HCC remains associated with a high mortality rate, in part related to initial diagnosis commonly at an advanced stage of disease. As with other cancers, outcomes are significanty improved if treatment is initiated earlier in the disease process. Because the vast majority of HCC occurs in people with certain chronic liver diseases, especially those with cirrhosis, liver screening is commonly advocated in this population. Specific screening guidelines continue to evolve over time as evidence of its clinical impact becomes available. In the United States, the most commonly observed guidelines are those published by the American Association for the Study of Liver Diseases (AASLD). The AASLD recommends screening people with cirrhosis with ultrasound every 6 months, with or without measurement of blood levels of tumor marker AFP. Elevated levels of AFP are associated with active HCC disease, although inconsistently reliable. At levels >20 sensitivity is 41-65% and specificity is 80-94%. However, at levels >200 sensitivity is 31, specificity is 99%.

On US, HCC often appears as a small hypoechoic lesion with poorly defined margins and coarse irregular internal echoes. When the tumor grows, it can sometimes appear heterogeneous with fibrosis, fatty change, and calcifications. This heterogeneity can look similar to cirrhosis and the surrounding liver parenchyma. A systematic review found that the sensitivity was 60 percent (95% CI 44-76%) and specificity was 97 percent (95% CI 95-98%) compared with pathologic examination of an explanted or resected liver as the reference standard. The sensitivity increases to 79% with AFP correlation.

There remains controversy as to the most effective screening protocols. For example, while there is data to support decreased mortality related to screening in people with hepatitis B infection, the AASLD notes that “there are no randomized trials [for screening] in Western populations with cirrhosis secondary to chronic hepatitis C or fatty liver disease, and thus there is some controversy surrounding whether surveillance truly leads to a reduction in mortality in this population of patients with cirrhosis.”

Methods of diagnosis in HCC have evolved with the improvement in medical imaging. The evaluation of both asymptomatic patients and those with symptoms of liver disease involves blood testing and imaging evaluation. Although historically a biopsy of the tumor was required to prove the diagnosis, imaging (especially MRI) findings may be conclusive enough to obviate histopathologic confirmation.

Many imaging modalities are used to aid in the diagnosis of primary liver cancer. For HCC these include sonography (ultrasound), computed tomography (CT) and magnetic resonance imaging (MRI). When imaging the liver with ultrasound, a mass greater than 2 cm has more than 95% chance of being HCC. The majority of cholangiocarcimas occur in the hilar region of the liver, and often present as bile duct obstruction. If the cause of obstruction is suspected to be malignant, endoscopic retrograde cholangiopancreatography (ERCP), ultrasound, CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are used.

Tumor markers, chemicals sometimes found in the blood of people with cancer, can be helpful in diagnosing and monitoring the course of liver cancers. High levels of alpha-fetoprotein (AFP) in the blood can be found in many cases of HCC and intrahepatic cholangiocarcinoma. Cholangiocarcinoma can be detected with these commonly used tumor markers: carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125). These tumour markers are found in primary liver cancers, as well as in other cancers and certain other disorders.

Prevention of cancers can be separated into primary, secondary, and tertiary prevention. Primary prevention preemptively reduces exposure to a risk factor for liver cancer. One of the most successful primary liver cancer preventions is vaccination against hepatitis B. Vaccination against the hepatitis C virus is currently unavailable. Other forms of primary prevention are aimed at limiting transmission of these viruses by promoting safe injection practices, screening blood donation products, and screening high-risk asymptomatic individuals. Aflatoxin exposure can be avoided by post-harvest intervention to discourage mold, which has been effective in west Africa. Reducing alcohol abuse, obesity, and diabetes would also reduce rates of liver cancer. Diet control in hemochromatosis could decrease the risk of iron overload, decreasing the risk of cancer.

Secondary prevention includes both cure of the agent involved in the formation of cancer (carcinogenesis) and the prevention of carcinogenesis if this is not possible. Cure of virus-infected individuals is not possible, but treatment with antiviral drugs such as interferon can decrease the risk of liver cancer. Chlorophyllin may have potential in reducing the effects of aflatoxin.

