Lenhard et al. BMC Cancer 2012, 12:2 http://www.biomedcentral.com/1471-2407/12/2 Page 4 of 8 Table 1 Patient characteristics of ovarian cancer patients whose tissue samples were stained by immunohistochemistry for hCG expression or serum samples were analyzed for hCG concentration Ovarian cancer patients (n) Age at primary diagnosis (a) Histology (%) Tumor grading (%) Tumor stage (FIGO) (%) Gonadotropin receptor expression (%) In addition, a positive correlation of hCG to LH- receptor expression (correlation coefficient 0.194, p = 0.037, Table 2) was identified. Interestingly, there was no correlation of hCG expression and FSH-receptor expression. serous mucinous endometrioid clear cell low grade intermediate high grade I II III IV LH-R positive FSH-R positive Tissue samples Serum samples 58 (range 18-88) 62 (range 21-80) 156 70.5 13.5 7.7 8.3 27.2 36.5 36.3 22.6 5.8 70.3 1.3 64.3 63.1 40 81.0 4.8 14.3 0.0 4.2 54.2 51.7 13.9 13.9 55.6 16.7 - - Prognostic value of hCG Statistical analysis was performed to test for a prognos- tic value of hCG expression in ovarian cancer tissue. The univariate Kaplan Meier analysis reveals no statisti- cal difference between patients positive and negative for hCG in ovarian cancer tissue (p = 0.618). Interestingly, there was an increased 5-year survival in patients with hCG positive tumors in the LH-R positive/FSH-R nega- tive subgroup (5-year survival: hCG positive 75.0% vs. hCG negative 50.5%; Figure 4, Table 3). Figure 1 Determination of hCG in sera of patients with diagnosed benign or malign diseases of the ovaries before surgery shown in boxplots. The boxes represent the range between the 25th and 75th percentiles with a horizontal line at the median. The bars delineate the 5th and 95th percentiles. The circle indicate values more than 1.5 box lengths, and the asterisk values more than 3.0 box lengths from the 75th percentile. Numbers at circle and asterisk indicate sample number. hCG levels were significantly lower in patients with benign compared to patients with malign diseases of the ovaries (p = 0.000). Figure 2 Representative slides of immunohistochemical staining for hCG expression for FIGO stage II (a, hCG negative), FIGO stage III (b, hCG positive) for grade 1 (c, weak hCG staining) and grade 2 (d, strong hCG staining) ovarian cancer tissue. No hCG immunoreactivity was detected in tumor stroma (magnification 10× and 25×).