Biochemotherapy of metastatic malignant melanoma. Predictive value of tumour-infiltrating lymphocytes

Prognostic value of tumor-infiltrating lymphocytes in melanoma: a systematic review and meta-analysis

Tumor-infiltrating lymphocytes (TILs) are associated with prognosis in various tumors. However, it remains controversial whether the presence of TILs is related to an improved prognosis in melanoma. This meta-analysis confirmed the favorable prognostic role of the CD3+, CD4+, CD8+, FOXP3+, and CD20+ TILs in the overall survival of melanoma patients and found an association between the TILs present and improved overall survival. Additionally, subgroup analysis demonstrated that brisk TILs were obviously associated with OS, RFS and DSS/MSS. Thus, TILs may be a predictive biomarker in melanoma. This analysis will provide more insight into the study of TILs and predictive biomarker.

Tumor image-derived texture features are associated with CD3 T-cell infiltration status in glioblastoma

This study analyzed magnetic resonance imaging (MRI) scans of Glioblastoma (GB) patients to develop an imaging-derived predictive model for assessing the extent of intratumoral CD3 T-cell infiltration. Pre-surgical T1-weighted post-contrast and T2-weighted Fluid-Attenuated-Inversion-Recovery (FLAIR) MRI scans, with corresponding mRNA expression of CD3D/E/G were obtained through The Cancer Genome Atlas (TCGA) for 79 GB patients. The tumor region was contoured and 86 image-derived features were extracted across the T1-post contrast and FLAIR images. Six imaging features—kurtosis, contrast, small zone size emphasis, low gray level zone size emphasis, high gray level zone size emphasis, small zone high gray level emphasis—were found associated with CD3 activity and used to build a predictive model for CD3 infiltration in an independent data set of 69 GB patients (using a 50-50 split for training and testing). For the training set, the image-based prediction model for CD3 infiltration achieved accuracy of 97.1% and area under the curve (AUC) of 0.993. For the test set, the model achieved accuracy of 76.5% and AUC of 0.847. This suggests a relationship between image-derived textural features and CD3 T-cell infiltration enabling the non-invasive inference of intratumoral CD3 T-cell infiltration in GB patients, with potential value for the radiological assessment of response to immune therapeutics.

Nanomedicine as a potent strategy in melanoma tumor microenvironment

Melanoma originated from melanocytes is the most aggressive type of skin cancer. Despite considerable progresses in clinical treatment with the discovery of BRAF or MEK inhibitors and monoclonal antibodies, the durability of response to treatment is often limited to the development of acquired resistance and systemic toxicity. The limited success of conventional treatment highlights the importance of understanding the role of melanoma tumor microenvironment in tumor developement and drug resistance. Nanoparticles represent a promising strategy for the development of new cancer treatments able to improve the bioavailability of drugs and increase their penetration by targeting specifically tumors cells and/or tumor environment. In this review, we will discuss the main influence of tumor microenvironment in melanoma growth and treatment outcome. Furthermore, third generation loaded nanotechnologies represent an exciting tool for detection, treatment, and escape from possible mechanism of resistance mediated by tumor microenvironment, and will be highlighted in this review.

Immunotherapy in Cancer: A Combat between Tumors and the Immune System; You Win Some, You Lose Some

