Digestive tract neoplasms

Overview

The most frequent type of cancer is digestive tract neoplasms, which afflict both men and women. Every year, around 28,600 Australians are diagnosed with it, and 39 Australians die as a result of it. The first step toward the most successful treatment of gastrointestinal (GI) cancer is a comprehensive and precise diagnosis.

The clinical, immunohistochemical, and molecular features of the most common digestive tract neoplasms (esophagus, stomach, colorectal) that might impact their biological activity, diagnosis, staging, and therapy are investigated.

Diagnostic Tests

Colonoscopy, endoscopy, biopsy, and imaging are some of the most popular diagnostic tests for gastrointestinal malignancies.

Endoscopy

Endoscopic tests allow us to view inside the body using an equipment called an endoscope, which is a flexible tube with a light and tiny camera connected to it. Endoscopic testing for GI cancer diagnosis may involve the following nonsurgical procedures:

Colonoscopy and sigmoidoscopy: Used to screen for colorectal cancer
Upper GI endoscopy: Examines the lining of the upper part of the gastrointestinal tract, including the esophagus, stomach, and duodenum

Biopsy

During a biopsy, we take a sample of the abnormal tissue so that a pathologist may evaluate it for malignancy. Endoscopic methods are frequently used to acquire a biopsy. Based on these biopsies, we can frequently make conclusions regarding a tumor's activity and develop the best treatment strategy.

Imaging

Diagnostic imaging for GI cancers might include:

Computed tomography (CT) scan: Using an X-ray that takes many pictures
Ultrasound: Using sound waves and their echoes to produce a picture
Magnetic resonance imaging (MRI): Using radio waves and magnets to produce an image
Positron emission tomography (PET) scan: Using radioactive sugar that is injected into the blood and observed with a special camera

Esophageal Cancer (Carcinoma)

The esophagus is the tube that links the mouth, throat, and stomach ("food pipe"). When a person swallows, the muscular wall of the esophagus contracts, assisting in the movement of food down to the stomach. The esophagus can be affected by one of two forms of cancer. Squamous cell carcinoma is more typically found in the upper or intermediate esophagus. Adenocarcinoma develops in the lower esophagus.

Symptoms

In most cases, very tiny tumors do not produce symptoms in their early stages. As the tumor becomes bigger and the esophagus narrows, patients frequently have trouble swallowing. Most people have difficulty swallowing solid things at first, such as meats, breads, or raw vegetables. As the tumor develops, the esophagus narrows, making it difficult to swallow even liquids. Indigestion, heartburn, vomiting, and choking can all be indications of esophageal cancer. Patients may also have coughing and hoarseness of voice. Weight reduction that is not voluntary is also prevalent. Patients may vomit blood in rare cases.

Causes/Risk Factors

In most cases, the doctor will begin by obtaining a thorough history and completing a physical examination. Anemia can be detected by routine lab tests. Endoscopy is a procedure in which a thin flexible-lit tool with a camera at the end is inserted via the mouth into the esophagus. The doctor may see the inner layer of the esophagus using this scope. If necessary, biopsies might be obtained during this process and sent to a pathologist for analysis under a microscope to detect cancer cells.

An esophagram, commonly known as a barium swallow, is a sequence of x-rays of the esophagus that can be performed as a preliminary test in some cases. The patient is advised to swallow a barium solution, which covers the esophagus. Following that, many x-rays are taken to examine for changes in the shape of the esophagus.

A CT scan of the neck, chest, and abdomen, as well as a whole-body PET scan, may aid in determining whether cancer has spread to other organs in the body, allowing the doctor to select the best course of treatment.

Endoscopic ultrasonography is a method that may be used to determine the depth of a tumor as well as the involvement of nearby lymph nodes. This equipment is identical to the endoscope described above, except that it has ultrasound at the tip of the scope. Any questionable lymph nodes can be aspirated using a fine needle under ultrasound supervision.

Screening/Diagnosis

In most cases, the doctor will begin by obtaining a thorough history and completing a physical examination. A barium swallow, commonly known as an esophagram, is a sequence of x-rays of the esophagus. The patient is advised to swallow a barium solution, which covers the esophagus. Following that, many x-rays are taken to examine for changes in the shape of the esophagus.

