Incidence, mortality, and survival trends of ovarian cancer in Hong Kong, 1997 to 2006: a population-based study

Objectives To assess the incidence and mortality of ovarian cancer, and the survival patterns of the invasive epithelial ovarian carcinoma in Hong Kong based on population-based cancer registry data. Design Historical cohort study. Setting Hong Kong. Patients All patients with ovarian cancer diagnosed between 1997 and 2006 were included. Patients eligible for survival analysis were followed up until 31 December 2007. Main outcome measures Age-standardised incidence and mortality rates with their estimated annual percent changes were determined. Cumulative observed and relative survival rates were estimated using a period approach. Results During the study period, in Hong Kong there was a steadily increasing ovarian cancer incidence rate (1.4% annually) but a steadily decreasing mortality rate (1.9% annually). The improvement in mortality was mainly in the age-group of 50-69 years (4.7% annually). Invasive epithelial ovarian carcinoma accounted for 79.6% of the study cohort. The 2-year and 5-year relative survival rates were 75.8% and 63.1%, respectively. Those diagnosed in the period 2002 to 2006 had significantly better survival than those diagnosed in the period 1997 to 2001 (65.3% vs 60.7%; P=0.008); a significant improvement was evident for patients with stage II disease and in the age-group of 50-69 years. Multivariate analyses confirmed that age, histological subtype, FIGO stage, and the period of diagnosis were independent prognostic indicators of invasive epithelial ovarian carcinoma. Conclusion In Hong Kong, invasive epithelial ovarian carcinoma showed an increasing incidence and an improving survival trend over the period 1997 to 2006. The survival data derived from this study provides a baseline from which to monitor the effectiveness of ovarian cancer treatment in Hong Kong.