In Dutch and Danish patients with FIGO III ovarian carcinoma, geographic survival differences are associated with differences in quantitative pathologic features

In a previous investigation, a group of Danish FIGO III and IV ovarian cancer patients from Aarhus were found to have more aggressive tumor characteristics compared with Dutch patients, concerning histologic grade, morphometric features and residual disease status. The aim of the present investigation was to investigate possible geographic differences in clinicopathologic and quantitative prognostic features in a large group of Dutch and Danish patients only with FIGO III ovarian carcinoma, from Copenhagen and to compare the survival of these two groups. One hundred and sixty-nine patients were included in the current investigation, all were treated with debulking surgery followed by cisplatin combination chemotherapy. Dutch patients (42% survived, median survival time 48 months) had a significantly better survival than the Danish patients (33% survived, median survival time 27 months) (Mantel-Cox (MC) = 6.0, P = 0.01). In the subgroup with residual disease larger than 2 cm, survival differences were even more striking: survival was 32% in Dutch patients (median survival time 24 months) and 15% in Danish patients (median survival time, 16 months). Logistic regression analysis revealed that the geographic survival difference was associated with differences in the morphometric feature mean nuclear area (MNA). The MNA was significantly larger in the Danish ovarian tumors (78 μm² vs 63 μm²). With a cut-off point for MNA of 75 μm², survival was similar for the Dutch and Danish patients with values below and also for those above that value, but Danish patients had many more values above 75 μm². Therefore, the MNA is a useful prognosticator in patients with FIGO III ovarian cancer treated with cisplatin combination chemotherapy, especially since this variable is not susceptible to geographic differences. The reason for the difference in MNA, and consequently worse survival in Danish patients, remains to be elucidated.