Morphology and tumour-infiltrating lymphocytes in high-stage, high-grade serous ovarian carcinoma correlated with long-term survival

AIMS

Advanced-stage ovarian high-grade serous carcinoma (HGSC) is a poor-prognosis cancer; however, a small and poorly characterised subset of patients shows long-term survival. We aimed to establish a cohort of HGSC long-term survivors for histopathological and molecular analysis.

METHODS AND RESULTS

Paraffin blocks from 151 patients with primary FIGO III/IV HGSC and progression-free survival (PFS) >5 years were collected within the Tumorbank Ovarian Cancer (TOC) Network; 77 HGSC with a PFS <3 years were used as a control group. A standardised analysis of histological type and morphological features was performed. Ki67 index, tumour-infiltrating lymphocytes (TILs) and major histocompatibility complex expression (MHC1/2) were determined by immunohistochemistry. A total of 117 of 151 tumours (77.5%) in the long-term survivor group fulfilled the World Health Organisation (WHO) criteria of HGSC after review, and of these, 83 patients (70.9%) fulfilled all clinical criteria for inclusion into our cohort. Tumours of long-term survivors had significantly higher CD3⁺ and CD8⁺ TILs and were more frequently positive for MHC2 than controls (P = 0.004, P = 0.025, P = 0.048). However, there were also long-term survivors (up to 20%) with low TILs or low MHC expression. TILs and MHC had no impact on survival in long-term survivors. Morphological and Ki67 analysis revealed no differences between long-term survivors and controls.

CONCLUSIONS

HGSC from long-term survivors have higher-level T cell infiltration and antigen-presentation capacity; however, this is not a prerequisite for an excellent prognosis. Histopathological criteria are not capable to identify these patients. Further extensive clinical and molecular characterisation of this enigmatic subgroup is ongoing to understand the reasons of long-term survival in HGSC.

Liposomal Formulations to Modulate the Tumour Microenvironment and Antitumour Immune Response

Tumours are complex systems of genetically diverse malignant cells that proliferate in the presence of a heterogeneous microenvironment consisting of host derived microvasculature, stromal, and immune cells. The components of the tumour microenvironment (TME) communicate with each other and with cancer cells, to regulate cellular processes that can inhibit, as well as enhance, tumour growth. Therapeutic strategies have been developed to modulate the TME and cancer-associated immune response. However, modulating compounds are often insoluble (aqueous solubility of less than 1 mg/mL) and have suboptimal pharmacokinetics that prevent therapeutically relevant drug concentrations from reaching the appropriate sites within the tumour. Nanomedicines and, in particular, liposomal formulations of relevant drug candidates, define clinically meaningful drug delivery systems that have the potential to ensure that the right drug candidate is delivered to the right area within tumours at the right time. Following encapsulation in liposomes, drug candidates often display extended plasma half-lives, higher plasma concentrations and may accumulate directly in the tumour tissue. Liposomes can normalise the tumour blood vessel structure and enhance the immunogenicity of tumour cell death; relatively unrecognised impacts associated with using liposomal formulations. This review describes liposomal formulations that affect components of the TME. A focus is placed on formulations which are approved for use in the clinic. The concept of tumour immunogenicity, and how liposomes may enhance radiation and chemotherapy-induced immunogenic cell death (ICD), is discussed. Liposomes are currently an indispensable tool in the treatment of cancer, and their contribution to cancer therapy may gain even further importance by incorporating modulators of the TME and the cancer-associated immune response.

Predictive value of improvement in the immune tumour microenvironment in patients with breast cancer treated with neoadjuvant chemotherapy

Background

Tumour-infiltrating lymphocytes (TILs) can be used to monitor the immune tumour microenvironment (iTME) and predict treatment response and outcome in breast cancer. We evaluated the prognostic significance of the levels of CD8⁺ TILs and forkhead box protein (FOXP3)-positive TILs before and after neoadjuvant chemotherapy (NAC).

Patients and methods

We examined 136 patients with breast cancer treated with NAC. The number of CD8⁺ TILs and FOXP3⁺ TILs in biopsy specimens and residual tumours was evaluated by immunohistochemistry.

Results

Patients with a high rate of change in the CD8/FOXP3 ratio (CFR) had significantly better recurrence-free survival (RFS) (p<0.001, log-rank). In multivariate analysis, the rates of change in the CD8⁺ TIL levels and the CFR were independent predictors for RFS (HR=2.304, p=0.036 and HR=4.663, p<0.001). In patients with triple-negative and hormone receptor-positive breast cancer, the rate of change in the CFR was an independent predictor for RFS (HR=13.021, p=0.002 and HR=4.377, p=0.003).

Conclusion

Improvement in the iTME following NAC is correlated with good outcome. The rate of change in the CFR may be a useful biomarker to predict prognosis of patients treated with NAC.

The Impact of Immune Interaction on the Metastatic Infiltration of Colorectal Carcinoma to Lymph Nodes

BACKGROUND/AIM

Tumour-infiltrating lymphocytes (TILs) and Granzyme B play crucial roles in immune reactions against colorectal carcinoma (CRCa). The inhibitor of Granzyme B is Serpin B9. The aim of this study was to evaluate the effect of immunohistological parameters of TILs on the prognosis of CRCa and presence of lymph node metastasis.

PATIENTS AND METHODS

A total of 152 patients who underwent surgery for CRCa were analyzed, including 63 patients in cohort stage II, according to the Union for International Cancer Control (UICC), and 89 patients in cohort UICC stage III. The TIL pattern was classified as peritumoural (PTL), intratumoural (ITL), intrastromal (ISL) or Crohn-like, and immunohistological staining of TIL and cancer cells was also performed.

RESULTS

A significantly higher density of CD8⁺ and CD4⁺ TILs was observed in the UICC II group, and significantly higher densities of CD4⁺ TILs were observed in the UICC II group in all distinguished patterns. In the same cohort, higher numbers of CD57⁺ cells and FoxP3⁺ TILs and Granzyme B levels were observed. In cohort UICC III, there was a higher density of ISL, PTL CD8⁺, CD25⁺ TILs and cancer cells showed staining for Serpin B9. CD57, Granzyme B and CD8 were demonstrated as positive prognostic factors of overall survival, and CD57 and CD4⁺ TILs were demonstrated as positive prognostic factors of recurrence.

CONCLUSION

TILs and CD57 are promising prognostic factors of CRCa. The association of Serpin B9 with lymph node metastasis reveals a potential mechanism for tumour resistance to immune reaction.

Possible Application of Ascites-infiltrating Gamma-delta T Cells for Adoptive Immunotherapy

BACKGROUND/AIM

Malignant ascites contain many tumour-infiltrating lymphocytes. γδ T cells with antitumour activity have attracted attention as effector cells in cancer immunotherapy. Vδ₂⁺ T cells were cultured from peripheral blood mononuclear cells (PBMCs) and ascites-infiltrating lymphocytes (AILs) to compare the differences in response to 2-methyl-3-butenyl-1-pyrophosphate (2M3B1-PP) and zoledronate (Zol) as antigens in vitro.

MATERIALS AND METHODS

To expand Vδ₂⁺ T cells from PBMCs and AILs from 29 patients with cancer, these cells were cultured and subjected to analysis.

RESULTS

The proliferation rate of Vδ₂⁺ T cells was higher in both PBMCs and AILs when cultured with Zol than with 2M3B1-PP. Although Vδ₂⁺ T cells show a higher rate of expansion in AILs compared to PBMCs, the number of mixed tumour cells in ascites was decreased when cultured with Zol.

CONCLUSION

Vδ₂⁺ T cells in AILs are cytotoxic to tumour cells in ascites and may be considered in adoptive immunotherapy.

Morphology and tumour-infiltrating lymphocytes in high-stage, high-grade serous ovarian carcinoma correlated with long-term survival

AIMS

Advanced-stage ovarian high-grade serous carcinoma (HGSC) is a poor-prognosis cancer; however, a small and poorly characterised subset of patients shows long-term survival. We aimed to establish a cohort of HGSC long-term survivors for histopathological and molecular analysis.

METHODS AND RESULTS

Paraffin blocks from 151 patients with primary FIGO III/IV HGSC and progression-free survival (PFS) >5 years were collected within the Tumorbank Ovarian Cancer (TOC) Network; 77 HGSC with a PFS <3 years were used as a control group. A standardised analysis of histological type and morphological features was performed. Ki67 index, tumour-infiltrating lymphocytes (TILs) and major histocompatibility complex expression (MHC1/2) were determined by immunohistochemistry. A total of 117 of 151 tumours (77.5%) in the long-term survivor group fulfilled the World Health Organisation (WHO) criteria of HGSC after review, and of these, 83 patients (70.9%) fulfilled all clinical criteria for inclusion into our cohort. Tumours of long-term survivors had significantly higher CD3⁺ and CD8⁺ TILs and were more frequently positive for MHC2 than controls (P = 0.004, P = 0.025, P = 0.048). However, there were also long-term survivors (up to 20%) with low TILs or low MHC expression. TILs and MHC had no impact on survival in long-term survivors. Morphological and Ki67 analysis revealed no differences between long-term survivors and controls.

