients' outcome was not available.

CONCLUSIONS

Our study revealed the independent predictive values of CD133 and cyclooxygenase-2 expressions in histological tumor regression after preoperative chemoradiotherapy.

Expression of p21WAF1 in Astler-Coller stage B2 colorectal cancer is associated with survival benefit from 5FU-based adjuvant chemotherapy

In several, but not all, previous studies, positive p21^WAF1 expression has been suggested as an indicator of a good prognosis in patients with stage III/IV colorectal cancer. However, it is not known whether the same is true for stage B2 patients. The purpose of this study is to assess the influence of p21^WAF1 expression in tumor cells on disease-free survival (DFS) and overall survival (OS) of Astler–Coller stage B2 and C patients with colorectal cancer who underwent 5-fluorouracil-based adjuvant chemotherapy. Nuclear p21^WAF1 was detected by immunohistochemistry in tissue microarrays from 275 colorectal cancers. The expression of p21^WAF1 was associated with DFS (p = 0.025) and OS (p = 0.008) in the subgroup of stage B2 patients that was treated with adjuvant chemotherapy. In multivariate analysis, it remained the only independent prognostic parameter in relation to DFS and OS (p = 0.035 and p = 0.02, respectively). In the subgroup of 72 stage B2 patients with positive p21^WAF1 expression but not in the subgroup of 61 stage B2 patients with negative p21^WAF1 expression, adjuvant chemotherapy was associated with better DFS (85% 5-year survival versus 65% without chemotherapy, p = 0.03) and OS (96% versus 82%, p = 0.014). In the combined stage B2 and C group of patients treated with adjuvant chemotherapy, positive p21^WAF1 expression was also associated with better DFS and OS (p = 0.03, p = 0.002, respectively). Expression of p21^WAF1 in colorectal tumor cells identifies a subgroup of Astler–Coller stage B2 patients who could benefit significantly from 5FU-based chemotherapy and may improve the selection of patients for adjuvant chemotherapy.

A multicenter, phase II study of bortezomib (PS-341) in patients with unresectable or metastatic gastric and gastroesophageal junction adenocarcinoma

PURPOSE

The transcription factor nuclear factor-kB (NFkB) is implicated in gastric cancer carcinogenesis and survival, and its inhibition by proteosome inhibition is associated with preclinical gastric cancer anti-tumor activity. We examined the single agent efficacy of bortezomib, a selective proteasome inhibitor, in gastric adenocarcinoma.

EXPERIMENTAL DESIGN

We performed a phase II trial of bortezomib in patients with advanced gastric adenocarcinoma. Bortezomib 1.3 mg/m(2) was administered on days 1, 4, 8, and 11 every 21 days. The primary endpoint was objective response rate(RR); the null hypothesis was RR <1% versus the alternative ≥15%. One response in the first stage(15 patients) was required before proceeding with an additional 18 patients. If at least 2 or more responses out of 33 were observed, further study with bortezomib was warranted. Correlative studies evaluated pre-treatment tumor expression of NFkB, IkB, p53, p21, and cyclin D1.

RESULTS

We enrolled 16 patients (15 evaluable for response) from four institutions. No patients demonstrated an objective response(95% CI, 0-22%); one patient achieved stable disease. Fourteen out of 16 patients experienced ≥ grade 2 toxicity. The most common toxicity was fatigue in six patients (n = 4 grade 2, n = 2 grade 3). Seven patients experienced neuropathy (n = 5 grade 1, and 1 each grade 2 and 3). Seven (60%) had high cytoplasmic staining for NFkB.

CONCLUSIONS

Single agent bortezomib is inactive in metastatic gastric adenocarcinoma and should not be pursued. Future study of proteasome inhibition in gastric adenocarcinoma should be considered in combination with targeted inhibition of other non-overlapping oncogenic pathways as a potential rational approach.

