The diagnostic process of cervical cancer; areas of good practice, and windows of opportunity.

OBJECTIVE: Despite an extensive screening programme in The Netherlands, some cases of cervical cancer are still diagnosed in late stages of disease. The aim of the present study was to investigate which elements in the diagnostic process of cervical cancer may be improved. METHODS: This is a retrospective study of 120 patients with cervical cancer diagnosed between January 1st 2008 and June 1st 2010 at the University Medical Center Utrecht. Patient charts, referral information, and pathology results were analyzed. RESULTS: 39.1% of cancer cases were screen or interval detected; the other 60.9% of patients had not been screened, either due to non-attendance or because they fell outside the age range for screening. The final diagnosis of cervical cancer was established by biopsy in 77 (64.2%) and by excision of the cervical transformation zone in 35 (29.2%) of the patients. Fifteen (43%) of these excisions could have been avoided if biopsies would have been taken at the first examination, and had shown invasive cancer. CONCLUSIONS: Cervical cancer screening aims at early detection of precursor lesions to decrease the incidence of cancer. This in-depth analysis suggests that improvement of quality of care is to be expected from correct recognition of cervical cancer by physicians and adjustments of the screening programme to reach younger women and non-responders.

Pelvic lymphadenectomy improves survival in patients with cervical cancer with low-volume disease in the sentinel node: a retrospective multicenter cohort study.

OBJECTIVE: In this study, we aimed to describe the value of pelvic lymph node dissection (LND) after sentinel lymph node (SN) biopsy in early-stage cervical cancer. METHODS: We performed a retrospective multicenter cohort study in 8 gynecological oncology departments. In total, 645 women with International Federation of Gynecology and Obstetrics stage IA to IIB cervical cancer of squamous, adeno, or adenosquamous histologic type who underwent SN biopsy followed by pelvic LND were enrolled in this study. Radioisotope tracers and blue dye were used to localize the sentinel node, and pathologic ultrastaging was performed. RESULTS: Among the patients with low-volume disease (micrometastases and isolated tumor cells) in the sentinel node, the overall survival was significantly better (P = 0.046) if more than 16 non-SNs were removed. No such significant difference in survival was detected in patients with negative or macrometastatic sentinel nodes. CONCLUSIONS: Our findings indicate that in patients with negative or macrometastatic disease in the sentinel nodes, an additional LND did not alter survival. Conversely, our data suggest that the survival of patients with low-volume disease is improved when more than 16 additional lymph nodes are removed. If in a prospective trial our data are confirmed, we would suggest a 2-stage operation.

Open versus laparoscopic pelvic lymph node dissection in early stage cervical cancer: no difference in surgical or disease outcome.

OBJECTIVE: This study aimed to investigate in a retrospective study the effect of laparoscopic surgery, introduced in our center in 1994 as part of the standard treatment of early stage cervical cancer, on surgical and disease outcomes. PATIENTS AND METHODS: A total of 169 women with cervical carcinoma stage IB1 (n = 150) or IB2 (n = 19) were included in the study. Seventy-six patients who underwent laparoscopic pelvic lymph node dissection (LPLND), followed either by open radical hysterectomy (n = 63) or, in case of positive lymph nodes, by primary chemoradiation (n = 13), were compared with an historic cohort of 93 patients who underwent a fully open, traditional Wertheim-Meigs procedure (WM). Recorded clinical characteristics of patients included age, International Federation of Gynecology and Obstetrics stage, histologic diagnosis, differentiation grade, tumor diameter, lymph node status, and adjuvant therapy. Operation time; lymph node yield; intraoperative, early, and late complications; site of recurrences; and disease-free and overall survival rates were analyzed and compared between groups. RESULTS: Clinical characteristics did not differ between groups. Duration of total surgery time was longer in patients with LPLND followed by open radical hysterectomy compared with that in the WM group (P < 0.001). In patients with negative lymph nodes (n = 129), the number of resected nodes was higher (P = 0.002) in the LPLND (median, 26 nodes; range, 8-55 nodes) than in the WM group (median, 21 nodes; range, 7-50 nodes). In patients with positive lymph nodes (n = 40), no significant difference in the number of resected lymph nodes between the 2 groups (P = 0.904) was found. Intraoperative, early, and late complications did not differ between the 2 surgical procedures. The number of locoregional recurrences, but not of distant metastases, was significantly higher (P = 0.018) in the WM group compared with the LPLND group. No difference in disease-free or disease-specific survival was found between the LPLND and WM group, neither with nor without adjuvant or primary (chemo)radiation. A benefit in disease-free survival (P = 0.044), but not in disease-specific survival (P = 0.070), was found in the LPLND compared with the WM group in those patients who received adjuvant therapy or primary chemoradiation. CONCLUSIONS: Introduction of a laparoscopic procedure in the surgical staging and treatment of cervical cancer patients did not have a detrimental effect on surgical or disease outcome, and this can be safely applied to the treatment of early stage cervical cancer.