Cancer immunotherapy has emerged as a treatment modality, mainly as the result of discoveries in the immune response regulation, including mechanisms that turn off immune responses. Immunogenic cutaneous melanoma is a canonical model for therapeutic immunotherapy studies. “Passive” immunotherapy with monoclonal antibodies (mAbs) has outpaced “active” immunotherapy with anti-tumor vaccines, and mAbs that antagonize the off responses have been recently introduced in clinical practice. Despite these recent successes, many unresolved practical and theoretical questions remain. Notably unknown are the identity of the lymphocytes that eliminate tumor cells, which white cells enter into tumors, through which endothelium, in what order, and how they perform their task. The parameters of size and location that could be used to determine in which tumors the immune response may be sufficient to eradicate the tumor are yet unknown. Immunotherapy has been so far more efficient to treat solid and hematologic tumors located outside the central nervous system, than primary brain tumors and brain metastases. In contrast to recent advances with mAbs, anti-tumor vaccine development has been lagging behind. The multiplicity of antigens that must be targeted to achieve significant clinical response is partially responsible for this lag, especially in melanoma, one of the most mutated tumors. Further hampering vaccination results is the fact that tumor elimination by the immune system is the result of a race between tumors with different growth rates and the relatively slow development of the adaptive immune response. The enhancement of the native arm of the immune response or the administration of targeted chemotherapy to slow tumor development, are approaches that should be studied. Finally, criteria used to analyze patient response to immunotherapeutic treatments must be perfected, and the patient populations that could benefit the most from this approach must be better defined.

Intratumoral TLR-4 Agonist Injection Is Critical for Modulation of Tumor Microenvironment and Tumor Rejection

The tumor microenvironment shelters a complex network of mechanisms that enables local Immunosuppression to support tumor growth. In this study we found that, B16F10 melanoma growth is inversely correlated with peritumoral infiltrate cell number and with cell numbers in draining lymph nodes. Tumor growth ensued even when a foreign antigen was expressed by B16F10 cells in the presence of naïve specific CD8+ T cells. Treatment with TLR agonists has shown to sometimes result in tumor regression, however, not always with long-lasting effects. We compared the relevance of different injection regimens of lipopolysaccharide (LPS). Tumor growth was arrested only by intratumoral LPS injection after the tumor was already established. This result was accompanied by a dramatic change in DC activation inside the tumor. Intratumoral LPS also enhanced antigen presentation and tumor-specific CD4+ T cell production of IFN-γ. Injection of LPS before tumor challenge or codelivery of tumor cells and LPS did not have any effect on tumor progression. Our results suggest that an efficient antitumor immune response leading to tumor regression can be achieved with proper TLR4 activation inside the tumor tissue, impacting the tumor microenvironment. These findings are relevant for the design of treatment for patients with malignant melanomas.

Immune suppression in tumors as a surmountable obstacle to clinical efficacy of cancer vaccines

Human tumors are usually not spontaneously eliminated by the immune system and therapeutic vaccination of cancer patients with defined antigens is followed by tumor regressions only in a small minority of the patients. The poor vaccination effectiveness could be explained by an immunosuppressive tumor microenvironment. Because T cells that infiltrate tumor metastases have an impaired ability to lyse target cells or to secrete cytokine, many researchers are trying to decipher the underlying immunosuppressive mechanisms. We will review these here, in particular those considered as potential therapeutic targets. A special attention will be given to galectins, a family of carbohydrate binding proteins. These lectins have often been implicated in inflammation and cancer and may be useful targets for the development of new anti-cancer therapies.

Longitudinal immune monitoring of patients receiving intratumoral injection of a MART-1 T-cell receptor-transduced cell line (C-Cure 709)

BACKGROUND AIMS

Adoptive transfer of tumor-specific lymphocytes is a promising strategy in the treatment of cancer. We conducted intratumoral administration of an allogeneic irradiated continuous T-cell line (C-Cure 709) expressing an HLA-A2-restricted MART-1-specific T-cell receptor (TCR) into HLA-A2(+) melanoma patients. The C-Cure 709 cell line is cytotoxic against MART-1(+) HLA-A2(+) melanoma cell lines and secretes several immune stimulatory cytokines upon stimulation.

METHODS

Anti-tumor immune responses against the commonly expressed tumor antigen (Ag) MART-1 were longitudinally analyzed in peripheral blood by fluorescence-activated cell sorting (FACS) before and after intratumoral injection of C-Cure 709.

