Chemotherapy-induced differential changes in lymphocyte subsets and natural-killer-cell function in patients with advanced breast cancer

Investigating tumor immunogenicity in breast cancer: deciphering the tumor immune response to enhance therapeutic approaches

The interplay between immune cells and malignant cells represents an essential chapter in the eradication of breast cancer. This widely distributed and diverse form of cancer represents a major threat to women worldwide. The incidence of breast cancer is related to several risk factors, notably genetic predisposition and family antecedents. Despite progress in treatment modalities varying from surgery and chemotherapy to radiotherapy and targeted therapies, persistently high rates of recurrence, metastasis, and treatment resistance underscore the urgent need for new therapeutic approaches. Immunotherapy has gained considerable ground in the treatment of breast cancer, as it takes advantage of the complex interactions within the tumor microenvironment. This dynamic interplay between immune and tumor cells has become a key point of focus in immunological research. This study investigates the role of various cancer markers, such as neoantigens and immune regulatory genes, in the diagnosis and treatment of breast tumors. Moreover, it explores the future potential of immune checkpoint inhibitors as therapeutically effective agents, as well as the challenges that prevent their efficacy, in particular tumor-induced immunosuppression and the difficulty of achieving tumor specificity.

Impact of Chemotherapy on Circulating Lymphocyte Subsets in Lung Cancer Patients

Purpose

Lung cancer remains a leading cause of cancer-related death and chemotherapy stands as a fundamental component in therapy. Chemotherapy-induced myelosuppression encompasses a spectrum of hematological declines, including not only neutrophils but also lymphocytes, hemoglobin levels and platelets. This retrospective cohort study investigates alterations in peripheral blood lymphocyte subsets. By uncovering these changes, our goal is to refine patient management strategies, ensuring that the benefits of chemotherapy are maximized while minimizing its detrimental effects.

Patients and Methods

We retrospectively analyzed 159 lung cancer patients. Patients were categorized as "NT" (n=108, no previous anti-tumor therapy), and "PT" (n=51, prior therapy followed by at least a two-month treatment-free interval). Post-chemotherapy, patients were reassessed and grouped into "EarlyCycle" for those who underwent four or fewer cycles, and "LateCycle" for those who underwent more than four cycles.

Results

The study focused on analyzing the percentages of lymphocyte subsets, including T cells (CD4+, CD8+), B cells, and natural killer (NK) cells, across these groups. For T cells, the EarlyCycle group exhibited a significant increase compared to NT (0.7783 vs 0.7271; p=0.0017) and PT (0.7783 vs 0.6804; p=1.6e-05). B cells showed a significant decrease from NT to LateCycle (0.1014 vs 0.0817; p=2.2e-05) and from PT to LateCycle (0.1317 vs 0.0817; p=6.2e-10). NK cells significantly decreased in the EarlyCycle group compared to NT (0.1109 vs 0.1462; p=0.00816) and PT (0.1109 vs 0.1513; p=0.00992), with no significant change in the LateCycle group compared to either NT or PT (p>0.05).

Conclusion

Chemotherapy significantly affects lymphocyte subsets in a treatment-specific manner. The EarlyCycle group experienced a reduction in NK cell and an increase in T cell, suggesting a damage of innate immunity and an early shift towards adaptive immunity. The LateCycle group showed a substantial decrease in B cell, indicating a delayed effect on humoral immunity components.

B-cell performance in chemotherapy: Unravelling the mystery of B-cell therapeutic potential

BACKGROUND AND MAIN BODY

The anti-tumour and tumour-promoting roles of B cells in the tumour microenvironment (TME) have gained considerable attention in recent years. As essential orchestrators of humoral immunity, B cells potentially play a crucial role in anti-tumour therapies. Chemotherapy, a mainstay in cancer treatment, influences the proliferation and function of diverse B-cell subsets and their crosstalk with the TME. Modulating B-cell function by targeting B cells or their associated cells may enhance chemotherapy efficacy, presenting a promising avenue for future targeted therapy investigations.

CONCLUSION

This review explores the intricate interplay between chemotherapy and B cells, underscoring the pivotal role of B cells in chemotherapy treatment. We summarise promising B-cell-related therapeutic targets, illustrating the immense potential of B cells in anti-tumour therapy. Our work lays a theoretical foundation for harnessing B cells in chemotherapy and combination strategies for cancer treatment.

KEY POINTS

Chemotherapy can inhibit B-cell proliferation and alter subset distributions and functions, including factor secretion, receptor signalling, and costimulation. Chemotherapy can modulate complex B-cell-T-cell interactions with variable effects on anti-tumour immunity. Targeting B-cell surface markers or signalling improves chemotherapy responses, blocks immune evasion and inhibits tumour growth. Critical knowledge gaps remain regarding B-cell interactions in TME, B-cell chemoresistance mechanisms, TLS biology, heterogeneity, spatial distributions, chemotherapy drug selection and B-cell targets that future studies should address.

Immunostimulatory Properties of Chemotherapy in Breast Cancer: From Immunogenic Modulation Mechanisms to Clinical Practice

Breast cancer (BC) is the most common malignancy among females. Chemotherapy drugs remain the cornerstone of treatment of BC and undergo significant shifts over the past 100 years. The advent of immunotherapy presents promising opportunities and constitutes a significant complementary to existing therapeutic strategies for BC. Chemotherapy as a cytotoxic treatment that targets proliferation malignant cells has recently been shown as an effective immune-stimulus in multiple ways. Chemotherapeutic drugs can cause the release of damage-associated molecular patterns (DAMPs) from dying tumor cells, which result in long-lasting antitumor immunity by the key process of immunogenic cell death (ICD). Furthermore, Off-target effects of chemotherapy on immune cell subsets mainly involve activation of immune effector cells including natural killer (NK) cells, dendritic cells (DCs), and cytotoxic T cells, and depletion of immunosuppressive cells including Treg cells, M2 macrophages and myeloid-derived suppressor cells (MDSCs). Current mini-review summarized recent large clinical trials regarding the combination of chemotherapy and immunotherapy in BC and addressed the molecular mechanisms of immunostimulatory properties of chemotherapy in BC. The purpose of our work was to explore the immune-stimulating effects of chemotherapy at the molecular level based on the evidence from clinical trials, which might be a rationale for combinations of chemotherapy and immunotherapy in BC.

Exercise Training and Natural Killer Cells in Cancer Survivors: Current Evidence and Research Gaps Based on a Systematic Review and Meta-analysis

Background

Exercise training can positively impact the immune system and particularly natural killer (NK) cells, at least in healthy people. This effect would be of relevance in the context of cancer given the prominent role of these cells in antitumor immunity. In this systematic review and meta-analysis, we aimed to summarize current evidence on the effects of exercise training on the levels and function of NK cells in cancer survivors (i.e., from the time of diagnosis until the end of life).

