Cancer can certainly cause jaundice, the yellowing of the skin and eyes. Jaundice is not a disease but a symptom signaling an underlying problem with the body’s processing of waste material. When cancer is the cause, it typically indicates that the malignancy is affecting the liver, bile ducts, or pancreas, disrupting normal metabolic processes.
What Jaundice Is and Why It Occurs
Jaundice is the yellow discoloration of the skin, mucous membranes, and eyes, caused by an excessive buildup of bilirubin in the blood. Bilirubin is a yellowish pigment that forms when old or damaged red blood cells are broken down. This recycling process occurs continuously.
The newly formed bilirubin is not water-soluble and travels through the bloodstream to the liver. Specialized cells chemically modify the bilirubin in a process called conjugation, making it water-soluble and ready for excretion. This conjugated bilirubin is then released into bile, which travels through the bile ducts into the small intestine.
From the small intestine, bilirubin leaves the body primarily in the feces, giving stool its brown color. Jaundice occurs when this pathway is disrupted, causing bilirubin to back up into the bloodstream and deposit in tissues. This disruption happens if the liver is damaged and cannot process bilirubin, or if the drainage system is blocked, preventing excretion.
Cancers That Cause Jaundice Through Obstruction
Cancer most commonly causes jaundice by physically blocking the bile ducts, creating an obstructive problem. This is often referred to as a plumbing issue, where the flow of bile carrying processed bilirubin is mechanically prevented from reaching the intestine. The resulting backup forces bile and bilirubin into the bloodstream, leading to the characteristic yellowing.
Pancreatic cancer is a frequent cause of obstructive jaundice, particularly when the tumor is located in the head of the pancreas. Since the head of the pancreas is adjacent to the common bile duct, even a small tumor can compress the duct, stopping bile flow. This compression makes jaundice an early and noticeable symptom for many people with this type of pancreatic tumor.
Other malignancies affecting the bile drainage system include bile duct cancer (cholangiocarcinoma) and gallbladder cancer. Cholangiocarcinoma originates within the bile ducts, and even a small growth can cause obstruction due to the ducts’ narrow diameter. A tumor in the gallbladder can also press upon or infiltrate adjacent bile ducts, causing a blockage and bilirubin backup.
Cancers That Cause Jaundice Through Liver Impairment
Cancer can also cause jaundice through direct damage or dysfunction of the liver tissue, resulting in hepatic impairment. In this situation, liver cells are overwhelmed or destroyed, compromising the organ’s ability to perform the chemical processing of bilirubin. This is a problem of filtration and processing, rather than a physical blockage.
Primary liver cancer (hepatocellular carcinoma) causes impairment by destroying a large portion of functioning liver cells. As the tumor grows and replaces healthy tissue, the remaining liver capacity may become insufficient to conjugate all the bilirubin produced. Extensive tumor growth can also mechanically compress smaller bile ducts inside the liver, contributing to dysfunction and obstruction.
Metastatic cancer, which has spread to the liver from a primary site elsewhere in the body, is another frequent cause of impairment-related jaundice. Cancers originating in the colon, breast, or lung commonly spread here. If metastatic tumors are numerous or large, they severely compromise the organ’s overall function. The liver is then unable to efficiently take up, process, or excrete bilirubin, causing its concentration to rise in the blood.
Identifying the Underlying Cause
When jaundice is observed, medical investigation begins immediately to pinpoint the cause, especially to determine if cancer is responsible. Initial steps involve blood tests to measure bilirubin levels, differentiating between unconjugated and conjugated forms, and checking liver enzyme levels. These enzyme patterns provide the first clues, indicating whether the jaundice is likely due to an obstruction or liver cell damage.
Following blood work, imaging tests visualize the liver, bile ducts, and pancreas to search for tumors or blockages. An abdominal ultrasound is a common first step; it is non-invasive and can quickly show if the bile ducts are dilated, a sign of obstruction. If an obstruction is found, a computed tomography (CT) scan or magnetic resonance imaging (MRI) scan provides detailed images of the tumor’s size and location.
If a mass or blockage is identified, an endoscopic procedure, such as endoscopic retrograde cholangiopancreatography (ERCP), may be necessary to gain a closer look, relieve the obstruction, and obtain tissue. Ultimately, a biopsy—taking a small sample of the suspicious tissue—is the only definitive way to confirm cancer. The combination of blood tests, imaging, and tissue analysis helps physicians determine the underlying cause of the jaundice.