Lung Cancer

Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer death worldwide, with about 2.5 million new cases and 1.8 million deaths in 2022. Overall rates are twice as high in men than women. The highest incidence and mortality rates in both sexes are found in most parts of Europe, North America, and Australia/New Zealand and the lowest in sub-Saharan Africa (Map 14.1).

The historical trends in lung cancer rates in each country follow trends in smoking prevalence, with a delay of at least 25 years. Trends over time show distinct sex-specific patterns, reflecting the past and current differences in tobacco use. Among men, lung cancer incidence rates have been decreasing in most countries, starting in the early 1970s (e.g., the United Kingdom), but not until the late-1990s in women, 20 years later than men. In some countries, lung cancer mortality rates in women have continued to increase, and have surpassed those in men, as seen in Sweden and Denmark. Such trends are not observed in transitioning countries in Asia and Africa, where rates tend to be either decreasing or are stable in men and remain low in women (Figure 14.1).

Today, 45% of lung cancers globally are estimated to be adenocarcinomas (39% in men and 57% in women, respectively) (Figure 14.2). The distribution of lung cancer subtypes is shifting from squamous cell carcinoma to adenocarcinoma due to changing smoking habits, cigarette composition, other environmental causes of lung cancer (such as air pollution), and opposing incidence trends with rates of adenocarcinoma rising and squamous cell carcinoma falling.

Adenocarcinoma accounts for a disproportionately higher burden of lung cancer in women compared to men.