Tertiary prevention includes treatments to prevent the recurrence of liver cancer. These include the use of chemotherapy drugs and antiviral drugs.

There are no specific blood tests that can diagnose cholangiocarcinoma by themselves. Serum levels of carcinoembryonic antigen (CEA) and CA19-9 are often elevated, but are not sensitive or specific enough to be used as a general screening tool. However, they may be useful in conjunction with imaging methods in supporting a suspected diagnosis of cholangiocarcinoma.

Ultrasound of the liver and biliary tree is often used as the initial imaging modality in patients with suspected obstructive jaundice. Ultrasound can identify obstruction and ductal dilatation and, in some cases, may be sufficient to diagnose cholangiocarcinoma. Computed tomography (CT) scanning may also play an important role in the diagnosis of cholangiocarcinoma.

Apart from not smoking, the American Cancer Society recommends keeping a healthy weight, and increasing consumption of fruits, vegetables, and whole grains, while decreasing consumption of red and processed meat, although there is no consistent evidence this will prevent or reduce pancreatic cancer specifically. A 2014 review of research concluded that there was evidence that consumption of citrus fruits and curcumin reduced risk of pancreatic cancer, while there was possibly a beneficial effect from whole grains, folate, selenium, and non-fried fish.

In the general population, screening of large groups is not currently considered effective, although newer techniques, and the screening of tightly targeted groups, are being evaluated. Nevertheless, regular screening with endoscopic ultrasound and MRI/CT imaging is recommended for those at high risk from inherited genetics.

The 2010 WHO classification of tumors of the digestive system grades all the pancreatic neuroendocrine tumors (PanNETs) into three categories, based on their degree of cellular differentiation (from "NET G1" through to the poorly differentiated "NET G3"). The U.S. National Comprehensive Cancer Network recommends use of the same AJCC-UICC staging system as pancreatic adenocarcinoma. Using this scheme, the stage-by-stage outcomes for PanNETs are dissimilar to those of the exocrine cancers. A different TNM system for PanNETs has been proposed by the European Neuroendocrine Tumor Society.

Upon discovery of a liver tumor, the main issue in the workup is to determine whether the tumor is benign or malignant. Many imaging modalities are used to aid in the diagnosis of malignant liver tumors. For the most common of these, hepatocellular carcinoma (HCC), these include sonography (ultrasound), computed tomography (CT) and magnetic resonance imaging (MRI). When imaging the liver with ultrasound, a mass greater than 2 cm has more than 95% chance of being HCC. The majority of cholangiocarcimas occur in the hilar region of the liver, and often present as bile duct obstruction. If the cause of obstruction is suspected to be malignant, endoscopic retrograde cholangiopancreatography (ERCP), ultrasound, CT, MRI and magnetic resonance cholangiopancreatography (MRCP) are used.

Tumor markers, chemicals sometimes found in the blood of people with cancer, can be helpful in diagnosing and monitoring the course of liver cancers. High levels of alpha-fetoprotein (AFP) in the blood can be found in many cases of HCC and intrahepatic cholangiocarcinoma. Cholangiocarcinoma can be detected with these commonly used tumor markers: carbohydrate antigen 19-9 (CA 19-9), carcinoembryonic antigen (CEA) and cancer antigen 125 (CA125). These tumour markers are found in primary liver cancers, as well as in other cancers and certain other disorders..

Medical imaging techniques such as X-rays, ultrasound, computed tomography (CT), and magnetic resonance imaging (MRI) are often used in evaluating animals with suspected liver tumors. Ultrasound-guided fine-needle aspiration or needle-core biopsy of liver masses are useful diagnostic tools that are minimally invasive to obtain samples for histopathological analysis.

Surgical treatment is recommended for cats and dogs diagnosed with primary liver tumors but not metastasis to the liver. There are not many treatment options for animals who have multiple liver lobes affected.

