Tumor Lysis Syndrome

00:00 Tumor lysis syndrome.

00:02 So again, if you have a bunch of tumor, a huge tumor burden, and then you successfully kill it, it's going to release ions and proteins, nucleic acids, phospholipids, etc.

00:13 that overwhelms the normal homeostatic mechanisms.

00:16 It's a huge deluge, it's a flood of all of these various things.

00:20 So think about the what's just inside the normal cytoplasm of any cell.

00:25 It's also within the cytoplasm of tumor cells so you can have as a result of tumor lysis syndrome, super high levels of potassium or hyperkalemia.

00:34 High levels of phosphates, again, ATP and ADP, aMP.

00:41 Those phosphates will end up causing a hyperphosphatemia.

00:44 You will have breakdown of nucleic acids giving you elevated levels of uric acid, hyperuricemia.

00:51 And because we have too much phosphate, we're sucking up, binding phosphate to all the calcium in the circulation, you can have a hypocalcemia.

01:01 The consequences of these hyperkalemia, hyperphosphatemia, hyperuricaemia, hypocalcemia is that you can have arrhythmias and particularly low calcium and high potassium are going to be associated with sudden death.

01:14 You can have with low calcium, seizures and hyperuricemia, hyperphosphatemia are going to be causes of renal failure.

01:23 So doing the right thing and in fact being so darn successful that you kill off a lot of the tumor cells can actually have secondary consequences as indicated here.

01:34 So let's walk through tumor lysis syndrome in a box form as we look at the individual constituents.

01:40 Cells are lysing, we're going to get release of nucleic acids, DNA and RNA.

01:46 As those get catabolized, we'll see elevated levels of uric acid, so the patient would be hyperuricemic and that can lead to renal nephropathy.

01:55 Patient's cells, the tumor cells are also releasing potassium so there'd be hyperkalemia.

02:02 Phosphate groups coming off ATP, ADP, aMP and off of phospholipids, etc will lead to hyperphosphatemia.

02:10 Elevated phosphate, well actually combined with circulating calcium and we'll get calcium hydroxyapatite, we'll actually get that precipitated out but that will lead to hypocalcemia as we sop up all the free calcium binding to those phosphate groups.

02:25 Hypocalcemia along with hyperkalemia will cause neuromuscular and cardiovascular effects, including fatal arrhythmias.

02:33 And that deposition of calcium and phosphate will lead to gastrointestinal disturbances, can cause worsening of any renal failure and renal insufficiency overall.

02:43 So, tumor lysis even when we're successful, we have to be vigilant to try to prevent some of these secondary consequences of our success.