IFN-gamma-producing human invariant NKT cells promote tumor-associated antigen-specific cytotoxic T cell responses.

CD1d-restricted invariant NKT (iNKT) cells can enhance immunity to cancer or prevent autoimmunity, depending on the cytokine profile secreted. Antitumor effects of the iNKT cell ligand alpha-galactosylceramide (alphaGC) and iNKT cell adoptive transfer have been demonstrated in various tumor models. Together with reduced numbers of iNKT cells in cancer patients, which have been linked to poor clinical outcome, these data suggest that cancer patients may benefit from therapy aiming at iNKT cell proliferation and activation. Herein we present results of investigations on the effects of human iNKT cells on Ag-specific CTL responses. iNKT cells were expanded using alphaGC-pulsed allogeneic DC derived from the acute myeloid leukemia cell line MUTZ-3, transduced with CD1d to enhance iNKT cell stimulation, and with IL-12 to stimulate type 1 cytokine production. Enhanced activation and increased IFN-gamma production was observed in iNKT cells, irrespective of CD4 expression, upon stimulation with IL-12-overexpressing dendritic cells. IL-12-stimulated iNKT cells strongly enhanced the MART-1 (melanoma Ag recognized by T cell 1)-specific CD8(+) CTL response, which was dependent on iNKT cell-derived IFN-gamma. Furthermore, autologous IL-12-overexpressing dendritic cells, loaded with Ag as well as alphaGC, was superior in stimulating both iNKT cells and Ag-specific CTL. This study shows that IL-12-overexpressing allogeneic dendritic cells expand IFN-gamma-producing iNKT cells, which may be more effective against tumors in vivo. Furthermore, the efficacy of autologous Ag-loaded DC vaccines may well be enhanced by IL-12 overexpression and loading with alphaGC.

SCC-Ag, lymph node metastases and sentinel node procedure in early stage squamous cell cervical cancer.

OBJECTIVES: We analyzed pretreatment SCC-Ag levels, lymph node (LN) status and disease outcome in early stage squamous cell (SCC) cervical cancer. METHODS: Serum SCC-Ag was measured before primary treatment in 91 patients (FIGO stage IB1 72, IB2 10, and IIA 9). Of these, 58 underwent laparoscopic sentinel lymph node (SLN) procedure followed by pelvic lymphadenectomy. RESULTS: No false negative SLN were observed. SCC-Ag levels were higher in patients with positive LN compared to patients with negative LN (p=0.010), but no difference was found in the SLN patients (p=0.344). The accuracy to predict LN metastases of SCC-Ag at ROC established cutoff of 1.65 ng/mL and 5.5 ng/mL was 76% and 78%, respectively, in stage IB1, and 53% and 79%, respectively, in stages IB2+ IIA. Whereas no deaths were observed in patients with negative LN and negative SCC-Ag levels (at previously established cutoff of 1.1 ng/mL), overall survival (OS) for patients with negative LN but elevated SCC-Ag was similar to that of patients with positive LN, irrespective of their marker levels (Kaplan-Meier analysis of all patients and in stage IB1, p=0.002 and p=0.026, respectively). CONCLUSIONS: SCC-Ag (>1.65 ng/mL) can predict LN metastases more accurately in stage IB1 than in stage IB2+ IIA. Since SCC-Ag levels above 1.1 ng/mL are already associated with a poor prognosis, the marker seems to identify a subgroup of LN negative patients with occult disease that may benefit from full lymphadenectomy following a SLN procedure.

Induction of IgG antibodies to MUC1 and survival in patients with epithelial ovarian cancer.