Endoscopy is a procedure in which a thin flexible lit tool with a camera at the end is inserted via the mouth into the esophagus. The doctor may see the inner layer of the esophagus using this scope. If necessary, biopsies might be obtained during this process and sent to a pathologist for analysis under a microscope to detect cancer cells.

A CT scan of the neck, chest, and abdomen may help establish if the cancer has spread to other organs in the body, allowing the doctor to select the best course of treatment.

Treatment

Depending on the stage of the esophageal cancer, the patient may be subjected to surgery, radiation, and/or chemotherapy. Many individuals with esophageal cancer are treated with a combination of surgery, radiation, and chemotherapy. Some patients with extremely early esophageal cancer may benefit from endoscopic resection without surgery, such as endoscopic mucosal resection or endoscopic submucosal dissection.

When the cancer cannot be entirely treated, alternative techniques to relieve symptoms may be used, such as stretching or dilatation, tube prosthesis (stent), and radiation or laser treatment to diminish the size of the tumor. Doctors are continually researching innovative drugs and therapy procedures in order to enhance treatment results and decrease adverse effects.

Stomach Cancer (Gastric Cancer)

The stomach is a digestive organ that links the esophagus to the small intestine. When food enters the stomach, the muscles of the stomach use a motion called peristalsis to help mix and mash the food. Stomach cancer can begin in any portion of the stomach and spread to other organs such as the small intestines, lymph nodes, liver, pancreas, and colon.

Symptoms

Patients may not have any symptoms in the early stages, and the diagnosis is frequently confirmed after the disease has progressed. The following are the most prevalent symptoms:

Pain or discomfort in the abdomen
Nausea and vomiting
Loss of appetite
Fatigue or weakness
Bleeding (vomiting blood or passing blood in stools)
Weight loss
Early satiety (cannot eat a complete meal)

Causes/Risk Factors

No one knows for certain what causes stomach cancer. Researchers have discovered that certain risk factors are linked to the development of stomach cancer. Those over the age of 55 are at a higher risk of developing stomach cancer. Men are afflicted twice as often as women, and African Americans are more frequently impacted than Caucasians.

Stomach cancer is more frequent in various countries, including Japan, Korea, portions of Eastern Europe, and Latin America. Some research suggests that Helicobacter pylori, a kind of bacterium that causes inflammation and ulcers in the stomach, may be a major risk factor for developing gastric cancer.

According to research, those who have had stomach surgery or who have a disease such as pernicious anemia or gastric atrophy (which results in less than normal production of digestive juices) are at a higher risk of getting gastric cancer. Additionally, there is some evidence that smoking increases the chance of getting stomach cancer.

Screening/Diagnosis

In addition to taking a complete history and performing a physical exam, your doctor may do one or more of the following tests:

Upper GI series - The patient is given a barium solution to consume. Subsequently x-rays of the stomach are obtained. The barium outlines the inside of the stomach, revealing any abnormal spots that might be cancerous. This test is utilized less often than it once was, and patients are now more likely to have endoscopy first.
Endoscopy - An endoscope is a lighted, flexible tube with a camera that is introduced through the mouth into the esophagus and subsequently into the stomach. Sedation is administered prior to the insertion of the endoscope. Biopsies (tissue samples) can be obtained and analyzed under a microscope to test for cancer cells if an abnormal region is discovered.

If cancer is discovered, the doctor may order additional staging tests to evaluate whether or not the disease has spread. A CT scan can help identify whether cancer has progressed to the liver, pancreas, lungs, or other organs around the stomach.

Endoscopic ultrasonography can also be used for gastric cancer staging. Endoscopic ultrasonography can assist detect the depth of the tumor's progress into the stomach wall and the involvement of surrounding organs, as well as any enlarged lymph nodes that may be infiltrated with cancer cells.

Treatment

Treatment plans may differ based on the tumor's size, location, and extent, as well as the patient's general health. Surgery, chemotherapy, and/or radiation therapy are all options for treatment. The most frequent therapy is surgery. The surgeon might remove a portion of the stomach or the complete stomach (gastrectomy). During surgery, lymph nodes around the tumor are usually removed to be examined for cancer cells.

Chemotherapy may be used before surgery to help decrease the tumor and after surgery to help destroy leftover tumor cells, according to researchers. Chemotherapy is administered in cycles that last several weeks depending on the medications employed.

