Incidence and survival of rare adult solid cancers in Europe (EUROCARE-6): A population-based study.

Background: Rare cancers correspond to approximately 200 clinical entities, which can be grouped into 12 families. Updated data are available for childhood and haematological cancers, ie, for only two of the 12 families of rare cancer. We provide incidence and survival for the remaining ten families of rare adult solid cancers (RAC), across 29 EU Member States and over time. We also evaluate the association between resources invested in health and survival from RACs.

Methods: We used the EUROCARE-6 database, which includes data from 108 cancer registries from 29 countries. We calculated incidence rates (IR) and 5-year relative survival (RS) for cases diagnosed during 2006-2013. We calculated 5-year RS in the follow-up period 2010-2014 using the period approach (last follow-up: December 31, 2014). We estimated changes in 5-year RS and IR over the period 2000-2013. We used a forest plot to report the differences in RS among countries with the highest and lowest health spending.

Results: RACs are heterogeneous in terms of incidence, survival, sex, and age distribution. Several RACs (eg, those of the hypopharynx, small intestine, and trachea) still have a 5-year RS < 30 %, which is not improving. Survival differs among European countries and is higher in countries with the greatest investments in health. The incidence of smoking-related RACs is decreasing but rising in HPV-related RACs.

Conclusion: Investments in health and healthcare networks at national and European level can help increase the survival of RACs, especially those requiring centralisation of care (eg, bone sarcomas, penile cancer). These investments are critical considering that survival from RACs is not significantly improving. Our results unmask the heterogeneity of RACs, which needs to be considered in clinical trial design. Finally, our findings support the importance of prevention strategies for known risk factors such as smoking.