Methods

Relevant articles were searched in PubMed, Scopus, Web of Science and Cochrane Central Register of Controlled Trials (until January 11, 2022). Randomized controlled trials (RCT) of exercise training (i.e., non-acute) interventions vs usual care conducted in cancer survivors and assessing NK number and/or cytotoxic activity (NKCA) before and upon completion of the intervention were included. Methodological quality of the studies was assessed with the PEDro scale, and results were meta-analyzed using a random effects (Dersimoian and Laird) model.

Results

Thirteen RCT including 459 participants (mean age ranging 11–63 years) met the inclusion criteria. Methodological quality of the studies was overall fair (median PEDro score = 5 out of 10). There was heterogeneity across studies regarding cancer types (breast cancer, non-small cell lung cancer and other solid tumors), treatment (e.g., receiving vs having received chemotherapy), exercise modes (aerobic or resistance exercise, Tai Chi, Yoga) and duration (2–24 weeks). No consistent effects were observed for NK number in blood (mean difference [MD]: 1.47, 95% confidence interval [CI] − 0.35 to 3.29, p = 0.113) or NKCA as assessed in vitro (MD: − 0.02, 95%CI − 0.17 to 0.14, p = 0.834). However, mixed results existed across studies, and some could not be meta-analyzed due to lack of information or methodological heterogeneity.

Conclusions

Current evidence does not support a significant effect of exercise training intervention on NK cells in blood or on their ‘static response’ (as assessed in vitro) in cancer survivors. Several methodological issues and research gaps are highlighted in this review, which should be considered in future studies to draw definite conclusions on this topic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00419-w.

Effects of physical exercise on natural killer cell activity during (neo)adjuvant chemotherapy: A randomized pilot study

Natural killer (NK) cells are a population of innate immune cells known to play a pivotal role against tumor spread. In multiple murine models, it was shown that physical exercise had the potential to increase NK cell antitumor activity through their mobilization and tissue redistribution in an interleukin (IL)-6 and epinephrine-dependent manner. The translation of this finding to patients is unclear. In this randomized pilot trial, we analyzed blood samples of patients with resectable breast or colon cancer who were randomized into an evidence-based moderate-high intensity resistance and aerobic exercise intervention (n = 8) or a control group (n = 6) during the first 9-12 weeks of (neo)adjuvant chemotherapy. In this pilot, we did not solely focus on statistical significance, but also explored whether average between-group differences reached 10%. NK cell degranulation was preserved in the exercise group whereas it decreased in the control group resulting in a between-group difference of 11.4% CD107a+ degranulated NK cells (95%CI = 0.57;22.3, p = 0.04) in the presence and 13.8% (95%CI = -2.5;30.0, p = 0.09) in the absence of an anti-epidermal growth factor receptor monoclonal antibody (EGFR-mAb). In line, the between-group difference of tumor cell lysis was 7.4% (95%CI = -9.1;23.9, p = 0.34), and 13.7% (95%CI = -10.1;37.5, p = 0.23) in favor of the exercise group in the presence or absence of EGFR mAb, respectively. Current explorative analyses showed that exercise during (neo)adjuvant chemotherapy may benefit NK cell activity. Future studies with a larger sample size are needed to confirm this finding and to establish its clinical potential. Trial registration: Dutch trial register number NTR4105.

The Peripheral Immune Landscape of Breast Cancer: Clinical Findings and In Vitro Models for Biomarker Discovery

Breast cancer is the deadliest female malignancy worldwide and, while much is known about phenotype and function of infiltrating immune cells, the same attention has not been paid to the peripheral immune compartment of breast cancer patients. To obtain faster, cheaper, and more precise monitoring of patients' status, it is crucial to define and analyze circulating immune profiles. This review compiles and summarizes the disperse knowledge on the peripheral immune profile of breast cancer patients, how it departs from healthy individuals and how it changes with disease progression. We propose this data to be used as a starting point for validation of clinically relevant biomarkers of disease progression and therapy response, which warrants more thorough investigation in patient cohorts of specific breast cancer subtypes. Relevant clinical findings may also be explored experimentally using advanced 3D cellular models of human cancer-immune system interactions, which are under intensive development. We review the latest findings and discuss the strengths and limitations of such models, as well as the future perspectives. Together, the scientific advancement of peripheral biomarker discovery and cancer-immune crosstalk in breast cancer will be instrumental to uncover molecular mechanisms and putative biomarkers and drug targets in an all-human setting.

Natural Killer Cells and Anti-Cancer Therapies: Reciprocal Effects on Immune Function and Therapeutic Response

Simple Summary

Natural Killer (NK) cells are innate lymphocytes that play an important role in the immune response against cancer. Their activity is controlled by a balance of inhibitory and activating receptors, which in cancer can be skewed to favor their suppression in support of immune escape. It is therefore imperative to find ways to optimize their antitumor functionality. In this review, we explore and discuss how their activity influences, or even mediates, the efficacy of various anti-cancer therapies and, vice versa, how their activity can be affected by these therapies. Knowledge of the mechanisms underlying these observations could provide rationales for combining anti-cancer treatments with strategies enhancing NK cell function in order to improve their therapeutic efficacy.

Abstract

Natural Killer (NK) cells are innate immune cells with the unique ability to recognize and kill virus-infected and cancer cells without prior immune sensitization. Due to their expression of the Fc receptor CD16, effector NK cells can kill tumor cells through antibody-dependent cytotoxicity, making them relevant players in antibody-based cancer therapies. The role of NK cells in other approved and experimental anti-cancer therapies is more elusive. Here, we review the possible role of NK cells in the efficacy of various anti-tumor therapies, including radiotherapy, chemotherapy, and immunotherapy, as well as the impact of these therapies on NK cell function.

Determining the sequence of novel therapies in the treatment of relapsed Hodgkin's lymphoma

INTRODUCTION

Hodgkin's lymphoma (HL) accounts for about 10% of all lymphomas in the U.S.A. Exceptional progress has been made in the treatment of HL with complete response (CR) rates up to 94% in limited stage and 88% in advanced stage disease with regimens such as adriamycin, bleomycin, vinblastine, and dacarbazine in the frontline setting. Nevertheless, up to 10% of patients with limited stage disease and 20-30% of those with advanced stage HL relapse. In the last decade, newer agents such as brentuximab vedotin (BV) and checkpoint inhibitors have been approved by the FDA for treatment of patients with relapsed or refractory HL. As these newer agents are increasingly incorporated in both the frontline and relapsed settings, their optimal sequence becomes challenging for clinicians. Areas covered: This review will discuss the evidence behind the approval of BV and checkpoint inhibitors in HL and the appropriate sequence for using them in relapsed HL. Expert commentary: The appropriate sequence of BV and/or checkpoint inhibitors in the relapsed setting depends on the regimen used in the frontline setting.

