Adipose Tissue Properties in Tumor-Bearing Breasts

The tissue stroma plays a major role in tumors' natural history. Most programs for tumor progression are not activated as cell-autonomous processes but under the conditions of cross-talks between tumor and stroma. Adipose tissue is a major component of breast stroma. This study compares adipose tissues in tumor-bearing breasts to those in tumor-free breasts with the intention of defining a signature that could translate into markers of cancer risk. In tumor-bearing breasts, we sampled adipose tissues adjacent to, or distant from the tumor. Parameters studied included: adipocytes size and density, immune cell infiltration, vascularization, secretome and gene expression. Adipose tissues from tumor-bearing breasts, whether adjacent to or distant from the tumor, do not differ from each other by any of these parameters. By contrast, adipose tissues from tumor-bearing breasts have the capacity to secrete twice as much interleukin 8 (IL-8) than those from tumor-free breasts and differentially express a set of 137 genes of which a significant fraction belongs to inflammation, integrin and wnt signaling pathways. These observations show that adipose tissues from tumor-bearing breasts have a distinct physiological status from those from tumor-free breasts. We propose that this constitutive status contributes as a non-cell autonomous process to determine permissiveness for tumor growth.

Neoadjuvant chemotherapy (NACT) increases immune infiltration and programmed death-ligand 1 (PD-L1) expression in epithelial ovarian cancer (EOC)

Background

Lymphocytic infiltration at diagnosis is prognostic in EOC, however, the impact of NACT on tumour infiltrating lymphocytes (TILs) or PD-L1 expression remains poorly described.

Patients and methods

Patients with EOC and sequential samples (pre-NACT, post-NACT or relapse) were retrospectively identified. TILs were evaluated on whole sections; stromal TILs (sTILs) scored as percentage of stromal area with high sTILs defined as ≥50%; intra-epithelial TILs (ieTILs) scored semi-quantitatively (0-3) with high ieTILs ≥2. A smaller number were available for PD-L1 evaluation, cut-off for positivity was ≥5% staining.

Results

sTILs were detected in all tumours at diagnosis (range 2-90%, median 20%), with 22% (25/113) showing high sTILs. Among evaluable paired pre/post-NACT samples (N = 83), an overall increase in median sTILs from 20% to 30% was seen following NACT (P = 0.0005); individually the impact of NACT varied with sTILs increasing in 51% (42/83), decreasing in 25%, and stable in 24%. Post-NACT sTILs were predictive of platinum-free interval (PFI), patients with PFI ≥6 months had significantly higher post-NACT sTILs (sTILs 28% versus 18% for PFI <6 months, P = 0.026); pre-NACT sTILS were not predictive. At diagnosis, 23% showed high ieTILs, and following NACT 33% showed increasing ieTILs. Proportion of tumours with PD-L1-positive immune cells was 30% (15/50) pre-NACT and 53% (27/51) post-NACT (P = 0.026). Among paired tumours, 63% of PD-L1-negative tumours became positive after NACT, furthermore cisplatin induced PD-L1 expression in PD-L1-negative EOC cell lines. On multivariate analysis, high sTILs both pre- and post-NACT were independent prognostic factors for progression-free survival (PFS) (HR 0.49, P = 0.02 and HR 0.60, P = 0.05, respectively). No prognostic impact of ieTILs or PD-L1 expression was detected.

Conclusions

In EOC, sTILs levels are prognostic at diagnosis and remain prognostic after NACT. TILs and PD-L1 expression increase following NACT. Evaluation of immune parameters in the post-NACT tumour may help select patients for immunotherapy trials.

Diagnosis of HPV driven oropharyngeal cancers: Comparing p16 based algorithms with the RNAscope HPV-test

BACKGROUND

Accurate identification of HPV-driven oropharyngeal cancer (OPC) is a major issue and none of the current diagnostic approaches is ideal. An in situ hybridization (ISH) assay that detects high-risk HPV E6/E7 mRNA, called the RNAscope HPV-test, has been recently developed. Studies have suggested that this assay may become a standard to define HPV-status.

