Long-term incidence and survival trends in cancer of the gallbladder and extrahepatic bile ducts in Denmark, Finland, Norway and Sweden with etiological implications related to Thorotrast

Cancers of the gallbladder and extrahepatic bile ducts (called here "GBC" because gallbladder cancer is the main component) are rare in Europe, including the Nordic countries. Their incidence has varied for unknown reasons and we hypothesize that Thorotrast, a previously used carcinogenic radiographic contrast medium, has contributed to the incidence trends. We obtained incidence and survival data from the NORDCAN database, which includes cancer registry data from Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE), which are globally the oldest national cancer databases, starting from 1943 in DK, 1953 in FI and NO and 1960 in SE, and extending to 2016. The incidence trend for GBC showed a broad maximum around 1980 in men (close to 3/100 000) and women (4/100 000), except for NO, where this phenomenon was not seen. In 1955, FI and NO incidence rates were equal but FI rates peaked and later declined similar to DK and SE rates. By 2010, the incidence was similar in all Nordic countries, for both men and women, at close to 2.0/100 000. Birth cohort analysis showed strong effects for countries other than NO. Relative 1-year survival increased for men from 20% to about 50% and similarly for women although at a 5 percentage points lower level. Survival in NO was better than in other countries in the 1980s. Thorotrast, causing a high risk of GBC, was extensively used in the Nordic countries between 1930 and end of 1940s, with the exception of NO, where these was no documented use. These data suggest that Thorotrast influenced GBC epidemiology and probably worsened survival in certain periods.Peer reviewe

Long-term survival trends for primary liver and pancreatic cancers in the Nordic countries

Publisher Copyright: © 2022 The Author(s)Background & Aims: Liver cancer (LC) and pancreatic cancer (PC) are often diagnosed at an advanced stage resulting in high mortality. High-quality survival data are rarely available for trend analyses over a long period. Methods: The Danish, Finnish, Norwegian, and Swedish cancer data were accessed at the NORDCAN database. We analysed relative 1- and 5-year survival trends in LC and PC between years 1970 and 2019. Results: Relative 1-year survival in LC for Nordic men and women was about 10% in the period between 1970 and 1974, and it increased moderately by year 2000 and steeply thereafter, eventually reaching 40–50%. The patterns in 5-year survival were similar, but after the year 2000, survival in Norway and Sweden increased steeply to 23%, whereas survival in Denmark and Finland lagged behind, reaching 10% to 15%. The patterns for PC also showed rapid improvement after the year 2000, with 1-year survival reaching 30% to 40% and 5-year survival reaching 10% for Finland and 15% for Norway and Sweden. Survival was best for patients diagnosed before age 50 years, and it was worst for older patients. For both cancers the difference between 1- and 5-year survival increased with time. Conclusions: Survival in LC and PC improved first modestly and then steeply over the 50-year period covered. The increase in 5-year survival was less than that of 1-year survival. The survival gains were most likely the result of earlier diagnosis, improved treatment, and better organised supportive care. The challenges are to keep up these positive trends, to extend survival benefits past Year 1, and to obtain similar results in elderly patients. Primary prevention through avoidance of risk factors would reduce case numbers. Lay summary: Liver and pancreatic cancers are among the most lethal of all cancers. In 50 years, survival in these cancers has slowly improved, and in the past 20 years, the development has been increasingly favourable. Widespread adoption of healthy lifestyles will be key to reducing the risk of these cancers.Peer reviewe

Survival in Colon, Rectal and Small Intestinal Cancers in the Nordic Countries through a Half Century

