1 mm progression on Tagrisso

Tue, 03/27/2018 - 00:00

March 26, 2018 at 10:40 pm #1294138

Hi, 64 Y/O female, asian, dx 12/2011 Stage 4 Adneo del 19 egfr+, Tarceva for almost 5 years, no progression, then small progression, Almita/Carbo 4 cycles as hold over, tissue biopsy T790M + , Lepidic predominant Adeno, Started Tagrisso 12/2016.
Ct scan today showed 1mm increase in size of a 3 mm nodule. Also a 3mm lesion is a bit more dense looking but unchanged in size. All other nodules and lesions remain unchanged.
Is this considered progression ? Does the RECIST criteria for progression apply to a small lesion like this?
Do we have to increase the frequency of the CT scans?

March 27, 2018 at 6:25 am #1294140
JimC Forum Moderator
JimC Forum Moderator
Hi bfarz,

Although a 1 mm change in a 3 mm nodule appears to be significant in terms of percentage increase, a change of 1 mm in any size nodule is not a clear indication of growth. Many factors related not to growth but to the scanning process can make an unchanged nodule appear to be a millimeter larger, such as the way the images “cut”, the use of a different CT machine and slight changes in the angle of the images. Most oncologists would not consider this clear evidence of progression and it would not impact their management of the cancer.

You didn’t state your current scan interval, but unless it’s quite long (a year or more), then your doctor will probably not see a need to shorten the interval. But that’s a matter of personal preference that varies from one oncologist to another, and given the stable results from the latest scan, there isn’t a strictly defined standard interval.

Forum moderator