METHODS

To further assess this test, we compared its performance against the strategies that are used in routine clinical practice: p16 immunohistochemistry (IHC) as a single test and algorithms combining p16-IHC with HPV-DNA identification by PCR (algorithm-1) or ISH (algorithm-2).

RESULTS

105 OPC specimens were analyzed. The prevalence of HPV-positive samples varied considerably: 67% for p16-IHC, 54% for algorithm-1, 61% for algorithm-2 and 59% for the RNAscope HPV-test. Discrepancies between the RNAscope HPV-test and p16-IHC, algorithm-1 and 2 were noted in respectively 13.3%, 13.1%, and 8.6%. The 4 diagnostic strategies were able to identify 2 groups with different prognosis according to HPV-status, as expected. However, the greater survival differential was observed with the RNAscope HPV-test [HR: 0.19, 95% confidence interval (CI), 0.07-0.51, p=0.001] closely followed by algorithm-1 (HR: 0.23, 95% CI, 0.08-0.66, p=0.006) and algorithm-2 (HR: 0.26, 95% CI, 0.1-0.65, p=0.004). In contrast, a weaker association was found when p16-IHC was used as a single test (HR: 0.33, 95% CI, 0.13-0.81, p=0.02).

CONCLUSIONS

Our findings suggest that the RNAscope HPV-test and p16-based algorithms perform better that p16 alone to identify OPC that are truly driven by HPV-infection. The RNAscope HPV-test has the advantage of being a single test.

Abstract PD4-4: Whole exome sequencing of aggressive rare breast cancers histologic subtypes reveals novel pathway for breast cancer progression

Background: Rare cancers sometimes present clonal evolution. Genomic characterisation of these rare entities could lead to identify new genes involved in the progression of more frequent cancers. In the present study, we have performed whole exome sequencing of three rare and aggressive histological subtypes in order to identify new targets that could subsequently be validated in common breast cancers.

Methods: Whole exome sequencing was applied in ten pleiomorphic lobular carcinoma, seven micropapillary BC and eight metaplastic BC. Each cancer sample was matched with normal DNA from the same patient. Overall 50 samples were therefore sequenced. Tumor samples were selected to present &gt;30% cancer cells. Histological diagnosis was confirmed by a BC pathologist. Whole exome sequencing (WES) was performed by BGI (Bejing Genomic Institute, Hong-Kong, China) using the Illumina Hiseq2000 platform (90bp paired-end reads, depth ≥80x). Genes recurrently mutated (with somatic mutations in &gt;2 cases) were selected for validation. The validation by IonTorrent target sequencing was performed on additional formalin-fixed paraffin-embedded (FFPE) tumor samples (&gt;30% of tumor cells).

Results: Complete results of both WES and targeted resequencing validation are available for pleiomorphic lobular carcinoma. Nine of the 10 DNA pairs were eligible for WES. Genes already implicated in BC were significantly mutated: PIK3CA (3/9), TP53 (3/9) and CDH1 (3/9). Novel significantly mutated genes were identified: PYGM (2/9), EMR1 (2/9), ALDH1A2 (2/9), and DCLK1 (2/9). The validation using target gene sequencing was performed on the same 9 cases and on 19 additional confirmed pleiomorphic lobular BC cases (n = 28). For 8 out of the 9 cases with WES data, the results were reproducible on FFPE samples. Validation set confirmed recurrent mutations on PYGM genes (25%). PYGM is involved in glycogen metabolism. Further analyses on gene expression array revealed that PYGM is downregulated in most of the common BC samples, as compared to normal tissue, suggesting a role for this gene in the metabolism of common BC.

