Late-Onset Crizotinib-Associated Renal Cysts With Subsequent Regression Following Dose Reduction: A Case Report.

Area of Science:

• Oncology
• Pharmacology
• Nephrology

Background:

• Crizotinib is an ALK/ROS1/c-MET inhibitor effective for ALK-positive non-small cell lung cancer (NSCLC).
• Crizotinib-associated renal cysts (CARCs) are a rare but significant adverse effect of this targeted therapy.
• Long-term administration of targeted therapies necessitates vigilance for late-onset toxicities.

Observation:

• A 68-year-old male with ALK-positive NSCLC developed complex renal cysts after 4 years of crizotinib treatment.
• Initial radiographic findings were ambiguous, leading to surgical intervention for suspected abscess or neoplasm.
• Recurrent cystic lesions appeared despite initial management, prompting suspicion of CARCs.

Findings:

• Crizotinib dose reduction resulted in regression of the renal cysts.
• The dose adjustment successfully managed the adverse renal effect without compromising anti-tumor efficacy.
• This case underscores the potential for late-onset toxicities with prolonged crizotinib use.

Implications:

• Clinicians should consider CARCs in patients on long-term crizotinib, even after years of treatment.
• Multidisciplinary evaluation is crucial for diagnosing and managing complex adverse events.
• Tailored dose adjustments can be an effective strategy to mitigate crizotinib-related toxicities while maintaining therapeutic benefit.