response
Meaning of response: A word doing two jobs: the body reacting to something, and the disease measurably changing after treatment.
Definition of response
Response is a measurable change in a disease or condition following treatment, most often an improvement such as a tumor shrinking or a symptom clearing. The word is also used more broadly for any reaction the body produces to a stimulus, whether a drug, an allergen or an infection. Which sense applies depends on the context.
How is a treatment response graded?
| Category | What it records |
|---|---|
| Complete | No evidence of the disease remains by the measures used |
| Partial | A defined degree of improvement, short of disappearance |
| Stable | Neither enough improvement nor enough worsening to count as either |
| Progression | The disease has advanced despite treatment |
The boundaries between these are set by written criteria rather than by judgment, and the criteria differ from one disease to another. A complete response in a solid tumor is defined by imaging, while in leukemia it rests on the bone marrow and blood counts. A partial response requires a specified amount of shrinkage, not merely some. An objective response is one demonstrated by measurement rather than by how a person reports feeling, which is what allows results from different centers to be pooled and compared.
What is measured, and when?
Assessment combines symptoms, physical examination, laboratory testing and imaging, weighted according to the condition being followed. Timing matters as much as method, because response is judged at set points rather than continuously, and a treatment can look ineffective if it is assessed too early. Some treatments produce swelling or inflammation before improvement appears, so an apparent increase in size on an early scan does not always mean the disease has grown. For this reason a change is often confirmed on a repeat assessment before being recorded.
What does response mean outside treatment?
In its wider sense the word simply names a reaction. An immune response is the coordinated activity of immune cells against something recognized as foreign. An allergic response is that machinery reacting to a harmless substance. A stress response describes the hormonal and nervous changes that follow a threat. In each of these the word points to what the body does, not to whether a treatment worked, so a response in this sense can be unwanted. Reading it correctly is a matter of noticing what the sentence is about, since a report of no response after treatment and a report of no response to a stimulus mean quite different things.
Used in a sentence
The patient achieved a partial response to treatment based on the follow-up imaging.
Good to know
A complete response is not the same as a cure, since it means no disease is detectable by current methods rather than that none remains, and the word response also carries a separate physiological sense of any reaction the body produces.