Convergence of decreasing male and increasing female incidence rates in major tobacco-related cancers in Europe in 1988–2010

Abstract

Introduction

Smoking prevalence has been declining in men all over Europe, while the trend varies in European regions among women. To study the impact of past smoking prevalence, we present a comprehensive overview of the most recent trends in incidence, during 1988–2010, in 26 countries, of four of the major cancers in the respiratory and upper gastro-intestinal tract associated with tobacco smoking.

Methods

Data from 47 population-based cancer registries for lung, laryngeal, oral cavity and pharyngeal, and oesophageal cancer cases were obtained from the newly developed data repository within the European Cancer Observatory (http://eco.iarc.fr/). Truncated age-standardised incidence rates (35–74 years) by calendar year, average annual percentage change in incidence over 1998–2007 were calculated. Smoking prevalence in selected countries was extracted from the Organisation for Economic Co-operation and Development and the World Health Organization databases.

Results

There remained great but changing variation in the incidence rates of tobacco-related cancers by European region. Generally, the high rates among men have been declining, while the lower rates among women are increasing, resulting in convergence of the rates. Female lung cancer rates were above male rates in Denmark, Iceland and Sweden (35–64 years). In lung and laryngeal cancers, where smoking is the main risk factor, rates were highest in central and eastern Europe, southern Europe and the Baltic countries. Despite a lowering of female smoking prevalence, female incidence rates of lung, laryngeal and oral cavity cancers increased in most parts of Europe, but were stable in the Baltic countries. Mixed trends emerged in oesophageal cancer, probably explained by differing risk factors for the two main histological subtypes.

Conclusions

This data repository offers the opportunity to show the variety of incidence trends by sex among European countries. The diverse patterns of trends reflect varied exposure to risk factors. Given the heavy cancer burden attributed to tobacco and the fact that tobacco use is entirely preventable, tobacco control remains a top priority in Europe. Prevention efforts should be intensified in central and eastern Europe, southern Europe and the Baltic countries.

Introduction

Tobacco was introduced into Europe by Spanish explorers returning from the Americas in the late fifteenth century. By the late nineteenth century, tobacco was being widely used by men in Europe [1], first in the forms of pipe-, cigar-smoking and snuff-taking. Then, after mass production became possible at the end of the nineteenth century, cigarettes, strongly promoted by advertising and marketing efforts, became the norm for tobacco consumption. From the 1930s, together with the forces of emancipation, women began adopting the habit on a large scale, first in North America and in northern and western Europe, until the 1970s. By the 1960s, the smoking prevalence in men was at least 70% in Denmark, the United Kingdom (UK) and Belgium and 90% in the Netherlands, and around 30% in women [2]. Thereafter, the proportion of smokers rapidly decreased in men in these parts of Europe, falling to around 40–50% by 1988. In contrast, in women, the prevalence rose gradually over time, but remained lower than in men. In southern Europe, the tobacco epidemic lagged behind that in northern and western Europe, especially in women. In Russia, a small but significant rise in the prevalence of tobacco smoking among men was reported, from 57% in 1992 to 63% in 2003, whereas rates among women more than doubled from 7% to 15% in the same period [3]. From the mid-1990s until 2002, the prevalence of smoking among men in Estonia, Latvia and Lithuania was around 50% (compared to 29% in Finland), and ranged between 10% and 20% among women. Smoking increased among Lithuanian women from 6% in 1994 to 13% in 2002, but decreased among Estonian men and women [4]. Mass cigarette use followed the economic development in Europe: firstly in northern and western Europe, secondly in southern Europe, thirdly in central and eastern Europe.

Cigarette smoking is a causal agent for cancers of the oral cavity, oropharynx, nasopharynx, hypopharynx, oesophagus, stomach, colorectum, liver, pancreas, nasal cavity, paranasal sinuses, larynx, lung, uterine cervix, ovary, urinary bladder, kidney, ureter and bone marrow (myeloid leukaemia). Second-hand tobacco smoke and smokeless tobacco also induce cancer [5]. The European Prospective Investigation into Cancer and Nutrition Study (EPIC) calculated that among the 19 above-mentioned tobacco-related cancer cases, 35% of them were attributable to cigarette smoking (42% in men and 23% in women) [6]. In 2012 in Europe (40 countries), there were an estimated almost 600,000 new cases of: lung (410,000), oral cavity and pharyngeal (100,000), oesophageal (46,000) and laryngeal cancer (40,000) [7], the cancers for which the fraction attributable to smoking is highest (with lower urinary tract). For each of these sites, men represented 71% to 90% of the patients.

Using high-quality population-based cancer registration data, this study aims to identify patterns in the incidence of major tobacco-related cancers (lung, laryngeal, oral cavity and oesophageal cancer), between 1988 and 2010, especially contrasting trends in men and women. We analysed data from 47 cancer registries covering 328 million inhabitants, representing 26 European countries, using age-standardised rates and average annual percentage change and compared smoking prevalence to lung cancer incidence.