Incidence and survival in laryngeal and lung cancers in Finland and Sweden through a half century

Abstract

Global survival studies have shown favorable development in most cancers but few studies have considered laryngeal cancer, particularly over extended periods or in populations for which medical care is essentially free of charge. We analyzed laryngeal and lung cancer incidence and survival in Finland (FI) and Sweden (SE) over a 50-year period (1970-2019) using data and statistical tools from the Nordcan database. Laryngeal cancer reached an incidence maximum in FI men in 1965, which in SE men occurred over 10 years later and peaking at 42% of the FI maximum. The FI incidence halved in 20 years while halving of the SE rate took almost twice as long. At maximum the male rate exceeded the female rate 20 times in FI and 10 times in SE. Incidence rates for lung cancer were approximately 10 times higher than those for laryngeal cancer, and they peaked 5 to 10 years after laryngeal cancer in both countries. The female lung cancer rates increased through the follow-up time but laryngeal cancer rates were relatively stable. Relative 1-year survival data for laryngeal cancer remained at around 85% through 50 years, and 5-year survival lagged constantly around 65%. For lung cancer 1-year survival improved and reached about 50% by 2019. Even 5-year survival improved reaching 20 to 30%, except for FI men. Incidence rates for laryngeal and lung cancers have drastically decreased in FI and SE men parallel to reduced smoking prevalence. In females, rates have clearly increased in lung but not in FI laryngeal cancer. This finding warrants further investigations into possible contributing factors, other than smoking. Survival in laryngeal cancer has not improved compared to the positive development in lung cancer. Historical smoking prevalence was unrelated of survival trends. As long-term survival in these cancers remains discouraging, the most efficient way to fight them is to target the main cause and promote non-smoking.