WES data are available for micropapillary and metaplastic BC. HSPA8 (coding for a Heat shock protein) was found mutated in 3/7 of micropapillary samples. Validation on additional FFPE samples is ongoing and will be presented. WES of metaplastic BC revealed a high frequency of TP53 and PIK3CA mutations (50% in both cases).

Conclusions: A novel mutated gene was identified in PLBC. PYGM is a gene involved in glycogen metabolism and was found downregulated in most of the common breast cancer. WES of micropapillary cancers suggests mutations on HSPA8, a gene encoding for a chaperon protein. Validation is ongoing. Deeper sequencing is ongoing for metaplastic BC that may help identifying new mutated genes in this multiclonal disease. Results will be presented.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr PD4-4.

Expression of EPHRIN-A1, SCINDERIN and MHC class I molecules in head and neck cancers and relationship with the prognostic value of intratumoral CD8+ T cells

Background

Our group has previously shown that EPHRIN-A1 and SCINDERIN expression by tumor cells rendered them resistant to cytotoxic T lymphocyte-mediated lysis. Whereas the prognostic value of EPHRIN-A1 expression in cancer has already been studied, the role of SCINDERIN presence remains to be established. In the present work, we investigated the prognosis value of EPHRIN-A1 and SCINDERIN expression in head and neck carcinomas. In addition, we monitored the HLA-class I expression by tumor cells and the presence of tumor-infiltrating CD8⁺ T cells to evaluate a putative correlation between these factors and the survival prognosis by themselves or related to EPHRIN-A1 and SCINDERIN expression.

Methods

Tumor tissue sections of 83 patients with head and neck cancer were assessed by immunohistochemistry for the expression of EPHRIN-A1, SCINDERIN, HLA class I molecules and the presence of CD8⁺ T cells.

Results

No significant prognosis value could be attributed to these factors independently, despite a tendency of association between EPHRIN-A1 and a worse clinical outcome. No prognostic value could be observed when CD8⁺ T cell tumor infiltration was analyzed combined with EPHRIN-A1, SCINDERIN or HLA class I expression.

Conclusion

These results highlight that molecules involved in cancer cell resistance to cytotoxic T lymphocytes by themselves are not a sufficient criteria for prognosis determination in cancer patients. Other intrinsic or tumor microenvironmental features should be considered in prognostic evaluation.

Human papillomavirus prevalence and prognostic implication in oropharyngeal squamous cell carcinomas

BACKGROUND

Human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (SCC) is associated with favorable survival. The purpose of this study was to evaluate the prevalence and prognostic significance of the HPV infection through both the p16 expression status and the oncogenic HPV DNA viral load.

METHODS

A retrospective chart review was conducted on all patients treated for oropharyngeal SCC between January 2007 and June 2009. P16 expression status by immunohistochemistry and HPV DNA viral load by quantitative polymerase chain reaction (qPCR) were evaluated on routine pretreatment tumor samples.

RESULTS

One hundred thirty-three patients (94 men and 39 women) were included in the study. Mean age was 59 years. One hundred twenty-two lesions (92%) were localized to lymphoid areas. Sixty-seven patients (50%) were p16+, and 87 patients (65%) harbored HPV DNA. The p16+/HPV DNA+ profile (48%) was associated with the most favorable prognosis. HPV16 was responsible for the majority of the infections (89%).

CONCLUSION

HPV is common among oropharyngeal SCC in France, and acts as an independent prognostic factor.

Oropharyngeal cancers: significance of HPV16 detection in neck lymph nodes

BACKGROUND

An increasing proportion of oropharyngeal squamous cell carcinomas (OPSCCs) is associated with human papillomavirus (HPV) type 16 infection. Several authors have suggested that HR-HPV DNA could be used as a marker of metastases in cervical cancers. Although HPV16 DNA has been detected in neck lymph node (LN) metastases of HPV16-positive OPSCC, its significance remains controversial. Does this presence correlate to metastatic involvement or is it just the consequence of LN filter function?

