Supplementary additional file for

Time trends of cancer incidence and mortality in Catalonia during 1993-2007

Methods section

Estimation of cancer incidence in Catalonia using provincial incidence from TCR and GCR and mortality data

TCR and GCR incidence and mortality rates were used to estimate the whole Catalan cancer incidence during the study period. The difference between the incidence and mortality rates for each cancer site considered and for each age-group was used to estimate cancer incidence in Catalonia as follows. Let IRijcbe the aggregated number of incident cases provided by the TCR and GCR for the i-th age-group, j-th year, c-cancer sitein the regions, R, considered. Let DRijc, PRijc the aggregated number of deaths and person-years in these provinces, respectively. We assumed that the difference between cancer incidence and mortality rates in these provinces is identical to that difference for the whole Catalonia territory, C, and thus we assumed that (IRijc-DRijc)/PRijc=(ICijc-DCijc)/PCijc. Since DCijc and PCijc data are also available in the whole territory, ICijcwas estimated through ICijc= ((IRijc-DRijc)/PRijc))·PCijc+ DCijc. The time trend of these estimates during 1993-2007 was smoothed through modeling and making use of simple linear and log-linear models(1).

The method used to estimate incidence was based on modeling a rate that is a result of the difference between the incidence and mortality rates in the regions with cancer registries and apply this rate to the whole Catalan territory making use of the mortality data available. This method outperforms slightly better than others, such as modeling the incidence to mortality ratio (2),when time trend of cancer data is modeled (1). However, if significant differences between incidence of regions with cancer registries and the rest of regions may exist, there is no clear evidence which method performs better than the other (1).

Comparison with the incidence and mortality data from European regions

To establish the relative burden of cancer in Catalonia, age-adjusted incidence/mortality rates of cancer during 2008 have been compared between European countries making use of Globocan 2008 data (2). The countries compared to our estimates were: Iceland,Denmark, Netherlands, Italy,UK, Czech Republic, Switzerland, Sweden, Germany, France, Finland,Slovenia, Poland,Ireland,Norway,Austria,Malta,Portugal and Spain (including Catalonia). Incidence rates in Catalonia during 2008 have been obtained applying the estimated rates in 2007 to its population pyramid for 2008.

Supplementary table. Classification for cancer cases/deaths using the International Classification of Diseases in the 9th and 10th revision.

Cancer Site / Code ICD-10 (*) / Code ICD-9 (**)
Oral Cavity and Pharynx / C00-C14 / 140-149
Oesophagus / C15 / 150
Stomach / C16 / 151
Colon, rectum, anus / C18-C21 / 153-154
Liver / C22 / 155
Gallbladder & Extrahepatic bile duct / C23-C24 / 156
Pancreas / C25 / 157
Larynx / C32 / 161
Lung / C33-C34 / 162
Melanoma of skin / C43 / 172
Breast / C50 / 174-175
Cervix uteri / C53 / 180
Corpus uteri / C54 / 182
Ovary / C56, C57.0-4 / 183
Penis / C60 / 187.1-187.4
Prostate / C61 / 185
Testis / C62 / 186
Kidney / C64 / 189.0
Urinary bladder / C67 / 188
Brain and other CNS / C70-C72 / 191-192
Thyroid / C73 / 193
Hodgkin’s lymphoma / C81 / 201
Non- Hodgkin’s lymphoma / C82-C85,C96 / 200,202
Multiple myeloma / C88, C90 / 203, 238.6
Leukaemia / C91-C95 / 204-208
Myelodisplasic syndromes / D45-D47 / 237.7, 238.4, 238.5, 238.7,
273.1, 284.9, 285.0
All except non-melanoma skin / C00-C97, (excude C44) / 140-208, 238.4-238.7, 237.7, 273.1, 284.9, 285.0 (exclude 173)
ICD: International Classification of Diseases; *: Classification used for Cancer mortality during the period 1999-2007 and for Cancer Incidence during the whole study period; **: Classification used for Cancer mortality during the period 1993-1998;

Figure S1. Time trends of all-cancer incidence and mortality in Catalonia during 1993-2007 stratified by age-groups.

References

1. Cleries R, Ribes J, Buxo M, Ameijide A, Marcos-Gragera R, Galceran J, et al. Bayesian approach to predicting cancer incidence for an area without cancer registration by using cancer incidence data from nearby areas. Stat Med. 2012;10 (31):978-87.

2. GLOBOCAN 2008, cancer incidence and mortality worldwide: IARC CancerBase no. 10 [Internet].: Lyon, France: International Agency for Research on Cancer; 2010; 2010.