Remission = a patient's cancer is undetectable by current methods of detection. A patient can be in remission after a diagnostic surgery, during chemotherapy, or whenever tests show no evidence of active disease.
Cure = a patient's cancer has been in constant remission long enough that the patient's chance of developing that same cancer again is no greater than if the patient had never had cancer.
I was surprised by the introductory comments about our perception of relapse. Mukherjee describes how when a patient's cancer goes into remission "we genuinely begin to believe that the disappearance is real, or even permanent, even though statistical reasoning might suggest the opposite...Cancer's 'relapse' thus implies a belief that the disease was once truly dead."
I'm not sure who he meant by "we," but all healthcare professionals and, I venture to say, most cancer survivors believe patients in remission may harbor undetectable residual cancer. And that relapse reflects growth of these cells to the level of detection.
This explains why patients with certain types of cancer receive so-called adjuvant chemotherapy after primary treatment puts their cancer into remission. The presumption is that the adjuvant treatment "mops up" and kills any undetectable cancer cells that may have persisted. Successful adjuvant therapy prevents relapse.
In my next post, I'll discuss what's new in tackling relapse.