OBJECTIVES

This study aims to analyse the relationship between HPV16 detection in neck LNs of HPV16-positive OPSCC and their pathological status.

STUDY DESIGN

HP16-viral load (VL) was quantified by real-time-polymerase-chain reaction in primary tumours and neck LNs, in 11 patients with HPV16-positive OPSCC and in three patients with HPV16-negative OPSCC. HPV16 in situ hybridisation and p16 immunohistochemistry were performed in all LNs.

RESULTS

A total of 45 LN levels were assessed. HPV16 DNA was not identified in HPV16-negative OPSCC LNs. All metastatic LNs from HPV16-positive OPSCC had a high VL and the viral DNA was located within tumoural cells. Among 27 pathologically tumour-free LN (PTFLN) levels 16/27 had no detectable VL, whereas the VL was low or medium (<10(5)copies/million cells) in 8/27 and high (>10(5)copies/million cells) in 3/27 PTFLN. In the latter group, no metastatic cell was identified and the viral DNA was located in immune cells.

CONCLUSION

HPV16 detection in LN is explained by its presence within either metastatic cells or immune cells. HPV16 detection in PTFLN is not necessarily correlated to occult LN metastases.

Circulating tumor cells in lung cancer

Circulating tumor cells (CTCs) have emerged as potential biomarkers in several cancers such as colon, prostate, and breast carcinomas, with a correlation between CTC number and patient prognosis being established by independent research groups. The detection and enumeration of CTCs, however, is still a developing field, with no universal method of detection suitable for all types of cancer. CTC detection in lung cancer in particular has proven difficult to perform, as CTCs in this type of cancer often present with nonepithelial characteristics. Moreover, as many detection methods rely on the use of epithelial markers to identify CTCs, the loss of these markers during epithelial-to-mesenchymal transition in certain metastatic cancers can render these methods ineffective. The development of personalized medicine has led to an increase in the advancement of molecular characterization of CTCs. The application of techniques such as FISH and RT-PCR to detect EGFR, HER2, and KRAS abnormalities in lung, breast, and colon cancer, for example, could be used to characterize CTCs in real time. The use of CTCs as a 'liquid biopsy' is therefore an exciting possibility providing information on patient prognosis and treatment efficacy. This review summarizes the state of CTC detection today, with particular emphasis on lung cancer, and discusses the future applications of CTCs in helping the clinician to develop new strategies in patient treatment.

Portrait of ependymoma recurrence in children: biomarkers of tumor progression identified by dual-color microarray-based gene expression analysis

Background

Children with ependymoma may experience a relapse in up to 50% of cases depending on the extent of resection. Key biological events associated with recurrence are unknown.

Methodology/Principal Findings

To discover the biology behind the recurrence of ependymomas, we performed CGHarray and a dual-color gene expression microarray analysis of 17 tumors at diagnosis co-hybridized with the corresponding 27 first or subsequent relapses from the same patient. As treatment and location had only limited influence on specific gene expression changes at relapse, we established a common signature for relapse. Eighty-seven genes showed an absolute fold change ≥2 in at least 50% of relapses and were defined as the gene expression signature of ependymoma recurrence. The most frequently upregulated genes are involved in the kinetochore (ASPM, KIF11) or in neural development (CD133, Wnt and Notch pathways). Metallothionein (MT) genes were downregulated in up to 80% of the recurrences. Quantitative PCR for ASPM, KIF11 and MT3 plus immunohistochemistry for ASPM and MT3 confirmed the microarray results. Immunohistochemistry on an independent series of 24 tumor pairs at diagnosis and at relapse confirmed the decrease of MT3 expression at recurrence in 17/24 tumor pairs (p = 0.002). Conversely, ASPM expression was more frequently positive at relapse (87.5% vs 37.5%, p = 0.03). Loss or deletion of the MT genes cluster was never observed at relapse. Promoter sequencing after bisulfite treatment of DNA from primary tumors and recurrences as well as treatment of short-term ependymoma cells cultures with a demethylating agent showed that methylation was not involved in MT3 downregulation. However, in vitro treatment with a histone deacetylase inhibitor or zinc restored MT3 expression.