Background: Survival studies in intestinal cancers have generally shown favorable development, but few studies have been able to pinpoint the timing of the changes in survival over an extended period. Here, we compared the relative survival rates for colon, rectal and small intestinal cancers from Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE). Design: Relative 1-, 5- and 5/1-year conditional survival data were obtained from the NORDCAN database for the years 1971–2020. Results: The 50-year survival patterns were country-specific. For colon and rectal cancers, the slopes of survival curves bended upwards for DK, were almost linear for NO and bended downwards for FI and SE; 5-year survival was the highest in DK. Survival in small intestinal cancer was initially below colon and rectal cancers but in FI and NO it caught up toward the end of the follow-up. Conclusions: Relative survival in intestinal cancers has developed well in the Nordic countries, and DK is an example of a country which in 20 years was able to achieve excellent survival rates in colon and rectal cancers. In the other countries, the increase in survival curves for colon and rectal cancer has slowed down, which may be a challenge posed by metastatic cancers

Long-term incidence in hepatocellular carcinoma and intrahepatic bile duct cancer in Denmark, Finland, Norway and Sweden, role of Thorotrast?

We analyzed long-term incidence trends in liver cancer (including hepatocellular carcinoma and intrahepatic cholangiocarcinoma) with an aim to interpret the changes in terms of known risk factors and hypothesize that historical exposure to Thorotrast, a radiographic contrast medium emitting alpha particles, has changed population rates. The NORDCAN database was used to collect cancer registry data from Denmark (DK), Finland (FI), Norway (NO) and Sweden (SE), which we used from 1953 (DK, FI and NO) and 1960 (SE) through 2019. Thorotrast, which caused a 100-fold risk of liver cancer was used in DK and SE, and probably also in FI between 1930 and 1950, but not in NO. The incidence trend for liver cancer showed a broad maximum at around 1980, most prominent and statistically significant in SE and DK men and women, and in all countries, a steadily increasing trend towards the end of follow-up. Incidence for NO was lower than for the other countries and the rates showed no peaking at around 1980. Birth cohort analysis identified a transient risk which could be dated to a period between 1930 and 1950 in countries other than NO. Considering a lag time between Thorotrast use and liver cancer appearance, the large incidence peak around 1980 in DK and DE was probably contributed by Thorotrast but considering the ecological nature of the findings, the association should be considered cautiously as hypothesis generating. The late increase in liver cancer risk is most likely lifestyle related and largely preventable.Peer reviewe

Long-term survival trends in solid cancers in the Nordic countries marking timing of improvements

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Familial Risks for Liver, Gallbladder and Bile Duct Cancers and for Their Risk Factors in Sweden, a Low-Incidence Country

Simple Summary Familial risk of cancer implies that two or more family members are diagnosed with the same cancer. This may be due to the genes or environmental factors that family members share. Familial risk for liver and gallbladder cancer is about 2.7 which means that when one family member is diagnosed with these cancers other family members have 2.7 times higher risk of being diagnosed with the same cancers compared to families were no member is yet diagnosed with these cancers. Risk between spouses is entirely due to shared environmental factors and for liver cancer there is a small risk. The most important way to prevent these cancers is to avoid their risk factors, alcohol, smoking and overweight, and to seek medical care for diabetes and liver infections. We used the Swedish Cancer Registry data to address familial risks for concordant (same) and discordant (different) hepatobiliary cancers, including their associations with any other cancers and with known risk factors. Risks were also assessed between spouses. The analysis covered Swedish families and their cancers between years 1958 and 2018. Adjusted familial risks were expressed as standardized incidence ratios (SIRs). Familial SIRs for concordant hepatocellular carcinoma (HCC) were 2.60, and for gallbladder cancer they were at the same level (2.76). Familial risk was also found for intrahepatic bile duct cancer and for female extrahepatic bile duct cancer. HCC was associated with lung and cervical cancers; extrahepatic bile duct and ampullary cancers were associated with colon and pancreatic cancers, suggesting Lynch syndrome. Among spouses, hepatobiliary cancer was associated with HCC, stomach, pancreatic, cervical and upper aerodigestive tract cancers. Among risk factors, family members diagnosed with alcohol-related disease showed association with HCC. The observed familial risks for hepatobiliary cancers were relatively high, and considering the poor prognosis of these cancers, prevention is of the utmost importance and should focus on moderation of alcohol consumption, vaccination/treatment of hepatitis viral infections and avoidance of overweight and other risk factors of type 2 diabetes.Peer reviewe

