What is gallbladder cancer
Gallbladder cancer usually does not cause signs or symptoms until later in the course of the disease, when the tumor is large. If the cancer is detected at an earlier stage, treatment has a better chance of cure. To understand this cancer, it is helpful to know about the gallbladder and how it works.
The gallbladder concentrates and stores bile, a fluid produced in the liver that helps digest fats in food as it passes through the small intestine. When food is being digested, the gallbladder sends bile through a small tube called the cystic duct. The gallbladder is a small pouch located just below the liver. Bile helps digest fats, but the gallbladder itself is not essential. Its removal in a healthy individual does not normally cause health or digestion problems.
Gallbladder cancer subtypes
Gallbladder cancers are rare and almost all are adenocarcinomas, but there are other types that are even less common. The subtypes of this disease, therefore, are:
- Adenocarcinoma – starts in gland-like cells that line many surfaces of the body, including the inside of the digestive system;
- Papillary adenocarcinoma – also called papillary cancer, is a rare type of adenocarcinoma of the gallbladder, with a better prognosis than most other types of adenocarcinomas of the gallbladder. The cells in these cancers are organized into finger-like projections. In general, papillary cancers are less likely to spread to the liver or nearby lymph nodes;
- Adenosquamous carcinoma;
- Squamous cell carcinoma;
Symptoms and signs of gallbladder cancer
The signs and symptoms of gallbladder cancer usually only manifest when the disease is already in an advanced stage, but in some cases they can appear at an earlier stage, when treatment is most effective. Some of the most common symptoms of gallbladder cancer are:
- Abdominal pain (usually in the upper right part of the abdomen);
- Nausea and vomiting;
- Jaundice (yellowing of the skin and whites of the eyes);
- Lumps in the abdomen.
Other less common symptoms include:
- Loss of appetite;
- Weight loss for no apparent reason;
- Intense itching;
- Light stools;
- Dark urine.
Diagnosis of gallbladder cancer
Some gallbladder cancers are found after the organ is removed because of gallstones or to treat chronic inflammation. Most gallbladder cancers, however, go undetected until a person seeks help because they have symptoms.
At the clinic appointment, the doctor will examine the abdomen, check the color of the skin and eyes, as well as check the lymph nodes for swelling. If symptoms and/or physical examination suggest gallbladder cancer, tests will be ordered. This may include lab tests, imaging and other procedures.
Discover the main ones below:
- Liver and gallbladder function tests – lab tests may be done to find out the amount of bilirubin in the blood, as problems with the gallbladder, bile ducts, or liver can raise the level of this substance. Tests for albumin, liver enzymes (alkaline phosphatase, AST, ALT and GGT) and other specific substances may also be ordered;
- Tumor markers – are substances produced by cancer cells that can be found in the blood. People with gallbladder cancer may have elevated levels of markers called CEA and CA 19-9 in their blood. These markers are not specific for gallbladder cancer – that is, other types of cancer or even some other health conditions can also increase them;
- Imaging tests – CT, MRI or ultrasound may be done for a number of reasons: to look for areas with suspected cancer, to help guide the needle to take samples and perform a biopsy, to check if and to what extent cancer spread and to define the best treatment;
- Ultrasound – This is usually the first imaging test done in people who have symptoms such as jaundice or pain in the upper right part of the abdomen. It’s easy to do and doesn’t use radiation. It can also be used to guide a needle to the suspicious area or lymph node so that cells can be removed and examined under a microscope. This is called an ultrasound-guided needle biopsy;
- Endoscopic or laparoscopic ultrasound – the doctor places the ultrasound transducer inside the body and close to the gallbladder – this provides more detailed images than a standard ultrasound. The transducer is at the end of a thin, lighted tube that contains a camera; the tube is passed through the mouth, stomach and near the gallbladder (endoscopic ultrasound) or through a small surgical cut in the belly (laparoscopic ultrasound). The test helps to see if and how far the cancer may have spread through the gallbladder wall;
- Computed tomography (CT) scan – can be used to help diagnose gallbladder cancer by showing tumors in the area, and is also helpful in staging. It may show the organs near the gallbladder (especially the liver), as well as the lymph nodes and distant organs to which the cancer may have spread. A CT scan called CT angiography can be used to look at blood vessels near the gallbladder, helping to confirm whether surgery is an option. In the biopsy, the CT scan helps guide the needle to the tumor mass to remove part of the tissue for analysis;
- Magnetic resonance imaging (MRI) – shows detailed images of the soft tissues of the body. A contrast material called gadolinium can be injected into a vein before the exam to see even better the details;
- Cholangiography – an imaging test that examines the bile ducts to see if they are blocked, narrowed, or dilated (widened). A tumor could be blocking a duct. The exam also helps in planning the surgery;
- Angiography – X-ray test used to look at blood vessels. A thin plastic tube (catheter) is inserted into an artery and a small amount of dye is injected to outline the blood vessels. Then x-rays are taken. Images show whether blood flow to an area is blocked or affected by a tumor, as well as any abnormal blood vessels in the area, helping to plan surgery. Angiography can also be done with a CT scan (tomographic angiography) or an MRI (magnetic resonance angiography);
- Laparoscopy – the doctor places a thin tube with a light and a small video camera at the end (laparoscopic) into a small incision (cut) in the front of the abdomen to look at the gallbladder, liver, and other nearby organs and tissues. If necessary, doctors may also place special instruments in the incisions to take biopsy samples for testing;
- Biopsy – During a biopsy, a doctor removes a sample of tissue to be examined under a microscope for cancer cells. In most types of cancer, a biopsy is needed to make the diagnosis, but one is not always done before surgery to remove a tumor from the gallbladder because there is a risk that manipulating the tumor with the needle will cause the cancer cells to spread.
