Standard criteria are used to describe a tumor's response to a therapeutic intervention. This can aid in the communication of findings and to help determine the next steps to take. The criteria apply to chemo-, radiation and immunologic therapy.


Measurements of tumor burden:

(1) diameter of one or more selected lesions

(2) volume of one or more lesions

(3) levels of serum markers



(1) Determine the tumor burden at baseline before therapy.

(2) Determine the tumor burden 4 weeks after therapy.



disappearance of all evidence of tumor

complete remission

decrease in total size of measured lesions >= 50%

partial response

decrease in total size of measured lesions 25-49%

minor response

no significant change in size and no new lesions

stable disease

increase >= 25% in one or more measurable lesions

progressive disease

appearance of new lesions

progressive disease



• A change in tumor size with a < 25% increase or decrease would be classed as stable disease.



• Since some therapies can be extended out to several days or weeks, the time at which to measure response needs to be standardized. Usually it is based on completion of a course.

• These criteria work when all of the tumor foci behave similarly (all regress, all are stable or all progress). If some foci enlarge and some regress, there may be some confusion.


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