We investigated whether epithelial ovarian cancer patients participating in a randomized phase III trial comparing single intraperitoneal (IP) administration of yttrium-90-labeled murine HMFG1 ((90)Y-muHMFG1) plus standard treatment (AT) vs. standard treatment (ST) alone developed IgG ab to MUC1 that had an impact on disease outcome. Serial serum samples from 208 patients in the AT and 199 patients in the ST arm were tested for IgG ab to MUC1 (anti-MUC1 IgG). Anti-MUC1 IgG at weeks 4, 8 and 12 ranked higher in the AT than in the ST arm (p < 0.001). The median (range) area under the curve (AUC) of anti-MUC1 IgG for weeks 1 to 12 was 5.53 (1.51-39.51) and 3.92 (1.17-68.74) for the AT and ST arm, respectively (p < 0.001). An anti-MUC1 IgG AUC > 13 was associated with a benefit in overall survival (OS) and disease-free survival (DFS) in the AT arm in univariate (p = 0.043 and 0.036, respectively), but not in multivariate analysis (Cox proportional hazards regression model). Kaplan-Meier analysis showed a benefit in OS and DFS in patients with an anti-MUC1 IgG AUC > 13 in the AT arm (p = 0.043 and 0.036, respectively), but not in the ST arm. A single IP injection with muHMFG1 did not lead to a survival benefit in the randomized trial, but it induced ab to MUC1 that were associated with an improved disease outcome in patients with highest levels of anti-MUC1 IgG. Immunotherapy against MUC1 could be effective in the treatment of epithelial ovarian cancer.

In vitro expanded human invariant natural killer T-cells promote functional activity of natural killer cells.

Invariant natural killer T (iNKT) cells play a pivotal role in cancer immunity through trans-activation of effector cells via swift cytokine secretion. In mice, iNKT cell activation by alpha-galactosylceramide (alpha-GC) induces potent NK cell-mediated anti-tumour effects. Here we investigated whether human iNKT cells could enhance NK cell functional activity in vitro. iNKT cell activation by alpha-GC treatment of peripheral blood mononuclear cells (PBMC) was not sufficient to enhance NK cell effector functions. However, addition of in vitro expanded iNKT cells to PBMC enhanced NK cell-mediated cytotoxicity in an alpha-GC-dependent manner. NK cell activation by iNKT cells was primarily mediated by soluble factors, and could be enhanced by the NK cell activating cytokine IL-21. These results suggest that adoptive transfer of ex vivo expanded iNKT cells will enhance NK cell function and is expected to enhance the efficacy of cancer immunotherapy, particularly in combination with IL-21 and alpha-GC.

A combination of serum tumor markers identifies high-risk patients with early-stage squamous cervical cancer.

We aimed to investigate whether pretreatment serum levels of squamous cell carcinoma (SCC) antigen (SCC-Ag), cytokeratin 19 (CYFRA 21-1) and two mucins (CA 15-3 and CA 125) identify patients with occult disease in early-stage SCC of the cervix. Therefore, pretreatment serum samples were obtained from 78 patients with SCC of the cervix (52 IB, 9 IIA and 18 IIB), and tumor markers were measured with commercial immunoassays. SCC-Ag, CYFRA 21-1 and CA 15-3 (analyzed as continuous variables) were significantly associated with overall (OS) and disease-free survival (DFS) in univariate analysis (p < 0.001 in all cases). Multivariate analysis identified lymph node status as the strongest predictor for OS and DFS (p < 0.001 and p = 0.001, respectively), followed by CYFRA 21-1 (p = 0.060 and p = 0.027, respectively) and CA 15-3 (p = 0.082 and p = 0.017, respectively). Clinical cutoff values for each marker were defined by maximizing the log-rank statistics for OS in the total population: 1.1 microg/l for SCC-Ag (n = 47, 60.3%), 1.4 microg/l for CYFRA 21-1 (n = 47, 60.3%), 40 U/ml for CA 15-3 (n = 11, 14.1%) and 30 U/ml for CA 125 (n = 10, 12.8%). Stage IB patients with positive SCC-Ag and CYFRA 21-1 had significantly lower OS (mean 8.3 years, 95% confidence interval, CI, 5.8-10.7 years) and DFS (mean 7.3 years, 95% CI 4.6-10 years) than all other stage IB patients (OS, mean 14.5 years, 95% CI 13.5-15.5 years; DFS, mean 13.9 years, 95% CI 12.5-15.4 years). Stage IB patients with tumors <4 cm or with negative lymph nodes and positive SCC-Ag and CYFRA 21-1 had significantly poorer OS and DFS compared to all other patients in the same group. Elevated levels of both CA 125 and CA 15-3 (3 patients) were associated with an extremely poor prognosis. In conclusion, a combination of SCC-Ag and CYFRA 21-1 may help to identify early-stage cervical cancer patients with occult disease requiring adjuvant therapy.