Lymphocyte Subpopulations in Patients with Advanced Breast Cancer Submitted to Neoadjuvant Chemotherapy

Aims and background

There is an enhanced immune response in patients with breast cancer after the use of chemotherapy. The objective of this study was therefore to investigate alterations in the number of peripheral lymphocytes in patients with breast cancer after neoadjuvant chemotherapy (NC) and the relationship with prognosis.

Methods

Thirty women were analyzed. Their UICC staging was IIb (only T3N0 included) and III (N3 not included). Sample analysis was performed using flow cytometry before the first cycle and 18 to 21 days after the last cycle of NC. The lymphocyte subsets studied were: T (CD3, CD4, CD8), B (CD19, CD23), natural killer (NK) (CD56, CD16), and interleukin-2 (CD25). CD3, CD56, CD8, and CD16 lymphocytes were analyzed with double marking. After x = 3.8 ± 1.3 cycles of 5-fluorouracil, epirubicin and cyclophosphamide (FEC), 16 patients showed a complete or partial response (group 1). After three cycles 14 showed no response or tumor progression (group 2). A control group of healthy women was used for pretreatment analysis.

Results

Before NC there was a significant increase in B lymphocytes and NK cells in comparison to the control group. After NC there was a significant percentage increase in CD3, CD4, CD8, CD25 and CD3+CD56+ cells and a decrease in CD19, CD23, CD56, CD16 and CD16+CD8+ cells. There was a significant fall in the absolute number of CD4, CD19, CD23, CD56, CD16 and CD16+CD8+ lymphocytes and an increase in GD3+CD56+ lymphocytes. Before NC the ratio CD4/CD8 in group 1 was 2.25 ± 0.5 and in group 2 it was 1.79 ± 0.5 (P <0.05).

Conclusions

Patients with advanced breast cancer showed increases in B and NK lymphocytes. Neoadjuvant chemotherapy (FEC) caused an increase in CD3+CD56+ and a decrease in B lymphocytes. Patients with an increased CD4/CD8 ratio have a better chance of responding to neoadjuvant chemotherapy.

Is There an Opportunity for Current Chemotherapeutics to Up-regulate MIC-A/B Ligands?

Natural killer (NK) cells are critical effectors of the immune system. NK cells recognize unhealthy cells by specific ligands [e.g., MHC- class I chain related protein A or B (MIC-A/B)] for further elimination by cytotoxicity. Paradoxically, cancer cells down-regulate MIC-A/B and evade NK cell’s anticancer activity. Recent data indicate that cellular-stress induces MIC-A/B, leading to enhanced sensitivity of cancer cells to NK cell-mediated cytotoxicity. In this Perspective article, we hypothesize that current chemotherapeutics at sub-lethal, non-toxic dose may promote cellular-stress and up-regulate the expression of MIC-A/B ligands to augment cancer’s sensitivity to NK cell-mediated cytotoxicity. Preliminary data from two human breast cancer cell lines, MDA-MB-231 and T47D treated with clinically relevant therapeutics such as doxorubicin, paclitaxel and methotrexate support the hypothesis. The goal of this Perspective is to underscore the prospects of current chemotherapeutics in NK cell immunotherapy, and discuss potential challenges and opportunities to improve cancer therapy.

Natural killer cells as a promising tool to tackle cancer-A review of sources, methodologies, and potentials

Immune cell-based therapies are emerging as a promising tool to tackle malignancies, both solid tumors and selected hematological tumors. Vast experiences in literature have documented their safety and added survival benefits when such cell-based therapies are combined with the existing treatment options. Numerous methodologies of processing and in vitro expansion protocols of immune cells, such as the dendritic cells, natural killer (NK) cells, NKT cells, αβ T cells, so-called activated T lymphocytes, γδ T cells, cytotoxic T lymphocytes, and lymphokine-activated killer cells, have been reported for use in cell-based therapies. Among this handful of immune cells of significance, the NK cells stand apart from the rest for not only their direct cytotoxic ability against cancer cells but also their added advantage, which includes their capability of (i) action through both innate and adaptive immune mechanism, (ii) tackling viruses too, giving benefits in conditions where viral infections culminate in cancer, and (iii) destroying cancer stem cells, thereby preventing resistance to chemotherapy and radiotherapy. This review thoroughly analyses the sources of such NK cells, methods for expansion, and the future potentials of taking the in vitro expanded allogeneic NK cells with good cytotoxic ability as a drug for treating cancer and/or viral infection and even as a prophylactic tool for prevention of cancer after initial remission.

Nodal tumor response according to the count of peripheral blood lymphocyte subpopulations during preoperative chemoradiotherapy in locally advanced rectal cancer

PURPOSE

The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer.

MATERIALS AND METHODS

From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT.

RESULTS

Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count - cell count at 4 weeks) was associated with node down staging (p = 0.034).

CONCLUSION

Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

Simultaneous detection of circulating immunological parameters and tumor biomarkers in early stage breast cancer patients during adjuvant chemotherapy

BACKGROUND

Chemotherapy-induced immune suppression has mainly been studied in patients with advanced cancer, but the influence of chemotherapy on the immune system in early stage cancer patients has so far not been studied systematically. The aim of the present study was to monitor the immune system during anthracycline- and taxane-based adjuvant chemotherapy in early stage breast cancer patients, to assess the impact of circulating tumor cells on selected immune parameters and to reveal putative angiogenic effects of circulating endothelial cells.

METHODS

Peripheral blood samples from 20 early stage breast cancer patients were analyzed using a flow cytometric multi-color of antibodies to enumerate lymphocyte and dendritic cell subsets, as well as endothelial and tumor cells. An enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of various serological factors.

RESULTS

During chemotherapy, all immunological parameters and angiogenesis surrogate biomarkers showed significant decreases. The numbers of circulating tumor cells showed significant inverse correlations with the numbers of T helper cells, a lymphocyte subset directly related to effective anti-tumor responses. Reduced T helper cell numbers may contribute to systemic immunosuppression and, as such, the activation of dormant tumor cells.