RESULTS

No treatment-induced increase in Ag-specific T-cell frequencies was observed in peripheral blood, and the phenotype of MART-1-specific T cells was very stable during the treatment. Interestingly, despite a very stable frequency of MART-1-specific T cells over the course of treatment, clonotype mapping revealed that the response was in fact highly diverse and dynamic, with new clonotypes emerging during treatment. Only a few clonotypes were recurrently detected in consecutive samples. One MART-1-specific T-cell clone disappearing from peripheral blood was later detected in a metastatic lesion.

CONCLUSIONS

Sequence analyzes of the CDR3 region revealed conserved structural characteristics in the MART-1-specific TCR used by T-cell clones.

Melanoma prognostic factors found in the dermatopathology report

Significant prognostic information is available in a routine melanoma dermatopathology report. Features that are enumerated in the pathology report and that portend a potentially poorer prognosis are older age, site (acral, head, neck), male sex, increasing Breslow tumor thickness, increasing Clark's level, ulceration, increasing number of mitoses, vertical growth phase, regression, absence of a host inflammatory response, increased tumor vascularity, angiotropism, vascular invasion, neurotropism, marked atypia, and satellite metastasis.

Predominant infiltration of macrophages and CD8(+) T Cells in cancer nests is a significant predictor of survival in stage IV nonsmall cell lung cancer

BACKGROUND

The purpose of this study was to investigate whether tumor-infiltrating immune cells in biopsy specimens can be used to predict the clinical outcome of stage IV nonsmall cell lung cancer (NSCLC) patients.

METHOD

The authors performed an immunohistochemical study to identify and count the number of CD68(+) macrophages, c-kit(+) mast cells, and CD8(+) T cells in both cancer nests and cancer stroma in pretreatment biopsy specimens obtained from 199 patients with stage IV NSCLC treated by chemotherapy, and then analyzed for correlations between the number of immune cells and clinical outcome, including chemotherapy response and prognosis.

RESULTS

There was no correlation between the number of immune cells in either cancer nests or stroma and chemotherapy response. Patients with more tumor-infiltrating macrophages in cancer nests than in cancer stroma (macrophages, nests > stroma) had significantly better survival than nests < stroma cases median survival time (MST 440 days vs 199 days; P < .0001). Patients with more tumor-infiltrating CD8(+) T cells in cancer nests than in cancer stroma (CD8(+) T cells: nests > stroma) showed significantly better survival than in nests < stroma cases (MST 388 days vs 256 days; P = .0070). The proportion of tumor-infiltrating macrophages or CD8(+) T cells between cancer nests and stroma became independent prognostic factors in the multivariate analysis. Neither the number of mast cells in nests nor in stroma correlated with the clinical outcome.

CONCLUSIONS

Evaluation of the numbers of macrophages and CD8(+) T cells in cancer nests and stroma are useful biomarkers for predicting the prognosis of stage IV NSCLC patients treated with chemotherapy, but could fail to predict chemotherapy response.

The prognostic role of blood lymphocyte subset distribution in patients with resected high-risk primary or regionally metastatic melanoma

The aim of this study was to investigate whether the profile of peripheral blood lymphocyte subsets of patients with high-risk malignant melanoma is associated with prognosis. Blood samples were systematically obtained from 31 patients with high-risk melanoma eligible for the Nordic Melanoma Cooperative Group adjuvant interferon study. The frequencies of peripheral blood lymphocyte subsets were monitored by flow cytometry using CD3, CD4, CD8, CD56, and CD69 monoclonal antibodies. Patients with low proportions of CD3+CD4+CD69+ cells and of CD3+CD56+ cells before treatment had an improved disease-free survival compared to those with high proportions [77.7 vs. 16.8 mo, hazard ratio (HR) 0.25, confidence interval (CI) 0.09-0.71, P=0.005 and 77.2 vs. 16.0 mo, HR: 0.25, CI 0.086-0.73, P=0.001, respectively]. Low pretreatment levels of these cell populations also correlated with a better overall survival (79.2 vs. 22.6 mo, HR: 0.17, CI 0.05-0.52, P=0.0005 and 78.2 vs. 21.4 mo, HR: 0.2, CI 0.07-0.59, P=0.001, respectively). In the multivariate analysis both the pretreatment proportion of CD3+CD4+CD69+ cells (P=0.01, HR: 0.21, CI 0.07-0.67) and CD3+CD56+ cells (P=0.01, HR: 0.22, CI 0.062-0.65) were independent prognostic factors for overall survival. Our data show that both the proportions of CD3+CD4+CD69+ cells and of CD3+CD56+ cells seem to have a prognostic potential in the natural course of melanoma. These results need to be confirmed in larger studies.

