Randomized, Double-Blind, Placebo-Controlled Trial of MUC1 Peptide Vaccine for Prevention of Recurrent Colorectal Adenoma.

PURPOSE: To assess whether MUC1 peptide vaccine produces an immune response and prevents subsequent colon adenoma formation. PATIENTS AND METHODS: Multicenter, double-blind, placebo-controlled randomized trial in individuals age 40 to 70 with diagnosis of an advanced adenoma ≤1 year from randomization. Vaccine was administered at 0, 2, and 10 weeks with a booster injection at week 53. Adenoma recurrence was assessed ≥1 year from randomization. The primary endpoint was vaccine immunogenicity at 12 weeks defined by anti-MUC1 ratio ≥2.0. RESULTS: Fifty-three participants received the MUC1 vaccine and 50 placebo. Thirteen of 52 (25%) MUC1 vaccine recipients had a ≥2-fold increase in MUC1 IgG (range, 2.9-17.3) at week 12 versus 0/50 placebo recipients (one-sided Fisher exact P < 0.0001). Of 13 responders at week 12, 11 (84.6%) responded to a booster injection at week 52 with a ≥2-fold increase in MUC1 IgG measured at week 55. Recurrent adenoma was observed in 31 of 47 (66.0%) in the placebo group versus 27 of 48 (56.3%) in the MUC1 group [adjusted relative risk (aRR), 0.83; 95% confidence interval (CI), 0.60-1.14; P = 0.25]. Adenoma recurrence occurred in 3/11 (27.3%) immune responders at week 12 and week 55 (aRR, 0.41; 95% CI, 0.15-1.11; P = 0.08 compared with placebo). There was no difference in serious adverse events. CONCLUSIONS: An immune response was observed only in vaccine recipients. Adenoma recurrence was not different than placebo, but a 38% absolute reduction in adenoma recurrence compared with placebo was observed in participants who had an immune response at week 12 and with the booster injection.

Circulating Myeloid Derived Suppressor Cells (MDSC) That Accumulate in Premalignancy Share Phenotypic and Functional Characteristics With MDSC in Cancer.

Myeloid derived suppressor cells (MDSC) are a heterogeneous population of immature myeloid cells that accumulate in circulation of cancer patients and at tumor sites where they suppress anti-tumor immunity. We previously reported that in a colon cancer prevention trial of a MUC1 vaccine tested in individuals at increased risk for colon cancer, those who did not mount immune response to the vaccine had higher pre-vaccination levels of circulating MDSC compared to those who did. We also reported that individuals with pancreatic premalignancy, Intraductal Papillary Mucinous Neoplasm (IPMN), had increased circulating levels of MDSC that inversely correlated with spontaneous antibody responses against the pancreatic tumor associated antigen MUC1, abnormally expressed on IPMN. Accumulation of MDSC in cancer and their immunosuppressive role had been well established but their presence in premalignancy was unexpected. In this study we compared MDSC in premalignancy with those in cancer with the hypothesis that there might be differences in the composition of various MDSC subpopulations and their immunosuppressive functions due to different lengths of exposure to disease and/or different tissue microenvironments. In cohorts of patients with premalignant polyps, colon cancer, premalignant IPMN, and pancreatic cancer, we confirmed higher levels of MDSC in premalignancy compared to healthy controls, higher levels of MDSC in cancer compared to premalignancy, but no difference in their subpopulation composition or immunosuppressive capacity. We show that levels of MDSC in premalignancy correlate negatively in vivo with spontaneous MUC1-specific antibody responses and in vitro with polyclonal T cell proliferation and IFN-γ secretion.

Anti-MUC1 Antibody in Nipple Aspirate Fluids Correlates with Tumor Aggressiveness in Breast Cancer: A Feasibility Study.

