Jaundice causes the skin and whites of the eyes to turn yellow due to an excess of bilirubin in the bloodstream. While it can stem from various health issues, it sometimes appears as a symptom in individuals with cancer.
Understanding Bilirubin
Bilirubin is a yellowish pigment formed when the body breaks down old red blood cells. It is a byproduct of hemoglobin, the protein in red blood cells that carries oxygen. Once formed, this unconjugated bilirubin travels through the bloodstream to the liver.
The liver plays a central role in processing bilirubin, converting it into a water-soluble form called conjugated bilirubin. This conjugated bilirubin then becomes a component of bile, a digestive fluid produced by the liver. Bile is stored in the gallbladder and released into the small intestine to aid in fat digestion. Most bilirubin is then eliminated from the body, primarily through stool, which gives stool its characteristic brown color, and a smaller amount through urine.
Cancer’s Impact on Bilirubin Processing
Cancer can lead to bilirubin accumulation and jaundice by disrupting its normal processing and excretion. One common way is through physical blockage of bile ducts. Tumors near or within the bile ducts can obstruct these tubes, preventing bile, and thus bilirubin, from flowing into the intestines. This blockage causes bilirubin to back up into the liver and spill into the bloodstream.
Another mechanism involves cancer spreading to or originating in the liver. If cancer cells damage liver tissue, the liver’s ability to process bilirubin is impaired. This hinders its capacity to convert unconjugated bilirubin into its conjugated form or excrete it into bile, resulting in buildup in the blood.
Less commonly, certain cancers or their treatments can cause the rapid breakdown of red blood cells, known as hemolysis. When red blood cells break down too quickly, the bilirubin produced can overwhelm the liver’s capacity to process it, leading to an excess in the bloodstream. This can occur with some blood cancers like lymphomas.
Cancers Frequently Causing Jaundice
Several types of cancer are commonly linked to the development of jaundice, often due to their proximity to the bile ducts or their tendency to affect the liver. Pancreatic cancer, particularly tumors located in the head of the pancreas, frequently causes jaundice. This is because the head of the pancreas is situated close to the common bile duct, and even a small tumor can compress or block this duct, leading to bilirubin buildup.
Cancers that originate in the bile ducts themselves, known as cholangiocarcinoma, or those in the gallbladder, can also directly obstruct the flow of bile. As these tumors grow, they can block the bile ducts, causing bilirubin to accumulate and leading to jaundice. Liver cancer, whether primary liver cancer or cancer that has spread to the liver (metastatic liver cancer), can also cause jaundice by damaging liver cells or by blocking intrahepatic bile ducts.
In some cases, cancers like certain lymphomas or leukemias can lead to jaundice through less direct means, such as causing an increased breakdown of red blood cells or by extensively infiltrating the liver. Cancers that metastasize to the liver from other parts of the body, such as colorectal cancer, can also induce jaundice if the metastatic tumors are extensive enough to impair liver function or obstruct bile flow.
What Jaundice Signifies in Cancer
When jaundice appears in a cancer patient, it provides important information to medical professionals about the disease’s progression and location. The presence of jaundice often suggests that a tumor is affecting the liver or the bile drainage system. For instance, if a patient with pancreatic cancer develops jaundice, it frequently indicates the tumor is located in a position where it is pressing on the bile duct.
Jaundice can signal that the cancer has reached a more advanced stage, especially in cases of liver or gallbladder cancer where symptoms may not appear until the disease has progressed. It highlights that the tumor is significantly impacting organ function, specifically the liver’s ability to process and excrete bilirubin. Observing jaundice prompts further investigation to pinpoint the exact cause and assess the extent of the cancer’s spread and its effect on vital organs.