Predictive utility of circulating methylated DNA in serum of melanoma patients receiving biochemotherapy

PURPOSE

Currently, no validated blood-based assays accurately predict treatment response or outcome in melanoma patients. We hypothesized that methylation of tumor-related genes detected in serum DNA could predict disease outcome and therapeutic response in patients receiving concurrent biochemotherapy (BC) for metastatic melanoma.

PATIENTS AND METHODS

American Joint Committee on Cancer stage IV melanoma patients (N = 50) had blood drawn before administration of BC. Patients (n = 47) were classified as BC responders or nonresponders. Responders (n = 23) demonstrated a complete or partial response following BC; nonresponders (n = 24) demonstrated progressive disease. Hypermethylation of Ras association domain family 1 (RASSF1A), retinoic acid receptor-beta2 (RAR-beta2), and O6-methylguanine DNA methyltransferase (MGMT) genes were assessed by methylation-specific polymerase chain reaction.

RESULTS

Circulating methylated RASSF1A was significantly less frequent for responders (three of 23 patients; 13%) than nonresponders (10 of 24 patients; 42%; P = .028). Patients with RASSF1A, RAR-beta2, or at least one serum methylated gene had significantly worse overall survival than patients with no methylated genes (log-rank, P = .013, .021, and .01, respectively). Methylated RASSF1A was the only factor that significantly correlated with overall survival and BC response (risk ratio, 2.38; 95% CI, 1.16 to 4.86; P = .018; odds ratio = 0.21; 95% CI, 0.05 to 0.90; P = .036).

CONCLUSION

Detection of circulating methylated DNA in serum can predict response to BC and disease outcome.

The predictive value of CD8, CD4, CD68, and human leukocyte antigen-D-related cells in the prognosis of cutaneous malignant melanoma with vertical growth phase

BACKGROUND

To establish the prognostic value of immune system cells that infiltrate melanoma, the authors evaluated the distribution and density of T lymphocyte subsets, macrophages, and dendritic cells in samples of primary cutaneous melanoma from 47 patients with Stage I and II melanoma according to the American Joint Committee on Cancer staging system.

METHODS

Immunohistochemical demonstrations of CD8 and CD4 lymphocytes, CD68 macrophages, human leukocyte antigen-D-related (HLA-DR) cells, S-100 protein, and melanoma-associated antigens Melan A and HMB-45 were performed. The results were derived from independent histopathologic reviews by two pathologists. The low-density, moderate-density, and high-density groups of cells that infiltrated the base of the tumor during the vertical growth phase were compared with the overall survival rate using the Kaplan-Meier method and the log-rank test. Clinical variables (gender, age, tumor location, Clark level, vascular/lymphatic invasion, and thickness) also were analyzed.

RESULTS

The CD8 lymphocytes exhibited independent statistically positive significance in survival (log-rank test, 8.49; P = 0.01) between patients in different lymphocyte density groups. There was a difference in 5-year survival among patients in the high-density group (78.8%), the moderate-density group (44.4%), and the low-density group (25.0%). The CD4 lymphocytes, which were less numerous than CD8 cells, had similar distribution. There also was a correlation of HLA-DR cells with overall survival (log-rank test, 5.29; P = 0.02). CD68 cell density was not found to be correlated with survival.