Conclusions/Significance

The most frequent molecular events associated with ependymoma recurrence were over-expression of kinetochore proteins and down-regulation of metallothioneins. Metallothionein-3 expression is epigenetically controlled and can be restored in vitro by histone deacetylase inhibitors.

FGFR1 and FGF Coamplification in Breast Cancer

Background:FGFR1 is a tyrosine kinase receptor involved in cell proliferation, migration and differentiation. FGFR1 gene is amplified in about 10% of breast cancer. Several studies have previously reported that FGFR1 inhibition could lead to a decrease in cell proliferation. Recent data obtained in prostate cancer have shown that FGFR1 activation could mediate epithelial to mesenchymal transition. In the present study, we evaluated the rational to target FGFR1 in clinical setting.Material and methods:We first assessed whether FGFR1 amplification was associated with a specific breast cancer phenotype. We assessed FGFR1 amplification by CGH array on 235 samples and by FISH (Z-2072, Spec FGFR1/Cen8 dual color probe, Zytovision®) on 260 samples, not included in the CGH part. We then assessed the functional effects of FGFR1 inhibitions in vitro. The antiproliferative effect of E3810 (FGFR1 inhibitor) was assessed both on FGFR1-non amplified (T47D/MCF7) and FGFR1 amplified (SUM44PE/MDA134) cell lines. Effect of FGFR1 inhibition was assessed on gene expression profiling.Results:When assessed by FISH, FGFR1 amplification was observed in 23/260 cases. Most of the samples (62%) exhibited an ER+/PR- phenotype, suggesting activation of intracellular kinase. FGFR1 amplification was observed in 24 out of 235 samples (10%). Interestingly, FGFR1 amplification was associated with gene gain in FGF3/FGF4/FGF19 (11q13) (55% versus 22%, p=0.05). FGFR1 inhibition by E-3810 inhibits MAPk phosphorylation, cell proliferation. A differential IC 50 for cell proliferation was observed between amplified cell lines and control cell lines. Preliminary data on gene expression profiling suggest that FGFR1 inhibition on breast cancer cells could lead to significant decrease in the Sox9 expression, a protein involved in epithelial to mesenchymal transition.Conclusion:FGFR1-amplified breast cancers present a discrete phenotype, including a high rate of ER+/PR- and high rate of FGF3/4/19 gains. Pharmacologic inhibition of FGFR1 leads to cell proliferation decrease and modulation of genes involved in EMT. These data suggest that there is a rational to target FGFR1 in clinical setting in patients with FGFR1-amplified breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4170.

p53 status correlates with histopathological response in patients with soft tissue sarcomas treated using isolated limb perfusion with TNF-alpha and melphalan

BACKGROUND

Recombinant tumor necrosis factor-alpha (TNF-alpha) combined to melphalan is clinically administered through isolated limb perfusion (ILP) for regionally advanced soft tissue sarcomas of the limbs. In preclinical studies, wild-type p53 gene is involved in the regulation of cytotoxic action of TNF-alpha and loss of p53 function contributes to the resistance of tumour cells to TNF-alpha. The relationship between p53 status and response to TNF-alpha and melphalan in patients undergoing ILP is unknown.

PATIENTS AND METHODS

We studied 110 cases of unresectable limbs sarcomas treated by ILP. Immunohistochemistry was carried out using DO7mAb, which reacts with an antigenic determinant from the N-terminal region of both the wild-type and mutant forms of the p53 protein, and PAb1620mAb, which reacts with the 1620 epitope characteristic of the wild-type native conformation of the p53 protein. The immunohistochemistry data were then correlated with various clinical parameters.

