Circulating Antinuclear Antibodies in Patients with Pelvic Masses Are Associated with Malignancy and Decreased Survival

BACKGROUND: Circulating autoantibodies occur more frequently in cancer patients than in patients without cancer. METHODS AND FINDINGS: We examined sera from patients referred for pelvic mass symptoms to a tertiary university clinic. A total of 127 were diagnosed with epithelial ovarian cancer while 386 had a benign condition. A screen for IgG anti-nuclear antibodies (ANA) by indirect immunofluorescence on HEp-2 cells confirmed a highly significant overrepresentation of ANA in the cancer group where 40% had detectable (i.e., a titer ≥160) ANA compared with less than 12% in the benign group. The overrepresentation of ANA in the cancer group persisted (p<0.0001) after matching the age-profile of the benign group with the ovarian cancer group. Only 19 out of 127 patients in the age-matched benign subgroup were positive for ANA corresponding to an 85% specificity at 40% sensitivity of ANA as the only marker for malignancy. No correlation of ANA positivity in either group with specific bands in immunoblots could be demonstrated even though immunoblot positivity was clearly increased in the malignant group (41% vs. 3%). The presence, strength, and type of ANA did not correlate with serum CA-125 values or with staging, and ANA outcome did not contribute with independent diagnostic information. However, survival was significantly shorter in ANA-positive compared with ANA-negative cancer patients and patients with CA-125 below the median CA-125 value in the cancer group had a significantly decreased survival when positive for ANA. ANA status made no difference in the group with CA-125 values above the median. Also, there was a significant correlation between speckled ANA-strength and histological tumor grade. CONCLUSIONS: Circulating antibodies are a promising source for new biomarkers in cancer. Characterization of epitope specificities and measurements of consecutive samples will be important for further elucidating the role of ANA in evaluating ovarian cancer patients

Feasibility of serodiagnosis of ovarian cancer by mass spectrometry

The emergence of new biological disease markers from mass spectrometric studies of serum proteomes has been quite limited. There are challenges regarding the analytical and statistical procedures, preanalytical variability, and study designs. In this serological study of ovarian cancer, we apply classification methods in a strictly designed study with standardized sample collection procedures. A total of 265 sera from women admitted with symptoms of a pelvic mass were used for model building. We developed a rigorous approach for building classification models suitable for the highly multivariate data and illustrate how to evaluate and ensure data quality and optimize data preprocessing and data reduction. We document time dependent changes in peak profiles up to 15 months after sampling even when storing samples at -20 degrees C. The developed classification model was validated using completely independent samples and a cross validation procedure which we call cross mode; validation was applied to get realistic performance values. The best models were able to classify with 79% specificity and 56% sensitivity, i.e., an analytical accuracy of 68%. However, the existing serum marker (CA-125) alone gave a better analytical accuracy (81%) in the same sample set Also, the combination of mass spectrometric data and levels of CA-125 data did not improve the predictive performance of models. In conclusion, proteomic approaches to biomarker discovery are not necessarily yielding straightforward diagnostic leads but lay the foundation for more work

Antinuclear Antibodies (ANA) specificities.

<p>Examples of ANA-patterns of strongly positive sera staining in a cytoplasmic (A) and a speckled (B) pattern. In (C) is shown the distribution of the main types of ANA patterns as well as the signal strength in the benign and the malignant group. Strongly positive samples are almost only seen in the group with malignancy.</p

No correlation between serum-CA-125 values and the presence and intensity of ANA.

<p>The immunofluorescence score is depicted as a function of CA-125 values for the samples from benign (red symbols) and malignant cases (green symbols). Cut-off for positivity in the CA-125 test is 35 U/mL. All patients with benign ovarian tumors and epithelial ovarian cancers are included in this figure.</p

Study demographics in patients diagnosed with borderline ovarian tumor, ovarian cancer or a benign ovarian tumor.

<p>*endometrioid adenocarcinoma N = 11, Clear cell neoplasms N = 6 and carcinosarcoma N = 4.</p><p>**No significant difference for the subset of 127 matched patients with benign conditions: Median age: 64 (range 54–90).</p

Relationship between ANA-staining intensity and histological grade of tumor (high, moderate, and poorly differentiated).

<p>While grading had no significant relationship with ANA-positivity of any specificity the presence of a speckled ANA pattern was significantly correlated with moderate-poor differentiation grade when compared with highly differentiated tumors (p = 0.04).</p

The frequency of different Antinuclear Antibodies (ANA)-patterns in sera from patients with epithelial ovarian cancer and benign pelvic conditions.

<p>Fisher's exact test was used to obtain <i>p</i>-values. Some sera contain ANAs of more than one specificity. Centr., centromere; Nuclear membr., nuclear membrane; Homog., homogeneous; cytopl., cytoplasmic; NS, non significant.</p