A cohort study of p27 localization in colon cancer, body mass index, and patient survival

Energy balance and the AKT pathway are important in colorectal cancer development and regulate p27 (cyclin-dependent kinase inhibitor-1B/CDKN1B/KIP1), which plays a role in preventing cell cycle progression. However, little is known on the clinical outcome or prognostic significance of p27 alterations in relation to patient body mass index (BMI). Among 630 colon cancers (stage I-IV) in two prospective cohort studies, we detected p27 alterations (cytoplasmic p27 localization or p27 loss) in 500 tumors (79%) by immunohistochemistry. The remaining 130 (21%) tumors were "p27-nuclear+." Cox proportional hazard models computed hazard ratios (HR) of deaths, adjusted for patient and tumoral characteristics, including p53, p21, cyclin D1, KRAS, BRAF, PIK3CA, cyclooxygenase-2, fatty acid synthase (FASN), beta-catenin, microsatellite instability (MSI), CpG island methylator phenotype (CIMP), and long interspersed nucleotide element-1 (LINE-1) hypomethylation. Compared with p27-nuclear+ patients, p27-altered patients experienced low colon cancer-specific [adjusted HR, 0.63; 95% confidence interval (95% CI), 0.42-0.94] and overall mortality (adjusted HR, 0.70; 95% CI, 0.51-0.95), independent of FASN, MSI, CIMP, LINE-1 methylation, and other potential confounders. The effect of p27 alteration on overall mortality significantly differed by BMI (P(interaction) = 0.013); adjusted HR (p27-altered versus p27-nuclear+ tumors) was 0.28 (95% CI, 0.13-0.59) for BMI >or=30 kg/m(2), 0.67 (95% CI, 0.40-1.14) for BMI 25 to 29 kg/m(2), and 0.91 (95% CI, 0.57-1.46) for BMI <25 kg/m(2). Obesity was associated with inferior overall survival among p27-nuclear+ cases (adjusted HR, 3.07; 95% CI, 1.49-6.32; versus nonobese cases), but not among p27-altered cases (adjusted HR, 1.08). In conclusion, p27 alterations in colon cancer are associated with superior prognosis. Adverse prognostic effect of obesity seems limited to patients with nuclear p27 expression, suggesting a host-tumor interaction.

p21 expression in colon cancer and modifying effects of patient age and body mass index on prognosis

p21 (Cyclin-dependent kinase inhibitor-1A, CDKN1A or CIP1) plays a role in regulating cell cycle, and its expression is lost in most colorectal cancers. p21 Is related with energy balance status, cellular senescence, and stem cell aging. Thus, the influence of p21 loss on tumor behavior and clinical outcome may be modified by patient age and body mass index (BMI). Using 647 colon cancers in two independent prospective cohorts, p21 loss was observed in 509 (79%) tumors by immunohistochemistry. Cox proportional hazard models computed hazard ratio (HR) for death, adjusted for potential confounders, including p53, cyclin D1, KRAS, BRAF, PIK3CA, LINE-1 hypomethylation, CpG island methylator phenotype (CIMP), and microsatellite instability (MSI). p21 Loss was independently associated with low colon cancer-specific mortality [HR, 0.58; 95% confidence interval (95% CI), 0.38-0.89; adjusted for the covariates including MSI, CIMP, and LINE-1 methylation]. The prognostic effect of p21 loss differed significantly by age at diagnosis (P(interaction) < 0.0001) and BMI (P(interaction) = 0.002). The adjusted HR for cancer-specific mortality (p21 loss versus p21 expression) was 4.09 (95% CI, 1.13-14.9) among patients <60 year old and 0.37 (95% CI, 0.24-0.59) among patients >or=60 year old. The adverse prognostic effect of obesity was limited to p21-expressing cases (adjusted HR, 5.85; 95% CI, 2.28-15.0; BMI, >or=30 versus <30 kg/m(2)), but no such effect was observed among p21-lost cases. In conclusion, p21 loss in colon cancer is associated with longer survival among patients >or=60 year old, whereas it is associated with shorter survival among patients <60 year old. Patient BMI also differentially influences prognosis according to p21 CDKN1A status. Our data suggest host-tumor interactions influencing tumor aggressiveness.