Radiation treatment is the use of high-energy radiation to destroy cancer cells and prevent their growth. Radiation only kills cancer cells in the treated region. Some individuals with extremely early stomach cancer that only affects the superficial layers of the stomach wall may benefit from endoscopic excision of the malignancy without surgery utilizing procedures such as endoscopic mucosal resection or endoscopic submucosal dissection.

Doctors are experimenting with several combinations of surgery, chemotherapy, and radiation therapy to discover which one will be most effective.

Liver Cancer (Hepatocellular Carcinoma)

The liver is one of the biggest organs in the body, and it is positioned in the upper right quadrant of the belly. The liver performs several vital activities, including removing toxins from the blood, metabolizing medications, producing blood proteins, and producing bile, which aids digestion. Hepatocellular carcinoma is a kind of cancer that develops in the liver. It's also referred to as hepatoma or primary liver cancer.

HCC is the world's fifth most frequent cancer. According to recent research, HCC is growing increasingly frequent in the United States. The source of this increase is likely to be chronic hepatitis C, an illness that can lead to HCC. The majority of malignancies identified in the liver in the United States spread or metastasis from other organs. These are not HCC malignancies, as HCC cancers develop in the cells of the liver. Colon, pancreatic, lung, and breast cancer are among the most frequent cancers that spread to the liver.

Symptoms

The most frequent symptom of HCC is abdominal discomfort, which generally occurs when the tumor is quite big or has progressed. In people with cirrhosis, unexplained weight loss or fevers are warning indications. Acute abdominal swelling (ascites), yellow coloring of the eyes and skin (jaundice), or muscular atrophy all point to HCC.

Causes/Risk Factors

Individuals infected with the hepatitis B and/or hepatitis C viruses are at a higher risk of developing HCC. Alcohol-related liver illness is another risk factor for HCC development.

Certain chemicals have been linked to liver cancer, including aflatoxin B1, vinyl chloride, and thorotrast. Aflatoxin is produced by the mold Aspergillus flavus and may be found in foods including peanuts, rice, soybeans, corn, and wheat. Furthermore, thorotrast is no longer utilized in radiologic examinations, and vinyl chloride is a chemical present in plastics.

Hemochromatosis, a disorder characterized by improper iron metabolism, is closely linked to liver cancer. Cirrhosis from any cause, including the hepatitis virus, hemochromatosis, and alpha-1-antitrypsin deficiency, increases the likelihood of developing HCC.

Screening/Diagnosis

Routine blood tests cannot be used to diagnose HCC. A blood test for the tumor marker alpha-fetoprotein (AFP) and radiological imaging are required. In order to detect tiny HCC, some clinicians recommend measuring AFP and imaging every 6 to 12 months in patients with cirrhosis. Sixty percent of HCC patients will have increased AFP levels, whereas the remaining may have normal AFP levels. As a result, a normal AFP level does not rule out HCC.

Ultrasound, CT scan (MRI magnetic resonance imaging), and angiography are all examples of radiological imaging investigations that are highly essential.

If HCC is suspected, an ultrasound scan of the liver is often the first test.
In the United States, a CT scan is a popular test used to diagnose liver tumors. A multi-phase CT scan with oral and IV contrast is the ideal study.
MRI may offer cross-sectional pictures of the body in various planes. MRI can really recreate pictures of the biliary tree as well as the liver's arteries and veins.

Angiography is a test that involves injecting contrast material into a major artery in the groin. The arterial blood flow to the liver is next assessed using X-ray images. If the patient has HCC, the newly generated aberrant tiny blood arteries that feed the tumor create a distinct pattern.

In individuals with a risk factor for HCC and increased AFP, a biopsy may not be necessary. Biopsy can be conducted if the diagnosis of HCC is in doubt or if the clinician believes the biopsy results will influence the course of treatment.

Treatment

Chemotherapy:

This may entail injecting anti-cancer drugs into the body via a vein or chemoembolization. Chemoembolization is a process in which chemotherapy medications are injected directly into the blood arteries that supply the tumor and tiny blood vessels are closed to keep the drug within the tumor. Chemotherapy might relieve symptoms and perhaps reduce tumor growth (in 50% of patients), but it is not curative.

Ablation:

Other treatment options include ablation (tissue destruction) therapy using radiofrequency waves, alcohol injection into the tumor, or proton beam radiation to the tumor site. There is no evidence that one of these therapies is superior to another.