Human anti-mouse IgM and IgG responses in ovarian cancer patients after radioimmunotherapy with 90Y-muHMFG1.

BACKGROUND: Human anti-mouse antibody (HAMA)-IgM and IgG in ovarian cancer patients treated with intraperitoneal (i.p.) 90Y-muHMFG1 as consolidating therapy were analyzed for a relationship with outcome of disease. PATIENTS AND METHODS: Serial serum samples from 208 ovarian cancer patients participating in a phase III trial of i.p. 90Y-muHMFG1 and 25 controls were analyzed for HAMA-IgM and HAMA-IgG. Results were correlated with time to, and location of, disease recurrence. RESULTS: Patients receiving i.p. 90Y-muHMFG1 developed a rapid HAMA-IgM peak (week 4 to 8), followed by a HAMA-IgG peak 2-4 weeks later. HAMA levels in the control group remained unchanged. Early maximum HAMA-IgG peaks were associated with early relapse [hazard ratio (HR), 0.975; 95% confidence interval (CI) 0.956 to 0.995; p=0.012]. Patients with a HAMA-IgG maximum before or at 8 weeks were at significantly higher risk for disease recurrence (HR, 1.6; 95% CI 1.1 to 25;p=0.021) as compared to patients with a HAMA-IgG maximum after 8 weeks. CONCLUSION: Besides time point of maximum HAMA-IgG, no evident relation could be found between HAMA-IgM or HAMA-IgG development and time to relapse or location of recurrence.

High level of MUC1 in serum of ovarian and breast cancer patients inhibits huHMFG-1 dependent cell-mediated cytotoxicity (ADCC).

The huHMFG-1 (AS1402) antibody is a humanised IgG1 directed against MUC1 and is currently in clinical trials for the treatment of breast carcinoma. Adenocarcinomas over-express and shed MUC1, and high MUC1 serum levels are associated with progressive disease. Here, we have investigated the effects of MUC1 present in sera from breast and ovarian cancer patients and that of NK cells on in vitro huHMFG-1-mediated ADCC, performed with and without the addition of various cytokines. Screening for patients with high levels of NK cells bearing the FcgammaRIIIa-158V polymorphism, adjusting the dosage to circulating levels of MUC1 and co-administration of NK cell activating cytokines may increase the efficacy of huHMFG-1 treatment.

Molecular basis of incomplete O-glycan synthesis in MCF-7 breast cancer cells: putative role of MUC6 in Tn antigen expression.

An incomplete elongation of O-glycan saccharide chains in mucins have been found in epithelial cancers, leading to the expression of shorter carbohydrate structures, such as the Tn antigen (GalNAc-O-Ser/Thr). This antigen is one of the most specific human cancer-associated structures and is capable of inducing effective immune responses against cancer cells. We aimed to investigate the causes of the expression of Tn antigen in the Tn-rich MCF-7 breast cancer cell line focusing on the first step of the O-glycosylation process. Interestingly, amino acid sequences derived from "non-mammary" apomucins (MUC5B and MUC6) were very good acceptor substrates for ppGalNAc-Ts, which are the enzymes catalyzing the Tn antigen synthesis. MUC6 peptide glycosylation with MCF-7 microsome extracts as source of ppGalNAc-T activity yielded 95% conversion of the peptide into MUC6-Tn. In addition, the MUC6-Tn glycopeptide was a poor acceptor substrate for core 1 beta3Gal-T, the next enzyme involved in the saccharide chain biosynthesis, yielding only 5% conversion of MUC6-Tn into MUC6-TF. These results indicate that non-mammary apomucin expression could be responsible, at least in part, for Tn antigen expression in MCF-7 breast cancer cells due to a combined action on glycosyltransferases: an increase of ppGalNAc-T activity and a decrease of core 1 beta3Gal-T activity. Our hypothesis is supported by experiments in vivo showing that (a) native MUC6 glycoproteins express the Tn antigen in MCF-7 cells and (b) Tn antigen expression is increased after transfection with a construct encoding for a MUC6 recombinant protein into the low Tn-expressing breast cancer cell T47D. These results open new horizons in breast cancer glycoimmunology, stressing the potential role of non-mammary apomucins.