Antibodies against MUC1 are found in circulation of breast cancer (BC) patients. We hypothesized that anti-MUC1 antibodies might be present in even a higher concentration in nipple aspirate fluid (NAF) and could be used to predict aggressiveness of BC. Serum and NAF samples were collected from high risk lesions, BC, and healthy contralateral breasts. ELISA was used to measure the amount of IgG, IgM, and IgA against a tumor-specific MUC1 peptide derived from the extracellular tandem repeat domain of MUC1. Tumor characteristics were recorded prospectively; 120 NAF samples were obtained from a total of 77 women in the study. There was no significant difference of anti-MUC1 antibody levels compared to BC with other lesions. Anti-MUC1 IgG level in NAF was higher in triple negative tumors (P = 0.02); serum anti-MUC1 IgG levels were significantly higher in patients with ER (-) tumor and recurrent disease (P = 0.01); NAF anti-MUC1 IgA levels were significantly higher in patients with LVI and Her2-neu (+) tumors (P < 0.05). These results show that NAF could be a reliable biomarker to predict tumor aggressiveness in BC. A larger study will be needed to confirm these data and to investigate the potential of anti-MUC1 antibodies in NAF and serum to predict disease outcome.

MUC1 vaccine for individuals with advanced adenoma of the colon: a cancer immunoprevention feasibility study.

Cancer vaccines based on human tumor-associated antigens (TAA) have been tested in patients with advanced or recurrent cancer, in combination with or following standard therapy. Their immunogenicity and therapeutic efficacy has been difficult to properly evaluate in that setting characterized by multiple highly suppressive effects of the tumor and the standard therapy on the patient's immune system. In animal models of human cancer, vaccines administered in the prophylactic setting are most immunogenic and effectively prevent cancer development and progression. We report results of a clinical study that show that in patients without cancer but with a history of premalignant lesions (advanced colonic adenomas, precursors to colon cancer), a vaccine based on the TAA MUC1 was highly immunogenic in 17 of 39 (43.6%) of vaccinated individuals, eliciting high levels of anti-MUC1 immunoglobulin G (IgG) and long-lasting immune memory. Lack of response in 22 of 39 individuals was correlated with high levels of circulating myeloid-derived suppressor cells (MDSC) prevaccination. Vaccine-elicited MUC1-specific immune response and immune memory were not associated with significant toxicity. Our study shows that vaccines based on human TAAs are immunogenic and safe and capable of eliciting long-term memory that is important for cancer prevention. We also show that in the premalignant setting, immunosuppressive environment (e.g., high levels of MDSC) might already exist in some individuals, suggesting an even earlier premalignant stage or preselection of nonimmunosuppressed patients for prophylactic vaccination.

Mumps and ovarian cancer: modern interpretation of an historic association.

BACKGROUND: Epidemiologic studies found childhood mumps might protect against ovarian cancer. To explain this association, we investigated whether mumps might engender immunity to ovarian cancer through antibodies against the cancer-associated antigen MUC1 abnormally expressed in the inflamed parotid gland. METHODS: Through various health agencies, we obtained sera from 161 cases with mumps parotitis. Sera were obtained from 194 healthy controls. We used an ELISA to measure anti-MUC1 antibodies and electro-chemiluminescence assays to measure MUC1 and CA 125. Log-transformed measurements were analyzed by t-tests, generalized linear models, and Pearson or Spearman correlations. We also conducted a meta-analysis of all published studies regarding mumps and ovarian cancer. RESULTS: Adjusting for assay batch, age, and sex, the level of anti-MUC1 antibodies was significantly higher in mumps cases compared to controls (p = 0.002). Free circulating levels of CA 125, but not MUC1, were also higher in cases (p = 0.02). From the meta-analysis, the pooled odds ratio estimate (and 95% CI) for the mumps and ovarian cancer association was 0.81 (0.68-0.96) (p = 0.01). CONCLUSION: Mumps parotitis may lead to expression and immune recognition of a tumor-associated form of MUC1 and create effective immune surveillance of ovarian cancer cells that express this form of MUC1.

Anti-MUC1 antibodies and ovarian cancer risk: prospective data from the Nurses' Health Studies.

