Appendix

Sometimes the unit of measure of interest is the number of people living with a past diagnosis of cancer rather than the number of cancers. In terms of individuals, 695,049 persons had been diagnosed with one or more primary invasive cancers in the previous ten years and were alive on January 1, 2005 (Appendix Table B). Of these, 441,155 (63%) had been diagnosed in the previous five years, and 212,606 (31%) in the previous two years (Appendix Table A). These figures correspond to 2.2% of the estimated population on January 1, 2005, or approximately 1 in 46 persons (ten-year); 1.4%, or 1 in 73 persons (five-year), and 0.7%, or 1 in 151 (two-year) (Appendix Table B). One in every 111 females alive on January 1, 2005 had been diagnosed with breast cancer in the previous 10 years; the figure for prostate cancer was 1 in every 118 males.

For all cancers combined, person-based prevalence was defined as the number of people who had been diagnosed with a primary invasive (or in situ bladder) cancer in a given time-frame and who were alive on January 1, 2005. For example, five-year person-based prevalence for all cancers combined refers to the number of people alive at the beginning of 2005 who had been diagnosed with cancer within the period 2000 to 2004.

Cancer-specific, person-based prevalence was defined as the number of people diagnosed with a particular cancer in a given time-frame and who were alive on January 1, 2005. When cancers were combined for reporting purposes (for example, oral cancers, colorectal, leukemias and other and unknown), grouping was done before prevalence counts were determined.

The following example illustrates how cancers were counted in persons with more than one primary tumour diagnosis. For a person diagnosed with invasive primary breast cancers in 2001 and 2004, and also an invasive primary lung cancer in 2003, the 2001 breast cancer case and the lung cancer case would be counted in their respective five- and ten-year cancer-specific prevalence estimates. In calculating two-year prevalence estimates (based on cases diagnosed from January 1, 2003 to December 31, 2004), the lung cancer case and the 2004 breast cancer case would be counted in their respective cancer-specific prevalence estimates. There are other ways of determining person-based prevalence estimates in the case of multiple primaries, depending on the underlying question of interest; readers are invited to consider this when comparing person-based prevalence estimates from different sources. Note that, as defined above, the estimates of the prevalence of the individual cancers will not sum to the estimate given for all cancers combined.