CONCLUSIONS

From our results we conclude that adjuvant chemotherapy suppresses immune function in early stage breast cancer patients. In addition, we conclude that the presence of circulating tumor cells, defined as pan-cytokeratin(+), CD326(+), CD45(-) cells, may serve as an important indicator of a patient's immune status. Further investigations are needed to firmly define circulating tumor cells as a predictor for the success of breast cancer adjuvant chemotherapy.

Immune response to cancer therapy: mounting an effective antitumor response and mechanisms of resistance

Chemotherapy and radiotherapy have been extensively used to eradicate cancer based on their direct cytocidal effects on rapidly proliferating tumor cells. Accumulating evidence indicates that these therapies also dramatically affect resident and recruited immune cells that actively support tumor growth. We now appreciate that mobilization of effector CD8⁺ T cells enhances efficacy of chemotherapy and radiotherapy; remarkable clinical advances have been achieved by blocking regulatory programs limiting cytotoxic CD8⁺ T cell activity . This review discusses immune-mediated mechanisms underlying efficacy of chemotherapy and radiotherapy, and provides a perspective on how understanding tissue-based immune mechanisms can be used to guide therapeutic approaches combining immune and cytotoxic therapies to improve outcomes for a larger subset of patients than currently achievable.

Single-fraction radiation therapy in patients with metastatic Merkel cell carcinoma

Merkel cell carcinoma (MCC) is an aggressive, polyomavirus-associated cancer with limited therapeutic options for metastatic disease. Cytotoxic chemotherapy is associated with high response rates, but responses are seldom durable and toxicity is considerable. Here, we report our experience with palliative single-fraction radiotherapy (SFRT) in patients with metastatic MCC. We conducted retrospective analyses of safety and efficacy outcomes in patients that received SFRT (8 Gy) to MCC metastases between 2010 and 2013. Twenty-six patients were treated with SFRT to 93 MCC tumors located in diverse sites that included skin, lymph nodes, and visceral organs. Objective responses were observed in 94% of the measurable irradiated tumors (86/92). Complete responses were observed in 45% of tumors (including bulky tumors up to 16 cm). “In field” lesion control was durable with no progression in 77% (69/89) of treated tumors during median follow-up of 277 days among 16 living patients. Clinically significant toxicity was seen in only two patients who had transient side effects. An exploratory analysis suggested a higher rate of in-field progression in patients with an immunosuppressive comorbidity or prior recent chemotherapy versus those without (30% and 9%, respectively; P = 0.03). Use of SFRT in palliating MCC patients was associated with an excellent in field control rate and durable responses at treated sites, and with minimal toxicity. SFRT may represent a convenient and appealing alternative to systemic chemotherapy for palliation, for which most patients with oligometastatic MCC are eligible. SFRT may also synergize with emerging systemic immune stimulants by lowering tumor burden and enhancing presentation of viral/tumor antigens.

Immune-based mechanisms of cytotoxic chemotherapy: implications for the design of novel and rationale-based combined treatments against cancer

Conventional anticancer chemotherapy has been historically thought to act through direct killing of tumor cells. This concept stems from the fact that cytotoxic drugs interfere with DNA synthesis and replication. Accumulating evidence, however, indicates that the antitumor activities of chemotherapy also rely on several off-target effects, especially directed to the host immune system, that cooperate for successful tumor eradication. Chemotherapeutic agents stimulate both the innate and adaptive arms of the immune system through several modalities: (i) by promoting specific rearrangements on dying tumor cells, which render them visible to the immune system; (ii) by influencing the homeostasis of the hematopoietic compartment through transient lymphodepletion followed by rebound replenishment of immune cell pools; (iii) by subverting tumor-induced immunosuppressive mechanisms and (iv) by exerting direct or indirect stimulatory effects on immune effectors. Among the indirect ways of immune cell stimulation, some cytotoxic drugs have been shown to induce an immunogenic type of cell death in tumor cells, resulting in the emission of specific signals that trigger phagocytosis of cell debris and promote the maturation of dendritic cells, ultimately resulting in the induction of potent antitumor responses. Here, we provide an extensive overview of the multiple immune-based mechanisms exploited by the most commonly employed cytotoxic drugs, with the final aim of identifying prerequisites for optimal combination with immunotherapy strategies for the development of more effective treatments against cancer.

Effects of adjuvant chemoradiotherapy on the frequency and function of regulatory T cells in patients with head and neck cancer

PURPOSE

Regulatory T cells (Treg) accumulate in tumor tissues and the peripheral blood of cancer patients and may persist after therapies. This cross-sectional study examines effects of adjuvant chemoradiotherapy (CRT) on Treg numbers and function in head and neck squamous cell carcinoma (HNSCC) patients.

EXPERIMENTAL DESIGN

The frequency and absolute numbers of CD4(+), ATP-hydrolyzing CD4(+)CD39(+) and CD8(+) T cells, and expression levels of CD39, CD25, TGF-β-associated LAP and GARP on Treg were measured by flow cytometry in 40 healthy donors (NC) and 71 HNSCC patients [29 untreated with active disease (AD); 22 treated with surgery; 20 treated with CRT]. All treated subjects had no evident disease (NED) at the time of phlebotomy. In an additional cohort of 40 subjects with AD (n = 15), NED (n = 10), and NC (n = 15), in vitro sensitivity of CD4(+) T-cell subsets to cisplatin and activation-induced cell death (AICD) was tested in Annexin V-binding assays.

RESULTS

CRT decreased the frequency of circulating CD4(+) T cells (P < 0.002) but increased that of CD4(+)CD39(+) Treg (P ≤ 0.001) compared with untreated or surgery-only patients. Treg frequency remained elevated for >3 years. CRT increased surface expression of LAP, GARP, and CD39 on Treg. In vitro Treg were resistant to AICD or cisplatin but conventional CD4(+) T cells (Tconv) were not. CRT-induced Treg from AD or NC subjects upregulated prosurvival proteins whereas Tconv upregulated proapoptotic Bax.

CONCLUSIONS

Highly suppressive, cisplatin-resistant Treg increase in frequency and persist after CRT and could be responsible for suppression of antitumor immune responses and recurrence in HNSCC.

