The intratumoural subsite and relation of CD8+ and FOXP3+ T lymphocytes in colorectal cancer provide important prognostic clues

Background:

To find improved tools for prognostic evaluation in patients with colorectal cancer (CRC), we have analysed how infiltration of cytotoxic T lymphocytes (CD8⁺) and regulatory T lymphocytes (FoxP3⁺) correlates to prognosis, not only according to quantity and relation, but also to subsite within tumours of different molecular characteristics (microsatellite instability and CpG island methylator phenotype status).

Methods:

CD8 and FOXP3 expression was evaluated by immunohistochemistry in 426 archival tumour tissue samples from patients surgically resected for CRC. The average infiltration of CD8⁺ and FOXP3⁺ cells was assessed along the tumour invasive front, in the tumour centre and within the tumour epithelium (intraepithelial).

Results:

We found that infiltration of CD8⁺ T lymphocytes within the tumour epithelium provided the strongest prognostic information (P<0.001). At the tumour invasive front and tumour centre, FOXP3 expression withheld the strongest association to prognosis (P<0.001), suggesting FOXP3⁺ T-lymphocyte infiltration to be a better prognostic tool than CD8⁺ T lymphocytes at these intratumoural subsites. We further analysed the possible prognostic impact of the relation between these T-cell subsets, finding that a high intraepithelial CD8 expression was associated with a better patient outcome, independent of FOXP3 infiltration. In groups of low intraepithelial CD8 expression, however, a high infiltration rate of FOXP3⁺ cells at the tumour invasive front, significantly improved prognosis.

Conclusions:

Analyses of intraepithelial infiltration of CD8⁺ T lymphocytes, infiltration of FOXP3⁺ T lymphocytes at the tumour front or centre, and the relation between these subsets, may be a valuable tool for predicting prognosis in colon cancer.     

Intratumoral regulatory T cells upregulate immunosuppressive molecules in head and neck cancer patients

Background:

Although regulatory T cells (Treg) are highly enriched in human tumours compared with peripheral blood, expression of the immune-checkpoint receptors, immunosuppressive molecules and function of Treg in these two sites remains undefined.

Methods:

Tumour-infiltrating lymphocytes and peripheral blood lymphocytes were isolated from a cohort of head and neck squamous cell carcinoma (HNSCC) patients. The immunosuppressive phenotypes and function of intratumoral Treg were compared with those of peripheral blood Treg.

Results:

The frequency of immune-checkpoint receptor-positive cells was higher on intratumoral FOXP3⁺CD25^hi Treg compared with circulating Treg (CTLA-4, P=0.002; TIM-3, P=0.002 and PD-1, P=0.002). Immunosuppressive effector molecules, LAP and ectonucleotidase CD39 were also upregulated on intratumoral FOXP3⁺ Treg (P=0.002 and P=0.004, respectively). CTLA-4 and CD39 were co-expressed on the majority of intratumoral FOXP3⁺CD4⁺ Treg, suggesting that these molecules have a key role in regulatory functions of these cells in situ. Notably, intratumoral Treg exhibited more potently immunosuppressive activity than circulating Treg.

Conclusion:

These results indicate that intratumoral Treg are more immunosuppressive than circulating Treg and CTLA-4 and CD39 expressed can be potential target molecules to inhibit suppressive activities of intratumoral Treg in situ.     

Tumour-infiltrating CD8+ lymphocytes as an independent predictive factor for pathological complete response to primary systemic therapy in breast cancer

Background:

Tumour-infiltrating lymphocytes (TILs) are known to be associated with response to primary systemic therapy (PST) in breast cancer. This study was conducted to assess the association of TIL subsets with pathological complete response (pCR) after PST in breast cancer in relation to breast cancer subtype, breast cancer stem cell (BCSC) phenotype and epithelial–mesenchymal transition (EMT).

Methods:

The pre-chemotherapeutic biopsy specimens of 153 breast cancer patients who underwent surgical resection after anthracycline- or anthracycline/taxane-based PST were analysed. TIL subsets (CD4+, CD8+, and FOXP3+ TILs), BCSC phenotype, and the expression of EMT markers were evaluated by immunohistochemistry and were correlated with pCR after PST.

