Key message:
The incidence of liver cancer varies between cancer networks in England with the highest incidence evident in London and North West England. This geographical pattern warrants further investigation.
Geographic variation in primary liver and gallbladder cancer
Background
Cancers of the liver and gallbladder are rare in the UK. Primary liver cancers arise in the liver and need to be distinguished from secondary cancers which have metastased from elsewhere in the body. Known risk factors for primary liver cancer are infection with Hepatitis B and Hepatitis C as well as cirrhosis, excessive alcohol consumption, smoking and diabetes. Known risk factors for gallbladder cancer are gallstones, cholecystitis (inflammation of the gallbladder) and obesity.
Results
Liver
Higher incidence of liver cancer was evident in London and North West England (Figure 1). Funnel plots showed significantly higher incidence compared to the national average in Merseyside & Cheshire, Greater Manchester & Cheshire, West London, North East London and South East London cancer networks in both sexes and also in North London for males (Figure 2-3). Thames Valley and Anglia cancer networks had a significantly lower incidence in both males and females. In males, East Midlands, Kent & Medway, Peninsula, Essex, Humber & Yorkshire Coast, 3 Counties, Arden and North Trent cancer networks also had significantly lower incidence (Figures 2-3).
Gallbladder
There was no distinct geographical pattern in incidence of gallbladder cancer (data not shown). However, North East London cancer network had a significantly higher incidence of gallbladder cancer compared to the national average. Thames Valley (for males) and Essex (for females) cancer networks had a significantly lower incidence of gallbladder cancer.
Methods
Data on patients diagnosed with liver (excluding intrahepatic bile duct) cancer (International Classification of Diseases (ICD10) C22.0, C22.2-C22.9) and gallbladder cancer (ICD10 C23) in England between 1998 and 2006 were extracted from the National Cancer Repository Dataset. The dataset comprised 11,598 patients with liver cancer and 3,824 patients with gallbladder cancer (Table 2).
Table 2: Number of cases (%) of gallbladder and liver cancer, males and females, England, 1998-2006
| Cancer site | ICD10 code | Males | Females | Total |
| N | (%) | N | (%) | N |
| Gallbladder |
C23 |
1,116 |
(29.2) |
2,708 |
(70.8) |
3,824 |
| Liver |
C22.0, C22.2 - C22.9 |
8,320 |
(71.7) |
3,278 |
(28.3) |
11,598 |
Age-standardised incidence rates (per 100,000 European standard population, ASR(E)), were calculated by sex and cancer network of residence. Incidence rates were displayed on maps and in funnel plots to assess variation in incidence between cancer networks. The funnel plots were produced using software available from the Eastern Region Public Health Observatory (ERPHO)
Final note
There is some geographical variation in the incidence of liver cancer in England with particularly high incidence in London cancer networks and also in Merseyside, Manchester and Cheshire. In 2006-07 hospital admissions with a primary diagnosis for diseases specifically related to alcohol were higherin North West, North East and London. This could indicate more excessive alcohol consumption in these areas and could, in part, explain the geographical variation in liver cancer observed in this data briefing. Additionally, Hepatitis C is more common in people of Pakistani Punjab descent and Hepatitis B is more common in the Pakistani and Bangladeshi population. The higher incidence of liver cancer in London and the North West may also be associated with the ethnicity of the population living in these areas and the increased risk of infection with Hepatitis B and C. Further investigation however is needed to explain the geographical variation in incidence.
The incidence of gallbladder cancer is higher in females compared to males. One of the main risk factors for gallbladder cancer is a history of gallstones and inflammation of the gallbladder.
Gallstones are more common in women, which may explain the higher incidence of cancer in females. Gallbladder cancer is also common in people originating from the Gangetic plains (North India and Bangladesh). The high incidence of gallbladder cancer in North East London may also be related to the high proportion of the Bangladeshi population living in this area.
FIND OUT MORE:
Thames Cancer Registry is the lead Cancer Registry for upper gastrointestinal cancers
Other useful resources within the NCIN partnership: