Chemotherapy is a systemic treatment designed to attack cancer by targeting cells that divide rapidly. A stomach ulcer, also known as a peptic ulcer, is a painful sore that develops in the lining of the stomach or the first part of the small intestine (the duodenum). Because chemotherapy agents do not distinguish between malignant and healthy cells with a fast turnover rate, they can damage the digestive tract lining. Therefore, chemotherapy can directly cause severe irritation, inflammation (gastritis), or conditions that lead to the formation of true stomach ulcers.
The Link Between Chemotherapy and Stomach Damage
The underlying issue connecting chemotherapy to stomach damage is mucositis, the inflammation and breakdown of the mucosal lining that protects the entire gastrointestinal (GI) tract. The cells lining the stomach and intestines are rapidly dividing, making them a primary, unintentional target for chemotherapy drugs. When these cells are damaged, the stomach’s protective barrier is compromised, leading to generalized inflammation known as gastritis.
This damage can progress to frank ulceration, the formation of a deep, open sore. A true peptic ulcer occurs when the damaged mucosal layer can no longer protect the underlying tissue from the stomach’s acid and digestive enzymes. While generalized gastritis is a common side effect of chemotherapy, a peptic ulcer is a less frequent but more severe outcome.
The risk of developing a true ulcer is increased when chemotherapy damage is combined with other factors. A pre-existing Helicobacter pylori (H. pylori) infection makes the compromised stomach lining more vulnerable to acid damage. Similarly, non-steroidal anti-inflammatory drugs (NSAIDs) suppress the production of protective mucus in the stomach. This synergy between chemotherapy damage and these risk factors can accelerate the progression from irritation to a painful ulcer.
Symptoms of Gastric Ulcers and Related Conditions
Recognizing the signs of gastric distress is important, as mild inflammation can quickly worsen. The hallmark symptom of a gastric ulcer is a burning pain in the upper abdomen, often described as gnawing or aching. This discomfort is typically felt between meals or when the stomach is empty, and it may also wake a person up at night. The pain may be temporarily relieved by eating or taking an antacid, as the food or medication neutralizes the acid irritating the sore.
Beyond localized pain, patients may experience nausea, vomiting, and a loss of appetite, which are common symptoms accompanying both gastritis and peptic ulcers. Persistent vomiting, especially if it contains visible blood or a dark, coffee-ground-like material (hematemesis), is an urgent warning sign of a bleeding ulcer.
A serious indication of internal bleeding is a change in stool appearance. Stools that are black and tarry, known as melena, signify that blood has been digested as it passed through the GI tract. Any sign of bleeding requires immediate medical attention, as the ulcer may be actively hemorrhaging.
Managing and Preventing Gastrointestinal Toxicity
Proactive strategies are employed to manage and prevent gastrointestinal toxicity associated with chemotherapy. Medical professionals often prescribe medications that reduce stomach acid to minimize irritation to the damaged lining. Proton pump inhibitors (PPIs) and H2 blockers are commonly used acid-suppressing agents. If an ulcer is present, a medication like sucralfate may be used, as it forms a protective coating over the ulcer surface, shielding it from further acid damage.
Patients can also reduce the burden on their digestive system during treatment. Modifying the diet to include soft, bland foods helps prevent mechanical irritation of the stomach lining. Staying hydrated and avoiding spicy, acidic, or very hot foods are effective self-care measures.
A major preventive step is the strict avoidance of substances known to aggravate the stomach lining. This includes all NSAIDs, which increase the risk of ulcer formation and bleeding by interfering with the stomach’s protective mechanisms. Limiting or eliminating tobacco and alcohol is also important, as both increase stomach acid production and impair healing.