Results:

Infiltration of CD4+ and CD8+ T lymphocytes was closely correlated with BCSC phenotype and EMT. High levels of CD4+, CD8+, and FOXP3+ TILs were associated with pCR, and CD8+ TILs were found to be an independent predictive factor for pCR. In addition, CD8+ TILs were associated with pCR irrespective of breast cancer subtype, CD44+/CD24− phenotype, EMT, and chemotherapeutic regimen in subgroup analyses.

Conclusion:

These findings indicate that CD8+ cytotoxic T lymphocytes are a key component of TILs associated with chemo-response and can be used as a reliable predictor of response to anthracycline- or anthracycline/taxane-based PST in breast cancer.     

Prognostic impact of tumour-infiltrating immune cells on biliary tract cancer

Background:

Biliary tract cancers (BTC) are relatively rare malignant tumours with poor prognosis. It is known from other solid neoplasms that antitumour inflammatory response has an impact on tumour behaviour and patient outcome. The aim of this study was to provide a comprehensive characterisation of antitumour inflammatory response in human BTC.

Methods:

Tumour-infiltrating T lymphocytes (CD4+, CD8+, and Foxp3+), natural killer cells (perforin+), B lymphocytes (CD20+), macrophages (CD68+) as well as mast cells (CD117+) were assessed by immunohistochemistry in 375 BTC including extrahepatic (ECC; n=157), intrahepatic (ICC; n=149), and gallbladder (GBAC; n=69) adenocarcinomas. Overall and intraepithelial quantity of tumour-infiltrating immune cells was analysed. Data were correlated with clinicopathological variables and patient survival.

Results:

The most prevalent inflammatory cell type in BTC was the T lymphocyte. Components of the adaptive immune response decreased, whereas innate immune response components increased significantly in the biliary intraepithelial neoplasia – primary carcinoma – metastasis sequence. BTC patients with intraepithelial tumour-infiltrating CD4+, CD8+, and Foxp3+ T lymphocytes showed a significantly longer overall survival. Number of total intraepithelial tumour-infiltrating Foxp3+ regulatory T lymphocytes (HR: 0.492, P=0.002) and CD4+ T lymphocytes (HR: 0.595, P=0.008) were tumour grade- and UICC-stage-independent prognosticators. The subtype-specific evaluation revealed that the tumour-infiltrating lymphocytic infiltrate is a positive outcome predictor in ECC and GBAC but not in ICC.

Conclusion:

Our findings characterise the immune response in cholangiocarcinogenesis and identify inflammatory cell types that influence the outcome of BTC patients. Further, we show that BTC subtypes show relevant differences with respect to density, quality of inflammation, and impact on patient survival.     

Digital pattern recognition-based image analysis quantifies immune infiltrates in distinct tissue regions of colorectal cancer and identifies a metastatic phenotype

Background:

Several studies in colorectal cancer (CRC) indicate a relationship between tumour immune infiltrates and clinical outcome. We tested the utility of a digital pattern recognition-based image analysis (DPRIA) system to segregate tissue regions and facilitate automated quantification of immune infiltrates in CRC.

Methods:

Primary CRC with matched hepatic metastatic (n=7), primary CRC alone (n=18) and primary CRC with matched normal (n=40) tissue were analysed immunohistochemically. Genie pattern recognition software was used to segregate distinct tissue regions in combination with image analysis algorithms to quantify immune cells.

Results:

Immune infiltrates were observed predominately at the invasive margin. Quantitative image analysis revealed a significant increase in the prevalence of Foxp3 (P<0.0001), CD8 (P<0.0001), CD68 (<0.0001) and CD31 (<0.0001) positive cells in the stroma of primary and metastatic CRC, compared with tumour cell mass. A direct comparison between non-metastatic primary CRC (MET−) and primary CRC that resulted in metastasis (MET+) showed an immunosuppressive phenotype, with elevated Foxp3 (P<0.05) and reduced numbers of CD8 (P<0.05) cells in the stroma of MET+ compared with MET− samples.

Conclusion:

By combining immunohistochemistry with DPRIA, we demonstrate a potential metastatic phenotype in CRC. Our study accelerates wider acceptance and use of automated systems as an adjunct to traditional histopathological techniques.     

Low stromal Foxp3+ regulatory T-cell density is associated with complete response to neoadjuvant chemoradiotherapy in rectal cancer

Background:

Foxp3⁺ regulatory T cells (Tregs) play a vital role in preventing autoimmunity, but also suppress antitumour immune responses. Tumour infiltration by Tregs has strong prognostic significance in colorectal cancer, and accumulating evidence suggests that chemotherapy and radiotherapy efficacy has an immune-mediated component. Whether Tregs play an inhibitory role in chemoradiotherapy (CRT) response in rectal cancer remains unknown.