BACKGROUND: The surface epithelial glycoprotein MUC1 becomes overexpressed and hypoglycosylated in adenocarcinomas; similar changes occur during nonmalignant inflammatory events. Antibodies developed against tumor-like MUC1 in response to such events could be one way through which ovarian cancer risk factors operate. METHODS: We evaluated the association between anti-MUC1 antibodies and risk of ovarian cancer in a prospective nested case-control study in the Nurses' Health Studies. We used an ELISA to measure plasma anti-MUC1 antibodies in 117 ovarian cancer cases collected at least 3 years before diagnosis and 339 matched controls. RESULTS: In controls, younger women (P-trend = 0.03), those with a tubal ligation (P = 0.03), and those with fewer ovulatory cycles (P-trend = 0.04) had higher antibody levels. In cases, women with late-stage disease (P = 0.04) and those whose specimen was >11 years remote from diagnosis (P = 0.01) had higher antibody levels. Overall, increasing anti-MUC1 antibody levels were associated with a nonsignificant trend for lower risk for ovarian cancer, but there was highly significant heterogeneity by age (P-heterogeneity = 0.005). In women <64 years, the antibody level in quartiles 2 to 4 versus quartile 1 were associated with reduced risk (relative risk = 0.53; 95% confidence interval, 0.31-0.93; P-trend = 0.03), whereas in women > or = 64 years, the corresponding relative risk was 2.11 (95% confidence interval, 0.73-6.04); P-trend = 0.05). CONCLUSION: Anti-MUC1 antibodies evaluated several years before diagnosis may be associated with lower risk of subsequent ovarian cancer in women <64 years old at assessment. IMPACT: Key elements of an "immune model" to explain ovarian cancer risk factors are confirmed and should be evaluated in larger prospective studies.

A phase I/II study of a MUC1 peptide pulsed autologous dendritic cell vaccine as adjuvant therapy in patients with resected pancreatic and biliary tumors.

Pancreatic and biliary cancers are relatively resistant to chemotherapy and radiation and may therefore provide an opportunity for testing the potential of immunotherapy. MUC1 is an epithelial cell glycoprotein that is highly overexpressed and aberrantly glycosylated in many adenocarcinomas, including pancreatic tumors, providing a tumor specific antigen and target. We performed a Phase I/II clinical trial of a MUC1 peptide-loaded DC vaccine in 12 pancreatic and biliary cancer patients following resection of their primary tumors. The primary endpoints were vaccine toxicity and immunogenicity and the secondary endpoint was clinical outcome. The vaccine was well tolerated and no toxicity was observed. Three patients had pre-existing MUC1 antibody responses that remained stable post vaccination. MUC1-specific T cell responses were difficult to evaluate due to increases in activity of all CD8 and CD4 T cells following each vaccination. Prior to vaccination, patients entered onto this trial had a significantly higher percentage of FoxP3+CD4+ T cells compared to age matched healthy controls. The percentage of these cells also increased transiently following each injection, returning to baseline or below before the next injection. Vaccinated patients have been followed for over four years and four of the twelve patients are alive, all without evidence of recurrence. Study of the immune parameters in long-term survivors several years after vaccination may yield the sought after immune correlates of clinical responses that analysis of immune responses shortly after vaccination has not revealed.

Incessant ovulation, mucin 1 immunity, and risk for ovarian cancer.

BACKGROUND: Risk for ovarian cancer correlates directly with "ovulatory years or cycles" estimated from time not pregnant, breast-feeding, or using oral contraceptives. Recently, we reported that several factors known to reduce ovarian cancer risk may operate by inducing antibodies against mucin 1 (MUC1), a glycoprotein overexpressed in ovarian cancer. Conversely, other events might increase risk by interfering with the development of protective immunity. In this study, we examined whether the total number of ovulatory cycles decreases the likelihood of anti-MUC1 antibodies and provides an immune basis for the association between "incessant ovulation" and ovarian cancer risk. METHODS: From 1998 to 2003, we enrolled 668 epithelial ovarian cancer cases and 721 controls residing in eastern Massachusetts or New Hampshire, collected information on menstrual and reproductive events, and obtained blood samples from controls to measure anti-MUC1 antibodies. Using logistic regression, we calculated odds ratios to evaluate the influence of reproductive factors, including the estimated lifetime number of ovulatory cycles on ovarian cancer risk and on the presence of MUC1 antibodies in controls. RESULTS: Overall, we observed that early age at first birth, cycle lengths >or=30 days, and oral contraceptive use increased the likelihood of having anti-MUC1 antibodies. Estimated ovulatory cycles were correlated positively with ovarian cancer risk and inversely with the presence of anti-MUC1 antibodies among controls ages 46 to 60 years. CONCLUSIONS: These data suggest that suppression of MUC1-specific immunity should be considered as an additional explanation for the observation that ovarian cancer risk increases with the lifetime number of ovulatory cycles.