CONCLUSIONS

The presence and number of infiltrating CD8 lymphocytes as well as the overall occurrence of HLA-DR cells may be considered independent, favorable prognostic factors in melanoma. The current results may be important for identifying other prognostic factors with which to evaluate disease progression and develop immune therapies for patients with melanoma.

The prognostic role of CD4+ and CD8+ lymphocytes during chemoimmunotherapy in metastatic melanoma

We have observed that an early increase in the CD4+/CD8+ ratio of metastatic melanoma patients during chemoimmunotherapy is the most favourable independent prognostic factor. In this study, 87 patients with metastatic melanoma were monitored for peripheral blood lymphocyte subsets (CD4+ and CD8+) before and during chemoimmunotherapy (dacarbazine, vinblastine, lomustine and bleomycin or dacarbazine alone plus interferon-alpha) to confirm our previous observation. Blood samples were systematically obtained from patients who received either of these chemoimmunotherapies. The frequencies of peripheral blood lymphocyte subsets were monitored by flow cytometry using monoclonal antibodies OKT4 (CD4+, T-helper cells) and OKT8 (CD8+, T-suppressor cells). The overall response rate was 46.5%, and the median overall survival was 9.3 months. Patients with pre-treatment CD4+ levels above the mean level, who later responded to therapy, had a median survival of 28.1 months vs. 10.2 months for responders with low pre-treatment CD4+ levels (P=0.053, log-rank test). Responders with decreasing CD8+ levels had a median survival of 27.8 months vs. 10.8 months for responders with increasing CD8+ levels (P=0.04, log-rank test). Similarly, responding patients with an increasing CD4+/CD8+ ratio had a median survival of 28.1 months vs. 10.5 months for those with decreasing ratios (P=0.002, log-rank test). Non-responders showed no difference in median survival irrespective of low or high pre-treatment CD4+ lymphocytes, increasing or decreasing CD8+ levels, or increasing or decreasing CD4+/CD8+ ratios. This follow-up study confirms that the monitoring of CD4+ and CD8+ lymphocytes may provide important predictive and prognostic information in metastatic melanoma patients receiving chemoimmunotherapy.

Leukocyte orchestration in blood and tumour tissue following interleukin-2 based immunotherapy in metastatic renal cell carcinoma

With the objective of evaluating leukocyte orchestration in situ, serial blood samples and tumour tissue core needle biopsies were obtained at baseline and repeated after 1 month of therapy, among 49 consecutive single-institution patients with metastatic renal cell carcinoma (mRCC). Patients were treated with outpatient low-dose subcutaneous interleukin 2 (IL-2) and interferon alpha (IFN-alpha) alone (n = 23) or in combination with histamine dihydrochloride (n = 26). Objective responses were achieved in ten of 49 patients (20%) with an overall median survival of 14 months and an estimated 1- to 4-year survival rate of 57, 35, 24 and 22%, respectively. Toxicity was mild to moderate with no treatment-related deaths. High numbers of blood monocytes and neutrophils were significantly correlated to short survival. By contrast, high numbers of intratumoural CD3+, CD4+, CD8+ and CD57+ lymphocytes were positively correlated to objective response and/or long-term survival. Intratumoural lymphocytes showed low zeta expression, whereas blood lymphocytes showed almost normal levels of zeta expression. Neutrophils, the most frequent peripheral blood leukocyte subset, were scarce within the tumour tissue. Intratumoural eosinophils were not observed. In progressing patients, both the absolute number and the relative composition of leukocyte subsets in blood and tumour tissue remained unaffected by cytokine therapy. However, in responding patients, cytokine therapy was followed by an absolute and relative increase in T cells in blood as well as tumour tissue, an absolute and relative reduction in neutrophils in peripheral blood and a relative reduction of intratumoural macrophages. Histamine did not influence levels of intratumoural or blood leukocyte numbers, zeta-chain expression or cytotoxicity. In conclusion, the present regimen of outpatient low-dose subcutaneous IL-2 and IFN-alpha in mRCC should attract interest based on response, survival and toxicity. In responding patients, cytokine therapy was followed by substantial changes in the blood and tumour tissue leukocyte composition, correlated to response and survival. No discernable differences in immunologic parameters studied could be detected between histamine- and nonhistamine-treated patients.

