better information --> better decisions --> better health1

Projections of cancer incidence in Scotland to 2020

Roger Black, Samuel Oduro, David Brewster

Information Services Division

better information --> better decisions --> better health2

Background

• First projections used for Cancer Scenarios report and Cancer in Scotland: Action for Change (2001)

• Updated for Cancer in Scotland: Sustaining Change and radiotherapy planning (2004)

• Further updated to account for revised population projections and used in Better Cancer Care (2008)

• Current exercise exploits availability of more historical baseline incidence data, more recent population projections and new statistical methodology

Data and methods

• Historical incidence data 1978-2007• GRO population estimates 1978-2007• GRO population projections 2008-2022• Age-Period-Cohort models using software

developed by the Norwegian Cancer Registry (NORDPRED)

Lung cancer risk varies by birth cohort

Source: Swerdlow et al, 1998

Age-Period-Cohort models

• Model works by estimating the simultaneous influence of age, period and birth cohort on individual risk

• Cohort effects highly predictable• Future period effects not so, e.g. new

screening programme, diagnostic test

Figure 6 Actual and projected total population compared with previous projections, 1983-2033

0

1,000

2,000

3,000

4,000

5,000

6,000

1983 1988 1993 1998 2003 2008 2013 2018 2023 2028 2033

Year

Per

son

s ('

000s

)

Actual 2008-based 2006-based 2004-based 2003-based

Source: GRO(S)

We have consistently underestimated population growth in Scotland …

Source: GRO(S)

… and most of the growth is in people aged 75+

Actual Projected2003-2007 2013-2017 % change

All Cancer(excluding C44) 27352 32256 18Lung 4692 4691 0Kidney 717 912 27Stomach 800 741 -7Melanoma of skin 927 1350 46Leukaemia 651 811 25Colorectal 3513 4202 20Colon 2332 2748 18Rectum 1180 1453 23Brain & CNS 382 398 4Head & neck 1040 1288 24Bladder 1610 1824 13Oesophagus 832 1030 24Hodgkins 141 156 11Non-Hodgkins 916 1212 32Panceas 634 711 12Other 3152 3690 17Breast 4004 4820 20Corpus Uteri 518 610 18Cervix 285 242 -15Ovarian 623 694 11Prostate 2577 3805 48Testis 197 221 12

Results(average number of new cases per annum)

ValidationActual Projected

2003-2007 2003-2007 % differenceAll Cancer(excluding C44) 27352 28090 3Lung 4692 4481 -4Kidney 717 714 0Stomach 800 864 8Melanoma of skin 927 865 -7Leukaemia 651 767 18Colorectal 3513 3765 7Colon 2332 2458 5Rectum 1180 1307 11Brain & CNS 382 404 6Head & neck 1040 1153 11Bladder 1610 1636 2Oesophagus 832 878 5Hodgkins 141 123 -13Non-Hodgkins 916 991 8Panceas 634 623 -2Other 3152 3295 5Breast 4004 4073 2Corpus Uteri 518 505 -3Cervix 285 312 10Ovarian 623 676 9Prostate 2577 2496 -3Testis 197 234 19

Comment on results

• Results reasonably reliable for most of the common cancers and the total

• Concern about prostate cancer (period effect)• We usually adopted the most conservative

results from the range of model predictions• Model choice is always to some extent

subjective

Conclusion

• New cancer cases expected to increase by approximately 8% every five years up to 2020

• This is mainly due to our aging population• Results for Scotland compatible with those for

England (33% increase from 2001 to 2020).