Infection as a cause of rapidly increasing pain in cancer patients

Rapid escalation of cancer-related pain is usually assumed to be due to progression of the neoplasm. Occult local infection is a poorly recognized alternative cause. We describe two patients who developed rapidly increasing pain that was determined in each case to be due to occult local infection. These cases suggest that all patients with rapid escalation of chronic cancer pain should undergo an evaluation to identify a cause of changing nociception, and that infection should be considered among the possible diagnoses. Lack of fever or leukocytosis does not exclude local infection, and empirical treatment with antibiotics is sometimes indicated.