Expression patterns of cyclins D1, E and cyclin-dependent kinase inhibitors p21waf1/cip1, p27kip1 in colorectal carcinoma: correlation with other cell cycle regulators (pRb, p53 and Ki-67 and PCNA) and clinicopathological features

Aberrations in the cell cycle regulators are common features of many tumours and several have been shown to have prognostic significant in colorectal cancer. The expression patterns of cyclins D1 and E as well as cyclin-dependent kinase (CDK) inhibitors p21waf1/cip1 and p27kip1 and their interrelationship with other cell cycle checkpoint proteins [p53, pRb, Ki-67 and proliferative cell nuclear antigen (PCNA)] were investigated in colorectal cancer in order to ascertain coregulation and influence on tumour behaviour or survival. These molecular markers were localisated immunohistochemically using the monoclonal antibodies anticyclin D1 (DCS-6), anticyclin E (13A3), anti-p21 (4D10), anti-p27 (1B4), anti-p53 (DO7), anti-Rb (AB-5), MIB1 and PC10 in colorectal cancer tissue from 97 patients. Data were analysed statistically using the spss software program. Overexpression of cyclin D1, cyclin E and p21waf1/cip1 proteins (>5% positive neoplastic cells) was observed in 5.9%, 30% and 7.2% of the cases respectively. Increased levels of cyclin D1 (p = 0.0001) and p21waf1/cip1 protein (p = 0.03) in tumours with mucous differentiation were observed. Overexpression of cyclin D1 was correlated with tumour stage (p = 0.03), the lymph node involvement (p = 0.02), as well as p21waf1/cip1 protein expression (p < 0.0001). Cyclin E was positively correlated with p21waf1/cip1 (p = 0.014), as well as with the cell proliferation as measured by PCNA-labelling index (p = 0.011) and Ki-67 score (p = 0.007). A positive relationship of p21waf1/cip1 expression with the proliferative-associated index Ki-67 was noted (p = 0.005). Downregulation of p27kip1 was observed in 47.4% of the cases and was correlated with downregulation of pRb (p = 0.002) and PCNA score (p = 0.004). The prognostic significance of cyclins D1, E and CDK inhibitors p21waf1/cip1, p27kip1 in determining the risk of recurrence and overall survival with both univariate (long-rang test) and multivariate (Cox regression) methods of analysis showed no statistically significance differences. In conclusion, these findings suggest that, the levels of the cell cycle regulators studied, do not seems to have a prognostic value, in terms of predicting the risk of early recurrence and overall survival. In addition, the interrelationships, probably means their contribution to the regulation of cell growth, through different pathways in colorectal carcinogenesis.

The Cdk inhibitor p27 in human cancer: prognostic potential and relevance to anticancer therapy

The cyclin-dependent kinase (Cdk) inhibitor p27 (also known as KIP1) regulates cell proliferation, cell motility and apoptosis. Interestingly, the protein can exert both positive and negative functions on these processes. Diverse post-translational modifications determine the physiological role of p27. Phosphorylation regulates p27 binding to and inhibition of cyclin-Cdk complexes, its localization and its ubiquitin-mediated proteolysis. In cancers, p27 is inactivated through impaired synthesis, accelerated degradation and by mislocalization. Moreover, studies in several tumour types indicate that p27 expression levels have both prognostic and therapeutic implications.

Concurrent EGFr and Cox-2 expression in colorectal cancer: proliferation impact and tumour spreading

BACKGROUND

Many reports were produced on single epidermal growth factor receptor (EGFr) and cyclo-oxygenase-2 (Cox-2) evaluation using immunohistochemical techniques (IHC), but very few works considered concurrent expression of these two proteins in the light of their impact on proliferation and tumour spreading. At least three molecular pathways (EGFr, Cox-2, and APC/beta-catenin molecular cascade) may interact in this malignancy giving rise to cross talking effects on proliferation and cancer spreading.

