2.3.4 Summary Measures

A series of summary measures was computed for each cancer site. The incidence of each cancer is expressed in terms of the average number of new cases each year between 1995 and 2007, and as a percentage of all new cancer cases, both including and excluding non-melanoma skin cancer.

Time trends

Estimated annual percentage rate of change in the number of cases was calculated over the period 1995-2007 (13 years) by taking the 12th root of the total percentage growth rate (12 years of growth).  

Cumulative risk

Cumulative risk to age 74 ( is the risk of developing a specified cancer or cancers up to and including age 74, in the absence of competing risks (Estève et al, 1994). This was calculated as follows:

where, if x is one of 15 five-year age groups from 0 to 74:

t_x=age-specific incidence rate

The cumulative risk is given as a percentage and also as a ratio (e.g. a cumulative risk of 4% is expressed as 1 in 25).

Prevalence

15-year prevalence was estimated as the total number of individuals diagnosed between 1/1/1994 and 31/12/2008 who were still alive on 31/12/2008. Numbers are given for those who were aged under 65 years on 31/12/2008, and for those who were aged 65 years or older on that date.