CONCLUSIONS

HGSC from long-term survivors have higher-level T cell infiltration and antigen-presentation capacity; however, this is not a prerequisite for an excellent prognosis. Histopathological criteria are not capable to identify these patients. Further extensive clinical and molecular characterisation of this enigmatic subgroup is ongoing to understand the reasons of long-term survival in HGSC.

Pre-treatment CD8+ tumour-infiltrating lymphocyte density predicts distant metastasis after definitive treatment in patients with stage III/IV hypopharyngeal squamous cell carcinoma

OBJECTIVES

Although inflammatory markers, such as the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio and local immune markers have been shown to have prognostic utility, limited information is available regarding inflammatory and pre-existing tumour-infiltrating lymphocyte density and their association with prognosis in patients with hypopharyngeal squamous cell carcinoma. We investigated the prognostic ability of inflammatory markers and tumour-infiltrating lymphocyte density in stage III and stage IV hypopharyngeal squamous cell carcinoma patients receiving definitive treatment.

DESIGN

Retrospective cohort study.

SETTING

Kurume University Hospital.

PARTICIPANTS

Ninety-six stage III or stage IV hypopharyngeal squamous cell carcinoma patients treated at the Kurume University Hospital between 2000 and 2014.

MAIN OUTCOME MEASURES

Inflammatory markers and pre-treatment tumour-infiltrating lymphocyte density were examined from recorded haematologic data and immunohistochemical analysis.

RESULTS

Multivariate analyses showed that the CD8⁺ tumour-infiltrating lymphocyte density was an independent predictive factor for distant metastasis and overall survival, whereas inflammatory markers, including the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio, were not correlated with distant metastasis or overall survival.

CONCLUSIONS

Higher pre-treatment CD8⁺ tumour-infiltrating lymphocyte density is a useful predictive biomarker for reduced distant metastasis and better prognosis.

Importance of choice of materials and methods in PD-L1 and TIL assessment in oropharyngeal squamous cell carcinoma

AIMS

A great deal of research is being conducted into PD-L1 immunohistochemistry (IHC) and tumour-infiltrating lymphocytes (TILs) as predictive or prognostic biomarkers for immunotherapy, although several practical issues exist concerning their assessment. The aim of this research was therefore to assess the importance of choice of materials and methods in PD-L1 and TILs scoring in oropharyngeal squamous cell carcinoma (OSCC).

METHODS AND RESULTS

IHC for PD-L1 (SP142 and 22C3 clone) and TILs subtyping was performed on formalin-fixed paraffin-embedded tissue slides (biopsy, resection and/or lymph nodes specimens) of 99 patients with OSCC. A comparative analysis of PD-L1 and TILs scoring was made between different types of tissue specimens, between different PD-L1 clones, between TILs and different subsets of TILs and between the quantitative and semiquantitative assessments. PD-L1 scoring resulted in fair to moderate agreement for 22C3 and SP142 between various tissue specimens, with higher agreement at higher cut-off values, and in moderate agreement for 22C3 versus SP142. Evaluation by four independent observers proved substantial inter-rater agreement for both clones with high consistency in their ratings. Moderate agreement was observed for TILs and TILs subsets for the comparison between biopsy and resection. Lastly, strong correlations were found between quantitative and semiquantitative assessment for all PD-L1 and TILs scores.

CONCLUSIONS

Our results highlight the challenges associated with the evaluation of PD-L1 and TILs in OSCC. Further research is warranted to evaluate the use of these biomarkers in order to allow implementation of PD-L1 and TILs infiltrate as biomarkers in daily clinical practice.

PD-L1 expression in tumour-infiltrating lymphocytes is a poor prognostic factor for primary acral melanoma patients

AIMS

Programmed cell death protein 1-programmed death-ligand 1 (PD-L1) blockade immunotherapy has shown notable therapeutic benefit in metastatic melanoma, but the clinical relevance of PD-L1 expression remains unclear in melanoma, especially in acral melanoma, which is the most common subtype in Asians. The aim of this study was to evaluate the clinical effect of PD-L1 expression in primary acral melanoma.

METHODS AND RESULTS

We used immunohistochemistry to evaluate PD-L1 expression in tumour cells and tumour-infiltrating lymphocytes (TILs), and analysed its associations with clinicopathological features and survival in 78 primary acral melanoma patients. We found that expression of PD-L1 in tumour cells and TILs occurred exclusively in a tumour-stroma interface pattern, consistent with the predominant pattern of TIL distribution. The presence of peritumoral TILs was also associated with high PD-L1 expression in tumour cells. Furthermore, PD-L1 expression in tumour cells and that in TILs showed a close relationship (Spearman's rho = 0.381, P = 0.001). However, neither PD-L1 expression in tumour cells nor that in TILs was significantly correlated with clinicopathological features. In univariate analysis, cases with PD-L1-positive TILs had significantly poorer survival than those with PD-L1-negative TILs (median disease-specific survival of 40.7 months versus 78.0 months; P = 0.008). In multivariate analysis, PD-L1 expression in TILs was an independent factor for poor prognosis (P = 0.032), whereas PD-L1 expression in tumour cells was not significantly correlated with survival in univariate analysis (P = 0.378) and multivariate analysis (P = 0.354).

CONCLUSION

This is the first study to demonstrate that PD-L1 expression in TILs, but not that in tumour cells, is an independent predictor of poor prognosis in acral melanoma.

Expression of PD-L1, indoleamine 2,3-dioxygenase and the immune microenvironment in gastric adenocarcinoma

AIMS

The tumour microenvironment is increasingly important in several tumours. We studied the relationship of key players of immune microenvironment with clinicopathological parameters in gastric adenocarcinomas.

METHODS AND RESULTS

Tissue microarrays were constructed from gastrectomy specimens, 2004-13. Immunohistochemistry was performed for programmed cell death ligand 1 (PD-L1), indoleamine 2,3-dioxygenase (IDO), tryptophanyl-tRNA synthetase (WARS), guanylate-binding protein 5 (GBP5), tumour-infiltrating lymphocytes (TIL) expressing CD3/CD8/FoxP3/PD1 and mismatch repair proteins (MMRs) MLH1, PMS2, MSH2 and MSH6. Clinicopathological parameters and clinical follow-up were recorded. The study included 86 patients; median follow-up was 34 months (0-148). Tumour types were 45% tubular, 38% diffuse, 17% mixed. PD-L1 was positive in 70%, epithelial IDO in 58%, stromal IDO in 91%, epithelial WARS in 67%, stromal WARS in 100%, epithelial GBP5 in 53% and stromal GBP5 in 71%. MMR-deficiency was found in 22%. There was no difference in biomarker expression by histological subtype, with the exception of fewer diffuse-type being MMR-deficient. Low stromal IDO was associated with decreased progression-free, overall and disease-specific survival. PD-L1-positive tumours were larger with MMR-deficiency and with increasing TILs, and had significantly higher FoxP3TILs.

CONCLUSIONS

PD-L1 is expressed in a large proportion of gastric carcinomas, suggesting that therapy targeting this pathway could be relevant to many patients. PD-L1 expression and MMR-deficiency are associated with increased TILs and larger tumour size, emphasising their role in tumour biology. Higher stromal IDO expression is associated with better prognosis. Finally, we observed that immune modulators WARS and GBP5 are expressed highly in gastric adenocarcinomas, suggesting an important role in tumour pathobiology.

Spatial distribution of FoxP3+ and CD8+ tumour infiltrating T cells reflects their functional activity

BACKGROUND

Regulatory and cytotoxic T cells are key players in the host's anticancer immune response. We studied the spatial distribution of FoxP+ and CD8+ cells to identify potential interactions.

METHODS

In 202 patients 103 pre-radiochemotherapy biopsies and 153 post-radiochemotherapy tumour specimens of advanced rectal cancer were available and an immunohistochemical double staining of FoxP3+ and CD8+ tumour-infiltrating lymphocytes was performed to investigate cell density and cell-to-cell distances.

RESULTS

FoxP3+ cells decreased after radiochemotherapy by a factor of 3 while CD8+ cells remained nearly unchanged. High epithelial (p=0.033) and stromal (p=0.009) FoxP3+ cell density was associated with an improved overall survival. Cell-to-cell distances of randomly distributed cells were simulated and compared to observed cell-to-cell distances. Observed distances shorter than the simulated, random distances were hypothesized to represent FoxP3+ cells actively interacting with CD8+ cells. Epithelial short distances were associated with a favourable prognosis while the opposite was true for the stromal compartment.

CONCLUSION

The analysis of cell-to-cell distances may offer a tool to predict outcome, maybe by identifying functionally active, interacting infiltrating inflammatory cells in different tumour compartments.

