RECIST 1.1

How oncologists use a system to objectively assess changes in changes the size of the tumors to determine if they are growing or shrinking.  It’s called RECIST - Response Evaluation Criteria in Solid Tumors. The oncologists take the largest diameter of a tumor (let’s say there’s a tumor that’s 1.4cm x 1.1cm, the 1.4  or 14cm will be used in the evaluation), add them up and get a percentage of growth or shrinkage.  They don’t use all tumors, just the significant ones.

The categories are as follows:

Complete Response (what every survivor hopes and prays for) - is the disappearance of target lesions.

Partial Response - greater than 30% decrease in target lesions. Happened to me at the very beginning when my protocol was initiated - Cabometyx (daily chemo pill) and Opdivo (once a month immunotherapy drug).  Example - the total tumor mass of 2 tumors in my liver on March 19, 2025 was 24.7mm.  By July 15 2025 it dropped to 0 (aka non-detectable tumors meaning they did not show up in scans, but possibly small enough to be still there). It remained at 0 for a few scans and there’s one tumor that’s a couple of months old that’s about 10mm.

Stable Disease (where I’m at so far) - neither growing nor shrinking of the lesions.

Progressive Disease- greater than 20% increase in size or an absolute greater than 5mm or the appearance of one or more new lesions.

RECIST does have it’s limitations.  It only measures arterially enhancing (with contrast) portions that can be detected by scans.  If immunotherapy is being used in treatment, another scan will be issued 4-8 weeks later to confirm disease progression.  There are other limitations as well, but those are the basics.

Oncologists use a metric called RECIST to track solid tumors by measuring the largest diameter of key lesions and calculating % change.

•  Complete Response: All target lesions gone

•  Partial Response: ≥30% decrease

•  Stable Disease: Neither significant growth nor shrinkage

•  Progressive Disease: ≥20% increase (or +5 mm absolute) or new lesions

I’m currently holding at 6% (started at 2–3%). Praying it stays or drops. By tracking every scan in a spreadsheet keeps me informed and helps me partner with my oncologist. The disease is in God’s hands, but knowledge gives a sense of control.

Do you know your %? Ask your doc.