Methods:

Foxp3⁺, CD3⁺, CD4⁺, CD8⁺ and IL-17⁺ cell density in post-CRT surgical samples from 128 patients with rectal cancer was assessed by immunohistochemistry. The relationship between T-cell subset densities and clinical outcome (tumour regression and survival) was evaluated.

Results:

Stromal Foxp3⁺ cell density was strongly associated with tumour regression grade (P=0.0006). A low stromal Foxp3⁺ cell density was observed in 84% of patients who had a pathologic complete response (pCR) compared with 41% of patients who did not (OR: 7.56, P=0.0005; OR: 5.27, P=0.006 after adjustment for presurgery clinical factors). Low stromal Foxp3⁺ cell density was also associated with improved recurrence-free survival (HR: 0.46, P=0.03), although not independent of tumour regression grade.

Conclusions:

Regulatory T cells in the tumour microenvironment may inhibit response to neoadjuvant CRT and may represent a therapeutic target in rectal cancer.     

Expression pattern of tumour-associated antigens in hepatocellular carcinoma: association with immune infiltration and disease progression

Background:

The distinct expression pattern of tumour-associated antigens (TAAs) might be a critical reason for the inefficacy of immunity-based treatments and heterogeneous postsurgical recovery in patients with solid tumours, including hepatocellular carcinoma (HCC). However, little is known about the clinical value of the coexpression patterns of multiple TAAs.

Methods:

We determined the expression of multiple TAAs with identified immunogenicity (GPC3, AFP, SSX-2, NY-ESO-1, EpCAM, midkine) and the density of tumour-infiltrating immune cells by immunohistochemistry in a panel of 362 primary HCC patients. We evaluated the association between the TAAs, immune cell infiltration, clinicopathological parameters, and prognosis.

Results:

Patients who coexpressed more TAAs had better prognosis (P<0.00001, overall survival). The integrated pattern of TAA was associated with good differentiation and small tumour size, and with more CD57⁺ natural killer and CD20⁺ B-cell infiltration (P<0.05). Multivariate Cox proportional hazards analysis identified the TAA index as an independent prognostic indicator (hazard ratio 0.625; 95% confidence interval 0.467–0.837; P=0.002), and could further predict patient prognosis in collaboration with local immune infiltration.

Conclusion:

Our results could provide new evidence for the improvement of prognostic molecular signatures in HCC, and a novel rationale for patient enrolment in future immunotherapeutic trials and/or clinical treatments.     

Prognostic and predictive value of immunological parameters for chemoradioimmunotherapy in patients with pancreatic adenocarcinoma

Background:

Chemoradioimmunotherapy of patients with pancreatic adenocarcinoma from the CapRI trial did not show any benefit of interferon-α in addition to a 5-fluorouracil (5FU)-based treatment. The aim of this study was to identify immunological parameters in patients from this trial to be used for predictive and/or prognostic purposes.

Methods:

The following methods were used: tumour immunohistology, FACS analyses, cytokine measurement, as well as cytotoxicity and ELIspot. Immunological parameters were correlated with patients'' survival using the Kaplan–Meier method.

Results:

Irrespective of therapy type, high lymphocyte accumulation in tumours and frequencies of NK cells and effector (eff) CD8⁺ T cells in peripheral blood of the patients were associated with patients'' survival. Amount of CD3⁺ and effector-memory CD8⁺ blood lymphocytes, expression of CD152 and interleukin (IL)-2 serum level showed a predictive value for chemoradioimmunotherapy. Tumoural accumulation of CD3⁺ and CD8⁺ cells was predictive for outcome of chemotherapy alone. Besides, we identified the frequencies of CD3⁺ lymphocytes, effCD8⁺ T cells and NK cells in the peripheral blood of the patients, and IL-10 amount in serum, to be predictive values for 5FU-based chemotherapy.

Conclusions:

Immunological parameters, identified in this trial as possible markers, may be of interest in personalized medicine towards the improvement of the treatment and prognosis of pancreatic carcinoma patients.     