Polypeptide GalNAc-transferases, ST6GalNAc-transferase I, and ST3Gal-transferase I expression in gastric carcinoma cell lines.

Mucin O-glycosylation in cancer is characterized by aberrant expression of immature carbohydrate structures leading to exposure of simple mucin-type carbohydrate antigens and peptide epitopes. Glycosyltransferases controlling the initial steps of mucin O-glycosylation are responsible for the altered glycosylation observed in cancer. We studied the expression in gastric cell lines of six UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferases (GalNAc-T1, T2, T3, T4, T6, T11) that catalyze the initial key step in the regulation of mucin O-glycosylation, the transfer of GalNAc from UDP-GalNAc to serine and threonine residues. We also studied the expression of ST6GalNAc-I, the enzyme responsible for the synthesis of Sialyl-Tn antigen (NeuAcalpha2,6GalNAc) and the ST3Gal-I, the enzyme responsible for the synthesis of Sialyl-T antigen (NeuAcalpha2,3Galbeta1,3GalNAc). This study was done using specific monoclonal antibodies, enzymatic assays, and RT-PCR. Our results showed that GalNAc-T1, -T2, and -T3 have an ubiquitous expression in all gastric cell lines, whereas GalNAc-T4, -T6, and -T11 show a restricted expression pattern. The immunoreactivity with MAb VU-2-G7 suggests that, apart from GalNAc-T4, another GalNAc transferase is involved in the glycosylation of the Thr in the PDTR region of the MUC1 tandem repeat. The expression of ST3Gal-I correlates with the expression of the Sialyl-T antigen in gastric cell lines and in the control cell lines studied. The expression of ST6GalNAc-I is low in gastric cell lines, in accordance with the low/absent expression of the Sialyl-Tn antigen.

Cellular and humoral responses after multiple injections of unconjugated chimeric monoclonal antibody MOv18 in ovarian cancer patients: a pilot study.

PURPOSE: Chimeric antibody MOv18 (c-MOv18) mediates antibody-dependent cellular cytotoxicity (ADCC) in vitro. To study the toxicity of c-MOv18 and its immunological effects, five ovarian cancer patients received intravenous injections for 4 weeks. METHODS: ADCC activity of c-MOv18 was tested in a (51)Cr-release assay using IGROV1 and KB cells. Patients' peripheral blood mononuclear cells (PBMC) were phenotyped for CD3, CD4, CD8, and CD25 by FACS analysis and tested for T-cell proliferation in vitro in the presence of c-MOv18 with and without IL-2. RESULTS: Toxicity was mild and transient. No human anti-chimeric antibodies were found. Increased ADCC levels corresponding with a slight increase in CD4+ and CD8+ fractions were observed after the first injection, while the CD4/CD8 ratio and the levels of CD25 remained unchanged. c-MOv18 did not have a mitogenic effect on patients' PBMC and adding IL-2 did not change the degree of proliferation. In three patients stable disease was achieved for up to 4 months, 9 months and 14 months, respectively. CONCLUSION: Immunotherapy aiming at the patient's immunological capacity has minor effects in ovarian cancer patients that have been heavily pretreated with chemotherapy. Such strategies should be evaluated in patients who are more immunocompetent, i.e., before excessive chemotherapy and after achieving microscopic or small volume disease.

Metastatic Breast Tumour Regression Following Treatment by a Gene-Modified Vaccinia Virus Expressing MUC1 and IL-2.

