Chemotherapy-Induced Mucositis

Prevention, grading, and evidence-based management of oral and gastrointestinal mucositis in cancer patients

Key Points

• Mucositis — inflammation and ulceration of the oral and gastrointestinal mucosa — affects up to 40% of patients receiving standard chemotherapy and nearly 100% of those undergoing high-dose conditioning for hematopoietic stem cell transplantation.
• The most severely mucosotogenic agents are methotrexate, 5-fluorouracil, capecitabine, cytarabine (high-dose), irinotecan, and anthracyclines; head and neck radiation causes the most severe oral mucositis.
• Oral cryotherapy (ice chips during infusion) is the single most effective and evidence-based prevention for 5-FU bolus and melphalan-based regimens.
• Palifermin (keratinocyte growth factor) is FDA-approved to reduce severe oral mucositis in HSCT patients receiving total body irradiation-based conditioning.
• GI mucositis from irinotecan and 5-FU causes severe diarrhea — "late diarrhea" from irinotecan requires high-dose loperamide (4 mg initially then 2 mg every 2 hours until 12 hours diarrhea-free).
• Oral hygiene — brushing with soft toothbrush, saline/sodium bicarbonate rinses, and avoidance of alcohol-based mouthwashes — remains the cornerstone of mucositis prevention and management.

Pathophysiology and Scope

Chemotherapy-induced mucositis is one of the most debilitating toxicities of cancer treatment — it causes pain, impairs nutrition, requires opioid analgesia, and is a leading reason for unplanned hospitalization and chemotherapy dose reductions. The gastrointestinal mucosa from the mouth to the rectum is among the most rapidly proliferating tissues in the body, with a complete mucosal cell turnover every 5–7 days. This high proliferative rate makes it exquisitely vulnerable to cytotoxic chemotherapy. **The five-phase model of mucositis pathogenesis (Sonis ST):** 1. **Initiation**: DNA damage…

Grading and Clinical Presentation

**NCI CTCAE v5.0 Oral Mucositis Grading:** - **Grade 1**: Asymptomatic or mild symptoms; no intervention required; minor mucosal erythema - **Grade 2**: Moderate pain or ulcers; not interfering with oral intake; modified diet indicated (soft foods) - **Grade 3**: Severe pain; severely limiting oral intake; IV hydration or IV nutrition (TPN) required; hospitalization may be warranted - **Grade 4**: Life-threatening; urgent intervention required (inability to eat or drink; respiratory compromise from oropharyngeal swelling) - **Grade 5**: Death **WHO Oral Mucositis Scale** (also widely used):…

Prevention Strategies

Prevention is far more effective than treatment once mucositis is established. Prophylactic measures should be started before chemotherapy initiation. **1. Oral cryotherapy (ice chips) — strongest Level I evidence:** Patients hold ice chips in their mouth for 30 minutes starting 5 minutes before and continuing throughout the infusion. Cold-induced vasoconstriction reduces mucosal blood flow and limits cytotoxic drug delivery to the oral mucosa. - **Evidence**: multiple RCTs demonstrate 50–60% reduction in severe mucositis with 5-FU bolus regimens and with melphalan-based HSCT conditioning…

Treatment of Established Mucositis

**Oral Mucositis Treatment:** *Pain management:* - **Magic mouthwash** (institution-specific formulations, commonly lidocaine + diphenhydramine + antacid): topical analgesia; onset rapid but short-lived (20–30 minutes); swish and spit every 4–6 hours - **Topical lidocaine 2%**: viscous lidocaine before meals; use with caution (lidocaine can be absorbed systemically through denuded mucosa — limit dose) - **Morphine oral rinse**: 2 mg/mL morphine sulfate solution — swish and spit; emerging evidence for superior analgesia compared to magic mouthwash; MASCC recommends consideration - **Systemic…

mTOR Inhibitor Stomatitis — A Distinct Entity

Stomatitis caused by mTOR inhibitors (everolimus, temsirolimus) is clinically and mechanistically distinct from chemotherapy-induced mucositis and requires different management. **Clinical features:** - Aphthous-like ulcers — discrete, round or oval, with a white/gray center and erythematous halo - Typically on the labial/buccal mucosa and tongue; less commonly on the hard palate and gingiva - Painful but generally less severe than chemotherapy mucositis; rarely progresses to grade 4 - Onset: typically within 2–4 weeks of starting mTOR inhibitor - Incidence: 40–70% of patients on everolimus…