PD-1+ CD8+ T cells are exhausted in tumours and functional in draining lymph nodes of colorectal cancer patients

Background:

The blockade of PD-1–PD-L1 pathway is emerging as an effective therapeutic strategy for several advanced cancers. But the immune regulatory role of PD-1–PD-L1 pathway is not clear in colorectal cancer (CRC) patients. This study aims to evaluate the role of PD-1–PD-L1 pathway in CD8⁺ T-cell functions in tumour-draining lymph nodes (TDLNs) and tumours of CRC patients.

Methods:

PD-1 expression on CD8⁺ T cells was examined by flow cytometry, and PD-L1 expression in TDLNs and tumour tissues were examined by immunohistochemistry. Production of IFN-γ, IL-2 and expression of granzyme B, perforin in CD8⁺ T cells were detected by intracellular staining.

Results:

PD-1 expression is markedly upregulated on CD8⁺ T cells in TDLNs and tumours compared with that in peripheral blood. PD-1-expressing CD8⁺ T cells are competent for production of cytokine (IL-2 and IFN-γ) and perforin in the tumour-free lymph nodes (TFLNs), but exhibit exhausted phenotypes in tumours. In addition, PD-L1 is highly expressed in tumours rather than TFLNs, which is closely correlated with the impairment of IFN-γ production of tumour-infiltrating PD-1⁺ CD8⁺ T cells.

Conclusions:

Our findings suggest a suppressive effect of PD-1 on CD8⁺ T-cell function in tumours, but not in TFLNs.     

Tumour-associated CD66b+ neutrophil count is an independent prognostic factor for recurrence in localised cervical cancer

Background:

The prognostic impact of tumour-promoting immune cells in cervical cancer is unclear.

Methods:

Federation of Gynaecology and Obstetrics (FIGO) stage IB and IIA cervical cancer patients (N=101) were assessed for tumour-associated CD66b⁺ neutrophils and CD163⁺ macrophages by immunohistochemistry in whole tissue sections using stereology. Results were correlated with previous results on tumour-infiltrating CD3⁺, CD4⁺, and CD8⁺ lymphocytes in the same cohort with recurrence-free survival (RFS) as end point.

Results:

The highest densities of CD66b⁺ neutrophils and CD163⁺ macrophages were observed in the peritumoural compartment (median 53.1 cells mm⁻² and 1.3% area fraction, respectively). Above median peritumoural and stromal CD66b⁺ neutrophils and peritumoural CD163⁺ macrophages were significantly associated with short RFS. Multivariate analysis identified high peritumoural neutrophils (HR 2.27; 95% CI 1.09–4.75; P=0.03), low peritumoural CD8⁺ lymphocytes (HR 3.67; 95% CI 1.63–8.25; P=0.002), and lymph node metastases (HR 2.70; 95% CI 1.26–5.76; P=0.01) as independent prognostic factors for short RFS, whereas CD163⁺ macrophages were not significant. An index of combined intratumoral and peritumoral CD66b⁺ neutrophils to CD8⁺ lymphocytes had good discriminatory power for each quartile with 5-year RFS of 92%, 80%, 62%, and 44% (P=0.001).

Conclusion:

Tumour-associated neutrophil count is an independent prognostic factor for short RFS in localised cervical cancer. Combining CD66b and CD8 may further improve prognostic stratification. These findings require prospective validation.     

Tumour-infiltrating CD4+ and CD8+ lymphocytes as predictors of clinical outcome in glioma

Background:

T lymphocyte infiltration has been detected in glioma, although its significance remains unclear. The purpose of the present study was to explore the prognostic value of CD4⁺ and CD8⁺ tumour-infiltrating lymphocytes (TILs) in glioma, and the prognostic value of infiltrating Forkhead box protein 3 (FoxP3⁺) regulatory T cells were also investigated.

Methods:

CD4⁺, FoxP3⁺ and CD8⁺ TILs were assessed by immunohistochemical staining of tissue microarray cores from 284 gliomas. Kaplan–Meier analysis and Cox proportional hazards models were used to examine the survival function of these TILs in 90 glioblastoma patients.