Intratumoural PD-L1 expression is associated with worse survival of patients with Epstein-Barr virus-associated gastric cancer

BACKGROUND

This study investigated the clinical relevance and prognostic impact of the overall expression of programmed cell death protein ligand-1 (PD-L1) and programmed cell death protein ligand-2 (PD-L2), in patients with Epstein-Barr virus-associated gastric cancer (EBVaGC).

METHODS

After reviewing 1318 consecutive cases of surgically resected or endoscopic submucosal dissected gastric cancers, the expression status of PD-L1 and PD-L2 in 120 patients with EBVaGC identified by EBV-encoded RNA in situ hybridisation was retrospectively analysed using immunohistochemistry (IHC). For each IHC marker, positivity was separately in intraepithelial tumour cells (iTu-) and immune cells in the tumour stroma area (str-).

RESULTS

Among 116 eligible patients, 57 (49.1%) and 66 patients (56.9%) were determined as iTu-PD-L1-positive and str-PD-L1-positive, respectively, whereas 23 (21.6%) and 45 patients (38.8%) were determined as iTu-PD-L2 positive and str-PD-L2 positive, respectively. Intraepithelial tumour cell PD-L1 positivity was found to be significantly associated with lymph node (LN) metastasis (P=0.012) and a poor disease-free survival (DFS) (P=0.032), yet not overall survival (P=0.482). In a multivariate analysis, iTu-PD-L1 positivity was independently associated with a poor DFS (P=0.006, hazard ratio=12.085). In contrast, str-PD-L2-positivity was related to a lower T category (P=0.003), absence of LN metastasis (P=0.032) and perineural invasion (P=0.028). Intraepithelial tumour cell and str-PD-L2 positivity showed a trend towards an improved DFS, although not significant (P=0.060 and P=0.073, respectively).

CONCLUSIONS

Intraepithelial tumour cells PD-L1 expression can be used to predict a poor outcome in patients with EBVaGC and can represent a rational approach for PD-1/PD-L pathway-targeted immunotherapy.

ADAR1 expression is associated with tumour-infiltrating lymphocytes in triple-negative breast cancer

Tumours with a high mutation burden exhibit considerable neoantigens and tumour-infiltrating lymphocytes. RNA editing by ADAR1 is a source of changes in epitope. However, ADAR1 expression in cancer cells and tumour-infiltrating lymphocyte levels in triple-negative breast cancer have not been well evaluated. We immunohistochemically examined ADAR1 expression in 681 triple-negative breast cancer patients and analysed their clinicopathological characteristics. We also analysed basal-like tumours using The Cancer Genome Atlas data. Among the 681 triple-negative breast cancer patients, 45.8% demonstrated high ADAR1 expression. Tumours with high ADAR1 expression exhibited high tumour-infiltrating lymphocyte levels, considerable CD8 + T lymphocyte infiltration, high histological grade and high expression of interferon-related proteins, including HLA-ABC, MxA and PKR. Among patients with lymph node metastasis, those with high tumour-infiltrating lymphocyte levels and low ADAR1 expression demonstrated the best disease-free survival. The Cancer Genome Atlas data analysis of basal-like tumours revealed significant positive correlation between ADAR1 and CD8B expression and positive association of high ADAR1 expression with immune responses and apoptosis pathways. We detected high ADAR1 expression in half of the triple-negative breast cancer patients. In addition to DNA mutations, RNA editing can be related to neoantigens; hence, we need to explore non-synonymous mutations exclusively found using RNA sequencing data to identify clinically relevant neoantigens.

Tumour infiltrating lymphocytes are predictors of lymph node metastasis in early gastric cancers

Lymph node metastasis (LNM) is an important factor for predicting prognosis and selecting appropriate treatment in early gastric cancers (EGCs). We investigated the histopathological and microenvironmental predictors of LNM in EGCs. We retrieved 43 cases of EGC without LNM and 59 cases with LNM. Clinicopathological variables and tumour-infiltrating lymphocytes (TILs), Crohn's-like lymphoid reaction (CLR), tumour stromal percentage (TSP), and FOXA1 expression were evaluated and correlated with LNM. Among the 102 cases, 68 cases (66.7%) had low TILs and 34 cases (33.3%) had high TILs. High TILs were significantly correlated with the absence of LNM (p<0.001), less extent of invasion (p=0.004), absence of LVI (p=0.035), conspicuous CLR (p<0.001), and the absence of TSP (p=0.009). Conspicuous CLR was observed in 47 cases (46.1%) and TSP was present in 17 cases (16.7%) and neither was correlated with LNM. High FOXA1 expression was significantly associated with presence of LNM, low TILs, and submucosal invasion. In multivariate analysis, low TILs (p=0.023), LVI (p=0.008), and submucosal invasion (p=0.001) were independent predictive factors for LNM in EGCs. Evaluation of TILs in biopsied or endoscopically resected EGC specimens may help to predict LNM and select subsequent proper treatment modalities and follow-up.

Predictive and prognostic impact of tumour-infiltrating lymphocytes in triple-negative breast cancer treated with neoadjuvant chemotherapy

INTRODUCTION

In locally and locally advanced triple-negative breast cancer (TNBC), neoadjuvant chemotherapy (NAC) only induces a pCR in 30-35% of patients. Clinical and pathological factors are not enough to distinguish the patients who have no chance of a pCR or not. The tumour microenvironment is critical for cancer and tumour-infiltrating lymphocytes (TIL). Moreover, the NAC scenario is the perfect setting to study possible changes in TIL levels.

MATERIAL AND METHODS

Using our prospective maintained breast cancer (BC) database, we identified 164 TNBC patients treated with NAC between 1998 and 2015 with enough samples of diagnostic biopsy and after surgery. Evaluation of TILs before and after NAC followed a standardised methodology for visual assessment on haematoxylin-eosin sections and the amounts of TILs were quantitated in deciles. We categorised lymphocyte-predominant breast cancer cutoff according to a receiver operating characteristic (ROC) analysis. We categorised LPBC as involving > 40% lymphocytic infiltration tumour stroma. The primary end point was predictive value of TILs to NAC, and the secondary end point was disease-free survival (DFS). DFS was analysed using the Kaplan-Meier method and the groups were compared with a long-rank test. Univariate and multivariate Cox models were used to generate hazard ratios for determining associations between variables such as TIL after NAC and DFS.

RESULTS

A total of 164 TNBC patients were treated with NAC and surgery. The main patients' characteristics are listed in Table 1. We identify different pathological complete response to anthracycline and taxane-based NAC; LPBC subgroup 51 from 58 patients (88%) pCR versus non- lymphocyte-predominant breast cancer (LPBC) subgroup 10 from 106 (9%) pCR, p = 0.001. At a median follow-up of 78 months, LPBC was associated with better DFS; the three-year Kaplan-Meier estimates for DFS were 2% and 30 % for patients with LPBC and non-LPBC, respectively, p = 0.01. Univariate and multivariate analysis confirmed TIL to be an independent prognostic marker of DFS.

CONCLUSIONS

Tumour-infiltrating lymphocytes could be routinely used in locally advanced TNBC treated with anthracycline and taxane, such as biomarker, to be enabled the identification of different two subgroups: LPBC patients have a very high response to NAC pCR 88%, meanwhile non-LPBC patients only achieve 9%. Moreover, non-LPBC patients have a worse prognosis than LPBC patients. This data verified the predictive and prognostic value of TIL.

Lymphocyte density determined by computational pathology validated as a predictor of response to neoadjuvant chemotherapy in breast cancer: secondary analysis of the ARTemis trial

BACKGROUND

We have previously shown lymphocyte density, measured using computational pathology, is associated with pathological complete response (pCR) in breast cancer. The clinical validity of this finding in independent studies, among patients receiving different chemotherapy, is unknown.

PATIENTS AND METHODS

The ARTemis trial randomly assigned 800 women with early stage breast cancer between May 2009 and January 2013 to three cycles of docetaxel, followed by three cycles of fluorouracil, epirubicin and cyclophosphamide once every 21 days with or without four cycles of bevacizumab. The primary endpoint was pCR (absence of invasive cancer in the breast and lymph nodes). We quantified lymphocyte density within haematoxylin and eosin (H&E) whole slide images using our previously described computational pathology approach: for every detected lymphocyte the average distance to the nearest 50 lymphocytes was calculated and the density derived from this statistic. We analyzed both pre-treatment biopsies and post-treatment surgical samples of the tumour bed.

RESULTS

Of the 781 patients originally included in the primary endpoint analysis of the trial, 609 (78%) were included for baseline lymphocyte density analyses and a subset of 383 (49% of 781) for analyses of change in lymphocyte density. The main reason for loss of patients was the availability of digitized whole slide images. Pre-treatment lymphocyte density modelled as a continuous variable was associated with pCR on univariate analysis (odds ratio [OR], 2.92; 95% CI, 1.78-4.85; P < 0.001) and after adjustment for clinical covariates (OR, 2.13; 95% CI, 1.24-3.67; P = 0.006). Increased pre- to post-treatment lymphocyte density showed an independent inverse association with pCR (adjusted OR, 0.1; 95% CI, 0.033-0.31; P < 0.001).

