Is the rate of biological Is the rate of biological ageing, as measured by age ageing, as measured by age at diagnosis of cancer, socio-at diagnosis of cancer, socio-

economically patterned?economically patterned?

Dr. Jean AdamsDr. Jean Adams

School of Population and Health School of Population and Health SciencesSciences

University of Newcastle upon TyneUniversity of Newcastle upon Tyne

Hypothesised causal Hypothesised causal pathwaypathway

SEP

Psycho-social social stressstress

Health related behaviours

Environmental risks and hazards

Rate of biological

ageingHealth

Biological ageingBiological ageing

Progressive decrease in ability to Progressive decrease in ability to meet physiological demandsmeet physiological demands

Due to accumulation of cellular Due to accumulation of cellular damagedamage Balance between damage and repairBalance between damage and repair

Some factors causing damage socio-Some factors causing damage socio-economically patternedeconomically patterned

Many factors causing damage also Many factors causing damage also associated with diseaseassociated with disease

Measuring biological ageingMeasuring biological ageing Cancers due to mutations in genes Cancers due to mutations in genes

that control cell growththat control cell growth

Genetic mutations are one form of Genetic mutations are one form of cellular damagecellular damage

Chronological age at development of Chronological age at development of cancer may be a good comparative cancer may be a good comparative marker of rate of biological ageingmarker of rate of biological ageing

HypothesisHypothesis

Age at development of cancer is not Age at development of cancer is not socio-economically patternedsocio-economically patterned

Individuals living in more socio-Individuals living in more socio-economically deprived circumstances economically deprived circumstances develop cancer earlier in lifedevelop cancer earlier in life

MethodsMethods All individuals registered with NYCRIS 1986-All individuals registered with NYCRIS 1986-

95 inclusive with:95 inclusive with: Colorectal cancer (ICD-10 C18, C19, C20)Colorectal cancer (ICD-10 C18, C19, C20)

Breast cancer (ICD-10 C50)Breast cancer (ICD-10 C50)

Prostate cancer (ICD-10 C61)Prostate cancer (ICD-10 C61)

Lung cancer (ICD-10 C33, C34)Lung cancer (ICD-10 C33, C34)

Age at diagnosis=date at incidence-date of Age at diagnosis=date at incidence-date of birthbirth

SEP=Townsend Deprivation Score of SEP=Townsend Deprivation Score of enumeration district (1991 census)enumeration district (1991 census)

ExclusionsExclusions Key data missingKey data missing

Death certification only registrationDeath certification only registration

Second primarySecond primary

Men with breast cancerMen with breast cancer

Youngest 25% from each groupYoungest 25% from each group

144 627 registrations 144 627 registrations 39 301 (27.2%) met one or more exclusion criteria39 301 (27.2%) met one or more exclusion criteria

105 326 included in analysis105 326 included in analysis

Results - descriptiveResults - descriptive

GroupGroup NN Median Median ageage

Median Median TDSTDS

ProstateProstate 12 12 828828

77.6377.63 -0.35-0.35

BreastBreast 25 25 697697

67.8467.84 -0.50-0.50

Color. menColor. men 12 12 656656

78.0578.05 0.030.03

Color. womenColor. women 13 13 538538

73.6773.67 0.060.06

Lung menLung men 14 14 165165

72.4672.46 1.281.28

Lung womenLung women 26 26 442442

72.9872.98 1.091.09

Results - analyticalResults - analytical

GroupGroupcoefficiecoefficie

ntntp-p-

valuevalue

Change in Change in age/TDS age/TDS

IQR*IQR*

ProstateProstate -0.073-0.073 <0.00<0.0011

-0.36 years-0.36 years

BreastBreast 0.1490.149 <0.00<0.0011

0.72 years0.72 years

Colo. menColo. men -0.042-0.042 0.0390.039 -0.21 years-0.21 years

Colo. Colo. WomenWomen

-0.063-0.063 0.0010.001 -0.33 years-0.33 years

Lung menLung men -0.214-0.214 <0.00<0.0011

-1.07 years-1.07 years

Lung Lung womenwomen

-0.161-0.161 <0.00<0.0011

-0.82 years-0.82 years

*change in age at diagnosis of cancer across IQR of TDS from most affluent to most deprived quintile

CommentComment Age at diagnosis not necessarily a good Age at diagnosis not necessarily a good

proxy age at development of cancerproxy age at development of cancer SE variations in diagnostic delay?SE variations in diagnostic delay? Controlling for stage/grade at diagnosis has no Controlling for stage/grade at diagnosis has no

effect on resultseffect on results

Age at diagnosis of cancer may be poor Age at diagnosis of cancer may be poor proxy for rate of biological ageing proxy for rate of biological ageing

Small effect size throughoutSmall effect size throughout Cancer not necessarily homogenous Cancer not necessarily homogenous

across age and SEP or by ICD categoryacross age and SEP or by ICD category

ConclusionsConclusions Tested a complex model of aetiology using Tested a complex model of aetiology using

routine data from cancer registryroutine data from cancer registry Those from more deprived areas tend to Those from more deprived areas tend to

develop prostate, colorectal and lung develop prostate, colorectal and lung cancer earlier in lifecancer earlier in life

Those from more deprived areas tend to Those from more deprived areas tend to develop breast cancer later in lifedevelop breast cancer later in life ?due to breast cancer screening programme?due to breast cancer screening programme

Rate of biological ageing may be socio-Rate of biological ageing may be socio-economically patternedeconomically patterned

AcknowledgementsAcknowledgements

Co-authorsCo-authors Dr Martin White (Newcastle University)Dr Martin White (Newcastle University) Prof. David Forman (NYCRIS & Leeds Prof. David Forman (NYCRIS & Leeds

University)University)

FundingFunding Faculty of Public Health/BUPA Joint Faculty of Public Health/BUPA Joint

Research Fellowship (2001-04)Research Fellowship (2001-04)