I just had my 4 month MRI in the phase II clinical trial of Cabozantinib, which I started in August. My tumors are still stable, although they’ve grown by a small amount. There were no new lesions or tumors found. My doctor said the growth was small, measured in millimeters, and was probably in the range of 5%. Under the RECIST criteria (described below), this counts as stable disease. I will continue on this clinical trial until my tumors are no longer stable. I am happy with this result and that my side effects from the drug are better now that I am on a lower dose.
I find the measurement criteria quite interesting. Most people believe that stable disease means the tumors have not grown at all since the last MRI/CT scan. In fact, these criteria say that the tumors can grow 20% from when the treatment started before being defined as progressive disease. This is assuming that there are no new tumors.
Below is a description of how solid tumors are measured:
Response Evaluation Criteria In Solid Tumors (RECIST).*
· Complete Response (CR): Disappearance of all target lesions
· Partial Response (PR): At least a 30% decrease in the sum of the longest diameter (LD) of target lesions, taking as reference point the baseline sum LD
· Stable Disease (SD): Neither sufficient shrinkage to qualify for PR nor sufficient increase to qualify for progressive disease (PD), taking as reference the smallest sum LD since the treatment started
· Progressive Disease (PD): At least a 20% increase in the sum of the LD of target lesions, taking as reference the smallest sum LD recorded since the treatment started or the appearance of one or more new lesions
* Source: Wikipedia
On this Thanksgiving I am thankful that my tumors are still stable and that things are status quo. I hope you can find something to be thankful for and I wish everyone a Happy Thanksgiving.