On the effect of biochemotherapy in metastatic malignant melanoma: an immunopathological evaluation

Although immunotherapy and biochemotherapy have shown promise, producing a subset of durable responses, for the majority of patients with metastatic melanoma the prognosis is still poor. Therefore there is a great need for predictive tests to identify patients with a high probability of responding. Furthermore, there is also a need for a better understanding of the mechanisms of action during treatment in order to be able to monitor the relevant antitumour reactivity during treatment and to optimize the efficacy of future immunotherapy and biochemotherapy. In the present study histopathological regression criteria were used to study the efficacy of biochemotherapy. Thirty-two patients with metastatic malignant melanoma (18 with regional disease and 14 with systemic disease) were treated with biochemotherapy (cisplatin 30 mg/m2 intravenously on days 1-3, dacarbazine 250 mg/m2 intravenously on days 1-3 and interferon-alpha2b 10 million IU subcutaneously 3 days a week, every 28 days). Pre-treatment fine needle aspirates were obtained from metastases to analyse the number of tumour-infiltrating CD4+ lymphocytes. Therapeutic efficacy was evaluated in metastases resected after treatment using histopathological criteria of tumour regression. Comparisons were also made with metastases from 17 untreated patients, all with regional disease. Regressive changes of 25% or more (of the section area) were found in two of the 17 untreated patients with regional disease compared with 13 of the 18 patients with regional disease and 10 of the 14 patients with systemic disease after biochemotherapy. Fifty per cent of the patients with regional disease showed a high degree of regressive changes (75-100% of the section area) after biochemotherapy. These results demonstrate the occurrence of an antitumour reactivity in the majority of patients. Patients with extensive regressive changes in 75-100% of the analysed biopsies were also found to have a longer overall survival (P = 0.019). In patients with regional disease there was a close correlation between a larger number of CD4+ lymphocytes pre-treatment and a higher degree of regressive changes post-treatment (P < 0.05). Thus, immunohistochemical analysis of tumour biopsies shortly after treatment seems to be a good surrogate endpoint. This technique also allows detailed analysis of antitumour reactivity and escape mechanisms.

Bcl-2 expression in metastatic malignant melanoma. Importance for the therapeutic efficacy of biochemotherapy

For the majority of patients with metastatic malignant melanoma the prognosis is poor. Immunotherapy and biochemotherapy have shown promise with a subset of durable responses, but there is still a great need for a better understanding of the mechanisms of action during treatment to optimize future treatment schedules. In the present study Bcl-2 expression was studied in biopsies from ten patients with metastatic malignant melanoma (five with regional disease and five with systemic disease) treated with biochemotherapy (cisplatinum 30 mg/m2 days 1-3, DTIC 250 mg/m2 days 1-3 i.v. and Interferon-alpha2b 10 MIU s.c. 3 days a week, on a 28-day cycle). The expression of Bcl-2 by the tumour cells was separately recorded in areas of histopathological regressive changes and in areas of unaffected tumour growth. Comparisons were made with biopsies from 14 untreated patients. In 10 of 10 treated patients a high expression of Bcl-2 by the tumour cells was found in areas of unaffected tumour growth. In contrast, only in 5 of 13 untreated patients was a high expression of Bcl-2 by the tumour cells found in these areas ( P=0.008). A significant difference was also found in the expression of Bcl-2 by the tumour cells between areas of unaffected tumour growth and areas of histopathological regressive changes ( P=0.03). The significantly higher expression of Bcl-2 by the tumour cells in areas of unaffected tumour growth in treated patients compared to untreated patients indicates that clones with a high expression of Bcl-2 may be present after therapy, preventing apoptosis and eventually in many patients resulting in progressive disease. Supporting this concept, a difference was also found between the expression of Bcl-2 in areas of unaffected tumour growth, i.e. in areas of treatment failure, and the expression in areas of histopathological regressive changes. Thus immunohistochemical analysis of tumour biopsies shortly after therapy seems to be a good surrogate endpoint that allows a detailed analysis of Bcl-2 expression. The high expression of Bcl-2 shown in unaffected tumour areas after therapy suggests the need for additional treatment, e.g. Bcl-2 antisense therapy.