MUC1 is expressed by glandular epithelial cells. It is overexpressed in the majority of breast tumours, making it a potential target for immune therapy. The objectives of the present study were to evaluate the anti-tumour activity and tolerance of repeated administration of TG1031 (an attenuated recombinant vaccinia virus containing sequences coding for human MUC1 and the immune stimulatory cytokine IL-2) in patients with MUC1-positive metastatic breast cancer. This was an open-label, randomised study comparing two dose levels, 5 x 10E6 and 5 x 10E7, with 14 patients in each arm. The treatment was administered intramuscularly every 3 weeks for the first 4 doses and every 6 weeks thereafter, until progression. Two patients had a partial tumour regression ( > 50%), and 15 patients had stable disease as their best overall response until at least the 5th injection. Partial regression lasted for 11 months in one patient and for 12 months in the second patient who then underwent surgical resection of her hepatic metastases. The most frequent adverse events included inflammation at injection site: 7 patients, itching or pain at injection site: 5 patients, and moderate fever: 6 patients. One responding patient developed antinuclear, anti-DNA, and increased anti-TPO antibodies after the fifth injection, and which resolved at the end of treatment. The treatment regimes were well tolerated with a low toxicity profile. Although clinical efficacy remains limited, this study demonstrates the potential use of MUC1-based immune therapy in breast cancer.

Clinical and technical evaluation of the ACS:OV serum assay and comparison with three other CA125-detecting assays.

BACKGROUND: In this study the clinical and technical performance of the CA125- detecting Bayer ACS:OV immunoluminometric serum assay was compared with three other well-established CA125-detecting assays. METHODS: A total of 1112 serum samples was included in this evaluation: 462 from apparently healthy women, 153 from patients with benign ovarian disease, 163 from patients with malignant ovarian disease, 10 from patients with borderline ovarian malignancies and 78 samples from 12 ovarian cancer patients during monitoring of disease. Serum samples from women with malignant endometrial (n = 68) and colon (n = 32) diseases were also included. Moreover, serum samples from women with benign uterine disease and endometriosis (n = 136) plus 10 serum samples from men (n = 7) and women (n = 3) with human anti-mouse antibodies (HAMA) after immunoscintigraphy were included. All samples were tested in duplicate with the Bayer ACS:OV, the Centocor CA125 II, the Abbott IMx CA125 and the Roche (formerly Boehringer Mannheim) Enzymun-Test CA125 II assays. RESULTS: The clinical performance of the Bayer ACS:OV assay, assessed in various patient groups, was similar to that of the two other automated assays. In serum from patients with benign diseases the highest values were found in patients with benign ovarian tumours. In the ovarian cancer patients followed during the course of disease we found similar marker patterns with all four assays. In contrast to the Roche Enzymun-CA125 II assay and to a lesser extent the Centocor CA125 II assay, the Bayer ACS:OV assay was less sensitive to interference from HAMA. CONCLUSION: The Bayer ACS:OV assay is a precise and reliable test for the quantification of CA125 in serum.

Natural and Induced Humoral Responses to MUC1.

MUC1 is a membrane-tethered mucin expressed on the ductal cell surface of glandular epithelial cells. Loss of polarization, overexpression and aberrant glycosylation of MUC1 in mucosal inflammation and in adenocarcinomas induces humoral immune responses to the mucin. MUC1 IgG responses have been associated with a benefit in survival in patients with breast, lung, pancreatic, ovarian and gastric carcinomas. Antibodies bound to the mucin may curb tumor progression by restoring cell-cell interactions altered by tumor-associated MUC1, thus preventing metastatic dissemination, as well as counteracting the immune suppression exerted by the molecule. Furthermore, anti-MUC1 antibodies are capable of effecting tumor cell killing by antibody-dependent cell-mediated cytotoxicity. Although cytotoxic T cells are indispensable to achieve anti-tumor responses in advanced disease, abs to tumor-associated antigens are ideally suited to address minimal residual disease and may be sufficient to exert adequate immune surveillance in an adjuvant setting, destroying tumor cells as they arise or maintaining occult disease in an equilibrium state. Initial evaluation of MUC1 peptide/glycopeptide mono and polyvalent vaccines has shown them to be immunogenic and safe; anti-tumor responses are scarce. Progress in carbohydrate synthesis has yielded a number of sophisticated substrates that include MUC1 glycopeptide epitopes that are at present in preclinical testing. Adjuvant vaccination with MUC1 glycopeptide polyvalent vaccines that induce strong humoral responses may prevent recurrence of disease in patients with early stage carcinomas. Furthermore, prophylactic immunotherapy targeting MUC1 may be a strategy to strengthen immune surveillance and prevent disease in subjects at hereditary high risk of breast, ovarian and colon cancer.