CONCLUSIONS

Lymphocyte density in pre-treatment biopsies was validated as an independent predictor of pCR in breast cancer. Computational pathology is emerging as a viable and objective means of identifying predictive biomarkers for cancer patients.

CLINICALTRIALS.GOV

NCT01093235.

Small Bowel Carcinomas in Coeliac or Crohn's Disease: Clinico-pathological, Molecular, and Prognostic Features. A Study From the Small Bowel Cancer Italian Consortium

BACKGROUND AND AIMS

An increased risk of small bowel carcinoma [SBC] has been reported in coeliac disease [CD] and Crohn's disease [CrD]. We explored clinico-pathological, molecular, and prognostic features of CD-associated SBC [CD-SBC] and CrD-associated SBC [CrD-SBC] in comparison with sporadic SBC [spo-SBC].

METHODS

A total of 76 patients undergoing surgical resection for non-familial SBC [26 CD-SBC, 25 CrD-SBC, 25 spo-SBC] were retrospectively enrolled to investigate patients' survival and histological and molecular features including microsatellite instability [MSI] and KRAS/NRAS, BRAF, PIK3CA, TP53, HER2 gene alterations.

RESULTS

CD-SBC showed a significantly better sex-, age-, and stage-adjusted overall and cancer-specific survival than CrD-SBC, whereas no significant difference was found between spo-SBC and either CD-SBC or CrD-SBC. CD-SBC exhibited a significantly higher rate of MSI and median tumour-infiltrating lymphocytes [TIL] than CrD-SBC and spo-SBC. Among the whole SBC series, both MSI─which was the result of MLH1 promoter methylation in all but one cases─and high TIL density were associated with improved survival at univariable and stage-inclusive multivariable analysis. However, only TILs retained prognostic power when clinical subgroups were added to the multivariable model. KRAS mutation and HER2 amplification were detected in 30% and 7% of cases, respectively, without prognostic implications.

CONCLUSIONS

In comparison with CrD-SBC, CD-SBC patients harbour MSI and high TILs more frequently and show better outcome. This seems mainly due to their higher TIL density, which at multivariable analysis showed an independent prognostic value. MSI/TIL status, KRAS mutations and HER2 amplification might help in stratifying patients for targeted anti-cancer therapy.

No additional prognostic value for MRE11 in squamous cell carcinomas of the anus treated with chemo-radiotherapy

BACKGROUND

The majority of anal cancers (84-95%) are driven by infection with human papillomavirus (HPV). HPV-positive tumours show significantly better responses to chemo-radiotherapy when compared with HPV-negative tumours. HPV infection is linked to alterations in DNA damage response proteins, including MRE11. MRE11 is a potential predictive biomarker for response to radiotherapy in muscle-invasive bladder cancer and may hold predictive power in other cancers.

METHODS

Using a previously reported cohort, we evaluated the levels of MRE11 in anal cancer and assessed its predictive value in this disease.

RESULTS

We found no association between the level of MRE11 and relapse-free survival following chemo-radiotherapy.

CONCLUSIONS

MRE11 has no predictive value in the analysis of relapse-free survival after chemo-radiotherapy in anal cancer and does not add to the prognostic value of p16 and tumour-infiltrating lymphocyte scores. Further investigation into the role of DNA repair proteins in anal cancer is required.

PD-L1 expression in extrahepatic cholangiocarcinoma

AIMS

To investigate the expression of the programmed cell death 1 (PD-1) receptor-programmed cell death ligand 1 (PD-L1) pathway and the clinicopathological characteristics in extrahepatic cholangiocarcinoma (eCCA).

METHODS AND RESULTS

Tissue samples from patients with eCCA [n = 69; perihilar cholangiocarcinoma (CCA), 40; and distal CCA, 29] who underwent surgical resection in the period from 2007 to 2015 were evaluated for PD-1, PD-L1, CD3 and CD163 expression, and correlations with clinicopathological characteristics, including survival data, were determined. PD-L1 was found on both tumour cells of eCCA (8/69, 11.6%) and tumour-associated macrophages (21/69, 30.4%). Significant correlations of PD-L1 expression on cancer cells with venous invasion (P = 0.031) and poor differentiation of the tumour (P = 0.048) were observed. In 19 of 69 (27.5%) samples, tumour-infiltrating lymphocytes (TILs) expressed PD-1, whereas infiltration with CD3-positive and CD163-positive cells was found in 63 of 69 (91.3%) and 68 of 69 (98.6%) cases, respectively. The presence of fewer than five CD3-positive cells per high-power field was significantly correlated with poorer differentiation (P = 0.015) and venous invasion (P < 0.001) of CCA. PD-L1 expression was not correlated with patient survival, but PD-L1 expression on tumour cells combined with low infiltration of CD3-positive TILs was associated with an unfavourable outcome (P = 0.027).

CONCLUSION

Only a small number of eCCA patients are PD-L1-positive, which might be important for future application of PD-1/PD-L1-targeted immune-modulating therapy in these patients. A small subgroup of eCCAs with PD-L1 expression and low lymphocytic infiltration showed more invasive growth and worse overall survival.

Suppression of murine tumour growth through CD8+ cytotoxic T lymphocytes via activated DEC-205+ dendritic cells by sequential administration of α-galactosylceramide in vivo

Cancer immunity is mediated through the effective priming and activation of tumour‐specific class I MHC molecule‐restricted CD8⁺ cytotoxic T lymphocytes (CTLs). DEC‐205⁺ dendritic cells (DCs) can cross‐present the epitope(s) of captured tumour antigens associated with class I MHC molecules alongside co‐stimulatory molecules to prime and activate tumour‐specific CD8⁺CTLs. Immunosuppressive tolerogenic DCs with reduced co‐stimulatory molecules may be a cause of impaired CTL induction. Hepa1‐6‐1 cells were established from the mouse hepatoma cell line Hepa1‐6; these cells grow continuously after subcutaneous implantation into syngeneic C57BL/6 (B6) mice and do not prime CD8⁺CTLs. In this study, we show that the growth of ongoing tumours was suppressed by activated CD8⁺CTLs with tumour‐specific cytotoxicity through the administration of the glycolipid α‐galactosylceramide (α‐GalCer), which is a compound known to stimulate invariant natural killer T (iNKT) cells and selectively activate DEC‐205⁺DCs. Moreover, we demonstrated that sequential repetitive intraperitoneal inoculation with α‐GalCer every 48 hr appeared to convert tolerogenic DEC‐205⁺DCs into immunogenic DCs with a higher expression of co‐stimulatory molecules and a stronger cross‐presentation capacity, which primed CTL precursors and induced tumour‐specific CD8⁺CTLs within the tumour environment without activating iNKT cells. These findings provide a new basis for cancer immunotherapy to convert tolerogenic DEC‐205⁺DCs within tumours into immunogenic DCs through the sequential administration of an immuno‐potent lipid/glycolipid, and then activated immunogenic DCs with sufficient expression of co‐stimulatory molecules prime and activate tumour‐specific CD8⁺CTLs within the tumour to control tumour growth.

Next-generation TCR sequencing - a tool to understand T-cell infiltration in human cancers

Tumour-infiltrating lymphocytes (TILs) are known to mediate potent anti-tumour activity. As T-cell-based therapies start to reach clinical practice, it becomes increasingly important to understand what characterizes a successful anti-tumour T-cell response and to exploit this knowledge for patient stratification. Next-generation sequencing of T-cell receptors (TCRs) promises to provide insights into the complexity of the tumour T-cell infiltrate that go beyond the phenotypic level. A recent study by Chen et al made use of this novel technology to demonstrate that the TIL repertoire of oesophageal squamous cell carcinoma patients is distinct from that of non-tumour sites and is characterized by significant intratumoural heterogeneity. This study illustrates the great potential of the method and addresses several technical and biological hurdles that need to be considered. Careful sampling, normalization, and error correction will be required to optimally use TCR sequencing to answer biological questions and define predictive biomarkers, e.g. for cancer immunotherapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

T cell receptor β-chain repertoire analysis reveals intratumour heterogeneity of tumour-infiltrating lymphocytes in oesophageal squamous cell carcinoma

