# Tumor Lysis: Treat the Metabolic Threat

Rebound and persistent tumor breakdown can recur. Reassess chemistry, urine output, volume, and the underlying oncologic treatment course.

![Infographic: Tumor Lysis: Treat the Metabolic Threat](https://urinenephrology.org/visual-reference/images/mastery-tls.png?v=20261003c)

## Cell breakdown releases load

Potassium, phosphate, and nucleic-acid metabolites can overwhelm excretion. Tumor lysis may follow therapy or occur spontaneously.

## Recognize high-risk trajectories

Rapidly rising solutes, falling urine output, arrhythmia, seizures, or worsening kidney function require urgent assessment. Solid tumors can also develop TLS.

## Risk-stratify before treatment

Combine tumor burden, proliferative rate, treatment sensitivity, baseline kidney function, and existing potassium/phosphate/urate abnormalities. High-risk patients need planned chemistry and urine-output surveillance. A solid-tumor diagnosis does not exclude TLS, but not every patient with the same cancer needs identical prophylaxis.

## Choose urate therapy for its purpose

Allopurinol reduces new uric-acid formation; rasburicase breaks down existing urate and has critical G6PD-related safety restrictions. Neither substitutes for emergency hyperkalemia care or management of phosphate release. Reassess fluid tolerance frequently when oliguria or cardiac disease limits hydration.

## Consider kidney replacement early

Refractory abnormalities, fluid overload, and ongoing solute release can require extracorporeal support. Treatment planning must anticipate continued production.

## Continue after the first improvement

Rebound and persistent tumor breakdown can recur. Reassess chemistry, urine output, volume, and the underlying oncologic treatment course.

## Source lessons

- [tls small cell lung cancer](https://urinenephrology.org/mastery/onconephrology/tls-small-cell-lung-cancer.html)
- [tumor lysis syndrome comprehensive review](https://urinenephrology.org/mastery/onconephrology/tumor-lysis-syndrome-comprehensive-review.html)

Read alongside the full lessons; the findings and decisions shown here require the stated clinical context.