Surgery:

Surgery is only available to individuals who have excellent liver function and tumors that are smaller than 3-5 cm in size and confined to the liver. If the procedure is successful, the patient's five-year survival rate is 30-40%. Many people may experience HCC recurrence in another area of the liver.

Liver Transplantation:

Patients with end-stage liver disease and minor HCC may benefit from liver transplantation. However, there is a serious scarcity of donors in the United States.

Pancreatic Cancer

The pancreas produces pancreatic secretions, which aid in digestion in the small intestines, as well as hormones such as insulin. It is placed in the rear of the abdomen, behind the stomach. The pancreatic duct enters the first segment of the small intestine (called the duodenum) via a nipple-like hole called the ampulla.

Symptoms

Because early pancreatic cancer seldom causes symptoms, it is regarded as the "silent" illness. As the tumor grows in size, the patient may experience one or more of the following symptoms:

Jaundice — If the tumor obstructs the bile ducts (the main bile duct runs via the pancreas), the patient may develop jaundice, a disease in which the skin and eyes get yellow and the urine turns black.
Abdominal discomfort — As the cancer progresses, the patient may experience abdominal pain that radiates to the back. Pain may worsen after eating or laying down.
Nausea
Decreased appetite
Weight loss

Causes/Risk Factors

It is unknown why some people get pancreatic cancer. According to research, there are several risk factors that enhance the likelihood of developing pancreatic cancer. Tobacco use is a risk factor. Alcohol use, a high-fat diet, and chronic pancreatitis may also be risk factors. People who have hereditary pancreatitis are also at a higher risk of developing pancreatic cancer. A family history of pancreatic cancer, as well as some hereditary and genetic disorders, are all crucial risk factors.

Screening/Diagnosis

Aside from obtaining a thorough history and completing a physical examination, the doctor may order endoscopic and radiologic tests such as a CT scan, MRI, or ultrasound. Endoscopic ultrasonography can also be used. This test may aid in the detection of tiny cancers that are less than 2-3 cm in size. In some situations, a biopsy of an aberrant region of the pancreas may be done by introducing a needle into the pancreatic under ultrasonic guidance.

A particular x-ray scan of the pancreatic duct and the common bile duct, known as an endoscopic retrograde cholangiopancreatogram (ERCP), may also be utilized to make the diagnosis. A flexible tube with a light and a camera at the end is introduced via the mouth into the stomach and then the small intestines for this test. Sedation is administered. A dye is then injected into the pancreatic and bile ducts to examine for aberrant filling or tumor occlusion of these channels. Biopsies can be obtained using a brush placed into the bile duct during this operation. After that, the biopsy specimens are analyzed under a microscope for cancer cells.

Treatment

Cancer of the pancreas is only treatable if discovered in its early stages. Treatment options include surgery, radiation, and chemotherapy. If necessary, surgery may be performed to remove all or part of the pancreas and surrounding structures. Radiation treatment can be used to harm cancer cells and stop them from developing. Radiation may be administered after surgery in certain trials to help eliminate any leftover cancer cells.

Chemotherapy will not cure pancreatic cancer, although it may help to halt the tumor's development or enhance the patient's quality of life. Many novel medications are being researched for pancreatic cancer chemotherapy, and individuals with this condition may be able to participate in one of the research studies for pancreatic cancer chemotherapeutic treatment.

In patients with pancreatic cancer, pain management may be difficult. Patients may be given pain medication or referred for a nerve block, which is performed by injecting alcohol into the bundle of nerves (celiac plexus) around the pancreas to reduce pain signals from the pancreatic cancer to the brain.

Gastrointestinal Stromal Cancer

GISTs are the most prevalent mesenchymal tumors of the gastrointestinal (GI) tract, accounting for 80 percent of all such GI tumors and 0.1 to 3 percent of all gastrointestinal malignancies. GISTs are malignant in around 30% of cases. GISTs can be found throughout the GI tract, however they are most typically seen in the stomach (60 percent) or small intestine (20 to 30 %).

GISTs can arise outside of the gastrointestinal tract, most typically in the omentum, mesentery, or retroperitoneum. GISTs were formerly assumed to be smooth muscle tumors; however, advances in immunohistochemistry and the detection of gain-of-function mutations during the last 20 years have led to the recognition of GISTs as a unique entity.