Results:

The number of CD8⁺ TILs was inversely correlated with tumour grade (P=0.025), whereas the number of CD4⁺ TILs was positively correlated with tumour grade (P=0.002). FoxP3⁺ TILs were only observed in glioblastomas, but not in low-grade astrocytomas or oligodendroglial tumours. Among patients with glioblastoma, none of CD4⁺ TILs, FoxP3⁺ TILs and CD8⁺ TILs alone was significantly associated with patient prognosis. However, the presence of high CD4⁺ and low CD8⁺ TIL levels was an independent predictor of poor progress-free survival (multivariate hazard ratio (HR) 1.618, 95% confidence interval (CI) 1.245–2.101, P<0.001) and poor overall survival (multivariate HR 1.508, 95% CI 1.162–1.956, P=0.002). Moreover, pseudoprogression was more often found in patients with high CD4⁺ TILs and high CD8⁺ TILs.

Conclusions:

The combination of CD4⁺ and CD8⁺ TILs is a predictor of clinical outcome in glioblastoma patients, and a high level of CD4⁺ TILs combined with low CD8⁺ TILs was associated with unfavourable prognosis.     

Tumour-infiltrating inflammation and prognosis in colorectal cancer: systematic review and meta-analysis

Background:

The role of tumour-infiltrating inflammation in the prognosis of patients with colorectal cancer (CRC) has not been fully evaluated. The primary objective of our meta-analysis was to determine the impact of tumour-infiltrating inflammation on survival outcomes.

Methods:

Ovid MEDLINE and EMBASE were searched to identify studies reporting the prognostic significance of tumour-infiltrating inflammation for patients with CRC. The primary outcome measures were overall survival (OS), cancer-specific survival (CS) and disease-free survival (DFS).

Results:

A total of 30 studies involving 2988 patients were identified. Studies were subdivided into those considering the associations between CRC survival and generalised tumour inflammatory infiltrate (n=12) and T lymphocyte subsets (n=18). Pooled analyses revealed that high generalised tumour inflammatory infiltrate was associated with good OS (HR, 0.59; 95% CI, 0.48–0.72), CS (HR, 0.40; 95% CI, 0.27–0.61) and DFS (HR, 0.72; 95% CI, 0.57–0.91). Stratification by location and T lymphocyte subset indicated that in the tumour centre, CD3⁺, CD8⁺ and FoxP3⁺ infiltrates were not statistically significant prognostic markers for OS or CS. In the tumour stroma, high CD8⁺, but not CD3⁺ or FoxP3⁺ cell infiltrates indicated increased OS. Furthermore, high CD3⁺ cell infiltrate was detected at the invasive tumour margin in patients with good OS and DFS; and high CCR7⁺ infiltrate was also indicated increased OS.

Conclusion:

Overall, high generalised tumour inflammatory infiltrate could be a good prognostic marker for CRC. However, significant heterogeneity and an insufficient number of studies underscore the need for further prospective studies on subsets of T lymphocytes to increase the robustness of the analyses.     

Synthetic phosphoethanolamine has in vitro and in vivo anti-leukemia effects

Background:

We recently showed that synthetic phosphoethanolamine reduces tumour growth and inhibits lung metastasis in vivo. Here, we investigated its anti-leukaemia effects using acute promyelocytic leukaemia (APL) as a model.

Methods:

Cytotoxic effects of Pho-s on leukaemia cells were evaluated by MTT assay. Leukaemic cells obtained from hCG-PML-RARa transgenic mice were transplanted to NOD/SCID mice. After the animals were diagnosed as leukaemic, treatment started with Pho-s using all-trans retinoid acid or daunorubicin as positive control or and saline control. Cell morphology and immunophenotyping were used to detect the undifferentiated blast cells in the spleen, liver and bone marrow. The induction of apoptosis in vitro and in malignant leukaemic clones was evaluated.

Results:

Synthetic phosphoethanolamine is cytotoxic and induces apoptosis through the mitochondrial pathway in vitro to leukaemia cell lines. In vivo Pho-s exhibits anti-proliferative effects in APL model reducing the number of CD117⁺ and Gr-1⁺ immature myeloid cells in the BM, spleen and liver. Synthetic phosphoethanolamine impairs the expansion of malignant clones CD34⁺/CD117⁺, CD34⁺ and Gr-1⁺ in the BM. In addition, Pho-s induces apoptosis of immature cells in the spleen and liver, a notable effect.

Conclusion:

Synthetic phosphoethanolamine has anti-leukaemic effects in an APL model by inhibiting malignant clone expansion, suggesting that it is an interesting compound for leukaemia treatment.     

