CDK4/6 inhibitor liver injury: zone 3 necrosis and lymphocytic cholangitis, resolving on withdrawal

Design

Retrospective single-centre case series

Population

7 women with metastatic breast cancer and biopsy-characterised CDK4/6 inhibitor liver injury, 2020–2024

Primary outcome

Histological pattern and clinical resolution

Effect

Zone 3 necrosis in all acute biopsies; lymphocytic cholangitis 5/7; all normalised after withdrawal (mean 63 days)

A retrospective single-centre series in Histopathology, published on 8 October, describes seven women with metastatic breast cancer who developed raised liver enzymes on a CDK4/6 inhibitor — six on ribociclib, one on palbociclib — and had a liver biopsy. All had a RUCAM causality score of at least 6 and other causes excluded.

Enzymes rose a mean of 60 days after starting treatment (range 20 to 114). Five biopsies showed severe acute hepatitis, one mild lobular hepatitis and one subacute hepatitis with early fibrosis. Every acute biopsy had perivenular (zone 3) confluent necrosis, three with bridging necrosis. Portal inflammation was universal and lymphocytic cholangitis present in five. Three patients were ANA positive, but none had histological features of autoimmune hepatitis.

All patients normalised biochemically after the drug was stopped, a mean of 63 days from the peak, and six were switched successfully to another agent.

For the pathologist, the pattern to recognise is acute hepatocellular injury centred on zone 3 with bile duct inflammation in a woman on a CDK4/6 inhibitor. A positive ANA should not steer the report towards autoimmune hepatitis without the histological features to support it.

• Ask for the oncology drug history on any liver biopsy from a woman with breast cancer — CDK4/6 inhibitors are easy to miss.
• Look for perivenular confluent necrosis with portal inflammation and lymphocytic cholangitis.
• Do not diagnose autoimmune hepatitis on a positive ANA alone; none of the ANA-positive patients here had its histology.
• Note the timing: injury appeared within about 3 to 16 weeks of starting treatment.
• State in the report that the pattern is compatible with drug-induced injury, so the oncologist can consider withdrawal.

Why it matters

Calling it autoimmune hepatitis would lead to steroids, when stopping the drug was enough for every patient.

Don't overread it

Seven biopsied cases from one centre; the pattern in milder, unbiopsied injury may differ.

The statistics, in plain English

With seven patients, percentages such as 71% mean five of seven. The series describes a pattern; it cannot estimate how often CDK4/6 inhibitors cause liver injury.

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