Lymphocyte subpopulation and dendritic cell phenotyping during antineoplastic therapy in human solid tumors

Patients with cancer show variable levels of immunosuppression at the time of the presentation, and cytotoxic antineoplastic therapy is the primary contributor to the clinical immunodeficiency often observed during the course of the disease. In both hematological and solid tumors, this phenomenon is primarily related to the T-cell depletion associated with inhibition of dendritic cell ability to induce both primary and secondary T- and B-cell responses. Complete restoration of immunocompetence following antineoplastic therapy implicates the progressive recovery of various cell subpopulations, and it is a complex process that also depends on the type, the dose, the scheduling, and the associations of the employed drugs. In the era of target therapies, several antiangiogenic drugs are increasingly used in combination with standard chemotherapy in the treatment of advanced solid tumors. Their clinical efficacy has been recently related not only to the specific antiangiogenic properties but also to an indirect hypothetical effect on the host immune system. In the present work, we have reviewed the most recent information regarding (1) the capacity of standard antineoplastic therapy to induce and maintain an immunodeficiency in patients with solid tumors and (2) the influence of the antiangiogenic treatment in association with standard chemotherapy on lymphocyte and dendritic cell subsets and the possible resulting additional antitumor mechanism.

Breast cancer and HIV in the era of highly active antiretroviral therapy: two case reports and review of the literature

The incidence of human immunodeficiency virus (HIV) infection is rising in US women; however its impact on breast cancer incidence, stage at presentation, response and treatment toxicity remains unknown. To address the impact of HIV infection and use of highly active antiretroviral therapy (HAART) on the natural history of breast cancer we present two cases of breast cancer in HIV-infected women and also review the literature. A literature search was done on Medline using the key words HIV/AIDS, breast cancer, and HAART therapy, restricted to English language. There were mostly case reports and one large series of 20 cases reported by Hurley et al. Data concerning the impact of HIV infection and HAART therapy regarding pathogenesis, stage at presentation, tumor type, response, and toxicity associated with treatment were reviewed. The literature review shows that the breast cancer incidence is either same or less in HIV-infected patients compared to the general population. However, the patients with HIV infection present with more advanced stage and aggressive disease, and they also have poor chemotherapy tolerance. The impact of HAART on breast cancer incidence in HIV-infected patients is still unclear.

Diet, physical activity and energy balance and their impact on breast and prostate cancers

Obesity, physical activity status and circulating levels of sex steroid hormones and growth factor proteins are intrinsically linked to energy balance. Epidemiological studies have previously reported associations between these factors and the risk of hormone-related cancers such as prostate and breast cancer in men and postmenopausal women. An increasing number of intervention studies in 'at-risk' populations and cancer survivors are now investigating the effects of lifestyle interventions that promote negative energy balance on circulating levels of sex hormones and growth factor proteins as surrogate markers of cancer risk. Evidence from these studies suggests that lifestyle interventions can improve insulin sensitivity, alter the balance of circulating sex steroid hormones and insulin-like growth factor (IGF) axis proteins (including IGF-1 and the IGF binding proteins 1 and 3) and change the functioning of immune cells in peripheral blood. Such changes could influence the risk of developing hormone-related cancers, as well as having the potential to improve disease-free survival in patients recovering from cancer treatment. However, despite promising results, the methodological quality of most intervention studies has been limited due to small subject numbers, lack of adequate control groups or non-randomised designs and the absence of long-term follow-up measures. More intervention studies with randomised controlled designs, higher numbers of subjects and longer-term follow-up measures are needed to establish which combination of specific dietary and physical activity interventions work best for reducing risk in 'at-risk' populations and survivors, optimal dose-response relationships and the magnitude of change in surrogate markers of cancer risk that is required to induce a protective effect.

Significant impairment in immune recovery after cancer treatment

BACKGROUND

Although immunosuppression from cancer adjuvant therapy has been documented, how these suppressed immune responses recover to baseline values after completion of cancer adjuvant therapy has not been studied systematically.

OBJECTIVES

The objective of this study was to examine the probability of immune recovery after cancer adjuvant therapy and the potential impact of cancer adjuvant therapy type and cancer stage on immune recovery in patients with newly diagnosed breast cancer.

METHODS

In a repeated-measures design, immune responses were measured four times in 80 patients with early-stage breast cancer: before and at 2, 6, and 12 months from the beginning of cancer adjuvant therapy. Natural killer cell activity, lymphokine-activated killer cell activity, lymphocyte proliferation, CD subsets (CD4, CD8, and CD56), and cytokines (interferon-gamma, interleukin [IL]-2, IL-4, IL-6, and IL-1alpha) were selected for their relevance to breast cancer. Immune recovery was defined by the level of immune response reaching to and above baseline levels. Data were analyzed using a multivariate generalized linear mixed-model approach.

RESULTS

Delayed immune recovery to pretreatment baseline levels continued to the 12-month time point in all parameters. The percentages of immune recovery ranged from 6% to 76% of the patients, varying among immune parameters. Overall, immune recovery was poorer for interferon-gamma, IL-2, IL-4, lymphocyte proliferation, and natural killer cell activity than was for CD subsets and IL-6. The type of cancer adjuvant therapy, not cancer stage, showed selective influence on immune recovery. Chemotherapy or chemotherapy and radiotherapy combination significantly delayed IL-2 recovery, whereas radiotherapy significantly delayed IL-4 recovery.

DISCUSSION

Immune recovery after breast cancer adjuvant therapy is delayed significantly for an extended time period in numerous immune parameters. The type of cancer adjuvant therapy has selective influence on immune recovery. Future investigations are warranted to elucidate the time course of immune recovery, clinical significance of poor immune recovery, and factors influencing immune recovery to develop potential interventions.

Tumor-infiltrating lymphocytes predict response to neoadjuvant chemotherapy in patients with breast carcinoma

Tumor-infiltrating leukocytes and other immunohistochemical parameters were evaluated in pretherapeutic biopsies and resection specimens in 73 patients undergoing neoadjuvant chemotherapy with doxorubicin and paclitaxel. Ten patients with pathological complete response had significantly higher p53 expression, CD3(+) lymphocyte and CD83(+) cell counts, and lower progesterone receptor expression. In the remaining 63 patients, a significant decrease in the percentage of Ki-67, vascular endothelial growth factor expression, CD68(+) monocytes, and increased CD31(+), CD34(+), and SMA(+) stromal vessels, maximal CD3(+) and CD56(+) lymphocyte, maximal and mean CD83(+) cell, maximal CD1a(+), and maximal and mean S100(+) cell counts were observed after neoadjuvant chemotherapy.

