Keytruda setback?

[Robert A.]

1st let me wish all the Mothers here a Happy Mothers Day. I have anther Keytruda question, my wife started her treatment of Keytruda and Carboplatin in November. I think we had our 1st scan done in January and it showed the Tumor shrinking. The  Dr. the put her on Keytruda Pemetrexed Maintenance then we scanned again in April and had a telephone conference with the Dr. where she informed us the tumor grew, was 5 cm when diagnosed went to 4 cm after the 1st treatment with Keytruda and now is at 6 cm after the latest scan. The Dr. wants to start her on a stronger treatment of chemo with Docetaxel. My question is,  is there a way to tell that it"s not a symptom of the Keytuda working making cells around the tumor making it look bigger. I now I should of asked the Dr. but didn't think of these questions at the time, but the more time I have to think these questions pop up. Anyone with similar reactions to Keytruda? Thanks Robert

[Steff]

Robert,

My mom had a "thickening" around the area of her tumor after her tumor initially shrunk (she was on Ketruda + Alimta + Carbo at the time).  Her docs suspected inflammation (which is quite common in the first 4-6 months of treatment) but they couldn't be positive.  My mom's pulmonologist biopsied the area to see if he could find any cancer cells.  All of the 20 or so biopsies came back negative for cancer. This only told us that where he biopsied did not have cancer cells, but it was not a definite answer as to whether or not the "thickening" was just inflammation.  But the biopsies helped us to decide to continue with immunotherapy and chemo for a bit longer to see if the "thickening" reduced.  Luckily, it did and after about 6 months, was gone.  It was then identified as just inflammation. 

So, long story short, I don't know of a specific test to see whether growth is cancer or inflammation.  It's hard to decide what the best treatment approach is.  Perhaps this would be a good time for a second opinion if you and your wife are questioning the treatment change.

[Robert A.]

Thank You Steff.