PATIENTS AND METHODS

To better detail these two latter aggressive features, we studied 205 sporadic colorectal cancer patients, comparing concurrent expression of EGFr, Cox-2, Ki-67, Cyclins D1-A, and E, with tumour spreading (budding) (BUD) and pN status.

RESULTS

Our results point to a different aggressive molecular profile due to Cox-2 expression. Cox-2 High expressing cases showed a clear EGFr proliferation-promoting role. On the contrary, EGFr seems directly involved in cancer cells spreading rather than in promoting cancer proliferation in Cox-2 Low/Negative cases.

CONCLUSIONS

Immunohistochemical profiling of colorectal cancer seems to be a promising approach, not only to define prognostic impact, but also to detail proliferation-related molecular interplays between EGFr and Cox-2 pathways, with these two latter proteins, at present, being the hottest pharmacological targets for colorectal cancer (CRC) chemoprevention and therapy.

Assessment of Clinical Outcome in Patients With Esophageal Squamous Cell Carcinoma Using TNM Classification Score and Molecular Biological Classification

BACKGROUND

The aim of this study was to assess the clinical outcome in patients with esophageal squamous cell carcinoma (ESCC) by using molecular biological classification based on immunohistochemical analysis in addition to tumor, node, metastasis system (TNM) classification.

METHODS

Samples from 71 patients with ESCC who underwent surgery were analyzed immunohistochemically. Cyclin B1, E-cadherin, Bag-1, and heat-shock protein 70 were selected as the molecular biological parameters. The utility of molecular biological classification on clinical impact was examined and compared with TNM classification.

RESULTS

Three patients were diagnosed as stage 0, 14 as stage I, 20 as stage II, 19 as stage III, and 15 as stage IV by TNM classification. Thirteen patients were classified as stage 0, 17 as stage I, 21 as stage II, 18 as stage III, and 2 as stage IV by molecular biological classification. Molecular biological stage (P < .0001) and TNM stage (P < .0001) were statistically significant prognostic parameters in univariate analysis. Twenty (28.2%) of 71 patients were assigned to the same stage by both classifications, and a significant correlation was identified between the two classifications (P = .0002). Molecular biological classification (P < .01) and TNM classification (P < .0001) were independent prognostic parameters in multivariate analysis. Combined TNM and molecular biological classification accurately reflected clinical outcome (P < .0001).

CONCLUSIONS

Molecular biological classification combined with TNM classification is useful for assessing the prognosis of patients with ESCC.

Assessment of epidermal growth factor receptor (EGFR) expression in primary colorectal carcinomas and their related metastases on tissue sections and tissue microarray

Metastatic colorectal carcinomas (CRC) resistant to chemotherapy may benefit from targeting monoclonal therapy cetuximab when they express the epidermal growth factor receptor (EGFR). Because of its clinical implications, we studied EGFR expression by immunohistochemistry on tissue sections of primary CRC (n=32) and their related metastases (n=53). A tissue microarray (TMA) was generated from the same paraffin blocks to determine whether this technique could be used for EGFR screening in CRC. On tissue sections, 84% of the primary CRC and 94% of the metastases were EGFR-positive. When matched, they showed a concordant EGFR-positive status in 78% of the cases. Moreover, staining intensity and extent of EGFR-positive cells in the primary CRC correlated with those observed in the synchronous metastases. On TMA, 65% of the primary CRC, 66% of the metastases, and 43% of the matched primary CRC metastases were EGFR-positive. There was no concordant EGFR status between the primary and the metastatic sites. A strong discrepancy of EGFR status was noted between TMA and tissue sections. In conclusion, EGFR expression measured in tissue sections from primary CRC and their related metastases was found to be similar and frequent, but it was significantly underestimated by the TMA technique.

Tissue microarrays: bridging the gap between research and the clinic

Tissue microarrays are a high-throughput method for the investigation of biomarkers in multiple tissue specimens at once. This technique allows for the analysis of up to 500 tissue samples in a single experiment using immunohistochemistry and in situ hybridization. Recently, cell lines and xenografts have been reduced to a tissue microarray format and are being applied to preclinical drug development. In clinical research, tissue microarrays are applied at multiple levels: comprehensive analysis of samples in the context of a clinical trial or across a population. Tissue microarrays play a central role in translational research, facilitating the discovery of molecules that have potential roles in the diagnosis, prognosis and prediction of response to therapy.

Pre-operative combined modality therapy in the management of locally advanced rectal cancer

AIMS

To review the use of pre-operative combined modality therapy (CMT, chemotherapy with radiotherapy) in the management of resectable rectal cancer.

METHODS

A systematic search was performed on pre-operative CMT and rectal cancer. Additional information was retrieved from hand searching the literature and from relevant congress proceedings. We addressed the following issues: Phase II studies of pre-operative CMT, pre-operative radiotherapy (RT) alone vs pre-operative CMT, pre-operative vs post-operative CMT, functional outcome and pathologic downstaging after CMT, prediction and importance of complete response to CMT.

RESULTS

Pre-operative CMT results in an average pathological complete response (pCR) rate of 18.5% in Phase II studies. Compared with pre-operative RT alone, the addition of CT significantly improves tumour response but not overall survival while acute toxicity increases and the effect on sphincter preservation is at present unclear. Pre-operative CMT has been proven to be superior to post-operative CMT in a German multicenter randomized trial. The scarce available data suggest that the addition of CT might worsen anorectal function compared to pre-operative RT alone. Although a significant pathological response is prognostically favourable, the clinical and imaging tools available at present do not allow to accurately predict pCR in clinical complete responders confirming the indication for surgery in this subgroup.

CONCLUSIONS

Pre-operative CMT enhances tumour response and could therefore, have a role in patients with possibly invaded resection margins or low lying cancers, although both acute toxicity and anorectal function are worse compared to RT alone. The final results of ongoing randomized trials will more accurately establish the role of pre-operative CMT in resectable rectal cancer patients.

Analysis of apoptosis protein expression in early-stage colorectal cancer suggests opportunities for new prognostic biomarkers

PURPOSE

Although most stage II colon cancers are potentially curable by surgery alone, approximately 20% of patients relapse, suggesting a need for establishing prognostic markers that can identify patients who may benefit from adjuvant chemotherapy. We tested the hypothesis that differences in expression of apoptosis-regulating proteins account for differences in clinical outcome among patients with early-stage colorectal cancer.

EXPERIMENTAL DESIGN

Tissue microarray technology was employed to assay the expression of apoptosis-regulating proteins by immunohistochemistry in 106 archival stage II colorectal cancers, making correlations with disease-specific survival. The influence of microsatellite instability (MSI), tumor location (left versus right side), patient age, and gender was also examined.

RESULTS

Elevated expression of several apoptosis regulators significantly correlated with either shorter (cIAP2; TUCAN) or longer (Apaf1; Bcl-2) overall survival in univariate and multivariate analyses. These biomarkers retained prognostic significance when adjusting for MSI, tumor location, patient age, and gender. Moreover, certain combinations of apoptosis biomarkers were highly predictive of death risk from cancer. For example, 97% of patients with favorable tumor phenotype of cIAP2(low) plus TUCAN(low) were alive at 5 years compared with 60% of other patients (P = 0.00003). In contrast, only 37% of patients with adverse biomarkers (Apaf1(low) plus TUCAN(high)) survived compared with 83% of others at 5 years after diagnosis (P< 0.0001).

CONCLUSIONS

Immunohistochemical assays directed at detection of certain combinations of apoptosis proteins may provide prognostic information for patients with early-stage colorectal cancer, and therefore could help to identify patients who might benefit from adjuvant chemotherapy or who should be spared it.