Randomized controlled trial of exercise and blood immune function in postmenopausal breast cancer survivors

The objective was to determine the effects of exercise training on changes in blood immune function in postmenopausal breast cancer survivors. Fifty-three postmenopausal breast cancer survivors were randomly assigned to an exercise (n=25) or control group (n=28). The exercise group trained on cycle ergometers three times per week for 15 wk. The control group did not train. The primary end point was change in natural killer cell cytotoxic activity in isolated peripheral blood mononuclear cells. Secondary end points were changes in standard hematological variables, whole blood neutrophil function, the phenotypes of isolated mononuclear cells, estimations of unstimulated and phytohemaglutinin-stimulated mononuclear cell function (rate of [3H]thymidine uptake), and the production of proinflammatory [interleukin (IL)-1alpha, tumor necrosis factor-alpha, IL-6] and anti-inflammatory cytokines (IL-4, IL-10, transforming growth factor-beta1). Statistical tests were two-sided (alpha <0.05). Fifty-two participants completed the trial. Intention-to-treat analyses, which included the baseline value as a covariate, showed significant differences between groups for change in percent specific lysis of a target natural killer cell at all five effector-to-target ratios (adjusted mean between-group change over all 5 effector-to-target ratios = +6.34%; P <0.05 for all comparisons), the lytic activity per cell (adjusted mean between-group change = -2.72 lytic units; P=0.035), and unstimulated [3H]thymidine uptake by peripheral blood lymphocytes (adjusted mean between-group change = +218 per dpm x 10(6) cells; P = 0.007). There were no significant differences between groups for change in any other end point. Exercise training increased natural killer cell cytotoxic activity and unstimulated [3H]thymidine uptake by peripheral blood lymphocytes in postmenopausal breast cancer survivors.

Cytotoxic T Lymphocyte Count and Survival Time in Women with Metastatic Breast Cancer

While prognostic factors in early stage breast cancer are well documented, few studies have examined predictors of the rate of metastatic progression. The purpose of this study was to examine cytotoxic T-cell lymphocyte (CTL) count as a marker of disease status in women with metastatic breast cancer. This study examined CTL subset counts as predictors of subsequent survival in 113 women with metastatic or recurrent breast cancer. Samples were measured by flow cytometry using monoclonal antibodies for cell surface antigens for percentages and absolute numbers of CTLs (CD3/CD8), total lymphocytes, T cells (CD3), helper T cells (CD3/CD4), and total white blood cell (TWC) count. Higher CTL counts emerged as a significant predictor of longer survival up to 7 years later (Wald = 7.40, p = 0.007; Cox regression model). The relationship of higher CTL count with enhanced survival was independent of the effects of medical treatment. CTLs were significantly associated with TWC count (r = 0.42, p < 0.001). However, TWC count was not associated with subsequent survival time. Higher CTL count was associated with Karnofsky performance status (r = 0.27, p = 0.004). However, after adjustment for the Karnofsky score, the CTL count/survival relationship remained significant (Wald = 4.33, p = 0.038). In conclusion, there is a robust relationship between CTL count and survival that is independent of the effects of medical treatments, TWC count, and Karnofsky performance status. Moreover, a reduced CTL count may be a mediator or marker of more rapid disease progression in metastatic breast cancer.

Functional significance of the activation-associated receptors CD25 and CD69 on human NK-cells and NK-like T-cells

The application of autologous ex-vivo expanded cytotoxic lymphocytes to cancer patients may help to control minimal residual disease. However, the number of effector cells and the resulting antitumoral activity that can be generated in vitro are remarkably variable. Thus, we separately assessed the proliferative and cytotoxic potential of CD56+ CD3- natural killer (NK) and CD56+ CD3+ T-cells in relation to their expression of CD25, CD69, and CD16 in vitro. Two-week lymphocyte cultures from peripheral blood (n = 51) and from G-CSF-mobilized progenitor cell harvests (n = 11) were performed repeatedly from 14 women with breast cancer throughout conventional- and high-dose chemotherapy. A large proportion of CD25+ cells on day 7 of the culture predicted high expandability (r = 0.69, p < 0.00001), while elevated expression of CD69 predicted augmented cytotoxicity (r = 0.72; p = 0.00001) and low expandability (r = -0.69, p < 0.00001). CD25 and CD69 expression were inversely correlated (r = -0.8, p < 0.0001). CD16 expression was not suited to predict functional properties. Additionally, NK-cells were sorted by FACS according to CD25 versus CD69 expression. In a [3H]thymidine incorporation assay the CD25+ NK-cell fraction exhibited a higher proliferation rate than did the CD69+ fraction in all of three experiments. Together, our data suggest that CD69 is a useful marker for cytotoxic activity of NK cells, whereas proliferative potential is indicated by CD25 expression. These findings should help optimizing the ex-vivo generation of large numbers of cytotoxic effector cells for immunotherapy.

The combination of chemotherapy and systemic immunotherapy and the concept of cure in murine leukemia and lymphoma

While important advances have been made in our understanding of the molecular and biochemical processes that lead to the malignant transformation of myeloid and lymphoid cells, no major breakthroughs leading to long-term survival of patients of acute myeloid leukemia (AML) and lymphoma have been achieved during the last decade. Treatment failure, particularly in AML, is mostly related to the problem of resistance to multiple chemotherapeutic drugs and the morbidity and mortality associated with intensive chemotherapy. Thus, a significant challenge that remains is to develop novel therapeutic strategies that would ideally be able to address these issues. Novel immune approaches to cancer immunotherapy, while promising for specificity and long-term protection as single therapies, have not typically proven potent enough to generate long-lasting therapeutic responses. Recent evidence suggests that combining immunotherapy with chemotherapy can lead to increased effectiveness of chemotherapy without making the treatment intolerable to patients. This review focuses on the role of T cell costimulation in tumor immunosurveillance and on the therapeutic efficacy of a combination regimen consisting of chemotherapy and immunotherapy with recombinant B7.2-IgG fusion protein in preclinical AML and lymphoma models.

Breast cancer in women with human immunodeficiency virus infection: implications for diagnosis and therapy

The rising incidence of the human immunodeficiency virus (HIV) infection in women and the prolonged survival increases the risk of development of breast cancer in this population. Through December 2001, 38 cases of breast cancer, two occurring in men, have been reported in persons infected with HIV. Between 1995 and 2001, five HIV infected premenopausal women presented with breast cancer to the Karmanos Cancer Institute. Three patients presented 3-5 years after the diagnosis of HIV infection. One patient presented with stage IV breast cancer, three with stage III, and one with stage II disease. Chemotherapy-induced myelosuppression was pronounced in all patients. Two patients had progression of HIV on treatment manifested by a rise in HIV-1 RNA or development of opportunistic infections. In general, the outcome of breast cancer in our small series of patients was worse than in a non-HIV population. HIV infection may influence the natural history and treatment of breast cancer.

