T-cell markers in tumor-infiltrating lymphocytes of head and neck cancer

CD8+ Tumor-Infiltrating Lymphocytes in Head and Neck Cancer: A Review

CD8+ tumor-infiltrating lymphocytes (TILs) are increasingly used in oncology as a prognostic and predictive tool to guide patient management. This review summarizes current literature on CD8+ TILs in head and neck squamous cell carcinoma (SCC). Published meta-analyses and clinical trials evaluating CD8+ TILs were analyzed. Consistent positive associations between elevated CD8+ TILs and overall survival have been observed across head and neck sites. CD8+ TILs have been found to predict response to treatment, most commonly immunotherapy, but also chemoradiation. Numerous trials have shown that increased CD8+ TIL frequencies in pretreatment biopsies could identify patients likely to respond to neoadjuvant therapies. CD8+ TIL infiltration has also been elevated in responders both during and after treatment. However, wider adoption of CD8+ TIL quantification as a biomarker has been limited by the need for clinical validation and universal measurement guidelines for head and neck SCC, as there are for other malignancies. Measurement variability includes which tumor compartment is sampled, how TILs are quantified, and which cutoffs are clinically relevant. For several head and neck SCC, measurement of CD8+ TILs in the central or intratumoral compartment, followed by the stromal compartment, has been most consistently associated with survival. Future studies are needed to evaluate subpopulations of CD8+ TILs and biomarker-based treatment selection.

Proposal of a scoring system for predicting pathological risk based on a semiautomated analysis of whole slide images in oral squamous cell carcinoma

BACKGROUND

The study aimed to evaluate the risk factors based on pathological findings comprehensively in oral squamous cell carcinoma (OSCC) using image analysis.

METHODS

Scanned images of hematoxylin and eosin-, pan-cytokeratin-, CD3-, and CD8-stained slides of OSCC cases from 256 patients were analyzed, and six variables were obtained including the tumor-stroma ratio, tumor budding per tumor bed area, and tumor infiltrating lymphocytes-associated variables. We determined the "score" of all cases based on the variables, and all cases were classified into low-, intermediate-, and high-risk groups.

RESULTS

A significant difference in prognosis was confirmed between the risk groups (p < 0.001), and even when evaluated within different tumor-node-metastasis (TNM) stages, the high-risk groups were associated with poor survival.

CONCLUSIONS

We report our work on a possible descriptive model that can predict prognosis based on pathological and imaging findings regardless of the TNM stage.

Tumor-Specific Antibody, Cetuximab, Enhances the In Situ Vaccine Effect of Radiation in Immunologically Cold Head and Neck Squamous Cell Carcinoma

In head and neck squamous cell carcinoma (HNSCC) tumors that over-expresses huEGFR, the anti-EGFR antibody, cetuximab, antagonizes tumor cell viability and sensitizes to radiation therapy. However, the immunologic interactions between cetuximab and radiation therapy are not well understood. We transduced two syngeneic murine HNSCC tumor cell lines to express human EGFR (MOC1- and MOC2-huEGFR) in order to facilitate evaluation of the immunologic interactions between radiation and cetuximab. Cetuximab was capable of inducing antibody-dependent cellular cytotoxicity (ADCC) in MOC1- and MOC2-huEGFR cells but showed no effect on the viability or radiosensitivity of these tumor cells, which also express muEGFR that is not targeted by cetuximab. Radiation enhanced the susceptibility of MOC1- and MOC2-huEGFR to ADCC, eliciting a type I interferon response and increasing expression of NKG2D ligands on these tumor cells. Co-culture of splenocytes with cetuximab and MOC2-huEGFR cells resulted in increased expression of IFNγ in not only NK cells but also in CD8+ T cells, and this was dependent upon splenocyte expression of FcγR. In MOC2-huEGFR tumors, combining radiation and cetuximab induced tumor growth delay that required NK cells, EGFR expression, and FcγR on host immune cells. Combination of radiation and cetuximab increased tumor infiltration with NK and CD8+ T cells but not regulatory T cells. Expression of PD-L1 was increased in MOC2-huEGFR tumors following treatment with radiation and cetuximab. Delivering anti-PD-L1 antibody with radiation and cetuximab improved survival and resulted in durable tumor regression in some mice. Notably, these cured mice showed evidence of an adaptive memory response that was not specifically directed against huEGFR. These findings suggest an opportunity to improve the treatment of HNSCC by combining radiation and cetuximab to engage an innate anti-tumor immune response that may prime an effective adaptive immune response when combined with immune checkpoint blockade. It is possible that this approach could be extended to any immunologically cold tumor that does not respond to immune checkpoint blockade alone and for which a tumor-specific antibody exists or could be developed.