Gastrointestinal stromal tumors are normally (70 percent) benign tumors that develop when genes governing tyrosine kinase expression get mutated, resulting in neoplastic development involving cells from the Cajal interstitial cell lineage. GISTs are most usually seen in the gastrointestinal system, however they can also form outside of the gastrointestinal tract in rare cases.

Subendothelial lesions detected on endoscopy or a contrast-enhancing mass with a smooth border on CT are the most prevalent GIST findings. Lymphatic dissemination is exceedingly rare in malignant GISTs, and these lesions most usually spread hematogenously (most commonly to the liver) or to the peritoneum.

GIST symptoms

Gastrointestinal stromal tumors can appear in a variety of ways. Patients with these tumors most usually appear with gastrointestinal bleeding, which can manifest as an acute bleed with melena or hematochezia, or as persistent bleeding with accompanying anemia and sequelae. GISTs may also show with signs and symptoms of a mass effect generated by the tumor, such as abdominal pain or discomfort, early satiety, abdominal distension, or palpable mass, in addition to gastrointestinal bleeding. GISTs are discovered inadvertently during surgery, imaging, or autopsy in an additional 15% to 30% of patients.

GIST diagnosis

The diagnostic workup will most likely be influenced by the presenting symptoms as well as the anatomic location of gastrointestinal stromal tumors. A history and physical, regardless of the presenting symptoms, should serve as the starting point for the diagnostic work-up in all patients. Contrast-enhanced CT with oral and intravenous (IV) contrast is the best modality for assessing patients who present with an abdominal mass. GISTs will appear as a solid, contrast-enhancing mass with smooth edges on a computed tomography (CT) scan. magnetic resonance imaging (MRI) is an alternate imaging option for individuals who are concerned about radiation exposure or are unable to receive iodinated contrast.

For patients who arrive with gastrointestinal bleeding, endoscopy is the primary method of assessment. GISTs most typically resemble other sub-epithelial lesions (SEL) on the endoscopic exam, with a smooth swelling covered by normal-appearing mucosa. Endoscopic ultrasonography (EUS) has shown to be a valuable technique in distinguishing GISTs from other SELs. A GIST will emerge on EUS as a hypoechoic solid mass originating in the second (muscularis mucosa) or fourth (muscularis propria) layers of the GI tract wall.

The pathologic features of the tissue sample are used to make the final diagnosis of GISTs, which includes both morphologic and immunohistochemical characteristics. Immunohistochemical testing for the presence of KIT should be performed for cellular patterns compatible with GIST on hematoxylin-eosin (H&E) staining to confirm the diagnosis.

A biopsy or surgical excision can be done to collect a tumor sample for pathology. Preoperative tissue biopsy may not be essential for tumors that are easily resectable and do not require preoperative treatment, and surgical pathology can be utilized to confirm the diagnosis of GIST. In this method, the risk of tumor dispersion or bleeding during biopsy is eliminated in these friable tumors. When a biopsy is required to make a diagnosis and/or plan preoperative therapy for tumors that are not easily resectable, EUS with fine-needle aspiration is the procedure of choice (FNA).

Mutational analysis is indicated for all GISTs due to the imparted resistance of some gene mutations to standard of therapy, such as imatinib. It is also suggested that patients with GIST get a CT scan with contrast or an MRI during their examination to assess for metastasis and tumor resectability.

GIST Treatment

The therapy of gastrointestinal stromal tumors, like that of many other gastrointestinal malignancies, is primarily determined by the degree of the illness. The therapy of GISTs smaller than 2 cm in size is still somewhat unclear, however given their lower malignant potential, these tumors may be able to be monitored by endoscopic ultrasonography.

Surgical resection remains the gold standard of therapy for localized, resectable disease larger than 2 cm. Preoperative imatinib can be given to assist reduce tumor burden before resection in patients with locally advanced disease if total surgical resection is regarded to be impossible or may result in mutilation or loss of function. Adjuvant treatment with tyrosine kinase inhibitors, particularly imatinib, for three years is indicated for individuals with high-risk illnesses.

Conclusion

Gastrointestinal (GI) cancer refers to malignancies that affect the digestive tract. Treatments are more successful when cancer is identified at an early stage, which can be difficult. The good news is that adopting a healthier lifestyle can help minimize the chance of developing GI cancer.