Oesophageal squamous cell carcinoma (ESCC) has a generally poor prognosis, due to the lack of effective treatment methods. Immunotherapeutic approaches based on tumour-infiltrating lymphocytes (TILs) have demonstrated that durable responses are produced in some patients with solid tumours, which suggests the potential feasibility of clinical application of immunotherapy for ESCC. However, many of the basic characteristics of TILs in ESCC are poorly understood, including clonality, specificity and spatial heterogeneity of the response of TILs, which depends on the interaction between antigens and T cell receptors (TCRs). We used ultra-deep sequencing of rearranged genes in TCR β-chain (TCRβ) to profile the basic characteristics of T cells in tumour tissues (four to six regions from each tumour) as well as matched adjacent normal tissue and peripheral blood from seven patients diagnosed with primary ESCC. We found that T cell clones within ESCCs were quite different from those of the peripheral blood and even the adjacent normal tissues in general. Although there was a relatively higher degree of overlap of intratumoural TCRβ repertoires than those between the tumour and other tissues, intratumoural TCRβ repertoires were spatially heterogeneous. Due to the restricted sampling, high-throughput TCRβ sequencing could characterize the diversity and composition of a limited (compartment-dependent) fraction of the respective T cell clones in any individual ESCC, expanding our understanding of immune behaviour and immune response and shedding more light on ESCC immunotherapy. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Intra-tumoral IFN-γ-producing Th22 cells correlate with TNM staging and the worst outcomes in pancreatic cancer

PDAC (pancreatic ductal adenocarcinoma) is the fifth leading cause of cancer-related death. The causes of this cancer remain unknown, but increasing evidence indicates a key role of the host immune response and cytokines in human carcinogenesis. Intra-tumoral IL (interleukin)-22 levels have been shown to be elevated in PDAC patients. However, little is known regarding the expression and clinical relevance of Th22 cells in human PDAC and, furthermore, which TILs (tumour-infiltrating lymphocytes) are the main producers of IL-22 is unknown. In the present study, we characterized the functional proprieties of the different subsets of IL-22-producing TILs and analysed their relationship with the TNM staging system and patient survival. We have demonstrated for the first time that, in PDAC patients, the T-cells co-producing IFN-γ (interferon γ) and exerting perforin-mediated cytotoxicity are the major intra-tumoral source of IL-22. In addition, isolated Th22 cells were able to induce apoptosis, which was antagonized by IL-22. Finally, we observed that the IL-22-producing T-cells were significantly increased in tumour tissue and that this increase was positively correlated with TNM staging of PDAC and poorer patient survival. These novel findings support the dual role of the anti-tumour immune system and that IL-22-producing cells may participate in PDAC pathogenesis. Therefore monitoring Th22 levels could be a good diagnostic parameter, and blocking IL-22 signalling may represent a viable method for anti-PDAC therapies.

Programmed death ligand 1 expression in triple-negative breast cancer is associated with tumour-infiltrating lymphocytes and improved outcome

AIMS

Triple-negative breast cancer (TNBC) patients generally have a poor outcome; there is a pressing need to identify more effective therapeutic strategies. Clinical trials targeting programmed death 1/programmed death ligand 1 (PD1/PDL1) in melanoma and non-small-cell lung cancer have reported high response rates, and tumoral PDL1 expression has been suggested as a potential biomarker to enrich for patient response to these treatments. There are only very limited data to date reporting the expression of PDL1 in TNBC.

METHODS AND RESULTS

PDL1 immunohistochemistry was performed on 161 primary TNBCs and assessed in the tumour as well as immune cells in the stromal compartment. PDL1 expression was very common in TNBC, expressed in the tumour cell membrane (64%), cytoplasm (80%) and stromal (93%) cellular compartments. Cytoplasmic tumoral expression of PDL1 was associated with a lower risk of breast cancer-specific death [hazard ratio (HR) 0.45, P = 0.035] while stromal PDL1 expression was associated with a lower rate of deaths from all causes (HR 0.305, P = 0.0042). Membranous expression of PDL1 was not associated with outcome. While both PDL1 expression and tumour-infiltrating lymphocytes were associated with a better outcome, only lymphovascular invasion and high tumour-infiltrating lymphocytes were independently prognostic for breast cancer-specific death.

CONCLUSION

While PDL1 expression is frequent in TNBC, it was not independently prognostic. There were differences in outcome depending on the cellular compartment of PDL1 expression. These data provide further impetus for investigating the utility of immune checkpoint therapies in TNBC, given the clinical significance of tumour-infiltrating lymphocytes (TILs) and PDL1 expression in this cohort.

Comparative study of various subpopulations of cytotoxic cells in blood and ascites from patients with ovarian carcinoma

AIM OF THE STUDY

A number of observations have indicated that the immune system plays a significant role in patients with epithelial ovarian cancer (EOC). In cases of EOC, the prognostic significance of tumour infiltrating lymphocytes has not been clearly explained yet. The aim is to determine the phenotype and activation molecules of cytotoxic T cell and NK cell subpopulations and to compare their representation in malignant ascites and peripheral blood in patients with ovarian cancer.

MATERIAL AND METHODS

Cytotoxic cells taken from blood samples of the cubital vein and malignant ascites were obtained from 53 patients with EOC. Their surface and activation characteristics were determined by means of a flow cytometer. Immunophenotype multiparametric analysis of peripheral blood lymphocytes (PBLs) and tumour infiltrating lymphocytes (TILs) was carried out.

RESULTS

CD3(+) T lymphocytes were the main population of TILs (75.9%) and PBLs (70.9%). The number of activating T cells was significantly higher in TILs: CD3(+)/69(+) 6.7% vs. 0.8% (p < 0.001). The representation of (CD3(-)/16(+)56(+)) NK cells in TILs was significantly higher: 11.0% vs. 5.6% (p = 0.041); likewise CD56(bright) and CD-56(bright) from CD56(+) cells were higher in TILs (both p < 0.001). The activation receptor NKG2D was present in 45.1% of TILs vs. 32.3% of PBLs (p = 0.034), but we did not find a significant difference in the numbers of CD56(+)/NKG2D(+) in TILs and PBLs.

CONCLUSIONS

These results prove that the characteristics and intensity of anti-tumour responses are different in compared compartments (ascites/PBLs). The knowledge of phenotype and functions of effector cells is the basic precondition for understanding the anti-tumour immune response.

Messenger RNA encoding constitutively active Toll-like receptor 4 enhances effector functions of human T cells

Adoptive T cell therapy of cancer employs a large number of ex-vivo-propagated T cells which recognize their targets either by virtue of their endogenous T cell receptor (TCR) or via genetic reprogramming. However, both cell-extrinsic and intrinsic mechanisms often diminish the in-vivo potency of these therapeutic T cells, limiting their clinical efficacy and broader use. Direct activation of human T cells by Toll-like receptor (TLR) ligands induces T cell survival and proliferation, boosts the production of proinflammatory cytokines and augments resistance to regulatory T cell (Treg) suppression. Removal of the TLR ligand-binding region results in constitutive signalling triggered by the remaining cytosolic Toll/interleukin-1 receptor (TIR) domain. The use of such TIR domains therefore offers an ideal means for equipping anti-tumour T cells with the arsenal of functional attributes required for improving current clinical protocols. Here we show that constitutively active (ca)TLR-4 can be expressed efficiently in human T cells using mRNA electroporation. The mere expression of caTLR-4 mRNA in polyclonal CD8 and CD4 T cells induced the production of interferon (IFN)-γ, triggered the surface expression of CD25, CD69 and 4-1BB and up-regulated a panel of cytokines and chemokines. In tumour-infiltrating lymphocytes prepared from melanoma patients, caTLR-4 induced robust IFN-γ secretion in all samples tested. Furthermore, caTLR-4 enhanced the anti-melanoma cytolytic activity of tumour-infiltrating lymphocytes and augmented the secretion of IFN-γ, tumour necrosis factor (TNF)-α and granulocyte-macrophage colony-stimulating factor (GM-CSF) for at least 4 days post-transfection. Our results demonstrate that caTLR-4 is capable of exerting multiple T cell-enhancing effects and can potentially be used as a genetic adjuvant in adoptive cell therapy.

High endothelial venule-like vessels and lymphocyte recruitment in testicular seminoma

Seminoma, the most common testicular malignant neoplasm, originates from germ cells and is characterized by the presence of numerous tumour-infiltrating lymphocytes (TILs). Although it is widely accepted that TILs function in surveillance and cytotoxicity in various tumours including seminoma, detailed mechanisms governing TIL recruitment are not fully understood. It has been shown that high endothelial venule (HEV)-like vessels are induced in inflamed and neoplastic tissues and contribute to lymphocyte recruitment in a manner similar to the way physiological lymphocyte homing occurs in secondary lymphoid organs. Here, we report that HEV-like vessels, which express MECA-79(+) 6-sulfo sialyl Lewis X-capped structures, are induced in TIL aggregates in seminoma, and that such vessels potentially recruit circulating lymphocytes, as an E-selectin•IgM chimera bound these vessels in a calcium-dependent manner. These HEV-like vessels express intercellular adhesion molecule 1 (ICAM-1), but not vascular cell adhesion molecule 1 (VCAM-1) or mucosal addressin cell adhesion molecule 1 (MAdCAM-1), which likely contributes to lymphocyte firm attachment. We also found that the number of T cells attached to the luminal surface of HEV-like vessels was greater than the number of B cells (p < 0.0001). Interestingly, while CD8(+) cytotoxic T lymphocytes (CTLs) attached to the lumen of HEV-like vessels were scarcely detected, significant numbers of proliferative CTLs were observed outside vessels. These histological findings strongly suggest that TILs, particularly T cells, are recruited to seminoma tissues via HEV-like vessels, and that tumour-infiltrating CTLs then undergo proliferation after transmigration through HEV-like vessels in testicular seminoma.

