I get asked fairly often if the chemotherapy course will be successful, or how we will know if it has succeeded.
The short layman’s (ie me, not being a clinician) answer is that we won’t.
All we will know is if we have failed, should the cancer come back as yet another metastasis. Success, in this context, is defined at best as an ongoing lack of failure.
Oncology is in this respect a peculiar discipline. An orthopedist knows when a broken bone has set and healed. An internist knows when a course of infection has been repelled. An obstetrician knows when the baby has been delivered. All of those are affirmative measures of success. Cancer can be an acute condition, like bone fractures or the flu, but its treatments far more resemble the managed approaches to chronic conditions.
In my case, once my chemotherapy course is completed, we’ll do bloodwork and medical imaging. As I’ve discussed before, there are four basic tests for whether I have a recurrence of metastatic disease.
Three are noninvasive imaging techniques, CT, PET and MRI, which respectively measure tissue density, metabolic activity and structure. (Again, this is my layman’s perspective.) Tumors are almost always more dense than the surrounding tissue, almost always more metabolically active than the surrounding tissue, and have distinctive structural characteristics.
The fourth test is an assessment of the presence of carcinoembryonic antigen (CEA) in my bloodstream, which is normally not present in healthy adults, or present at trace levels, but which my particular type of cancer can produce in measurable and even high levels.
So in December we’ll baseline my CEA levels and do a CT scan to see if any new metastatic tumors have appeared. Neither of these tests can detect ‘seeds’, small clumps of a few cancer cells that may be migrating through my lymph system or bloodstream, and which in turn can anchor onto healthy tissue and develop into new metastatic tumors. The point of chemotherapy is to kill off those seed cell clumps, but success cannot be directly measured, only inferred by a lack of further metastatic disease.
If I can stay clean on CEA levels and CT scans for five years, I will be considered cured. Until then, every few months I will go through the highly stressful process of being checked. Checks that have twice now revealed metastatic disease despite the best hopes and efforts of my medical team.
There is no affirmative measure of success in this business except for survival. Much like life itself, in truth.
Still, one might wish for more.