Personal comorbidities and their subsequent risks for liver, gallbladder and bile duct cancers

Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers.Peer reviewe

Familial Risks for Liver, Gallbladder and Bile Duct Cancers and for Their Risk Factors in Sweden, a Low-Incidence Country

Simple Summary Familial risk of cancer implies that two or more family members are diagnosed with the same cancer. This may be due to the genes or environmental factors that family members share. Familial risk for liver and gallbladder cancer is about 2.7 which means that when one family member is diagnosed with these cancers other family members have 2.7 times higher risk of being diagnosed with the same cancers compared to families were no member is yet diagnosed with these cancers. Risk between spouses is entirely due to shared environmental factors and for liver cancer there is a small risk. The most important way to prevent these cancers is to avoid their risk factors, alcohol, smoking and overweight, and to seek medical care for diabetes and liver infections. We used the Swedish Cancer Registry data to address familial risks for concordant (same) and discordant (different) hepatobiliary cancers, including their associations with any other cancers and with known risk factors. Risks were also assessed between spouses. The analysis covered Swedish families and their cancers between years 1958 and 2018. Adjusted familial risks were expressed as standardized incidence ratios (SIRs). Familial SIRs for concordant hepatocellular carcinoma (HCC) were 2.60, and for gallbladder cancer they were at the same level (2.76). Familial risk was also found for intrahepatic bile duct cancer and for female extrahepatic bile duct cancer. HCC was associated with lung and cervical cancers; extrahepatic bile duct and ampullary cancers were associated with colon and pancreatic cancers, suggesting Lynch syndrome. Among spouses, hepatobiliary cancer was associated with HCC, stomach, pancreatic, cervical and upper aerodigestive tract cancers. Among risk factors, family members diagnosed with alcohol-related disease showed association with HCC. The observed familial risks for hepatobiliary cancers were relatively high, and considering the poor prognosis of these cancers, prevention is of the utmost importance and should focus on moderation of alcohol consumption, vaccination/treatment of hepatitis viral infections and avoidance of overweight and other risk factors of type 2 diabetes.Peer reviewe

Second Primary Cancers After Liver, Gallbladder and Bile Duct Cancers, and These Cancers as Second Primary Cancers

Background: Second primary cancers (SPCs) are important clinically as they may negatively influence patient survival and they may tell about therapeutic side effects and general causes of cancer. Population-based literature concerning SPCs after hepatobiliary cancers is limited and here we assess risks of SPCs after hepatocellular cancer (HCC), and cancers of the gallbladder, bile ducts and ampulla of Vater. In reverse order, we consider the risk of hepatobiliary cancers as SPCs after any cancer. Methods: We used standardized incidence ratios (SIRs) to estimate bidirectional relative risks of subsequent cancers associated with hepatobiliary cancers. Cancer diagnoses were obtained from the Swedish Cancer Registry from years 1990 through 2015. Results: We identified 9997 primary HCCs, 1365 gallbladder cancers and 4721 bile duct cancers. After HCC, risks of four SPCs were increased: gallbladder (SIR = 4.38; 95% confidence interval 1.87-8.67), thyroid (4.13; 1.30-9.70), kidney (2.92; 1.66-4.47) and squamous cell skin (1.55; 1.02-2.26) cancers. In reverse order, HCC as SPC, in addition to the above cancers, associations included upper aerodigestive tract, esophageal, small intestinal and bladder cancers and non-Hodgkin lymphoma. For gallbladder and bile duct cancers, associations were found with small intestinal and pancreatic cancers. Conclusion: The results suggested that HCC is associated with two types of SPC, one related to shared environmental risk factors, such as alcohol, exemplified by upper aerodigestive tract and esophageal cancer, and the other related to immune dysfunction, exemplified by squamous cell skin cancer. SPCs associated with gallbladder and bile duct cancers suggest predisposition to mutations in the mismatch repair gene MLH1.Peer reviewe