Humoral immune response to MUC5AC in patients with colorectal polyps and colorectal carcinoma.

BACKGROUND: MUC5AC is a secreted mucin aberrantly expressed by colorectal polyps and carcinoma. It has been hypothesized that aberrant expression of MUC5AC in colorectal carcinoma tissues increased the overall survival of patients with colorectal carcinoma. The present study investigates the incidence of naturally occurring MUC5AC antibodies in the sera of normal individuals, patients with colonic polyps and patients with advanced colorectal carcinoma. A second aim was to determine the relationship of MUC5AC antibody with the prognosis of colorectal carcinoma. METHODS: Free circulating MUC5AC antibodies were measured using an enzyme-linked immunosorbent assay with a synthetic peptide corresponding to an 8 aa. segment of MUC5AC tandem repeat region. Immunohistochemical analysis was completed to demonstrate MUC5AC expression in the polyp specimens. RESULTS: MUC5AC antibodies were detected in 6 of 22 (27.3%) healthy subjects, 9 of 20 (45%) polyp patients, 18 of 30 (60%) patients with colorectal cancer. The presence of circulating free MUC5AC antibody levels was significantly correlated with expression of MUC5AC in polyp sections. Serum MUC5AC antibody positivity was higher in patients with colon located tumors, advanced stage and poorly differentiated tumors were found negatively affecting patient survival in our study. MUC5AC antibody positivity was higher in patients with poor prognostic parameters. Disease free survival and overall survival were shorter in this group of patients. In the multivariate analysis MUC5AC antibody positivity didn't find an independent prognostic factor on prognosis. CONCLUSION: Decreased survival in colorectal carcinoma patients with MUC5AC antibody positivity may be due to a decrease in the MUC5AC expression in tumor tissues of surviving carcinoma patients.

Conditions associated with antibodies against the tumor-associated antigen MUC1 and their relationship to risk for ovarian cancer.

Many cancers, including ovarian, overexpress epithelial mucin (MUC1) and promote anti-MUC1 antibodies that may correlate with more favorable prognosis. By extension, risk for ovarian cancer might be reduced by preexisting MUC1-specific immunity. We measured anti-MUC1 antibodies in 705 control women, identified events predicting antibodies, and estimated ovarian cancer risk by comparing profiles of events generating antibodies in controls with those in 668 ovarian cancer cases. Factors predicting antibodies included oral contraceptive use, breast mastitis, bone fracture or osteoporosis, pelvic surgeries, nonuse of talc in genital hygiene, and to a lesser extent intrauterine device use and current smoking. There was a significant increase in the likelihood of having anti-MUC1 antibodies from 24.2% in women with 0 or 1 condition, to 51.4% in those with five or more conditions. By the same index of events, the risk for ovarian cancer was inversely associated with number of conditions predisposing to anti-MUC1 antibodies. Compared with having experienced 0 or 1 event, the adjusted risk for ovarian cancer decreased progressively with relative risks (and 95% confidence limits) of 0.69 (0.52-0.92), 0.64 (0.47-0.88), 0.49 (0.34-0.72), and 0.31 (0.16-0.61), respectively for women with two, three, four, and five or more events related to the presence of antibodies (P(trend) < 0.0001.) We conclude that several traditional and new risk factors for ovarian cancer may be explained by their ability to induce MUC1 immunity through exposure of MUC1 to immune recognition in the context of inflammatory or hormonal processes in various MUC1-positive tissues.

