We studied a total of 61 patients from the Hadassah Medical Centre, of whom 49 were men (80.3%) and 12 were women (19.7%). The male to female ratio was 4.7 : 1. In Israel the age adjusted incidence rate for bladder carcinoma is 4.7 higher in Jewish men compared with Jewish women,19
whereas in the USA the ratio is approximately 3 : 1.20
The mean age was found to be 68 years (SD, 13). This is similar to the age of patients with bladder cancer in the USA, which is primarily encountered in men 50–70 years (median and mean 64 and 68 years, respectively).
We excluded patients with carcinoma in situ not accompanied by papillary cancer. Of the remaining 56 patients, the expression of H19 in more then 5% of the cells was found in 47 of the 56 (84%) tumours. The mean quantity of H19 was calculated for each tumour grade and was found to be 2.02 (SD, 0.90) for grade I carcinoma (32 cases), 1.50 (SD, 0.97) for grade II (10 cases), and 1.18 (SD, 1.12) for grade III (14 cases). The difference was found to be significant (p = 0.03) by the Kruskal-Wallis one way ANOVA test (fig 2).
Figure 2 The mean fraction of tumour cells expressing H19 (defined as “quantity of H19”) calculated for tumour grade (WHO classification) in 56 patients. The “quantity” was defined as follows: only a few cells (< 5%), ± (more ...)
Normal bladder mucosa, when present in the sample, was always negative, as we have reported previously.8,13
Because of the small number of invasive tumours we grouped together all the stages of invasive cancer (superficial and deep). The quantity of H19 was calculated for tumour stage, and non-invasive tumours (Ta) were compared with superficially and deeply invasive tumours (T1–T4). We found that in 39 non-invasive tumours (Ta), the mean quantity of H19 expressing cells (1.91 (SD, 1.02)) was significantly higher than in invasive tumours (T1–T4), which had a mean quantity of 1.05 (SD, 0.96; Mann-Whitney test, p = 0.03) (fig 3).
Figure 3 The mean fraction of tumour cells expressing H19 (defined as “quantity of H19”) calculated for tumour stage, non-invasive (0) or invasive (> 0), of 56 patients. There was a significant decrease of quantity of H19 in invasive tumours (more ...)
Disease free survival was calculated for quantity of H19, as defined previously. Only patients with no residual disease, and hence only patients with no evidence of deep invasion, were included in this analysis. For quantity grading 3, 2, and < 2, the median survival was found to be 8.3, 38, and 51 months respectively (p = 0.05 by log rank test; p = 0.04 by Breslow test). See fig 4 for survival curves.
Figure 4 Disease free survival in months of 48 patients with no evidence of residual disease calculated for “quantity of H19” as defined above (see fig 2). The disease free survival was shorter for the quantity of H19 defined as 3 (log (more ...)
The intensity of ISH staining and the combined value of intensity plus quantity was not significant in relation to tumour grade, stage, or disease free survival.
Our finding that H19 expression is more abundant in low grade bladder carcinoma but that it is also a marker of early tumour recurrence prompted us to analyse further the data controlling for grade. The disease free survival in our series was reduced with increasing tumour grade in accordance with the literature. In our series, the median disease free survival for grade I was found to be 34.5 months, for grade II 19.2 months, and for grade III 6.4 months. We then selectively analysed the risk of tumour recurrence for quantity of H19 in those patients with grade I tumours. The median disease free survival for quantity of H19 grading 3, 2, and < 2 was found to be 8.3, 37.5, and 54.6 months, respectively (p = 0.03 by log rank test; p = 0.02 by Breslow test).