Immune cell infiltration as an indicator of the immune microenvironment of pancreatic cancer

Background:

The host immune reaction is represented by immune/inflammatory cell infiltrates. Here we systematically analysed tumour-infiltrating immune/inflammatory cells in pancreatic ductal carcinoma (PDC) and evaluated their clinicopathological impact.

Methods:

Using immunohistochemistry, we examined tumour-infiltrating CD68⁺ pan-macrophages, HLA-DR⁺CD68⁺ M1 macrophages (M1), CD163⁺ or CD204⁺ M2 macrophages (M2), CD66b⁺ neutrophils (Neu), CD4⁺ T cells (CD4⁺T), CD8⁺ T cells (CD8⁺T), and FOXP3⁺CD4⁺ regulatory T cells (Treg) in 212 cases of PDC, and conducted correlation and survival analyses using the Kaplan–Meier method and Cox proportional hazards model.

Results:

Higher levels of tumour-infiltrating pan-macrophages, M2, Neu, or the ratio of Tregs to CD4⁺T (%Treg) were significantly associated with shorter survival, whereas higher levels of tumour-infiltrating CD4⁺T, CD8⁺T, or the ratio of M1 to pan-macrophages (%M1) were significantly associated with longer survival. Survival analysis of pairs of these variables revealed that some of the resulting patient groups had exclusively longer survival. We then connected the apparently related factors, and two significant variables emerged: tumour-infiltrating CD4⁺T^high/CD8⁺T^high/%Treg^low and tumour-infiltrating %M1^high/M2^low. Multivariate survival analysis revealed that these variables were significantly correlated with longer survival and had a higher hazard ratio.

Conclusion:

Tumour-infiltrating CD4⁺T^high/CD8⁺T^high/%Treg^low and %M1^high/M2^low are independent prognosticators useful for evaluating the immune microenvironment of PDC.     

Tumour-infiltrating lymphocytes predict response to definitive chemoradiotherapy in head and neck cancer

Background:

We aimed to investigate the prognostic value of tumour-infiltrating lymphocytes'' (TILs) expression in pretreatment specimens from patients with head and neck squamous cell carcinoma (HNSCC) treated with definitive chemoradiotherapy (CRT).

Methods:

The prevalence of CD3+, CD8+, CD4+ and FOXP3+ TILs was assessed using immunohistochemistry in tumour tissue obtained from 101 patients before CRT and was correlated with clinicopathological characteristics as well as local failure-free- (LFFS), distant metastases free- (DMFS), progression-free (PFS) and overall survival (OS). Survival curves were measured using the Kaplan–Meier method, and differences in survival between the groups were estimated using the log-rank test. Prognostic effects of TIL subset density were determined using the Cox regression analysis.

Results:

With a mean follow-up of 25 months (range, 2.3–63 months), OS at 2 years was 57.4% for the entire cohort. Patients with high immunohistochemical CD3 and CD8 expression had significantly increased OS (P=0.024 and P=0.028), PFS (P=0.044 and P=0.047) and DMFS (P=0.021 and P=0.026) but not LFFS (P=0.90 and P=0.104) in multivariate analysis that included predictive clinicopathologic factors, such as age, sex, T-stage, N-stage, tumour grading and localisation. Neither CD4 nor FOXP3 expression showed significance for the clinical outcome. The lower N-stage was associated with improved OS in the multivariate analysis (P=0.049).

Conclusion:

The positive correlation between a high number of infiltrating CD3+ and CD8+ cells and clinical outcome indicates that TILs may have a beneficial role in HNSCC patients and may serve as a biomarker to identify patients likely to benefit from definitive CRT.     

Detailed analysis of inflammatory cell infiltration in colorectal cancer

Background:

Higher-grade inflammatory infiltrate is a promising marker for better prognosis in colorectal cancer (CRC). However, the knowledge on the interrelationships between different inflammatory cells and classifications is fragmentary.

Methods:

We analysed the densities of eight types of inflammatory cells in a prospectively recruited group of 117 CRC patients and determined their interrelationships and contributions to Klintrup–Mäkinen (K–M) score of overall peritumoural inflammation. We characterised the inflammatory infiltrate in relation to stage and recurrences in 24-month follow-up.

Results:

There were high positive correlations between the inflammatory cell densities, with the exception of mast cells and CD1a⁺ immature dendritic cells. High K–M score associated with high peri- and intratumoural densities of CD3⁺, CD8⁺, CD68⁺, CD83⁺, and FoxP3⁺ cells and neutrophils. Advanced stage associated with low K–M score, as well as low CD3⁺, CD8⁺, CD83⁺, and FoxP3⁺ cell counts, of which low K–M score, low CD3⁺ T-cell count, and low FoxP3⁺ T-cell count were linked to higher recurrence rate.