Tumour-infiltrating lymphocytes predict for outcome in HPV-positive oropharyngeal cancer

BACKGROUND

Human papillomavirus (HPV)-positive oropharyngeal cancer (OPSCC) is associated with improved survival compared with HPV-negative disease. However, a minority of HPV-positive patients have poor prognosis. Currently, there is no generally accepted strategy for identifying these patients.

METHODS

We retrospectively analysed 270 consecutively treated OPSCC patients from three centres for effects of clinical, pathological, immunological, and molecular features on disease mortality. We used Cox regression to examine associations between factors and OPSCC death, and developed a prognostic model for 3-year mortality using logistic regression analysis.

RESULTS

Patients with HPV-positive tumours showed improved survival (hazard ratio (HR), 0.33 (0.21-0.53)). High levels of tumour-infiltrating lymphocytes (TILs) stratified HPV-positive patients into high-risk and low-risk groups (3-year survival; HPV-positive/TIL(high)=96%, HPV-positive/TIL(low)=59%). Survival of HPV-positive/TIL(low) patients did not differ from HPV-negative patients (HR, 1.01; P=0.98). We developed a prognostic model for HPV-positive tumours using a 'training' cohort from one centre; the combination of TIL levels, heavy smoking, and T-stage were significant (AUROC=0·87). This model was validated on patients from the other centres (detection rate 67%; false-positive rate 5.6%; AUROC=0·82).

INTERPRETATION

Our data suggest that an immune response, reflected by TIL levels in the primary tumour, has an important role in the improved survival seen in most HPV-positive patients, and is relevant for the clinical evaluation of HPV-positive OPSCC.

FOXP3+ cell density in lymphoid follicles from histologically normal mucosa is a strong prognostic factor in early stage colon cancer

There are few clearly established prognostic factors available to guide the use of adjuvant chemotherapy in early stage colon cancer patients. Some of the most promising candidates include the invasion of extramural blood vessels by tumour cells and the densities of FOXP3+ T regulatory cells (Tregs) in tumour and adjacent normal colonic mucosal tissue. The aim of our study was to evaluate the prognostic significance of these markers in AJCC stage II colon cancer, with particular reference to lymphoid follicles in the mucosa. Histopathological review for the presence of vascular and serosal invasion was conducted on a series of 165 stage II colon cancers treated by surgery alone. Immunohistochemical staining for FOXP3 was performed on tumour tissue and histologically normal colonic mucosa from the surgical margin. Image analysis software was used to evaluate the density of FOXP3+ cells in the tumour core, invading margin and lymphoid follicles from the colonic mucosa. For survival analysis, cases were classified into high- or low-density of FOXP3+ cells according to the median value. The mean density of FOXP3+ Tregs in lymphoid follicles was twofold and fivefold higher than in the invading margin and tumour core, respectively. Multivariate analysis identified extramural vascular invasion (HR, 2.47; 95% CI: 1.00-6.07; P = 0.05) and high FOXP3+ cell density in lymphoid follicles (HR, 4.22; 95% CI: 1.49-11.91; P = 0.007) as independent factors for worse survival, whereas a high frequency of lymphoid follicles in histologically normal colonic mucosa was associated with better survival (HR, 0.31; 95% CI: 0.12-0.79; P = 0.014). Our data suggest that host factors related to the immune system have major prognostic significance in early stage colon cancer. The density of FOXP3+ cells within lymphoid follicles and the frequency of these structures in normal colonic mucosa represent novel and independent prognostic factors.

Immunohistochemical analysis of glioma-infiltrating leucocytes after peripheral therapeutic immunization with interferon-gamma-transfected glioma cells

We have shown previously that rejection of preinduced rat brain tumours is possible following therapeutic immunizations with interferon-gamma (IFN gamma)-transfected glioma cells (N32-IFN gamma). In the present study we have used the same model to evaluate whether quantitative differences in tumour-infiltrating lymphocytes can be detected between animals receiving therapeutic immunizations with either IFN gamma-transfected glioma cells, wild-type glioma cells or no treatment. Since leucocyte transpedesis into the tumour can be anticipated to depend on the state of vascularization, we have mapped the development of microvessels in the tumour in parallel with the leucocyte infiltration. Our results show that microvessels start to form at day 7 and then gradually increase in number and size, indicating the establishment of an extensive vascularization by day 24. Leucocyte infiltration displays a biphasic pattern after tumour grafting. We have therefore studied the infiltration kinetics after an early immunization (1 day after intracerebral isografting) and compared the effects with those of a late immunization (10 days after intracerebral isografting) with N32-IFN gamma or wild-type N32. Our results show (1) an early infiltration of granulocytes 3 days after isografting; (2) a T-cell-receptor-positive (TCR+) T-cell infiltration starting on day 10; (3) a macrophage infiltration starting on day 13; (4) a CD8+ cell infiltration starting on day 13. The proportions of TCR+ T cells, CD8+ cells and natural killer cells differs significantly between animals immunized with N32-IFN gamma and those receiving wild-type N32, when analysed 14 days after immunization at day 10. This difference can only be detected when animals are immunized at later stages of tumour growth. We propose that this could depend on an early-immunization-independent leucocyte infiltration during tumour establishment. This has to be considered when evaluating studies of leucocyte infiltration in experimental tumours.

Melanoma antigen recognition by tumour-infiltrating T lymphocytes (TIL): effect of differential expression of melan-A/MART-1

We have isolated, from an individual patient with metastatic melanoma, a series of eight TIL clones capable of lysing autologous melanoma cell targets. Six of the eight clones expressed TCRAV2S1 and lysed targets expressing HLA-A2 and the Melan-A/MART-1 peptide: AAGIGILTV. Polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP) analysis showed that the Melan-A/MART-1-specific clones were predominant in the bulk culture prior to cloning. However, the tumour progressed in vivo even in the presence of these tumour cell-lytic clones. Using the anti-Melan-A/MART-1 MoAb (A-103), we noted that Melan-A/MART-1 expression on three melanoma cell lines varied considerably during in vitro culture, in the absence of T cell immunoselection, relative to cell density. Tumour cells which spontaneously decreased Melan-A/MART-1 expression were less susceptible to specific TIL lysis. Melan-A/MART-1 expression and susceptibility to lysis increased in cells cultured at lower density. These data suggest that modulation of tumour antigen may account for tumour progression in the presence of tumour cell-lytic T lymphocytes. The observations suggest a possible explanation for the common finding of Melan-A/MART-1-specific lytic TIL in clinically progressing melanomas, as well as a possible pathway for therapeutic intervention.

Studies of the mechanism of cytolysis by tumour-infiltrating lymphocytes

In order to determine the mechanism of tumour destruction by tumour-infiltrating lymphocytes (TIL), we examined the ability of both CD4+ and CD8+ effector TIL, and TIL clones, to manifest granzyme-mediated and Fas-mediated destruction of tumour targets. In many in vitro studies TIL have been shown to manifest anti-tumour reactivity, yet many tumours escape immunological destruction. To investigate the role of Fas expression and the concomitant sensitivity to the inducibility of apoptotic death, we derived TIL from four melanomas and one glioma. The glioma, and all but one of the melanomas, expressed Fas, but Fas-mediated apoptosis could only be detected if the targets were treated with cyclohexamide. The melanomas and the glioma all expressed detectable cytoplasmic Bcl-2 protein, known to exert anti-apoptotic activity. Lysis of tumours by CD8-enriched cultures and CD8+ clones was Ca2+-dependent and could not be modified by an anti-Fas MoAb. In CD4-enriched cultures or CD4+ clones with cytotoxic potential against tumour cells, cytotoxicity was also Ca2+-dependent. As Ca2+-dependent cytotoxicity is usually the result of secretion of perforin/granzyme-B, we investigated the presence of perforin in cytotoxic CD4+ clones and demonstrated the presence of granular deposits of this enzyme in some of the CD4+ clones. Although an anti-Fas MoAb did not block the lysis of melanoma targets by CD4+ clones, the examination of Fas-dependent targets demonstrated that these clones also had the potential to kill by the Fas/Fas ligand system. These data suggest that the predominant mechanism in tumour killing by TIL appears to be perforin-granzyme-dependent, and that the solid tumour cell lines we studied are less susceptible to Fas-mediated apoptosis. As non-apoptotic pathways may enhance tumour immunogenicity, exploitation of the perforin-granzyme-dependent cytotoxic T lymphocyte (CTL) pathways may be important for achieving successful anti-tumour responses.