A treatise on endothelial biology and exosomes: homage to Theresa Maria Listowska Whiteside

Exosomes are the current primary research focus of Dr. Theresa L. Whiteside. They are key mediators of intercellular communication in the head and neck, as well as other sites. Their effects in the tumor microenvironment are manifold and include suppression of immunity, promotion of angiogenesis, enabling of metastasis, as well as reprogramming of fibroblasts and mesenchymal stromal cells. The aim of this communication is to summarize Dr. Whiteside's contribution to the field of exosome research and details the interactions of exosomes with endothelial cells leading to recent findings on how to target endothelial cells using exosomes as a therapeutic approach.

The association of ultraviolet radiation-B (305 nm), season of diagnosis, and latitude on the survival outcome of prostate cancer in the high UV environment of Australia

BACKGROUND

Positive associations between sun exposure and cancer survival have been observed in regions of high latitudes, where ambient solar ultraviolet (SUV) radiation is generally low.

PURPOSE

We examined the effects of ambient ultraviolet-B radiation (UVB) at time of diagnosis, season of diagnosis and latitude of residence on survival outcome from prostate cancer.

METHOD

Regression models for relative survival were used to estimate relative excess risks (RER) of death after diagnosis of prostate cancer from cancer registries in Eastern Australia (Queensland, New South Wales, Victoria and Tasmania).

RESULTS

Relative excess risks was increased with diagnosis in summer (RER = 1.20; 95 % CI 1.14-1.26) relative to winter, high ambient UVB at the time of diagnosis (>60 mW/m(2); RER = 1.10; 95 % CI 1.05-1.15) relative to low SUV (<30 mW/m(2)), and with residence in high latitudes (35°S-43°S; RER = 1.20; 95 % CI 1.14-1.26) relative to low latitudes (9°S-29.9°S). RER was highest for summer diagnosis in all three latitude bands, after adjusting for age, follow-up period, and socioeconomic status.

CONCLUSION

The contradictory outcome from season and latitude suggests that their use as surrogates for UV warrants validation. Our data suggest that high ambient solar ultraviolet radiation at the time of diagnosis of prostate cancer increases the risk of dying from this cancer.

Comparative analysis of tumor-infiltrating lymphocytes in a syngeneic mouse model of oral cancer

OBJECTIVE

To perform a comparative analysis of infiltrating immune cells in a newly developed C57BL/6 background syngeneic transplantable mouse oral cancer (MOC) model.

STUDY DESIGN/SETTING

Scientific study in an academic medical center.

METHODS

Use of carcinogen-induced tumorigenesis, tissue culture, cell line transplantation, and flow cytometric analysis techniques.

RESULTS

Previously, the authors established a series of cell line models that displayed dichotomous growth phenotypes when transplanted into immunocompetent mice. They now show that the indolent growth pattern of the MOC1-generated tumors is associated with increased baseline and inducible major histocompatibility complex class I expression and increased CD8(+) T-cell infiltration into the tumor microenvironment. Conversely, the aggressive and metastatic pattern of MOC2-generated tumors has decreased basal and inducible class I expression and is associated with FOXP3(+)CD4(+) regulatory T-cell infiltration. Delayed primary tumor growth after targeted monoclonal antibody therapy of these FOXP3(+) regulatory cells further suggests that these immune cells contribute to the aggressive phenotype of MOC2.

CONCLUSION

These data validate that key infiltrating immune cells identified here parallel findings in human head and neck cancer, making this newly developed syngeneic model a critical platform for the continued dissection of tumor-host interactions in head and neck cancer.