On the biological relevance of MHC class II and B7 expression by tumour cells in melanoma metastases

A large number of studies have indicated that specific immune reactivity plays a crucial role in the control of malignant melanoma. In this context, expression of MHC I, MHC II and B7 molecules by melanoma cells is seen as relevant for the immune response against the tumour. For a better understanding of the biological relevance of MHC II and B7 expression by tumour cells in metastatic melanoma, we studied the expression of these molecules in melanoma metastases in relation to the inflammatory response, regression of the tumour and survival from 27 patients treated with biochemotherapy (30 mg m(-2) Cisplatin and 250 mg m(-2) decarbazine (dimethyl-triazene-imidazole-carboxamide, DTIC) on days 1-3 i.v., and 10(7) IU IFN-alpha 2b 3 days a week s.c., q. 28d). In 19 out of 27 lesions studied, we found expression of MHC II by the tumour cells, while only in one out of 11 tumour biopsies obtained from untreated metastatic melanoma patients, MHC II expression was detected. Expression of B7.1 and B7.2 by tumour cells was found in nine out of 24 and 19 out of 24 lesions, respectively. In all cases where B7.1 expression was found, expression of B7.2 by the tumour cells was also seen. In general, no or only few inflammatory cells positive for B7 were found. Expression of MHC II by tumour cells was positively correlated with the presence of tumour-infiltrating lymphocytes, regression of the lesion, and with time to progression (TTP) and overall survival (OS) of the patient. However, no significant correlation between B7.1 or B7.2 expression and regression of the tumour, TTP or OS was found. In light of other recent findings, these data altogether do support a role as biomarker for MHC II expression by tumour cells; however, its exact immunological pathomechanism(s) remain to be established.

Intratumoural and peripheral blood lymphocyte subsets in patients with metastatic renal cell carcinoma undergoing interleukin-2 based immunotherapy: association to objective response and survival

The aim of the present study was to analyse lymphocyte subsets in consecutive peripheral blood samples and consecutive tumour tissue core needle biopsies performed before and during interleukin-2 based immunotherapy, and to correlate the findings with objective response and survival. Twenty-six patients with metastatic renal cell carcinoma were treated with low dose s.c. interleukin-2, interferon-alpha and histamine. A total of 250 blood samples and 62 core needle biopsies from 23 and 19 of these patients, respectively, were analysed. After 2 weeks of treatment, a significant positive correlation between absolute number of peripheral blood lymphocytes (P=0.028), CD3 (P=0.017), CD57 (P=0.041) and objective response was demonstrated. There was no correlation between any peripheral blood leukocyte subsets and survival. Cytotoxicity of peripheral blood mononuclear cells was not correlated to objective response or survival. Within the tumour tissue at baseline, a significant positive correlation between CD4 (P=0.027), CD8 (P=0.028), CD57 (P=0.007) and objective response was demonstrated. After one month of immunotherapy, a significant positive correlation between intratumoral CD3 (P=0.026), CD8 (P=0.015), CD57 (P=0.009) and objective response was demonstrated. A significant positive correlation between intratumoral baseline CD4 (P=0.047), baseline CD57 (P=0.035), CD3 at one month (P=0.049) and survival was demonstrated. These data provide novel in vivo evidence of the possible contribution of lymphocyte subsets in the tumour reduction in responding patients during interleukin-2 based immunotherapy. Confirmation of the results requires further studies including a larger number of patients.