Gastrointestinal (GI) cancer appertains to a group of cancers that affect the digestive system, which includes the oesophagus, stomach, liver, pancreas, intestines, and rectum. Despite their differences, all of these cancers start in organs that are necessary for digestion and nutrient absorption.
There are distinct risk factors, symptoms, and treatment options for each type of gastrointestinal cancer, and survival rates can become significantly better by early detection. In this article, we will explore Gastrointestinal Cancer, covering its types, symptoms, risk factors, and treatment options to provide an in-depth understanding of this disease.
Types of Gastrointestinal Cancers
The types of Gastrointestinal Cancer include:
Esophageal Cancer
Esophageal cancer begins in the lining of the oesophagus—a muscular tube responsible for moving food from the throat to the stomach. Adenocarcinoma, which originates in cells that secrete mucus, and squamous cell carcinoma, which starts in the flat cells lining the oesophagus, are the two main varieties. Alcohol and tobacco use, obesity, chronic acid reflux disease (GERD), and specific eating patterns are risk factors for oesophagal cancer.
Gastric (Stomach) Cancer
Stomach cancer, or gastric cancer, typically begins in the mucus-producing cells of the stomach and is referred to as adenocarcinoma. Early symptoms are often subtle, which makes early detection difficult. Risk factors for gastric cancer include smoking, Helicobacter pylori infection, diets high in salt and preserved foods, and a family history of gastric cancer.
Colorectal Cancer
Colorectal cancer infects the colon or rectum and is one of the most common gastrointestinal cancers worldwide. It often begins as benign polyps in the colon lining that may turn cancerous over time.
Risk factors include age, a sedentary lifestyle, diets low on fibre and high in red or processed meats, obesity, smoking, and genetic predispositions. Screening methods, like colonoscopies, are effective in early detection and prevention by removing precancerous polyps.
Pancreatic Cancer
Pancreatic cancer typically arises in the exocrine cells of the pancreas responsible for enzyme production. Known for its aggressive nature, pancreatic cancer often presents with few symptoms until it is advanced, leading to a high mortality rate. Risk factors include smoking, chronic pancreatitis, obesity, and a family history of pancreatic cancer.
Liver Cancer
Liver cancer, or hepatocellular carcinoma, manifests in the liver and is often linked to chronic liver conditions, such as cirrhosis, hepatitis B or C infections, and fatty liver disease. Additional risk factors include alcohol abuse, obesity, and exposure to certain toxins like aflatoxins.
Small Intestine Cancer
The cells lining the small intestine can develop small intestinal cancer, though this is uncommon. Depending on the cell of origin, this type of cancer is typically categorised as either adenocarcinoma, lymphoma, sarcoma, or carcinoid tumour. Inflammatory bowel disease (IBD), genetic disorders, and a diet heavy in red meat are risk factors.
Symptoms of Gastrointestinal Cancers
Symptoms of gastrointestinal cancers vary based on the location and progression of the tumour. Common symptoms include:
Unintentional weight loss
A frequent symptom across many types of cancer, significant and unexplained weight loss is generally an early indicator. It can occur as the body uses more energy to fight the disease or due to loss of appetite associated with the illness.
Abdominal pain
Pain may be localised or widespread depending on the affected organ. It can also increase in intensity over time or present as a persistent ache, often mistaken for common digestive issues.
Change in bowel habits
Diarrhoea, constipation, or any changes in stool consistency or frequency, particularly in colorectal cancer. Blood in the stool, changes in colour, or an unusual odour may also be warning signs of gastrointestinal cancer.
Difficulty swallowing
Dysphagia is usually one of the first signs of gastric and oesophagal cancers. Patients may feel as though food is stuck in their throat or experience pain while swallowing.
Nausea and vomiting
Often experienced in cancers affecting the upper digestive tract. Persistent nausea, with or without vomiting, can also lead to dehydration and malnutrition over time.
Loss of appetite
Patients with pancreatic and stomach cancers often experience feelings of fullness even after consuming small amounts of food. It may have an impact on general health by accelerating weight loss and malnutrition.
Fatigue and anaemia
These can be caused by internal bleeding, especially in cancers affecting the stomach or intestines. Anaemia due to blood loss may cause pale skin, weakness, and a reduced ability to concentrate or perform daily activities.
Causes
Several risk factors have been identified for gastrointestinal cancers:
Diet and Lifestyle
High consumption of red and processed meats, low fibre intake, and diets high in salt and smoked foods are linked to higher risks. Smoking and alcohol consumption are also notable risk factors for oesophagal, stomach, and liver cancers.
Obesity
Increased body weight has been linked to many types of gastrointestinal cancers, particularly colorectal, pancreatic, and liver cancers.
Chronic Inflammation and Infections
Chronic infections, such as Helicobacter pylori (stomach cancer), hepatitis B and C (liver cancer), and inflammatory bowel disease (colorectal cancer), contribute to chronic inflammation and increase cancer risk.
Genetic Predispositions and Hereditary Syndromes
Some gastrointestinal cancers are linked to genetic mutations and hereditary conditions. Examples include Lynch syndrome and familial adenomatous polyposis (FAP), which are related to colorectal cancer, and BRCA1 and BRCA2 gene mutations, responsible for increasing the risk of pancreatic cancer.
Age and Gender
Gastrointestinal cancers are more common in individuals over the age of 50. Some types, such as stomach and oesophageal cancer, are more prevalent in males.
Treatment Options for Gastrointestinal Cancers
The treatment for gastrointestinal cancers varies based on the cancer type, stage, patient health, and other individual factors. Common treatments include:
Surgery
Surgically removing the tumour and nearby affected tissues is a standard approach for localised cancers, especially for stomach, colorectal, and liver cancers. In some cases, parts of the affected organ may be removed to reduce the risk of cancer recurrence.
Radiation Therapy
High-energy radiation is used to eliminate cancer cells or shrink tumours. Radiation is commonly blended with other treatments, especially for oesophagal and rectal cancers, and can help alleviate symptoms in advanced stages of cancer.
Chemotherapy
Chemotherapy drugs are administered to destroy or inhibit the growth of cancer cells. It is often used for gastrointestinal cancers that have spread or in combination with surgery and radiation to help prevent recurrence and improve survival rates.
Targeted Therapy and Immunotherapy
Targeted therapy drugs focus on specific molecules involved in cancer growth, and immunotherapy harnesses the body’s immune system to target cancer cells. These are promising approaches for cancers like gastric, liver, and colorectal cancers with specific genetic mutations, offering more personalised and potentially less toxic treatment options.
Conclusion
In conclusion, the term “gastrointestinal cancer” refers to the wide range of cancers that impact the digestive system, each with its unique characteristics, risk factors, and treatment challenges.
Early detection through lifestyle modifications, regular screenings, and awareness of family history can greatly improve outcomes, as many GI cancers are treatable in their initial stages. Advances in treatment, including targeted therapies and immunotherapies, offer hope for more effective, personalised care.
By understanding the symptoms, causes, and prevention strategies, individuals can take preventive measures to reduce their risks and improve overall digestive health, contributing to better management and outcomes for those affected by gastrointestinal cancers.