Increased lymphocyte infiltration in patients with head and neck cancer treated with the IRX-2 immunotherapy regimen

Twenty-seven subjects with squamous cell cancer of the head and neck received the neoadjuvant IRX-2 immunotherapy regimen prior to surgery in a Phase 2 trial. Pretreatment tumor biopsies were compared with the primary tumor surgical specimens for lymphocyte infiltration, necrosis and fibrosis, using hematoxylin and eosin stain and immunohistochemistry in 25 subjects. Sections were examined by three pathologists. Relative to pretreatment biopsies, increases in lymphocyte infiltration (LI) were seen using H and E or immunohistochemistry. CD3+ CD4+ T cells and CD20+ B cells were primarily found in the peritumoral stroma and CD3+ CD8+ T cells and CD68+ macrophages were mainly intratumoral. LI in the surgical specimens were associated with reductions in the primary tumor size. Improved survival at 5 years was correlated with high overall LI in the tumor specimens. Neoadjuvant IRX-2 immunotherapy regimen may restore immune responsiveness presumably by mobilizing tumor infiltrating effector lymphocytes and macrophages into the tumor.

Prognostic value of CD25 expression on lymphocytes and tumor cells in squamous-cell carcinoma of the head and neck

CD4(+) CD25(+) T-cells play a central role in initiating and maintaining anticancer immune response. On the other hand, CD25(+) is also expressed on tumor cells, the meaning of which is currently unclear. Therefore, this study was designed to determine the prognostic value of the presence of CD4(+) CD25(+) T-cells in squamous-cell carcinoma of the head and neck (SCCHN) and of CD25 on SCCHN tumor cells. Thirty-five (35) patients diagnosed with a primary untreated SCCHN were included in this study. Instantly snap-frozen resection or biopsy specimens were analyzed by immunohistochemistry. Histologic results obtained were related to overall, disease-free survival. On univariate analysis, both lymph-node status and the number of CD25(+) lymphocytes were associated with disease-free survival (p=0.039 and 0.04). On multivariate analysis, only the number of CD25(+) lymphocytes showed an association with disease-free survival (p=0.036), whereas both factors showed an independent association with overall survival (p=0.007 and 0.003). Contrarywise, the CD25 expression on SCCHN tumor cells was not associated with disease-free survival nor with overall survival. The presence of a high number of SCCHN-infiltrating CD4(+) CD25(+) lymphocytes is associated with a good prognosis in SCCHN patients. Contrarywise, the CD25 expression on SCCHN tumor cells is not associated with a prognosis in SCCHN patients, and its role and meaning remains to be elucidated.

An autologous system for culturing head and neck squamous cell carcinomas for the assessment of cellular therapies on the chorioallantois membrane

The evaluation of novel immunotherapeutic anti-cancer strategies requires target and effector cells from the autologous host to avoid false positive results because of allo-reactivity. Head and neck squamous cell carcinoma cells (HNSCC) do not proliferate under standard culture conditions in plastic ware. To create an autologous model, the chorioallantois membrane (CAM) of chicken embryos was employed to culture HNSCC and peripheral blood mononuclear cells (PBMC). Separated tumor cells were co-incubated with a cytostatic agent, PBMC, or mere cell culture medium as a control. Tumor cell lysis was assessed by acridine orange staining or by flow cytometry analysis of iodide marked cells after 24 and 48 h of co-incubation. Incubation with cisplatin resulted in a decrease of viable cells by 49% after 24 h and 48 h. In contrast, incubation with mere culture medium resulted in an increase of viable tumor cells by 5% after 24 h and a decrease of 4% after 48 h; the incubation of tumor cells and PBMC led to a non-significant decrease by 14% after 24 h and 16% after 48 h. Taken together, the CAM supports a favorable environment for the co-culture of HNSCC and PBMC, thus providing an approximated in vivo autologous model to assess the efficacy of new cell-therapeutical approaches.

Cell-mediated immunity and head and neck cancer: with special emphasis on betel quid chewing habit

