Histological subtype of lung cancer in relation to socio-economic deprivation in South East England

Previous studies have found differences in the histological subtypes of lung cancers affecting males and females. Our objective was to investigate trends in the incidence of histological subtypes of lung cancer in males and females in relation to socio-economic deprivation in South East England.

Data on 48,031 males and 30,454 females diagnosed with lung cancer between 1995 and 2004 were extracted from the Thames Cancer Registry database. Age-standardised incidence rates for histological subtypes were calculated for each year, using the European standard population. Using the Income Domain of the Multiple Index of Deprivation 2004, patients diagnosed between 2000 and 2004 were classified into quintiles of socio-economic deprivation based on their postcode of residence. Age-standardised rates for each histological subtype were then calculated for each deprivation quintile. A Poisson regression model was fitted to the data for males and females separately to test the hypothesis that the relationship between socio-economic deprivation and adenocarcinoma was less strong than for other subtypes.

In males all specific histological subtypes except adenocarcinoma declined in incidence. Squamous cell carcinoma remained the most common specific subtype and large cell carcinoma the least common. In females squamous cell carcinoma was initially most common, but its incidence declined slightly and that for adenocarcinoma increased. In both sexes the overall age-standardised incidence rate of lung cancer increased with increasing deprivation. However, these trends were less strong for adenocarcinoma than for the other subtypes in both males (p < 0.001) and females (p = 0.003).

The temporal trends and distribution of histological subtypes of lung cancer in males and females are similar to that reported from other western populations. In both males and females, adenocarcinoma was less strongly related to deprivation than other subtypes. This may be because its development is less strongly linked to individual smoking history.