complete response
Meaning of complete response: The best result a scan can show, and a statement about the limits of measurement as much as about the cancer.
Definition of complete response
A complete response is an outcome in which every detectable sign of cancer has disappeared after treatment, judged by imaging, laboratory testing and physical examination. It is the strongest category of response reported in cancer care and in clinical trials. Detectable is the operative word, since the finding describes what the available tests can no longer find.
How does it compare with the other response categories?
| Category | What was found at reassessment |
|---|---|
| Complete response | No detectable disease remains by the measures used |
| Partial response | The disease has shrunk substantially but has not gone |
| Stable disease | Little change either way |
| Progressive disease | The disease has grown or new sites have appeared |
These categories are defined by written criteria rather than by impression, and the criteria differ by disease. For a solid tumor, named lesions are measured on imaging and the change compared against the starting measurements, so a partial response means a defined reduction rather than any visible shrinkage. For leukemia the assessment rests on the bone marrow and the blood count instead. Grouping results this way is what allows one treatment to be compared with another, and the proportion of people reaching a given category is reported as a response rate.
Is a complete response the same as a cure?
No, and the distinction is the reason the term exists. Imaging and laboratory tests have a floor below which disease cannot be seen, and a deposit of cancer cells too small to register still counts as no detectable disease. This is why the phrase minimal residual disease is used for cancer cells that sensitive laboratory methods can still find after a complete response has been recorded by conventional measures. Some cancers return after a complete response, sometimes long afterward, which is why monitoring continues rather than stopping at the result.
How does it relate to remission?
The two are close in meaning and are often used interchangeably. Response describes the change produced by a specific treatment and is measured at defined points, which is why it is the language of clinical trials. Remission describes the state of the disease itself and how long that state lasts. Complete remission carries the same caution as complete response: it means the signs and symptoms have gone, not that every cancer cell has.
Also known as
Used in a sentence
Follow-up imaging showed a complete response to the treatment regimen.
Good to know
A complete response records the absence of detectable disease rather than a confirmed cure, since cancer can recur afterward and follow-up assessment continues past the result.