Adjuvant adoptive immunotherapy with tumour-infiltrating lymphocytes and modulated doses of interleukin-2 in 22 patients with melanoma, colorectal and renal cancer, after radical metastasectomy, and in 12 advanced patients

Adoptive tumour infiltrating lymphocytes (TIL) in combination with a modulated dosage of interleukin-2 (IL-2) can be used with acceptable toxicity in the treatment of immunogenic tumours. Following an experience of reinfusion in advanced melanoma, colorectal and renal cancer patients, treatment was given to disease-free patients after metastasectomy. The high risk of relapse and favourable ratio between reinfused TIL and possible microscopic residual disease determined this choice of adjuvant treatment. A group of 12 patients with advanced disease (7 melanoma, 4 colorectal carcinoma, 1 kidney carcinoma) were treated with TIL (median 5.8 x 10(10) cells) and IL-2 (West's schedule) modulated towards a lower dosage (from 12 to 6 MIU/day) in order to maintain an acceptable level of toxicity. As treatment was well tolerated, it was offered to another 22 patients in an adjuvant setting after metastasectomy (11 melanoma, 10 colorectal carcinoma, 1 renal cancer), the median dose of TIL reinfused being 4.95 x 10(10) cells. No objective response was observed in advanced patients: all patients progressed after a median of 1.5 months (0-8 months) and median survival was 8 months (3-22+ months). Thirteen patients from the second group are still disease-free after a median of 23+ months (9+ - 47+ months). The remaining 9 patients relapsed after a median of 5 months (3-18 months). Toxicity was moderate as clinical and hepatic/renal function parameters were used to assess the need for dose reductions. Consequently, there was great diversity in IL-2 dosages administered. In particular, there seemed to be a difference in IL-2 doses administered between disease-free cases and those who progressed (17.5 MIU/day versus 7 MIU/day in melanoma patients; 11.2 MIU/day versus 7.1 MIU/day in colorectal cancer patients). By contrast, no differences were observed between number of TIL reinfused and clinical response. Phenotypical characteristics of reinfused TIL were similar to those reported in the literature: 97% were CD3 and 92% were CD8. Aspecific cytolytic activity was evaluated on 12 cases whereas, in 2 melanoma cases, autologous tumour tissue was available for the specific cytotoxicity test. Perforin levels in TIL measured at the end of culture were generally high or very high. Cytokine levels were measured on the supernatant at the end of culture, with an estreme variability in results. Finally, delta chain and p56lck were histologically assessed on the resected tissue from which TIL were cultivated. There were virtually none of the former and a complete absence of the latter, which concurs with data reported in the literature. The same immunocytochemical analysis was carried out on TIL at the end of culture. This time an almost complete restoration of both functions was seen, especially in melanoma patients, who are still free from disease. The study is on-going and it has been decided to focus on disease-free patients after metastasectomy in order to increase the number and possibility of clinical and histological correlations.

Phenotype, cytokine production and cytolytic capacity of fresh (uncultured) tumour-infiltrating T lymphocytes in human renal cell carcinoma

We investigated the phenotype and functional capacities of tumour-infiltrating lymphocytes (TIL), freshly isolated from primary renal cell carcinoma (RCC) specimens (n = 20). Three-colour flow cytometry immunophenotyping revealed that RCC TIL consist mainly of CD3+ T cells, with a clear predominance of CD4- CD8+ over CD4+ CD8- T cells, and a marked population of CD4+ CD8+ T cells. Natural killer (NK) cells were also strongly represented (> 25% in 15 of 20 tumour samples), while B cells constituted a minor TIL subset (< 5% in 18 of 20 tumour samples). More importantly, the T and NK cells within the tumour displayed a significantly higher expression of the early activation marker CD69 than their counterparts in adjacent normal renal tissue and in peripheral blood. Expression of CD54 and of HLA-DR was also elevated on CD3+ TIL, and HLA-DR expression was further vigorously up-regulated following ex vivo stimulation with anti-CD3, all suggesting enhanced immune activity within the tumour microenvironment. CD3+ CD4+ TIL displayed a normal capacity to up-regulate CD25 expression and to secrete both Th1-type (IL-2, tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma)) and Th2-type (IL-4, IL-5 and IL-10) cytokines upon triggering with anti-CD3. Furthermore, cytokine production was susceptible to modulation by CD28 costimulation. CD3+ CD8+ TIL, on the other hand, consistently demonstrated a poor up-regulation of CD25 upon triggering with anti-CD3, and displayed poor ex vivo cytolytic activity in an anti-CD3-redirected 4-h cytotoxicity assay against murine P815 cells. Collectively, our findings indicate that the CD3+ CD4+ TIL in RCC have normal functional capacities, whereas the proportionally major CD3+ CD8+ TIL are functionally impaired. The relevance of these findings to the in vivo local immune response in RCC is discussed.

Characterisation of gamma delta T cells in renal cell carcinoma patients by polymerase chain reaction analysis of T cell receptor transcripts

Renal cell carcinomas (RCC) contain tumour infiltrating lymphocytes (TIL) but these are essentially immunosuppressed in that they do not generate effective antitumour immune responses in vivo. These TIL comprise predominantly alpha beta T cells, although gamma delta T cells are also present. The repertoire of gamma delta T cells in RCC, however, has not been fully investigated. To identify the gamma delta T cell populations infiltrating RCC, this study has characterised the gamma delta T cell receptor (TCR) repertoire expression in these tumours and compared this to autologous normal kidney and autologous peripheral blood. A semi-quantitative reverse transcriptase/polymerase chain reaction technique was used for amplification of rearranged TCR V-C mRNA transcripts. Primers specific for the four human TCR V gamma and six V delta subfamilies were used, each in conjunction with a primer specific for either the C gamma or C delta region. The specificity of the PCR products was confirmed by Southern blotting and hybridisation with an internal C region probe. A densitometry score was assigned to each DNA band and the level of V gene expression was determined as ratio of C delta gene expression. The gamma delta TCR expression in each sample was determined as a ratio of C delta: glyceraldehyde phosphate dehydrogenase densitometry score. This demonstrated that TCR C delta gene expression was significantly higher in RCC compared to normal kidney (P < 0.019), suggesting a selective infiltration of gamma delta T cells into the tumour. Furthermore, we observed differences in the TCR V gamma and V delta repertoires between RCC and peripheral blood. V gamma l expression was significantly decreased (P < 0.043) whereas there was an over-representation of V gamma 4 transcripts (P < 0.028) in RCC compared to blood. A significant reduction in expression of both V delta 1 (P < 0.028) and V delta 3 (P < 0.051) was also observed within kidney tumour compared to peripheral blood. These findings show that expression of the gamma delta TCR repertoire in RCC differs from that in peripheral blood and normal kidney.

Predominance of a type 2 intratumoural immune response in fresh tumour-infiltrating lymphocytes from human gliomas

Increasing evidence suggests the existence of polarized human T cell responses described as Th1-type (promoting cell-mediated immunity) and Th2-type (promoting humoral immunity), characterized by a dominant production of either interferon-gamma (IFN-gamma) or IL-4, respectively. Little is known about the intratumoural activation of infiltrating lymphocytes (TIL) in human gliomas. Therefore, we assessed fresh TIL at cellular and molecular levels to find out if they were activated and polarized into a type 1 or 2 immune response. Flow cytometry analysis of TIL revealed that the major subset was made of T lymphocytes. Double labelling with alpha-CD3 and adhesion/ activation markers revealed T cell subsets expressing CD49a, CD49b, CD54, and CD15, some of which were almost absent in autologous T peripheral blood lymphocytes (T-PBL). Furthermore, the proportions of T-TIL expressing CD56, CD65, or CD25 were several-fold higher than in T-PBL. Intratumoural functional activation of TIL was tested by semiquantitative assessment in relative units (RU) of lymphokine gene activation with mRNA reverse transcriptase-polymerase chain reaction (RT-PCR). All TIL populations except one significantly expressed IL-4 1 to 2 logs of RU above healthy PBL baseline. Similarly, all patients expressed granulocyte-macrophage colony-stimulating factor (GM-CSF) in a range comparable to IL-4. However, most TIL populations did not express IFN-gamma, IL-2, and tumour necrosis factor-beta (TNF-beta) at higher levels than healthy normal PBL. The increase proportion of T cells expressing activation markers and the consistent detection of significant IL-4 and GM-CSF lymphokine gene activation in TIL populations suggested a predominant type 2 intratumoural immune response that does not promote cell-mediated tumouricidal activity and may contribute to the inefficiency of the antiglioma immune response.

