Sunday, April 4, 2010

Katharsis

My body went through a lot last week. I was basically a human pin cushion, with a vertebral biopsy, a contrast CT scan of my chest, and an MR scan with contrast of my spine.

First things first:
The biopsy results are back and it is indeed the same cancer which I've had for the last 5 years that spread to my 5th thoracic vertebrae.

Now, what does that mean? Well, at this point the exact diagnosis is 'well-differentiated papillary thyroid carcinoma', similar to the tissue seen below (note-not my tissue):


One of the concerns about my situation is that my thyroid cancer is weird relative to other patients with similar cancer. 'Papillary' represents 75-85% of all thyroid cancer, although it is most commonly found in female patients and associated with radiation exposure (neither of which, obviously or not, apply to me). It is also not generally aggressive as long as it is well differentiated (that is what is taught in medical school and based on my case, clearly that isn't entirely true), it can invade the lymphatics and metastasize to nodes (1/2 of cases) and to the lower lobes of the lungs (10-15% of cases). There are 3 distinct mutations in cellular pathways that can lead to papillary carcinoma.
-First, there are rearrangements of the oncogenes RET (10q11) tyrosine kinase receptor or the NTRK1 (1q21) receptor, that make the kinase domains constitutive. Both of these receptors signal through MAP kinase pathways and neither is normally present on thyroid follicular cells. Together, these make account for ~50% of papillary thyroid cancers. Chromosomal inversions or translocations cause recombination of the intracellular kinase-encoding RET domain with a heterologous gene called H4 or PTC. Recombination generates the RET/PTC chimeric oncogene. This seems to be induced by radiation, but can also occur randomly. It is interesting to note that 60% of post-Chernobyl PTC harbored this mutation.
-Second, an activating V599E mutation in a gene called BRAF is present in 33-50% of cases. BRAF codes for a MAP kinase pathway signal transducer. Virtually all papillary carcinomas exhibit either BRAF or RET/NTRK1 mutations. With BRAF mutation commonly being more aggressive. Although I’ve never been genetically tested, my tumor almost certainly harbors a BRAF mutation.
-Third, involves RAS mutations in 10% to 20% of papillary carcinomas.

Treatment for papillary: Tumors < 1 cm→Lobectomy & isthmusectomy. Those >2cm→ Thyroidectomy + neck dissection followed by I-131 treatment if there is evidence of metastatic disease. Thyroidectomy alone if the nodule is solitary.

Prognosis: 10-year survival rate is in excess of 95%. Overall prognosis depends on age (younger=better), presence of extrathyroidal extension, and presence of distant metastases.

It is that prognosis part that is the concern. To the knowledge of the physicians treating me, it is extremely rare for papillary thyroid cancer to spread to bone in a young person. The fact that it is now proven to have done so in me means:
a. My situation warrants a 'case report' (meaning, some doctor writes up my case and publishes it in a journal for others to read)
b. No one knows what the hell to do with me.
c. Now that we know what we're dealing with, hopefully we can get a better treatment plan

At this point, the plan we have is a good one. Next monday I'll go to MD Anderson to talk with someone who often deals with aggressive cases of thyroid cancer.

I think I'm tired now of writing about this. At a certain point, it is like there's a switch that someone flips where I just shut-down if I think about it too much. I don't know why I felt the need to put all the medical stuff on the blog...I imagine very few people found it helpful. Oh well, sorry about that. Like I've said in the past, this blog exists partially as a katharsis.

Cycling news:
Managed to ride almost 300 miles last week. Very psyched about that. Next week is a helluva race and I'm going to be aiming just to finish.

1 comment:

rudy said...

fyi, i find your med scripts fascinating, tho i don't know 70% of the words...it shows what a miracle it is that more things don't go wrong...and even when they do...there are probably many anom. people like myself who are rooting for you...go, dan!