I have received four High-dose Interleukin-2 (IL-2) cycles at Providence Cancer Center. Following the second cycle, a CT scan was taken to see whether I am responding to the treatment. My oncologist found that my tumors had regressed by about 20% and my reward was two more cycles of IL-2.
Following the fourth cycle in June, 2014 my oncologist inspected the images from the CT Scan and reported, “I am seeing a 2-millimeter regression in your tumors. That means that you are eligible for the last two cycles of IL-2.”
I said, “I’m very happy to be eligible for the last two cycles of treatment. But I’m disappointed that the regression sounds minuscule, less than the margin of error in image resolution.”
Doctor replied, “It’s not minuscule, but smaller than required to classify you as Partial Response. In research terms, this result is classified as Stable Disease. I recommend that you complete the last two cycles of IL-2. It’s important that you complete the last two cycles because our research shows that people who get all six cycles have longer survival. Six weeks after the last cycle, we will order a CT-PET scan. This PET scan will light up areas with a high metabolic rate, including any remaining active melanoma. Your tumors are mostly composed of necrotic cells, which aren’t threatening. If we see active cancer cells around the periphery of these tumors we will consider radiation and other options. I’d rather wait and see before we discuss these options. It is possible that you won’t have any active melanoma after your last treatment, and in that case we will not do further treatment.”
Completing the treatment was a “no-brainer” for me; the likelihood of helping far outweighs the likelihood of harm. I said, “OK, the next step is clearly to continue the treatment.”
I also wanted to wrap my mind around my status as Stable Disease, to discover more about Providence findings about IL-2 treatment outcomes, and whether Stable Disease can be a durable outcome. A quick online search led me to Durable responses and reversible toxicity of high-dose interleukin-2 treatment of melanoma and renal cancer in a Community Hospital Biotherapy Program by Roxanne Payne and others. This paper discusses an analysis of outcomes for 500 patients receiving IL-2 treatment at Providence from 1997 – 2012.
I studied the results in the paper, including tables and graphs. This confirmed my belief that patient longevity varies a lot and will be correlated with response to treatment. Response is classified, from most desirable to least desirable, as: Complete Response, Partial Response, Stable Disease, Progressive Disease. Best Response refers to the most desirable response achieved in the course of treatment.
Median survival for Complete Response is more than 5 years, for Partial Response is 40.7 months and for Stable Disease is 32.6 months. These are averages. Some patients have outcomes significantly better or worse than the average.
The paper reports that a significant fraction of patients with less than Complete Response needed no additional treatment following IL-2. About ten percent (9.5%) of the patients with a best response of Partial Response or Stable Disease required no additional treatment.
My conclusion is that I could expect to enjoy a durable remission (more than 5-year longevity) if my best response improves to a Complete Response during the upcoming treatment. If my response remains Stable Disease, or Partial Response, I have a small, but statistically significant, hope for 5-year longevity. However, I’m not liking the one in ten odds; this leaves me asking myself, “What else can I do to strengthen the efficiency of my Immune System?”