Vaccine-induced antibody responses in patients with carcinoma.

Cancer vaccines based on defined antigens are capable of inducing antibodies that recognize and kill tumor cells. Antibodies are ideally suited to address minimal residual disease, and vaccination in an adjuvant setting may favorably influence the outcome of a disease. The present article gives a short summary of antibody production by B cells, and the mechanism of action of antibodies, as well as a description of the current methods for measuring antibody responses and for assessing their antitumor efficacy in the context of clinical trials. It concludes with an overview of antibody responses induced by vaccines based on structurally defined tumor-associated antigens tested in patients with carcinomas. Correlation between antibody responses, T-cell responses and clinical outcome has been noted in a few studies, signaling the importance of vaccine design and adjuvants to exploit the interactions of the innate and adaptive immune system. However, humoral responses, which may provide a surrogate marker for T-helper responses and simplify monitoring of large Phase III trials, are still not or incompletely explored in many vaccination trials.

Differential indirect activation of human invariant natural killer T cells by Toll-like receptor agonists.

AIM: Invariant natural killer (iNK) T cells are activated by bacterial glycosphingolipids presented by CD1d on dendritic cells (DCs). Here, it was investigated whether Toll-like receptor (TLR) ligands derived from various microorganisms can either directly or indirectly (through DC activation) activate iNKT cells. MATERIALS & METHODS: TLR expression by iNKT cells was examined and the ability of various TLR ligands to activate iNKT cells was evaluated. RESULTS: Although human iNKT cells express all TLRs, apart from TLR8, they did not respond directly to TLR ligands. However, iNKT cells became strongly activated when total peripheral blood mononuclear cells were stimulated with TLR2/6, 7/8 and 9 ligands, but not or to a lesser extent with TLR3, 4 and 5 ligands. TLR-stimulated monocyte-derived DCs promoted iNKT cell phenotypic activation and, in turn, these activated iNKT cells further enhanced DC maturation. CONCLUSION: TLR agonists may act as strong adjuvants for immunotherapy by promoting combined and reciprocal activation of iNKT cells and DCs.

Immunoglobulin allotypes influence antibody responses to mucin 1 in patients with gastric cancer.

There are significant interindividual differences in naturally occurring antibody responses to the tumor-associated antigen mucin 1 (MUC1), but the host genetic factors that might contribute to these differences have not been identified. The aim of the present investigation was to determine whether the variation in naturally occurring antibody levels to MUC1 in patients with gastric cancer is associated with GM and KM allotypes, genetic markers of IgG heavy chains and kappa-type light chains, respectively. A total of 169 Caucasian subjects with gastric cancer were allotyped for several GM and KM markers. These subjects were also characterized for IgG and IgM antibodies to MUC1. GM 3 23 5,13 phenotype was highly significantly associated with MUC1 IgG levels; subjects with this phenotype had lower antibody levels compared with those lacking this phenotype (median IgG level 65.5 relative units versus 91.0 relative units, P = 0.0058). In addition, this phenotype had an interactive effect with KM phenotypes on the levels of IgG antibodies to this antigen (P = 0.0081). Levels of MUC1 IgM antibodies were not associated with these genetic markers. These results show, for the first time, that GM and KM allotypes contribute to the interindividual differences in humoral immunity to MUC1.

Toll-like receptor agonists and invariant natural killer T-cells enhance antibody-dependent cell-mediated cytotoxicity (ADCC).

huHMFG-1 (AS1402) is a humanised IgG1 against MUC1, which exerts tumour cell killing through antibody-dependent cellular cytotoxicity (ADCC) mediated by natural killer (NK) cells. Here, we explored the capacity of invariant NKT (iNKT) cells, which are known to activate NK cells, and toll-like receptor (TLR) ligands which activate both iNKT and NK cells, to enhance huHMFG-1-ADCC. Addition of iNKT cells, as well as TLR2/6, 7, 8 and 9 agonists to PBMC improved the efficacy of huHMFG-1. These results suggest that transfer of ex vivo expanded iNKT cells or TLR agonist treatment may improve the efficacy of NK cell-mediated antibody-based tumour immunotherapies.