RESULTS

P53DO7 was found expressed at high levels in 28 patients, whereas PAb1620 was negative in 20. The tumours with poor histological response to ILP with TNF-alpha and melphalan showed significantly higher levels of p53-mutated protein.

CONCLUSIONS

Our results might be a clue to a role of p53 protein status in TNF-alpha and melphalan response in clinical use.

Imaging of the distribution of (90)y-ibritumomab tiuxetan in bone marrow and comparison with pathology

PURPOSE

Radioimmunotherapy with anti-CD20 antibodies (Abs) labeled with beta-emitters is now used in the treatment of non-Hodgkin's lymphoma (NHL). Because (90)Y is a pure beta-emitter, no direct image of its distribution can be obtained in humans. In this paper, we present in this study imaging data of (90)Y-Ab distribution in human-mantle-cell lymphoma within a mouse model. Describing the actual distribution of the radionuclide at the level of particles range may have important impact on patient dosimetry and therapy treatment planning.

EXPERIMENTAL DESIGN

NOD/SCID mice were grafted with a human NHL cell line that involves the bone marrow. The mice were treated with (90)Y-ibritumomab tiuxetan (Zevalin); Schering AG, Germany) and sacrificed 2 hours after Zevalin administration. Tissue sections were then prepared and viewed under conventional microscopy. The distribution of the radioactivity in mouse femur was determined by using digital autoradiography and subsequently correlated with immunohistochemical results.

RESULTS

Various extent of bone marrow infiltration was investigated and found to be reproducible. Zevalin uptake was heterogeneous within the bone marrow. However, unspecific mouse monoclonal uptake by accessory myeloid cells gave nonspecific background radioactivity. Treating mice with an irrelevant mouse IgG1 monoclonal antibody (mAb) before Zevalin injection controlled this unspecific uptake, and images were strongly correlated with bone marrow infiltration on histologic analysis.

CONCLUSIONS

Our model was reproducible, and allows for the study of various bone marrow involvement with good sensitivity. We demonstrated that imaging of the beta-emitter was possible with good image quality and that (90)Y-Zevalin is distributed heterogeneously within bone marrow. These data suggest that detailed pharmacokinetics may be developed with this model.

Efficacy of adjuvant chemotherapy according to Prion protein expression in patients with estrogen receptor-negative breast cancer

BACKGROUND

Prion protein (PrPc) has been previously reported to be associated with resistance to proapoptotic stimuli. We evaluated whether the expression of PrPc was associated with the resistance to adjuvant chemotherapy in patients with estrogen receptor (ER) -negative breast cancer.

PATIENTS AND METHODS

The expression of PrPc by primary tumors was assessed by immunohistochemistry in a series of 756 patients included in two randomized trials that compared anthracycline-based chemotherapy to no chemotherapy. The PrPc expression was correlated with ER expression and the benefit of adjuvant chemotherapy was assessed according to PrPc expression in patients with ER-negative tumors.

RESULTS

Immunostaining analysis showed that PrPc was mainly expressed by myoepithelial cells in normal breast tissue. Tissue microarray analysis from 756 breast tumors showed that PrPc was associated with ER-negative breast cancer subsets (P < 0.001). Adjuvant chemotherapy was not associated with a significant risk reduction for death in patients with ER-negative/PrPc-positive disease [adjusted hazard ratio (HR) for death = 0.98, 95% confidence interval (CI) 0.45-2.1, P = 0.95], while it decreased the risk for death (HR = 0.39, 95% CI 0.2-0.74, P = 0.004) in patients with ER-negative/PrPc-negative tumors.

CONCLUSION

These data indicate that ER-negative/PrPc-negative phenotype is associated with a high sensitivity to adjuvant chemotherapy.

Can ERCC1 and topoisomerase II-alpha predict histological response and outcome after induction chemotherapy in locally advanced soft tissue sarcomas (LASTS)?

