6.1. Introduction

Lung cancer is the most common cancer in the world. It is estimated that there are nearly one and a quarter million new cases diagnosed each year, resulting in over one million deaths (Ferlay et al., 2001). The vast majority of these cases are caused by tobacco smoking.

In the West Midlands, lung cancer is the second most common cancer in men (after prostate cancer) and the third most common cancer in women (after breast cancer and colorectal cancer). Over 3,000 new lung cancer cases are diagnosed each year. The incidence rate in men is currently more than double that in women.

This chapter presents an overview of lung cancer incidence in the West Midlands and examines how it varies with deprivation. Men and women diagnosed with a primary lung tumour in the period 1981-2001 were identified from the West Midlands Cancer Intelligence Unit registration database (n=146,422 and n=58,657, respectively). Using the postcode at diagnosis, cases were assigned a deprivation quintile (the Department of the Environment, Transport and the Regions’ Index of Multiple Deprivation 2000: IMD [2000]) and a Primary Care Trust (PCT) of residence. Incidence rates were directly age standardised to the European Standard Population.

6.2. Lung Cancer Incidence

The incidence trends of lung cancer are quite different in men and women, reflecting the past smoking behaviour of the two sexes (CRC, 2001). Figure 6.1 shows the directly age standardised incidence rates in men and women diagnosed in the period 1981–2001, and Table 6.1 presents the data for the Figure.

	Figure 6.1. Directly Age Standardised Incidence Rates in Men and Women Diagnosed in the Period 1981-2001
	Table 6.1. Directly Age Standardised Incidence Rates in Men and Women Diagnosed in the Period 1981-2001 See Figure 6.1 for graph

As shown in Figure 6.1, the incidence rates in men have decreased dramatically since the early 1980s, whereas the incidence rates in women have increased slightly. These trends have caused the incidence rates in the two sexes to converge over time, such that the incidence rate in men has dropped from being 4.64 times greater than that in women (1981-1983) to 2.29 times greater than that in women (1999-2001).

6.3. Variation in Lung Cancer Incidence with Deprivation

	Figure 6.2. Directly Age Standardised Incidence Rates by IMD (2000) Quintile in Men and Women Diagnosed in the Period 1999-2001
	Table 6.2. Directly Age Standardised Incidence Rates by IMD(2000) Quintile in Men and Women Diagnosed in the Period 1999-2001

As shown in Figure 6.2, lung cancer incidence displays a strong positive association with deprivation in both men and women. Whilst the incidence rates are much higher in men than they are in women, the association with deprivation is remarkably similar in the two sexes. For example, the most deprived men and women have incidence rates 1.90 times greater and 1.94 times greater, respectively, than those in the least deprived men and women.

In order to try and assess whether the gaps between the incidence rates in the most and the least deprived men and women have changed over time, Figure 6.3 shows the directly age standardised incidence rate ratios (most:least deprived) for men and women diagnosed in the periods 1981-1983, 1987-1989, 1993-1995 and 1999-2001. Table 6.3 presents the data for the Figure.

	Figure 6.3. Directly Age Standardised Incidence Rate Ratios (Most:Least Deprived) in Men and Women Diagnosed in the Periods 1981-1983, 1987-1989, 1993-1995 and 1999-2001
	Table 6.3. Directly Age Standardised Incidence Rate Ratios (Most:Least Deprived) in Men and Women Diagnosed in the Periods 1981-1983, 1987-1989, 1993-1995 and 1999-2001

As shown in Figure 6.3, the incidence rate ratios in men have increased slightly over the four diagnosis periods, indicating a small widening of the deprivation gap. This is because, whilst the incidence rates in the most and the least deprived men have both decreased over time, there has been a slightly greater decrease in the incidence rate in the least deprived men. In women, the incidence rate ratios have increased dramatically over the four diagnosis periods, indicating a considerable widening of the deprivation gap. In contrast to men, this widening has been caused by a large increase in the incidence rate in the most deprived women and very little change in the incidence rate in the least deprived women.

6.4. Variation in Lung Cancer Incidence with Deprivation and PCT

Figure 6.4 shows the directly age standardised incidence rates by PCT in men and women diagnosed in the period 1999-2001, and Table 6.4 presents the data for the Figure. The PCTs are ordered from the least deprived to the most deprived using the population-weighted average ward score (WMPHO, 2002).

	Figure 6.4. Directly Age Standardised Incidence Rates by PCT in Men and Women Diagnosed in the Period 1999-2001
	Table 6.4. Directly Age Standardised Incidence Rates by PCT in Men and Women Diagnosed in the Period 1999-2001

As shown in Figure 6.4, there is a wide variation in lung cancer incidence rates in men and women from the 30 PCTs across the West Midlands. The positive association with deprivation is clearly evident in both sexes, as the incidence rates increase with the increasing levels of deprivation in each PCT. However, this association is not strictly linear across the PCTs, and some PCTs have higher incidence rates than expected from their IMD (2000) average ward scores. For example, men in North Stoke PCT have the highest incidence rate overall but North Stoke is only the sixth most deprived PCT. Furthermore, the incidence rate in men from North Stoke PCT is significantly higher than the incidence rate in men from the most deprived PCT overall, Heart of Birmingham PCT (as shown by the 95% confidence intervals). A similar situation is also observed in women from Rowley Regis and Tipton PCT. These women have the highest incidence rate overall but Rowley Regis and Tipton is only the fifth most deprived PCT. As with men, the incidence rate in women from Rowley Regis and Tipton PCT is significantly higher than that in women from Heart of Birmingham PCT.

6.5. Conclusion

In conclusion, lung cancer incidence displays a strong positive association with deprivation. Incidence rates in the most deprived men and women are currently almost double those in the least deprived men and women. The gap between the most deprived and the least deprived men and women appears to have widened since the early 1980s, particularly in women, although these data need to be interpreted with caution as levels of deprivation may have changed over time. The variation in lung cancer incidence across PCTs in the West Midlands can be partly explained by differences in deprivation. However, some PCTs have higher than expected incidence rates when compared to other PCTs with similar deprivation levels, thus highlighting areas where further investigation may be required.

For information on how the incidence of other cancer sites vary with deprivation, please see the West Midlands Cancer Intelligence Unit’s report on ‘Cancer and Deprivation’ (WMCIU, 2002).

References

CRC (2001). Cancer Research Campaign Cancer Stats: Lung Cancer and Smoking – UK. Please also see references therein.

J. Ferlay, F. Bray, P. Pisani and D.M. Parkin (2001). GLOBOCAN 2000: Cancer Incidence, Mortality and Prevalence Worldwide, Version 1.0. IARC CancerBase No. 5. Lyon, IARCPress. A limited version is available from [http://www.dep.iarc.fr/globocan/globocan.html]

WMCIU: G. Lawrence, C. Livings and R. Smith (2002). Cancer and Deprivation. A pdf version is available to download from [http://www.wmpho.org.uk/wmciu/]

WMPHO: S. Walton, P. Fryers and L. Somervaille (2002). Patterns of Deprivation in the West Midlands. A pdf version is available to download from [http://www.wmpho.org.uk/]

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