Betel quid (BQ) chewing is popular in Taiwan, India, and many southeast-Asian countries. BQ chewing has strong association with the risk of oral leukoplakia (OL), oral submucous fibrosis (OSF), and oral cancer (OC). BQ components exhibit genotoxicity and may alter the structure of DNA, proteins and lipids, resulting in production of antigenicity. BQ ingredients are also shown to induce keratinocyte inflammation by stimulating the production of prostaglandins, TNF-alpha, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) in keratinocytes. These events may provoke tissue inflammation, early cell-mediated immunity (CMI), and immune surveillance in BQ chewers. However, BQ components also directly affect the functional activities of immunocompotent cells, and moreover tumor cells may hypo-respond to the CMI via diverse mechanisms such as induction of apoptosis of lymphocytes, induction of production of suppressor T cells, downregulation of MHC molecules in tumor cells, etc. Clinically, an alteration in lymphocyte subsets, a decrease in total number of lymphocytes, and a reduction in functional activities of CMI have been observed in isolated peripheral blood mononuclear cells (PBMC) and tumor infiltrated lymphocytes (TIL) in patients with OSF, OL or OC. Adaptation of tumor cells to immune system may promote clonal selection of resistant tumor cells, leading to immune tolerance. Future studies on effects of BQ components on CMI and humoral immunity in vitro and in vivo can be helpful for chemoprevention of BQ-related oral mucosal diseases. To elucidate how virus infection, tobacco, alcohol and BQ consumption, and other environmental exposure affect the immune status of patients with oral premalignant lesions or OC will help us to understand the immunopathogenesis of OC and to develop immunotherapeutic strategies for OC.

Intratumoral T cell subset ratios and Fas ligand expression on brain tumor endothelium

INTRODUCTION

T cell presence in TIL, and the ratio of CD8+ and CD4+ T cell subsets in particular, can correlate with tumor prognosis in some tumors, although the significance of such infiltration into glioma is controversial. However, gliomas represent a lower extreme in their extent of T cell infiltration, and are thus useful in assessing factors that can decrease T cell presence within tumor tissue. Fas ligand, a pro-apoptotic cell surface protein, may play a key role in reduction of T cells in tumor tissue.

OBJECTIVE

To assess the level of FasL expression on brain tumor endothelium and to correlate this with relative levels of CD4+ and CD8+ T cell subsets in TIL from brain tumors.

METHODS

CD3+, CD4+, and CD8+ cells were quantified in fresh TIL by flow cytometry. Paraffin embedded sections of tumors, including meningiomas and gliomas as well as extracranial malignancies, underwent immunohistochemical staining for FasL and Von-Willebrand's factor (Factor VIII) to determine expression levels of endothelial FasL.

RESULTS

FasL expression was high in aggressive intracranial malignancies compared to more indolent neoplasms, and correlated inversely with CD8+/CD4+ TIL ratios in all tumor classes combined (ANOVA, p < 0.05).

CONCLUSION

Low levels of T cells within TIL, as well as low CD8+/CD4+ TIL ratios appear to be a property of parenchymal tumor presence. Together with the inverse correlation seen between FasL expression and CD8+/CD4+ TIL ratios, the high levels of endothelial FasL expression in gliomas suggests that FasL decreases T cell presence in brain tumors in a subset-selective manner, thus contributing to glioma immune privilege.

Nodal metastases: predictive factors

Squamous cell carcinoma of the upper respiratory and digestive tract has a high risk for neck metastasis, which reduces the probability of regional control and survival. We analyzed the literature and our own experience to review the possible risk factors for the occurrence of metastasis. The most significant risk factors were: tumor site and size, grade of histologic differentiation, tumor thickness (tongue and floor of mouth carcinoma), vascular embolization, and perineural infiltration. A series of biomarkers has been studied over the last 10 years, but no one has proved to be significant enough for clinical use. Based on several multivariate analysis, it is recommended elective treatment of the neck for high-risk patients.

Limiting dilution analysis of proliferating and cytotoxic lymphocytes in the peripheral blood and tumours of oral cancer patients

Frequencies of proliferating and cytotoxic lymphocytes from the peripheral blood and tumour tissue of oral cancer patients and healthy individuals were monitored using limiting dilution analysis. Significantly lower precursor frequencies of proliferating lymphocytes were observed in the peripheral blood and tumour tissue of oral cancer patients. A high frequency of natural killer (NK) cells but low cytotoxic T lymphocytes (CTL) was observed in the peripheral blood compartment of oral cancer patients as compared to healthy individuals. A marked reduction in both NK and CTL frequencies in the tumour tissue compared to the peripheral blood was observed. In the tumour tissues, increased percentages of activated CD4+ lymphocytes as compared to CD8+ lymphocytes were observed. Our results suggest that impaired proliferative and cytotoxic potential of tumour infiltrating lymphocytes may play an important role in the escape of tumour cells from the immune system.

