Coffee and alcohol consumption and liver cancer morbidity rates in Poland

Abstract

Introduction: Liver cancer occurs in approximately 1% of Poles affected by all cancers. In 2014 its standardised incidence rates amounted to 2.9/100 thousand for males and 1.3/100 thousand for females. The aim of the study was to examine the relationship between trends in coffee and alcohol consumption and liver cancer morbidity in the past decades in Poland. Methods: The study was based on liver cancer incidence rates in 1980-2014 derived from the National Cancer Registry. Data on coffee and alcohol consumption were derived from national statistical yearbooks. Coffee consumption was determined on the basis of data on imports quantities expressed as kg/person/year. Alcohol consumption reflected consumption of all major types of alcoholic beverages and their alcohol content expressed as liters of pure alcohol per person/year. Spearman correlation coefficients were used to estimate the relationship between the examined variables. Results: In 1980-2014 imports of coffee to Poland increased from 1.04 to 3.02 kg/person/year. In the 1980s of the last century coffee wasn’t an easily available item in Poland. Alcohol consumption was 9.09 in 1980 and 9.92 l/person/year in 2014. However in the in the early 80's an important decline was noted. Alcohol consumption was systematically growing through a decade since the mid of the 1990s, while in the last years it stabilized. Liver cancer incidence rates were rather stable in the decade of the 80’s of the 20th century, whilst since the beginning of the 90's downward trends were observed. Adverse correlations were found between coffee consumption and liver cancer: -0.68 for males and -0.80 for females. Obtained results do not indicate positive correlations between liver cancer incidence rates and alcohol consumption. Conclusion: The increase in coffee consumption could favourably affect liver cancer morbidity rates in Poland and probably was one of the reasons of the observed decline in that cancer incidence in recent years. It is difficult to determine the influence of alcohol consumption on liver cancer morbidity. It is not unlikely that downward trends observed since beginning of the 90's were affected among others by earlier decline in alcohol consumption, but statistical analysis did not confirm it. It could be possible that the unfavourable effect of the high alcohol consumption was neutralized by the others factors acting favourably, among others, by the growing coffee consumption.