Early diagnosis is not generally possible. People at high risk, such as women or Native Americans with gallstones, are evaluated closely. Transabdominal ultrasound, CT scan, endoscopic ultrasound, MRI, and MR cholangio-pancreatography (MRCP) can be used for diagnosis. A biopsy is the only certain way to tell whether the tumorous growth is malignant or not.

Ultrasonography of liver tumors involves two stages: detection and characterization. Tumor detection is based on the performance of the method and should include morphometric information (three axes dimensions, volume) and topographic information (number, location specifying liver segment and lobe/lobes). The specification of these data is important for staging liver tumors and prognosis. Tumor characterization is a complex process based on a sum of criteria leading towards tumor nature definition. Often, other diagnostic procedures, especially interventional ones are no longer necessary. Tumor characterization using the ultrasound method will be based on the following elements: consistency (solid, liquid, mixed), echogenicity, structure appearance (homogeneous or heterogeneous), delineation from adjacent liver parenchyma (capsular, imprecise), elasticity, posterior acoustic enhancement effect, the relation with neighboring organs or structures (displacement, invasion), vasculature (presence and characteristics on Doppler ultrasonography and contrast-enhanced ultrasound (CEUS).

Xanthogranulomatous cholecystitis (XGC) is a rare form of gallbladder disease which mimics gallbladder cancer although it is not cancerous. It was first discovered and reported in the medical literature in 1976 by J.J. McCoy, Jr., and colleagues.

The most common method of testing for hepatoblastoma is a blood test checking the alpha-fetoprotein level. Alpha-fetoprotein (AFP) is used as a biomarker to help determine the presence of liver cancer in children. At birth, infants have relatively high levels of AFP, which fall to normal adult levels by the first year of life. The normal level for AFP in children has been reported as lower than 50 nanograms per milliliter (ng/ml) and 10 ng/ml. An AFP level greater than 500 (ng/ml) is a significant indicator of hepatoblastoma. AFP is also used as an indicator of treatment success. If treatments are successful in removing the cancer, the AFP level is expected to return to normal.

Screens for gastric cancer using photofluorography due to the high incidence there.

Treatment can consist of surgery (hepatectomy), chemotherapy and/or therapies specifically aimed at the liver like radiofrequency ablation, transcatheter arterial chemoembolization, selective internal radiation therapy and irreversible electroporation. For most patients no effective treatment exists because both lobes are usually involved, making surgical resection impossible. Younger patients with metastases from colorectal cancer confined to one lobe of the liver and up to 4 in number may be treated by partial hepatectomy. In selected cases, chemotherapy may be given systemically or via hepatic artery.

In some tumors, notably those arising from the colon and rectum, apparently solitary metastases

or metastases to one or other lobes may be resected. A careful search for other metastases is required, including local recurrence of the original primary tumor (e.g., via colonoscopy) and dissemination elsewhere (e.g., via CT of the thorax). 5 year survival rates of 30-40% have been reported following resection.

The U.S. Preventive Services Task Force (USPSTF) issues recommendations for various cancers:

- Strongly recommends cervical cancer screening in women who are sexually active and have a cervix at least until the age of 65.

- Recommend that Americans be screened for colorectal cancer via fecal occult blood testing, sigmoidoscopy, or colonoscopy starting at age 50 until age 75.

- Evidence is insufficient to recommend for or against screening for skin cancer, oral cancer, lung cancer, or prostate cancer in men under 75.

- Routine screening is not recommended for bladder cancer, testicular cancer, ovarian cancer, pancreatic cancer, or prostate cancer.

- Recommends mammography for breast cancer screening every two years from ages 50–74, but does not recommend either breast self-examination or clinical breast examination. A 2013 Cochrane review concluded that breast cancer screening by mammography had no effect in reducing mortality because of overdiagnosis and overtreatment.

In FHCC, plasma neurotensin and serum vitamin B12 binding globulin are commonly increased and are useful in monitoring the disease and detecting recurrence.

FHCC has a high resectability rate, i.e. it can often be surgically removed. Liver resection is the optimal treatment and may need to be performed more than once, since this disease has a very high recurrence rate. Due to such recurrence, periodic follow-up medical imaging (CT or MRI) is necessary.