Tumour-infiltrating lymphocytes mediate lysis of autologous squamous cell carcinomas of the head and neck

Tumour-infiltrating lymphocytes (TIL) and tumours from six patients with squamous cell carcinomas of the head and neck (SCCHN) were investigated. The six tumours all expressed major histocompatibility complex (MHC) class I antigens both in vivo and as tumor cell lines grown in vitro. In addition, the cancer cells either overexpressed the tumour-suppressor gene product p53 or harboured human papilloma virus 16/18 (HPV). The TIL were expanded in vitro in the presence of interleukin-2, immobilised anti-CD3 mAb and soluble anti-CD28 mAb. Expanded TIL cultures contained both CD4+ and CD8+ T cells, but generally contained few CD56+CD3- cells of the natural killer (NK) phenotype. CD8+ T cells dominated the individual TIL cultures from five of the six patients and showed significant autologous tumour cell lysis. In TIL cultures derived from four of these tumour-reactive TIL cultures, killing could be partially blocked by an anti-MHC class I mAb. TIL cultures reacting with autologous tumour cells also showed strong TCR/CD3-redirected cytotoxicity when assayed against hybridoma cells expressing anti-TCR/CD3 mAb as well as natural-killer(NK)-like activity. A number of TIL cultures devoid of autologous tumour cell lysis were capable of lysing the natural-killer(NK)-sensitive K562 cell line suggesting that the SCCHN cells themselves are resistant to NK-like lysis. In conclusion, TIL cultures from head and neck carcinomas contain T cells which, upon expansion in vitro, can lyse autologous tumour cells in a MHC-class-I-restricted fashion. Thus, the results of the present study document that carcinomas of the head and neck in some patients are infiltrated by cytotoxic T cell precursors potentially capable of rejecting the autologous tumour.

Two cases of tongue cancer treated with intra- and peri-tumoral injection of recombinant interleukin-2 alone: immunohistochemistochemical considerations to clinical tumor response

SUBJECTS AND METHODS

Two cases with stage II tongue cancer who exhibited different responses to intra- and peri-tumoral administration of rIL-2 alone are presented. Special consideration is given to the relationship between tumor responses to rIL-2 and clinicopathological and immunohistopathological findings.

RESULTS

The patient who responded completely to treatment showed an exophytic tumor growth pattern, low-grade cancer invasion, and predominant infiltration of CD8+ lymphocytes over CD4+ lymphocytes in cancer cell nests. The non-responder showed endophytic tumor growth, high-grade cancer invasion, and uniform distribution of both CD4+ and CD8+ lymphocytes in cancer cell nests.

CONCLUSIONS

Distribution of adequate amounts of T lymphocytes subsets may be necessary in order for good tumor response to biotherapy with rIL-2; other clinical and histopathological variables predicting the effect for cancer chemotherapy remain to be identified.

In vivo infiltration of mononuclear cells in squamous cell carcinoma of the head and neck correlates with the ability to expand tumour-infiltrating T cells in vitro and with the expression of MHC class I antigens on tumour cells

A series of 18 head and neck squamous cell carcinoma biopsies, 6 primary and 12 recurrent, were investigated for tumour-infiltrating mononuclear cells with monoclonal or polyclonal antibodies. Our results suggest that the number of T cells at the tumour edge in vivo correlates well with their ability to expand in vitro in the presence of high-dose interleukin-2 (2000 U/ml). High MHC class I antigen expression on tumour cells was found to be positively correlated with p53 overexpression, suggesting that p53-derived peptides, wild-type or mutated ones, presented by MHC class I antigens, are potential targets for MHC-restricted cytotoxic T cells in head and neck squamous cell carcinomas. However, lack of correlation between peritumoural T cell infiltration in vivo and T cell expansion in vitro, on the one hand, and p53 overexpression on tumour cells, on the other hand, suggests absence of p53-peptide-specific T cells in the patients. Eight out of ten expanded tumour-infiltrating lymphocyte (TIL) cultures showed T-cell-mediated cytotoxicity. "Promiscuous" cytotoxic T cell activity against the natural-killer-cell-sensitive K562 target cell line was observed in three out of ten TIL expansion cultures.

