Progress Against Cancer in Kuwait: Trends in Incidence, Survival and Mortality.

Introduction: To assess progress against cancer, trends in incidence, survival and mortality need to be interpreted simultaneously.

Methods: Data were obtained from the Kuwait Cancer Registry (KCR) for all Kuwaiti children (0-14 years) and adults (15-99 years) diagnosed with one of 18 common cancers during 2000-2013, with follow-up for vital status to 31 December 2015. World-standardised average annual incidence and mortality rates were calculated for 2000-2004, 2005-2009, 2010-2013. Five-year net survival was estimated with the Pohar Perme estimator, corrected for background mortality using life tables of all-cause mortality. Survival estimates were agestandardised using the International Cancer Survival Standard weights.

Results: For liver cancer, five-year net survival increased from 11.4% to 13.4% for patients diagnosed between 2000-2004 and 2010-2013, while incidence and mortality rates fell from 5.5 to 3.6 and from 3.9 to 3.0 per 100,000, respectively. Similar patterns were seen for acute lymphoblastic leukaemia (ALL) and lymphoma in children. Survival and mortality remained stable for cancers of the lung, cervix and ovary, but incidence declined from 10.2 to 7.4, 4.9 to 2.4 and 5.8 to 4.3 per 100,000, respectively. For breast cancer, survival increased from 68.3% to 75.2%, while incidence and mortality rose from 45.6 to 58.7 and from 5.8 to 12.8 per 100,000, respectively. For colon cancer, incidence and mortality rates rose from 11.4 to 12.6 and from 2.3 to 5.4 per 100,000, respectively. Five-year survival fell from 64.8% to 50.2% between 2000-2004 and 2005-2009, before rising to 58.5% for 2010-2013.

Conclusion: Increasing survival, alongside falling incidence and mortality rates, represents progress in cancer control, attributable to effective prevention (e.g. tobacco control and lung cancer) and early diagnostic activity (e.g. mammography for breast cancer), or better treatment (e.g. childhood ALL). The increasing prevalence of obesity, linked to rising incidence for breast and colon cancers, suggests the need for public health prevention campaigns.