T cell-dependent antibody responses against aberrantly expressed cyclin B1 protein in patients with cancer and premalignant disease.

PURPOSE: Cyclin B1-derived peptides were shown by us to be targets of tumor-specific CD8(+) T cells in patients with breast and head and neck cancer. We obtained further evidence of cyclin B1 immunogenicity and its potential to serve as a tumor-specific antigen by analyzing its ability to elicit T cell-dependent humoral immune responses in vivo in patients with different types of tumors. EXPERIMENTAL DESIGN: Recombinant cyclin B1 protein from two different sources was purified and used as antigen in ELISA assays to test sera from patients with breast, pancreatic, colon, and lung cancer for the presence of anti-cyclin B1 antibody. We also analyzed patients with benign lung disease, premalignant disease, and a known history of heavy smoking. RESULTS AND CONCLUSIONS: Cyclin B1 elicits helper T cell-dependent antibody responses in vivo. Tumors with higher level of cyclin B1 expression elicit higher anti-cyclin B1 antibody levels. Antibodies in patients with breast and colon cancer are primarily of the IgG isotype whereas patients with pancreatic and lung cancer have in addition anti-cyclin B1 IgA. Cyclin B1-specific IgG was also detected in long-term smokers and in patients with preneoplastic lung disease. Immune responses to aberrantly expressed cyclin B1 in tumors and premalignant lesions should be further explored as diagnostic and prognostic markers, in addition to their immunotherapeutic potential.

Phase I study of a MUC1 vaccine composed of different doses of MUC1 peptide with SB-AS2 adjuvant in resected and locally advanced pancreatic cancer.

MUC1 is a glycoprotein overexpressed in tumors as a hypoglycosylated form. A vaccine composed of a 100-amino acid peptide corresponding to five 20-amino acid long repeats, and SB-AS2 adjuvant, was tested in a phase I study for safety, toxicity, and ability to elicit or boost MUC1-specific immune responses. Patients with resected or locally advanced pancreatic cancer without prior chemotherapy or radiotherapy were eligible. Escalating doses of the peptide (100, 300, 1,000, and 3,000 mug) were admixed with SB-AS2 and administered intramuscularly every 3 weeks for three doses, in cohorts of four patients. Sixteen patients were enrolled. Common adverse effects were grade 1 flu-like symptoms, tenderness, and erythema at the injection site. Delayed-type hypersensitivity (DTH) sites showed few or no T cells prevaccination (Pre V), but increased T-cell infiltration postvaccination (Post V). There was an increase in the percentage of CD8(+) T cells in the peripheral blood Post V. An increase in total MUC1-specific antibody was seen in some patients, and several patients developed IgG antibody. Two of 15 resected pancreatic cancer patients are alive and disease free at follow-up of 32 and 61 months. MUC1 100mer peptide with SB-AS2 adjuvant is a safe vaccine that induces low but detectable mucin-specific humoral and T-cell responses in some patients. No difference was seen between different peptide doses. Further evaluation is warranted to examine the effect on disease-free survival and overall survival, especially in early disease and in the absence of immunosuppressive standard therapy.

Mucins in gastrointestinal cancers.

The mucin family has been under study by molecular biologists, biochemists, pathologists and immunologists interested in cancer because of the role these molecules can play in the diagnosis and treatment of cancer. Immense knowledge has been accumulated, but the high speed of progress in the laboratory has not been matched by the progress towards applying this knowledge in the clinic. For example, specific knowledge of cancer-associated changes in the expression and glycosylation of various mucins, which can aid in the diagnosis as well as prognosis of GI cancers, has not yet led to the use of a panel of anti-mucin antibodies as a standard diagnostic tool. Similarly, many more opportunities exist for using mucin-based therapies than are currently being considered in the clinic. This chapter aimed to highlight some of these opportunities and to interest clinician scientists in exploring them in the near future.