Functional and phenotypic analysis of T-lymphocytes in laryngeal carcinoma

We studied the functional response and phenotypic characterization of peripheral blood T cells and their correlation with the clinical stage of disease in 29 males with previously untreated carcinoma of the larynx and 24 healthy male controls. Peripheral blood T cells, phenotypically CD2+ CD3+, were significantly decreased in the patients relative to the controls. Patients with advanced locoregional extension (T4 and N1, 2, 3) also showed a diminution of the CD4+ subpopulation of T cells. DNA synthesis by purified T cells showed similar blastogenic responses in patients and controls; the interleukin-2 production of phytohemagglutinin stimulated lymphocytes was also normal. We conclude that in patients with laryngeal carcinoma there is a phenotypic alteration of the T cells that is variable according to tumor stage, without functional alterations in blastogenic capacity or IL-2 production.

Comparison of in vivo and in vitro prostaglandin E2 production by squamous cell carcinoma of the head and neck

Prostaglandin E2 has been identified as an immunosuppressive factor in patients with squamous cell carcinoma of the head and neck. Spontaneous prostaglandin E2 production by 21 cancer cell lines, which were obtained from 17 patients with squamous cell carcinoma of the head and neck, was determined by radioimmunoassay. In comparison with normal keratinocyte cultures, prostaglandin E2 production by cancer cell lines was significantly decreased (p < 0.0001). Prostaglandin E2 levels demonstrated no correlation to the site, stage, or histopathologic differentiation of the tumor. In a separate group of 17 patients with squamous cell carcinoma of the head and neck, tumor cells were isolated from fresh tumor specimens, and 24-hour PGE2 production in vitro was assayed. No correlation was found with tumor site, stage, or 2-year disease-free survival. Although prostaglandin E2 may have biologic significance in vivo in patients with squamous cell carcinoma of the head and neck, these findings suggest that measurements of tumor cell-derived prostaglandin E2 are not predictive of biologic behavior.

Sense and nonsense of scar creams and gels

The wish to prevent or improve scars, whether they are of surgical or traumatic origin, has led to the development of scar creams and gels that are said to influence the aesthetic appearance of a scar. In this article the literature on results of the topical application of various scar creams and gels is reviewed. It is concluded that no single modality has been proven to manage hypertrophic scarring except maybe silicone and BAPN. Further research into the physiology and pharmacophysiology of scar tissue is needed. With respect to scars, it still applies that even "plastic surgeons can't erase without a trace."

In situ hybridisation for cytokine gene transcripts in the solid tumour microenvironment

To determine if mononuclear cells (MNC) infiltrating various types of human solid tumours express genes for cytokines, in situ hybridisation with 35S-labelled cDNA antisense probes for interleukin 2 (IL2), interferon gamma (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), interleukin 1-beta (IL1-beta), transforming growth factor beta (TGF-beta) and interleukin 2-receptors (IL2R) was performed. Fresh-frozen tissue samples of ovarian carcinomas (n = 13), breast carcinomas (n = 12), and squamous cell carcinomas of the head and neck (SCCHN, n = 7) were evaluated for the presence and localization in the tumour of MNC positive for cytokine genes. In ovarian tumours and those breast carcinomas producing little or no mucin, only rare positive MNC were observed. In contrast, breast carcinomas producing mucin and all SCCHN contained numerous MNC expressing gene transcripts for IL2, IFN-gamma, TNF-alpha, IL2R as well as TGF-beta. In tumour-involved lymph nodes of patients with SCCHN, MNC expressing genes for cytokines were found around tumour metastases but not in non-involved areas. These data suggest that tumours expressing immunogenic antigens (e.g. mucin) contain many activated MNC, while other tumours either fail to activate or suppress functions of infiltrating MNC. In SCCHN or tumour-draining lymph nodes, local down-regulation of antitumour responses might be mediated by TGF-beta produced by activated tumour-infiltrating MNC.

Survey of immunosuppressive acidic protein and other immunological parameters in head and neck cancer patients

Serum levels of immunosuppressive acidic protein (IAP) and other immunological parameters were examined in 95 head and neck cancer patients and 27 control patients. The mean values of IAP in patients in the advanced stage were significantly higher than in early stage patients. Statistically significant increases in the mean concentration of IAP were also observed in patients with a recurrence, as compared to findings in those in the advanced stages. The mean values of blastogenesis response to PHA and NK cell activity in the cancer patients were lower than in disease free individuals, but with no statistical differences. In the endstage patients, the IAP concentration was considerably elevated and the blastogenesis response showed a statistically significant decrease. Thus, the monitoring of serum IAP, in combination with other immunological parameters, aids in planning and assessing clinical staging in head and neck cancer patients.