10074

Background: The impact of histological response (± 95% of necrosis) on patients (pts) outcome with LASTS treated by induction chemotherapy (CT) is still debated. Methods: From 1995 to 2005, 79 LASTS pts received induction CT consisting in two cycles of API-AI regimen and results were already reported (Gomez-Abuin, ASCO 2004). ERCC1, HER2 and Topoisomerase IIa (TopoII) was assessed by IHC on initial biopsies after paraffin embedding and correlated to histological response and pts outcome. Results: The median age of the 43 males and 36 females was 43 years (yr) (range 18–68) and the median tumor size at diagnosis was 109 mm (range 10–250 mm). CR was achieved in 4 pts, PR in 25 pts, SD in 45 pts and PD in 5 pts. R0 surgery was possible in 82% of pts; histological necrosis (HN) after chemotherapy was >95% in 25 pts, between 50–95% in 28 pts and <50% in 25 pts (median HN was 70%). All pts but one received postoperative radiotherapy. Relapse occurred in 37 pts; local in 3, distant in 33 and both in 1. After a median follow-up of 48 months (9–118 months) 51 pts are alive. The 5 yr DFS and OS were 45% and 60% respectively. Multivariate analysis correlated median HN to a better EFS and a non grade 3 to a better OS. Regarding protein expression (54 pts analyzed), a higher protein expression of TopoII was correlated to a better EFS (p=0.032) by univariate analysis and to OS by multivariate analysis (p=0.025). ERCC1 protein expression was not related to EFS and/or OS. There is no correlation between over expression of both proteins and any percentage of HN. Conclusions: A high rate of HN (> 70%) after induction chemotherapy treatment is predictive for a better EFS. TopoII expression seems to be a relevant early predictive marker for outcome of pts with LASTS treated with doxorubicine-containing induction CT.

No significant financial relationships to disclose.

Genome-wide expression profiling and tissue array analysis for prediction of recurrences in stage II-III colorectal cancer (CRC)

3572

Background: Despite substantial progress in molecular pathogenesis of colon cancer (CC), no reliable biomarkers of outcome have yet been identified in patients with resected stage II-III CC. Methods: We analyzed genome-wide mRNA expression profiles in 20 stage II or III left side CC from 10 patient who developed metastasis (M+) and 10 disease free patients followed up for at least 4 years (M-) using high-density oligonucleotide microarrays (Agilent technology). RNA from tumor tissue (T) was hybridized against normal tissue (NT) from the same patient and each experiment was replicated 4 times (with 2 dye-swaps). The goal was to select genes both differentially expressed between T and NT and between M+ and M-. A tissu-array was constructed using 212 stage II and III resected CRC (164 CC, 64 rectal cancers) and their matched NT. For survival analysis, immunohistochemistry (IHC) data was dichotomized at the median value. Results: Analysis of microarray data yielded 27 genes that had a 2-fold difference between the expression in T and NT in at least 5 out of 20 patients and for which the average expression was significantly different between M+ and M- (p<0.01, t-test). Among the 6 most differentially expressed genes between M+ and M- in T, 4 of them were found to be involved in interferon γ pathway and could be evaluated by IHC: CXCL9, CXCL13, PPARγ, THSD. In order to assess macrophage and natural killer (NK) cell infiltration, CD68 and CD57 were also analyzed. Intensity was measured by semi-quantitative scores for the first 4 genes and by the number of infiltrating cells for the others. CXCL9, PPARGγ, CXCL13, CD57 and CD68 were significantly underexpressed in T as compared to NT (p<0.0001, paired t-test). The logrank test stratified by cancer site indicated that high IHC expression of CD57 possessed a significantly better recurrence-free survival (RFS) than those low expression (p=0.004). Multivariate Cox analysis identified tumor site (p=0.001), node stage (p<0.001) and CD57 (p=0.002) as independent predictors of RFS. Conclusions: NK cell infiltration within colorectal cancers is associated with prolonged recurrence-free survival in stage II and III CRC.

No significant financial relationships to disclose.