Gallbladder cancer (GC) is a rare malignancy that begins when abnormal cells grow out of control within the gallbladder. This small, pear-shaped organ, located beneath the liver in the upper right abdomen, stores and concentrates bile, a digestive fluid. When cancer forms, it typically starts in the innermost layer and can spread outward through the walls. The overall incidence of gallbladder cancer is significantly lower than many other common cancers.
Global and National Incidence Statistics
Gallbladder cancer is rare in the United States, with fewer than two cases diagnosed annually per 100,000 people. Approximately 5,000 new cases are diagnosed each year, making it one of the least frequent cancers of the digestive system. Incidence rates rise sharply for individuals over 65 years old.
Globally, the disease is ranked as the 22nd most common cancer, accounting for about 1.2% of all cancer diagnoses worldwide. This low incidence contrasts sharply with highly prevalent cancers like breast, prostate, or lung cancer. Despite its low frequency, gallbladder cancer carries a disproportionately high mortality rate compared to its incidence.
Disparities in Prevalence
The prevalence of gallbladder cancer is not uniform across all populations and geographical regions. A higher burden is observed in specific geographic hotspots, particularly in parts of South America, Eastern Europe, and East Asia. Countries like Chile and India often report some of the highest incidence rates globally.
Significant disparities are also evident among certain ethnic groups within the United States. Specific Native American populations, such as Alaska Natives, experience markedly elevated incidence rates compared to the national average. This elevated risk is also observed in some Hispanic populations.
GC is more common in women than in men, who may be two to six times more likely to develop the disease. This sex disparity is often linked to the higher prevalence of gallstones in women, a significant risk factor for GC development.
Key Contributing Risk Factors
A major predisposing factor for gallbladder cancer is chronic inflammation, which often stems from long-standing conditions affecting the organ. The most common risk factor is the presence of gallstones (cholelithiasis), found in approximately 85% of diagnosed individuals. Although gallstones are widespread, only a small percentage of people with them will ever develop gallbladder cancer.
A condition known as “porcelain gallbladder,” where the organ wall becomes calcified due to chronic irritation, significantly increases risk. Other chronic medical issues, lifestyle factors, and environmental exposures also contribute to heightened risk:
- Obesity and diabetes
- Certain types of chronic viral hepatitis
- Chronic infection of the biliary system, such as with Salmonella typhi
- Exposure to specific industrial chemicals and a history of smoking
Survival Rates and Staging
The rarity of gallbladder cancer translates into challenging outcomes because the disease is difficult to detect in its earliest, most curable stages. The organ’s location and the cancer’s tendency to be asymptomatic mean that only about one in five cases are found when the cancer is still confined to the gallbladder. For this reason, the cancer is often only discovered incidentally during surgery for gallstones or when it has advanced enough to cause noticeable symptoms.
The five-year survival rate depends heavily on the stage of diagnosis. If the cancer is still localized to the organ, the five-year survival rate is substantially higher. However, for cancer that has spread regionally to nearby lymph nodes, or distantly to other organs, the survival rates drop significantly. The overall five-year survival rate for all stages combined in the United States is approximately 19%.