Prognostic gene expression signature for high-grade serous ovarian cancer

BACKGROUND

Median overall survival (OS) for women with high-grade serous ovarian cancer (HGSOC) is ∼4 years, yet survival varies widely between patients. There are no well-established, gene expression signatures associated with prognosis. The aim of this study was to develop a robust prognostic signature for OS in patients with HGSOC.

PATIENTS AND METHODS

Expression of 513 genes, selected from a meta-analysis of 1455 tumours and other candidates, was measured using NanoString technology from formalin-fixed paraffin-embedded tumour tissue collected from 3769 women with HGSOC from multiple studies. Elastic net regularization for survival analysis was applied to develop a prognostic model for 5-year OS, trained on 2702 tumours from 15 studies and evaluated on an independent set of 1067 tumours from six studies.

RESULTS

Expression levels of 276 genes were associated with OS (false discovery rate < 0.05) in covariate-adjusted single-gene analyses. The top five genes were TAP1, ZFHX4, CXCL9, FBN1 and PTGER3 (P < 0.001). The best performing prognostic signature included 101 genes enriched in pathways with treatment implications. Each gain of one standard deviation in the gene expression score conferred a greater than twofold increase in risk of death [hazard ratio (HR) 2.35, 95% confidence interval (CI) 2.02-2.71; P < 0.001]. Median survival [HR (95% CI)] by gene expression score quintile was 9.5 (8.3 to -), 5.4 (4.6-7.0), 3.8 (3.3-4.6), 3.2 (2.9-3.7) and 2.3 (2.1-2.6) years.

CONCLUSION

The OTTA-SPOT (Ovarian Tumor Tissue Analysis consortium - Stratified Prognosis of Ovarian Tumours) gene expression signature may improve risk stratification in clinical trials by identifying patients who are least likely to achieve 5-year survival. The identified novel genes associated with the outcome may also yield opportunities for the development of targeted therapeutic approaches.

Evidence for a time-dependent association between FOLR1 expression and survival from ovarian carcinoma: implications for clinical testing. An Ovarian Tumour Tissue Analysis consortium study

BACKGROUND

Folate receptor 1 (FOLR1) is expressed in the majority of ovarian carcinomas (OvCa), making it an attractive target for therapy. However, clinical trials testing anti-FOLR1 therapies in OvCa show mixed results and require better understanding of the prognostic relevance of FOLR1 expression. We conducted a large study evaluating FOLR1 expression with survival in different histological types of OvCa.

METHODS

Tissue microarrays composed of tumour samples from 2801 patients in the Ovarian Tumour Tissue Analysis (OTTA) consortium were assessed for FOLR1 expression by centralised immunohistochemistry. We estimated associations for overall (OS) and progression-free (PFS) survival using adjusted Cox regression models. High-grade serous ovarian carcinomas (HGSC) from The Cancer Genome Atlas (TCGA) were evaluated independently for association between FOLR1 mRNA upregulation and survival.

RESULTS

FOLR1 expression ranged from 76% in HGSC to 11% in mucinous carcinomas in OTTA. For HGSC, the association between FOLR1 expression and OS changed significantly during the years following diagnosis in OTTA (Pinteraction=0.01, N=1422) and TCGA (Pinteraction=0.01, N=485). In OTTA, particularly for FIGO stage I/II tumours, patients with FOLR1-positive HGSC showed increased OS during the first 2 years only (hazard ratio=0.44, 95% confidence interval=0.20-0.96) and patients with FOLR1-positive clear cell carcinomas (CCC) showed decreased PFS independent of follow-up time (HR=1.89, 95% CI=1.10-3.25, N=259). In TCGA, FOLR1 mRNA upregulation in HGSC was also associated with increased OS during the first 2 years following diagnosis irrespective of tumour stage (HR: 0.48, 95% CI: 0.25-0.94).

CONCLUSIONS

FOLR1-positive HGSC tumours were associated with an increased OS in the first 2 years following diagnosis. Patients with FOLR1-negative, poor prognosis HGSC would be unlikely to benefit from anti-FOLR1 therapies. In contrast, a decreased PFS interval was observed for FOLR1-positive CCC. The clinical efficacy of FOLR1-targeted interventions should therefore be evaluated according to histology, stage and time following diagnosis.

Evidence for a time-dependent association between FOLR1 expression and survival from ovarian carcinoma: implications for clinical testing. An Ovarian Tumour Tissue Analysis consortium study

BACKGROUND

Folate receptor 1 (FOLR1) is expressed in the majority of ovarian carcinomas (OvCa), making it an attractive target for therapy. However, clinical trials testing anti-FOLR1 therapies in OvCa show mixed results and require better understanding of the prognostic relevance of FOLR1 expression. We conducted a large study evaluating FOLR1 expression with survival in different histological types of OvCa.

METHODS

Tissue microarrays composed of tumour samples from 2801 patients in the Ovarian Tumour Tissue Analysis (OTTA) consortium were assessed for FOLR1 expression by centralised immunohistochemistry. We estimated associations for overall (OS) and progression-free (PFS) survival using adjusted Cox regression models. High-grade serous ovarian carcinomas (HGSC) from The Cancer Genome Atlas (TCGA) were evaluated independently for association between FOLR1 mRNA upregulation and survival.

RESULTS

FOLR1 expression ranged from 76% in HGSC to 11% in mucinous carcinomas in OTTA. For HGSC, the association between FOLR1 expression and OS changed significantly during the years following diagnosis in OTTA (Pinteraction=0.01, N=1422) and TCGA (Pinteraction=0.01, N=485). In OTTA, particularly for FIGO stage I/II tumours, patients with FOLR1-positive HGSC showed increased OS during the first 2 years only (hazard ratio=0.44, 95% confidence interval=0.20-0.96) and patients with FOLR1-positive clear cell carcinomas (CCC) showed decreased PFS independent of follow-up time (HR=1.89, 95% CI=1.10-3.25, N=259). In TCGA, FOLR1 mRNA upregulation in HGSC was also associated with increased OS during the first 2 years following diagnosis irrespective of tumour stage (HR: 0.48, 95% CI: 0.25-0.94).

CONCLUSIONS

FOLR1-positive HGSC tumours were associated with an increased OS in the first 2 years following diagnosis. Patients with FOLR1-negative, poor prognosis HGSC would be unlikely to benefit from anti-FOLR1 therapies. In contrast, a decreased PFS interval was observed for FOLR1-positive CCC. The clinical efficacy of FOLR1-targeted interventions should therefore be evaluated according to histology, stage and time following diagnosis.

GI Epidemiology: nutritional epidemiology

BACKGROUND

Nutritional epidemiology is the assessment of diet and its relationship to disease aetiology in populations. The choice of dietary assessment method depends on the disease pathology. Events such as cancer that are chronic and complicated by exposure time require methods that capture consumption patterns of populations over a period of years. Although several methods of dietary assessment exist for collecting information on groups of individuals, their application to epidemiologic studies requires an understanding of the effect of variability in nutrient intake, sources of measurement error, and statistical issues unique to the study of nutritional epidemiology.

AIM

This review provides an overview of commonly-used methods of dietary assessments in epidemiologic studies, and identifies their strengths and limitations and application to epidemiologic study designs. It concludes with a brief discussion of assumptions of nutrient databases and objectives of energy-adjustment and measurement error correction models.

CONCLUSIONS

Nutritional epidemiology has contributed significantly to our understanding of the relationships between diet and disease. Ongoing investigations that further characterize important exposure periods (early life, in utero) and clarify associations within the context of genetic susceptibility will continue to elucidate our understanding of the pathophysiology of complex diseases, and support future recommendations for disease prevention.

Patients with breast and ovarian cancer generate immune responses to the folate receptor alpha

20043

Background: Studies have demonstrated that the generation of endogenous immunity to specific tumor antigens is associated with improved prognosis for many cancers. Thus, there has been increased efforts to identify tumor-associated antigens to which there is immunity, as these may be tumor rejection antigens. A candidate antigen is the folate receptor alpha (FRα) which is overexpressed in malignancies, especially breast and ovarian cancer. Prior studies involving ovarian and breast cancer patients have demonstrated the presence of FRα-specific cytotoxic T cells in the tumor-associated lymphocyte population. Methods: Using the RANKPEP CD4 T cell epitope prediction algorithm, we predicted promiscuous immunogenic regions of FRα, and tested for immunity in 30 breast or ovarian cancer patients and 18 healthy volunteer donors in order to attain a better understanding of the levels and extent of the endogenous FRα immune response. Immunity was examined using IFN-γ ELIspot analysis and IgG ELISAs. Results: Fourteen peptides were predicted as potential epitopes to which T cells may respond, seven each from the carboxy- and amino-terminus halves of the protein. Greater than 70% of patients demonstrated T cell immunity to at least one of the fourteen peptides. Patients responded to an average of 3 ± 0.7 peptides while healthy donors responded to only 1 ± 0.5 peptides (p = 0.02). Five peptides were recognized by >25% of patients. Responses to three of these peptides were higher (p > 0.05) in the patients than in healthy donors, suggesting that patients generated immunity upon cancer development. Compared to healthy individuals, patients developed higher immunity to the amino-terminus half of the receptor, suggesting natural epitope spreading (p = 0.03). There was no difference between patients and healthy donors in the immune responses to either non-specific stimuli (p = 0.2) or viral peptides (p = 0.5). Patients had detectable FRα-specific IgG antibody consistent with active FRα-specific helper T cell immunity. Conclusions: These findings demonstrate that the FRα is a target of the immune system in patients with breast or ovarian cancer. Understanding the antigens that are naturally targeted by the immune system may be important for diagnosis, prognosis, and immune-based therapies.

No significant financial relationships to disclose.

Dietary determinants of one-carbon metabolism and the risk of non-Hodgkin's lymphoma: NCI-SEER case-control study, 1998-2000

The role of dietary one-carbon determinants remains largely unexplored for non-Hodgkin's lymphoma (NHL). In a population-based case-control study of non-African-American adult (aged 20-74 years) women and men from four US Surveillance, Epidemiology, and End Results study centers (Detroit, Michigan; Iowa; Los Angeles, California; and Seattle, Washington; 1998-2000), the authors examined folate; vitamins B2, B6, and B12; methionine; and a one-carbon antagonist, alcohol, in 425 incident NHL cases and 359 controls who completed a detailed food frequency questionnaire. Adjusted odds ratios and 95% confidence intervals were estimated by using unconditional logistic regression. Higher intake of one-carbon determinants from food was associated with a lower risk of NHL, but that for only vitamin B6 (highest vs. lowest quartile: odds ratio = 0.57, 95% confidence interval: 0.34, 0.95; p trend = 0.01) and methionine (odds ratio = 0.49, 95% confidence interval: 0.31, 0.76; p trend = 0.002) reached statistical significance. Folate from food was inversely associated with diffuse subtype (odds ratio = 0.47, 95% confidence interval: 0.23, 0.94; p trend = 0.03). The authors found no association between total (food plus supplement) vitamins and NHL. Nonusers of alcohol had an elevated NHL risk compared with users, and alcohol did not modify other nutrient-NHL associations. Findings suggest that one-carbon nutrients, particularly vitamin B6 and methionine, may be protective against NHL.