If imaging tests show a gallbladder tumor and there are no clear signs that it has spread, the doctor may decide to proceed directly to surgery and treat the tumor as a gallbladder cancer.
The main treatment is surgery. There are two general types of surgery for gallbladder cancer:
- Potentially curative surgery (resectable disease) – done when imaging tests or results from previous surgeries show that there is a good chance the surgeon can remove all of the cancer;
- Palliative surgery – done to relieve pain symptoms or treat (or even prevent) complications such as blockage of the bile ducts. This type of surgery is done when the tumor is too widespread to be removed completely and does not cure the cancer, but it can help the patient feel better and live longer.
In addition to surgery, radiation therapy can be used, usually after surgery, to kill any cancer cells left behind (adjuvant therapy), or as part of treatment for advanced cancers that have spread widely throughout the body and cannot be removed. It is also used as palliative therapy, relieving symptoms of very advanced cancer.
Some side effects of radiation therapy are:
- Skin problems similar to sunburn (redness, blisters and scaling on the treated area);
- Nausea and vomiting;
- Tiredness (fatigue);
- Liver damage.
Chemotherapy is another type of treatment for gallbladder cancer. It can be oral or intravenous, and can be given with the aim of curing the patient (after surgery with complete removal of the tumor) or just to control the disease (when it is not possible to surgically remove the entire tumor). Rarely, chemotherapy may be given along with radiation therapy to increase its effectiveness.
Knowing the risk factors for the development of gallbladder cancer can be a way to prevent it – at least in relation to preventable factors, such as smoking. Factors that cannot be changed, such as family history or the presence of a specific health condition, should be monitored to minimize the risk of diagnosing cancer only at an advanced stage.
Regarding gallbladder cancer, its development may be related in some way to chronic inflammation (long-lasting irritation and swelling) in the gallbladder. There are also risk factors:
- Gallstones – are the most common risk factor for this cancer. Gallstones are collections of cholesterol and other substances that form in the gallbladder and can cause chronic inflammation. Up to 4 in five people with gallbladder cancer have gallstones when they are diagnosed;
- Porcelain gallbladder – condition in which the gallbladder wall becomes covered with calcium deposits. It sometimes occurs after long-term inflammation of the gallbladder (cholecystitis), which can be caused by gallstones. People with this condition have a higher risk of developing gallbladder cancer, possibly because both conditions may be related to inflammation;
- Gender – Gallbladder cancer occurs more in women than in men. Gallstones and gallbladder inflammation are important risk factors for gallbladder cancer and are also much more common in women than men;
- Obesity – patients with gallbladder cancer are more often obese or overweight than people without this disease. Obesity is also a risk factor for gallstones, which may help explain this link;
- Age – Gallbladder cancer is mostly seen in older people, but younger people can develop it too. The average age of people when they are diagnosed is 72;
- Gallbladder polyps – is a “nodule” that protrudes from the surface of the inner wall of the gallbladder. Some polyps are formed by cholesterol deposits in the gallbladder wall, others can be small tumors (cancer or not) or can be caused by inflammation. Polyps larger than 1 centimeter are more likely to be cancer. Because of this, doctors often recommend removing the gallbladder in patients with polyps this size or larger;
- Exposure to chemicals used in the rubber and textile industries;
- Exposure to nitrosamines.