Physical exercise and immune system function in cancer survivors: a comprehensive review and future directions

BACKGROUND

There are a limited number of interventions for cancer survivors following completion of primary therapy that might reduce the risk of cancer recurrence and/or secondary malignancies and increase survival times. It has been proposed that physical exercise may be beneficial by enhancing the anticancer immune system response. The purpose of the current article is to: 1) briefly describe the immune system response to tumors, 2) discuss the impact of anticancer therapy on immune system function in cancer survivors, 3) provide a systematic and comprehensive review of the extant literature examining physical exercise and immune system function in cancer survivors, and 4) offer a critical analysis of this literature and outline directions for future research.

METHODS

A comprehensive literature search up to March 2001 identified empirical articles that examined the effects of physical exercise training on immune system function in cancer survivors from CD-ROM database searches and manual searches.

RESULTS

To the authors' knowledge, six empirical studies published between 1994 and 2000 have examined physical exercise and immune system function in cancer survivors. Overall, four out of six studies reported statistically significant improvements in a number of cancer-related immune system components as a result of exercise. However, there are several limitations that must be considered when interpreting the findings of these studies. These limitations involve the samples, designs, physical exercise interventions, physical fitness assessments, and immunologic assessments.

CONCLUSIONS

Additional research is needed to determine if physical exercise in cancer survivors may reduce the risk of cancer recurrence and secondary malignancies and increase survival times.

Changes in cellular immunity during chemotherapy for testicular cancer

BACKGROUND

The changes in vivo in immunocyte functions during chemotherapy that is administered in combination with granulocyte colony-stimulating factor (G-CSF) in humans have not been fully investigated. This study was designed to examine neutrophil functions and the activities of natural killer (NK) cells, during the administration of chemotherapy and G-CSF for the treatment of testicular cancer.

METHODS

Seven patients with germ cell tumors at stage IIA, IIB or IIIB, who were treated with bleomycin, etoposide and cisplatin (BEP), were enrolled in the study. Numbers and activities of neutrophils and NK cells were measured at various times during and after the first course of chemotherapy. Neutrophil phagocytosis was quantitated by flow cytometry with fluorescent latex beads. Bactericidal activity was measured in terms of colony-forming units. The activity of NK cells was measured by monitoring the release of 51Cr.

RESULTS

After BEP chemotherapy, CD16+ and CD56+ cell counts, and neutrophil granulocyte counts decreased while there were no significant changes in the number of lymphocytes. Phagocytosis by neutrophils was enhanced after administration of G-CSF. The activity of NK cells was severely impaired after chemotherapy and did not change after administration of G-CSF.

CONCLUSIONS

After BEP chemotherapy for testicular cancer with G-CSF, neutrophil function was not at all inferior to those before treatment. Natural killer cell activity was suppressed by the BEP chemotherapy and did not change after administration of G-CSF.

Optimal timing for the collection and in vitro expansion of cytotoxic CD56(+) lymphocytes from patients undergoing autologous peripheral blood stem cell transplantation

To identify the optimal time for the collection of CD56(+) cytotoxic lymphocytes for adoptive immunotherapy in patients undergoing high-dose chemotherapy (HDCT) and peripheral blood stem cell (PBSC) transplantation, 18 breast cancer patients receiving either three cycles of epirubicin/paclitaxel (CT x 3) followed by HDCT and PBSC transplantation (n = 12) or CTx6 (n = 6) were studied. Blood samples were obtained before each CT/HDCT cycle, from PBSC collections, and repeatedly after autografting for up to 12 months. The number of CD56(+)3(-) and CD56(+)3(+) lymphocytes, their in vitro expandability with interleukin-2, and their cytotoxicity against MCF-7 and Daudi cells were analyzed. Six healthy females served as controls. CD56(+) cell counts in both treatment groups were subnormal but stable during the observation period. The cytotoxicity of the expanded CD56(+) cells was normal and unaffected by the treatment. The in vitro CD56(+) cell expandability (controls, 100 +/- 31-fold, mean +/- SEM) was normal before CT1 and CT2, but reduced in PBSC harvests performed after CT2 and application of G-CSF (21 +/- 6-fold; p < 0.01). After PBSC harvesting, the CD56(+) cell expandability increased to 185 +/- 74-fold and 170 +/- 69-fold (before CT3 and HDCT). This increase was not observed in those patients who did not undergo PBSC mobilization. Two weeks after autografting, the CD56(+) cell expandability was minimal (6 +/- 1-fold), and recovered to 34 +/- 6-fold. Thus, CT, HDCT and autografting do not alter the frequency and inducible cytotoxicity of CD56(+) cells in breast cancer patients. However, the proliferative capacity of CD56(+) cells obtained from PBSC harvests and after autografting is impaired. Therefore, instead of the PBSC graft, maximally expandable CD56(+) cells obtained at least 1 week after PBSC collection should be considered for adoptive immunotherapy after PBSC autografting.

The CD3- 16+ 56+ NK cell count independently predicts autologous blood stem cell mobilization

Better predictive factors for autologous blood stem cell mobilization (BSCM) are needed. The purpose of this study was to determine if an independent association exists between lymphocyte or NK cell counts and BSCM. Data were analyzed on 141 consecutive patients aged 19-69 years (median 45) who received combined chemotherapy plus G-CSF for BSCM, and who had measurements of immune cells prior to BSCM. Of the 141 patients, 41% had breast cancer, 14% Hodgkin's disease, 34% non-Hodgkin's lymphoma, and 11% other diagnoses. BSCM involved dose-intensive cyclophosphamide, etoposide, cisplatin (DICEP) plus G-CSF 300 microg (<70 kg) or 480 microg (>70 kg) for 45% of patients, while the remaining 55% received other chemotherapy plus similar doses of G-CSF. Only a single apheresis was performed for 94% of patients. The following factors were analyzed for predictors of BSCM: age, gender, prior chemotherapy, prior radiotherapy, diagnosis, disease status, marrow involvement, mobilization regimen, Hb, WBC, platelet count, B cell, T cell, and NK cell counts. The peripheral blood CD34+ counts on the first day of apheresis (PBCD34) were 6-1783 x 10(6)/l (median 150). The PBCD34 count correlated strongly with the number of CD34+ cells collected/l blood apheresed and with the number of CD34+ cells collected/kg. By multivariate analysis using continuous variables, relapsed status (P = 0.0003), not using DICEP mobilization (P = 0.0001), female gender (P = 0.0057), low platelet count (P = 0.051), and low CD3- 16+ 56+ count (P = 0.0158) were associated with low PBCD34 counts. Using categorical variables, the only factors that independently predicted a PBCD34 count <150 x 10(6)/l were: >1 prior chemotherapy regimen (odds ratio = 5.12, P = 0.0003), not using DICEP mobilization (odds ratio = 4.94, P = 0.0001), and CD3- 16+ 56+ count <125 x 10(6)/l (odds ratio= 2.58, P = 0.0157). In conclusion, the CD3- 16+ 56+ count may be a useful additional predictor of BSCM and warrants further study.