As the tumor is quite rare, there is no standard chemotherapy regimen. Radiotherapy has been used but data is limited concerning its use.

The survival rate for fibrolamellar HCC largely depends on whether (and to what degree) the cancer has metastasized, i.e. spread to the lymph nodes or other organs. Distant spread (metastases), significantly reduces the median survival rate. Five year survival rates vary between 40-90%.

A number of liver function tests (LFTs) are available to test the proper function of the liver. These test for the presence of enzymes in blood that are normally most abundant in liver tissue, metabolites or products. serum proteins, serum albumin, serum globulin,

alanine transaminase, aspartate transaminase, prothrombin time, partial thromboplastin time.

Imaging tests such as transient elastography, ultrasound and magnetic resonance imaging can be used to examine the liver tissue and the bile ducts. Liver biopsy can be performed to examine liver tissue to distinguish between various conditions; tests such as elastography may reduce the need for biopsy in some situations.

Due to lack of symptoms, until the tumor is sizable, this form of cancer is often advanced when diagnosed. Symptoms include vague abdominal pain, nausea, abdominal fullness, malaise and weight loss. They may also include a palpable liver mass. Other presentations include jaundice, ascites, fulminant liver failure, encephalopathy, gynecomastia (males only), thrombophlebitis of the lower limbs, recurrent deep vein thrombosis, anemia and hypoglycemia.

The usual markers for liver disease - aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase - are often normal or only slightly elevated. FHCC often does not produce alpha fetoprotein (AFP), a widely used marker for conventional hepatocellular carcinoma. It is associated with elevated neurotensin levels.

Diagnosis is normally made by imaging (ultrasound, CT or MRI) and biopsy

Anti-viral medications are available to treat infections such as hepatitis B. Other conditions may be managed by slowing down disease progression, for example:

- By using steroid-based drugs in autoimmune hepatitis.

- Regularly removing a quantity of blood from a vein (venesection) in the iron overload condition, hemochromatosis.

- Wilson’s disease, a condition where copper builds up in the body, can be managed with drugs which bind copper allowing it to be passed from your body in urine.

- In cholestatic liver disease, (where the flow of bile is affected due to cystic fibrosis) a medication called ursodeoxycholic acid (URSO, also referred to as UDCA) may be given.

Surgical removal of the tumor, adjuvant chemotherapy prior to tumor removal, and liver transplantation have been used to treat these cancers. Primary liver transplantation provides high, long term, disease-free survival rate in the range of 80%, in cases of complete tumor removal and adjuvant chemotherapy survival rates approach 100%. The presence of metastases is the strongest predictor of a poor prognosis.

As outlined above, there is no recommended alcohol intake with respect to cancer risk alone as it varies with each individual cancer. See Recommended maximum intake of alcoholic beverages for a list of governments' guidances on alcohol intake which, for a healthy man, range from 140–280g per week.

One meta-analysis suggests that risks of cancers may start below the recommended levels. "Risk increased significantly for drinkers, compared with non-drinkers, beginning at an intake of 25 g (< 2 standard drinks) per day for the following: cancers of the oral cavity and pharynx (relative risk, RR, 1.9), esophagus (RR 1.4), larynx (RR 1.4), breast (RR 1.3), liver (RR 1.2), colon (RR 1.1), and rectum (RR 1.1)"

World Cancer Research Fund recommends that people aim to limit consumption to two drinks a day for a man and one for a woman. It defines a "drink" as containing about 10–15 grams of ethanol.

A liver metastasis is a malignant tumor in the liver that has spread from another organ affected by cancer. The liver is a common site for metastatic disease because of its rich, dual blood supply (the liver receives blood via the hepatic artery and portal vein). Metastatic tumors in the liver are 20 times more common than primary tumors. In 50% of all cases the primary tumor is of the gastrointestinal tract, other common sites include the breast, ovaries, bronchus and kidney.

Tumor emboli entering the sinusoids through the liver blood supply appear to be physically obstructed by the Kupffer cells, but if tumor emboli are larger, they tend to become lodged in the portal venous branches.