Culture of tumour-infiltrating lymphocytes from melanoma and colon carcinoma: removal of tumour cells does not affect tumour-specificity

The therapeutic potential of adoptive therapy using tumour-infiltrating lymphocytes (TIL) has been demonstrated in a number of clinical trials. However, freshly isolated tumour-infiltrating lymphocytes (TIL) are often impaired in their proliferative and cytotoxic responses, which limits their use in immunotherapy. Several hypotheses with regard to the poor effector function of TIL have been postulated, including the production of immunosuppressive factors by tumour cells. In a previous paper we reported the efficient expansion of immunoreactive TIL from a variety of solid tumours by stimulation with a combination of monoclonal antibodies (mAbs) against CD3 and CD28. In the present study we analysed whether this protocol would be improved by the removal of tumour cells at the start of the culture. We tested a highly immunogenic tumour, melanoma, and a poorly immunogenic tumour, colon carcinoma. Removal of tumour cells highly improved anti-CD3/CD28 stimulated expansion of TIL from colon carcinoma, resulting in a significantly higher percentage of potentially tumour-specific CD8-positive T-cells and a reduced CD4/CD8 ratio compared to expansion in the presence of tumour cells. In contrast, expansion and CD4/CD8 ratio of melanoma-derived TIL was not significantly influenced by the removal of autologous tumour cells. CD3/CD28-stimulated melanoma TIL cultured in the absence of tumour cells showed specific lysis of autologous tumour cells comparable to melanoma TIL cultured in high-dose IL2. However, no cytotoxicity could be detected in colon TIL irrespective of the culture conditions used. On the other hand, 3/8 colon carcinoma TIL cultures and 9/12 melanoma-derived TIL cultures showed IFN gamma secretion upon stimulation with autologous tumour cells. We conclude that stimulation of TIL with a combination of mAbs to CD3 and CD28 in the absence of tumour cells induces efficient expansion of potentially tumour-specific cells from a highly and a poorly immunogenic tumour. Removal of tumour cells does not have a negative influence on the generation of tumour-specific T cells, while cell yield improves. Therefore, for large-scale cultures this protocol can efficiently induce the outgrowth of tumour-specific TIL, at the same time providing a useful source of autologous tumour cells that can be stored and used to direct or test antitumour specificity.

Detection of oligoclonal T lymphocytes in lymph nodes draining from advanced non-small-cell lung cancer

Despite the combined use of surgery and chemoradiotherapy, the poor prognosis of advanced non-small-cell lung cancer (NSCLC) requires the definition of new therapeutic approaches. The presence of T lymphocytes, with peculiar phenotypic, functional and molecular characteristics within the tumour, suggested the possible use of these cells, expanded in vitro, in protocols of adoptive immunotherapy. We have described how a population of oligoclonal T lymphocytes, derived from advanced NSCLC, can be expanded in vitro and has the capability of lysing autologous cancer cells. What is more important, we observed that patients with advanced NSCLC, treated with TIL expanded in vitro and recombinant interleukin-2, seemed to have a disease-free period longer than that of patients treated with conventional chemoradiotherapy. In an attempt to find new sources of specific lymphocytes for immunotherapy, we describe the analysis of the phenotypic, functional and molecular characteristics of T lymphocytes, derived from lymph nodes draining advanced NSCLC. In this paper we show that these cells, have restriction patterns of T cell receptor beta chain similar to those detectable in the population of infiltrating T lymphocytes. This finding suggests that T cells derived from draining lymph nodes of advanced NSCLC have peculiar characteristics and can be a suitable source of effector cells for protocols of adoptive immunotherapy in lung cancer treatment.

Different pattern of T cell receptor delta gene rearrangement in tumour-infiltrating lymphocytes and peripheral blood in patients with solid tumours

Tumour-infiltrating lymphocytes (TIL) and peripheral blood lymphocytes (PBL) from four patients with renal-cell carcinoma (three paired with blood), two colon carcinomas (both paired with blood) and two melanomas (blood was not available) were analysed for the T cell receptor (TCR) delta gene repertoire. Polymerase chain reaction analysis, employing a panel of specific primers for TCR delta gene segments, showed different gene rearrangement patterns in TIL and PBL in all patients. Simultaneous analysis of TIL and PBL revealed the presence of lymphoid cells in the tumour tissue that were not present in the periphery. These results demonstrate that, although tumour-infiltrating lymphocytes contain gamma/delta T cells within the range observed in peripheral blood, these cells differ from those in peripheral blood in their gene repertoire and this may account for selective accumulation or/and in situ amplification of gamma/delta lymphocytes at the tumour site, indicating a unique type of host reaction against tumour.

Expression of aminopeptidase N/CD13 in tumour-infiltrating lymphocytes from human renal cell carcinoma

We have previously demonstrated the expression of aminopeptidase N (APN, CD13) on synovial T cells from patients with different forms of arthritis. T cells of peripheral blood and serous body fluids are CD13-negative but can be stimulated to express CD13 after activation, e.g., with Con A. In the present report, double-labelling and flow cytometry analyses were performed to characterize the phenotype of tumour-infiltrating lymphocytes (TIL). A large panel of antibodies specific for different activation-associated molecules on T cells was used. In contrast to TIL of lung cancer, TIL of renal cell carcinoma (RCC) consisted of significantly higher percentages of T cells expressing CD13, dipeptidylpeptidase N (DPIV, CD26) and HLA-DR, whereas T cells of lung cancer expressed more CD25, CD69 and CD54/ICAM1. No differences could be found in the expression of CD45RO, CD49a/VLA-1 and CD62L/L-selectin. Our results demonstrate that T cells in RCC and lung cancer differ in their phenotype, especially with respect to surface aminopeptidases. Investigations into the function of APN on T cells could be of help in gaining deeper insight into tumour defence as well as into general mechanisms of T cell functions.

Reduced expression of distinct T-cell CD molecules by collagenase/DNase treatment

DNase/collagenase treatments are widely used to obtain single-cell suspensions of tumour cells and tumour-infiltrating T lymphocytes (TIL) from solid tumours. Since the functional integrity of such cells has been questioned, we have studied whether treatments with commonly used preparations of these enzymes could affect the expression of lymphocyte surface molecules and lymphocyte proliferative responsiveness. With peripheral-blood-derived T cells as a model, flow-cytometric analysis revealed strongly reduced expression of distinct CD molecules for each enzyme, notably CD2, CD4, CD8 and CD44 for DNase, and CD4, CD14, CD16, and CD56 for collagenase. The effects were found to be due to protease contaminations present in all but the purest enzyme preparations tested. Addition of serum or trypsin inhibitor abolished the effects. Since serum-free media are widely used to expand tumour-infiltrating T cells for clinical therapeutic use, data from early phenotypic analyses can be strongly misleading. Even after an 18-h rest period following the enzyme treatments, re-expression of the affected membrane markers was still far from complete. On the other hand, despite strongly reduced expression of CD2 molecules on the lymphocyte membrane, anti-CD2-induced proliferation was not affected, showing the redundancy of this signal molecule. Since other important T cell activation molecules (TCR, CD3, CD28) were not affected by enzymatic treatment, the use of expensive, highly purified collagenase/DNase preparations does not seem to be mandatory in clinical studies with expanded TIL.

Phenotypic and functional analysis of lymphocytes infiltrating paediatric tumours, with a characterization of the tumour phenotype

Tumour-infiltrating lymphocytes (TIL) of paediatric tumours obtained from 37 lesions of different histotype (12 osteosarcomas, 5 Wilms' tumours, 7 soft-tissue sarcomas, 5 neuroblastomas and 8 miscellaneous) were studied to establish their potential for therapy. Fresh isolated TIL were cultured for the first 2 weeks with low doses of interleukin-2 (IL-2) (20 Cetus U/ml) to select for "tumour-specific" lymphocytes potentially present in the neoplastic lesion, followed by culture with high doses of IL-2 (1000 Cetus U/ml) to achieve TIL expansion. TIL were grown with more than 10-fold expansion in only 9 cases (mean expansion: 58-fold, range 13.5-346). In 17 cases no viable cells were obtained. After 30 days of culture with IL-2 the proliferative ability of TIL declined sharply in the majority of cases and TIL became refractory to any further stimulus, including addition of IL-4, tumour necrosis factor alpha (TNF alpha) or interferon gamma, and activation with OKT3 in solid phase. In 20 out of 37 cases TIL were available for phenotypic and functional analysis. TIL after long-term culture were predominantly CD3+ but 2 cases of osteosarcoma showed a predominance of CD3+TcR gamma/delta cells. The CD4/CD8 ratio was more than 1 in 10 cases, without correlation with tumour histology, site of lesion or TIL growth. The number of CD16+ and CD25+ lymphocytes decreased progressively during culture, the latter concomitantly with a reduction of TIL growth rate. The lytic pattern of TIL against allogenic and autologous tumour (Auto-Tu) cells was variable, but specific lysis of Auto-Tu was seen in only one case (Wilms' tumour) after culture with TNF alpha and irradiated Auto-Tu cells. The immunohistochemical analysis of tumour lesions revealed a limited lymphocyte infiltrate, a low expression of histocompatibility leukocyte antigens (HLA) class I and of the adhesion molecules ICAM1, LFA3, and a significant production of transforming growth factor beta (TGF beta). These data indicate that TIL obtained from paediatric patients are difficult to expand at levels required for immunotherapy and lack a significant number of tumour-specific T lymphocytes. A low expression of immunomodulatory molecules on tumour cells or the production of suppressive factors may prevent activation and expansion of TIL in paediatric tumours.