Conclusion:

The density of CRC inflammatory infiltrate declines as stage advances. Especially, low K–M score and low T-cell counts predict higher recurrence rate. The high positive correlations between the individual inflammatory markers support the value of overall inflammatory reaction scoring.     

CD44s signals the acquisition of the mesenchymal phenotype required for anchorage-independent cell survival in hepatocellular carcinoma

Background:

Circulating tumour cells (CTCs) have an important role in metastatic processes, but details of their basic characteristics remain elusive. We hypothesised that CD44-expressing CTCs show a mesenchymal phenotype and high potential for survival in hepatocellular carcinoma (HCC).

Methods:

Circulating CD44⁺CD90⁺ cells, previously shown to be tumour-initiating cells, were sorted from human blood and their genetic characteristics were compared with those of tumour cells from primary tissues. The mechanism underlying the high survival potential of CD44-expressing cells in the circulatory system was investigated in vitro.

Results:

CD44⁺CD90⁺ cells in the blood acquired epithelial–mesenchymal transition, and CD44 expression remarkably increased from the tissue to the blood. In Li7 and HLE cells, the CD44^high population showed higher anoikis resistance and sphere-forming ability than did the CD44^low population. This difference was found to be attributed to the upregulation of Twist1 and Akt signal in the CD44^high population. Twist1 knockdown showed remarkable reduction in anoikis resistance, sphere formation, and Akt signal in HLE cells. In addition, mesenchymal markers and CD44s expression were downregulated in the Twist1 knockdown.

Conclusions:

CD44s symbolises the acquisition of a mesenchymal phenotype regulating anchorage-independent capacity. CD44s-expressing tumour cells in peripheral blood are clinically important therapeutic targets in HCC.     

The in situ local immune response,tumour senescence and proliferation in colorectal cancer

Background:

Immune cell infiltrates are important determinants of colorectal cancer (CRC) outcome. Their presence may be driven by tumour or host-specific factors. From previous studies in mice, senescence, a state of cell cycle arrest, may moderate tumour progression through upregulation of antitumour immune responses. The relationships between senescence and immune infiltrates have not previously been studied in humans. We explore whether a marker of senescence (p16^ink4a) in combination with low level expression of a proliferation marker (ki-67) relate to T cell infiltrates in CRC, and whether p16^ink4a, Ki-67 and immune infiltrates have similar prognostic value.

Methods:

Immunostaining of p16^inka and Ki-67 was performed within a CRC tissue microarray. Nuclear p16^inka and Ki-67 were categorised as high/low. T-cell markers, CD3, CD45RO, CD8 and FOXP3 were scored separately as high/low grade in three areas of the tumour: the invasive margin (IM), tumour stroma and cancer cell nests (CCNs).

Results:

Two hundred and thirty stage I–III cancers were studied. High nuclear p16^ink4a was expressed in 63% and high proliferation (Ki-67 >15%) in 61%. p16^ink4a expression was associated with reduced CD45RO+ cells at the IM (P<0.05) and within the stroma (P<0.05) and reduced CD8+ cells at the IM (P<0.01). A low Ki-67 proliferative index was associated with reduced density of CD3+ cells in CCNs (P<0.01), reduced CD45RO+ cells at the IM (P<0.05) and within the CCNs (P<0.001), reduced FOXP3+ cells at the IM (P<0.001), within the stroma (P=0.001) and within CCNs (P<0.001) and reduced CD8+ cells at the IM (P<0.05) and within the CCNs (P<0.05). Tumours with both a low proliferative index and expression of p16^ink4a demonstrated similar consistent relationships with reduced densities of T-cell infiltrates. On multivariate analysis, TNM stage (P<0.001), low CD3 cells at the IM (P=0.014), low CD8 cells at the IM (P=0.037), low proliferation (Ki-67; P=0.013) and low senescence (p16^ink4a; P=0.002) were independently associated with poorer cancer survival.

Conclusion:

Senescence, proliferation and immune cell infiltrates are independent prognostic factors in CRC. Although related to survival, p16^ink4a-associated senescence is not associated with an upregulation of antitumour T-cell responses.