stable disease
Tumor response category indicating neither significant shrinkage nor growth of cancer lesions.
Full Definition
Stable disease (SD) is an oncological response classification indicating that target lesions have neither shrunk sufficiently to qualify as partial response nor increased sufficiently to qualify as progressive disease. According to RECIST criteria, stable disease represents less than 30% decrease and less than 20% increase in the sum of longest diameters of target lesions. While not considered an objective response, stable disease can represent clinical benefit, particularly in aggressive malignancies where disease control is therapeutically meaningful. Duration of stable disease is an important endpoint in clinical trials.
Usage
Usage note: Duration of stable disease should always be specified as it affects clinical significance.
In Context
- "Stable disease lasting more than six months was considered clinically meaningful." — Clinical trial protocol
- "The patient maintained stable disease for 14 months before progression." — Case report documentation