The combination of chemotherapy and systemic immunotherapy with soluble B7-immunoglobulin G leads to cure of murine leukemia and lymphoma and demonstration of tumor-specific memory responses

Major mechanisms underlying poor immune responses to autologous tumor-associated antigens are overwhelming tumor kinetics and the absence of effective T-cell costimulation by antigen-presenting cells. To address these issues, leukemia and lymphoma mice were treated with the combination of chemotherapy and systemic immunotherapy with recombinant soluble murine B7-immunoglobulin G (IgG) molecules. In this report, 3 murine models were used, a radiation-induced SJL acute myeloid leukemia, a transplantable spontaneous SJL lymphoma, and the C57BL/6 EL-4 thymic lymphoma. Various treatment modalities were evaluated: single treatments with either B7-IgG or chemotherapy as well as combination therapies. The results demonstrate the following: (1) in all tumor models, the combination of chemotherapy and soluble B7-IgGs is more potent than either therapy alone, leading to cure of tumor-bearing animals; (2) the therapeutic responses are T-cell-dependent, because combined therapy is not efficacious in severe combined immunodeficient mice; (3) the rejection of tumor cells leads to the development of tumor-specific immunity, because cured mice are immune to the rejected tumor but not to a different syngeneic tumor; and (4) (51)Cr release assays show that rejection of tumor cells leads to the development of very potent tumor-specific cytotoxic T-lymphocyte activity. On the basis of these results, it is proposed that chemotherapy-mediated tumor reduction, together with consequent augmented tumor-antigen presentation to activated T cells, are primary mechanisms leading to curative responses. The safety profile of the B7-IgG fusion proteins and their synergy with chemotherapy strongly suggest that the combination regimen is a promising strategy in cancer treatment.

Determination of natural killer cell function by flow cytometry

Natural killer cells (NK cells) are a subset of peripheral blood lymphocytes that mediate non-major histocompatibility complex-restricted cytotoxicity of foreign target cells. The "gold standard" assay for NK cell activity has been the chromium release assay. This method is not easily performed in the clinical laboratory because of difficulties with disposal of radioactive and hazardous materials, short reagent half-lives, expense, and difficulties with assay standardization. We describe a flow cytometric assay for the clinical measurement of NK cell activity. This study compared the chromium release assay and the flow cytometric assay by using clinically relevant specimens. There were no significant differences between the two assays in the measurement of lytic activity for 17 peripheral blood specimens or in reproducibility in repeated samplings of healthy individuals. We also established a normal range of values for NK activity in healthy adults and identified a small cluster of individuals who have exceptionally high or low levels of NK activity. The flow cytometric assay was validated by testing specimens from subjects expected to have abnormally low levels of NK activity (pregnant women) and specimens from healthy individuals in whom the activity of NK cells was enhanced by exposure to interleukin-2 or alpha interferon. Treatment with these agents was associated with a significant increase in NK activity. These results confirm and extend those of others, showing that the flow cytometric assay is a viable alternative to the chromium release assay for measuring NK cell activity.

Natural killer cells and cancer

BACKGROUND

Natural cytotoxicity, mediated by natural killer (NK) cells and cell with lymphokine-activated killer (LAK) activity, is believed to play an important role in host anti-cancer mechanisms.

METHODS

The authors critically review recent publications on the role of natural cytotoxicity in patients with cancer.

RESULTS

In patients with cancer, several studies have noted variations in the numbers and activity of NK and cells with LAK activity in different body compartments. NK cell activity in the peripheral blood lymphocytes (PBLs) is higher than that found in lymph nodes and within tumors, and this appears to be due to the presence of suppressor factors. The natural cytotoxicity of PBLs in patients with different types of cancers varies. However, there appears to be a trend for natural cytotoxicity to be reduced in certain cancer patients, possibly related to tumor volume or dissemination. Anti-cancer treatments (e.g., surgery, hormonal modulation, radiotherapy and chemotherapy) can also result in suppression of natural cytotoxicity, although the long-term effect on response to treatment and development of metastases is at present unknown.

CONCLUSIONS

NK and LAK cells, through the use of immune biologic modifiers, have been demonstrated to have a therapeutic role in the treatment of human cancers. Further studies are required to determine the optimal dosages and combinations of chemotherapeutic agents, the timing of surgery, and the adjuvant use of immune biologic response modifiers. An increasing awareness and understanding of this field, may allow for the future development of anti-cancer therapies.

Natural immunity in breast cancer patients during neoadjuvant chemotherapy and after surgery

Breast cancer is the most common cancer in women. Surgery, and more recently neoadjuvant chemotherapy, are being utilized as the initial treatment for breast cancer; however little is known about their effects on the natural immune system. The natural immune system (natural killer [NK] cells) is thought to be important in immune surveillance, including protection from metastasis during the intravascular tumour seeding that occurs during surgery. To investigate the effects of surgery on the natural immune system, we studied the pre-operative and post-operative peripheral blood lymphocytes (PBL) of 10 patients with stage I or II breast cancer: there was a 71.6 +/- 25.3% post-operative reduction in NK cell function (P < 0.005, Student's paired t-test). To investigate the effects of neoadjuvant chemotherapy and surgery, we examined PBL from five patients with stage III breast cancer: NK cell function dropped 95.7 +/- 1.9% after neoadjuvant chemotherapy, and there was a further 51.0 +/- 23.4% decrease after surgery (P < 0.05, Student's paired t-test). Neither group of patients had decreased numbers of NK cells, changes in the percentage of T helper or suppressor cells, or alterations in the production of cytotoxic factor by NK cells. These findings suggest that the impairment in NK cell function reflects a defect in the ability of NK cells to recognize and/or bind to tumour target cells. We conclude that the initial treatment of breast cancer patients, whether it involves surgery alone or with neoadjuvant chemotherapy, profoundly impairs their natural immune system and could increase the risk of metastasis. Further studies are needed to delineate the mechanism of this derangement in natural immunity and possibly alter its course.

Coley's toxins, tumor necrosis factor and cancer research: a historical perspective

As far back as the 1700s, it was recorded that certain infectious disease processes could exert a beneficial therapeutic effect upon malignancy. Most prominent among the numerous deliberate efforts made to take advantage of these observations was that of a pioneering New York surgeon, William B. Coley, active career 1891-1936. Using a bacterial vaccine to treat primarily inoperable sarcoma. Coley accomplished a cure rate of better than 10%. This review examines the history of these efforts and presents a discussion of their corresponding relevance to present day immunotherapy.