Disease flare after discontinuing gefitinib in a patient with lung adenocarcinoma and concomitant epithelial growth factor receptor mutation and anaplastic lymphoma kinase translocation

Prolonged Disease Control Despite ALK Inhibitor Discontinuation in Advanced ALK-Positive NSCLC

Introduction

EML4-ALK is an oncogenic driver, seen in around five per cent of advanced non-small-cell lung cancer (NSCLC) patients, which can be targeted with anaplastic lymphoma kinase tyrosine kinase inhibitors with great response rates. Disease flare refers to sudden rapid disease worsening on tyrosine kinase inhibitors (TKI) discontinuation, which is associated with shorter survival and worse outcomes. Here, we review cases previously published in the literature where patients developed disease flares, and contrast this with our patients who had prolonged survival despite TKI discontinuation.

Case description

We report three different patients with advanced ALK-positive NSCLC seen at our institute, who had EML4-ALK translocation variant 1 oncogenic driver on next-generation sequencing. They received treatment with several different ALK inhibitors before opting to discontinue TKI. They were able to come off TKI safely without developing disease flare and had prolonged survival.

Discussion

Shorter time to progression on TKI, presence of symptoms with disease progression or central nervous system/pleural metastasis have been previously linked with development of flare, although this was not seen in our case series. Tumour response at the time of treatment discontinuation, line of therapy, overall disease burden, fusion variant and co-alteration status can affect the prognosis of these patients after ALK TKI cessation. In particular, variant 1 and wild-type TP53 status may be a suitable patient population for dose optimisation strategies. Intermittent TKI dosing strategies may help to avoid acquiring resistance mutations and prevent long-term treatment toxicities.

Conclusion

It is important for clinicians to identify patients at risk for developing disease flare on TKI discontinuation to improve outcomes. Intermittent TKI dosing strategies require further investigation.

LEARNING POINTS

Patients who develop disease flare after cessation have poor survival and worse outcomes.Certain phenotypic and molecular characteristics of the tumour may help clinicians identify which patients are likely and which are unlikely to develop disease flare on TKI discontinuation.Advanced ALK-positive NSCLC with variant 1 and wild-type TP53 may be a suitable patient population for intermittent TKI dosing investigations.

Rapid disease progression following discontinuation of ibrutinib in patients with chronic lymphocytic leukemia treated in routine clinical practice

We identified all patients with chronic lymphocytic leukemia at Mayo Clinic treated with ibrutinib outside the context of a clinical trial; timing and reasons for discontinuation were ascertained, as were symptoms, exam and radiographic findings, and laboratory changes following discontinuation. Of 202 patients who received ibrutinib, 52 discontinued therapy (estimated 1- and 2-year risk of discontinuation 18% and 28%, respectively). The most common reasons for discontinuation were toxicity (56%) and progression of disease (32%, including Richter's transformation in 15%). Rapid progression of disease within 4 weeks after discontinuation was observed in 9/36 (25%) patients with adequate records for review, mostly in those stopping ibrutinib for disease progression (n = 8) rather than toxicity (n = 1). This was evident by sudden worsening of disease-related symptoms (n = 9), exam/radiographic changes (n = 7), and laboratory changes (n = 8). An estimated one in every three patients discontinued ibrutinib by 2 years, with 25% developing rapid disease progression afterwards.

Rapid Progression of Metastatic Panspinal Epidural Non-Small Cell Lung Cancer After Discontinuation of Alectinib

BACKGROUND

Rapid progression of metastatic non-small cell lung cancer (NSCLC) after discontinuation of tyrosine kinase inhibitors or anaplastic lymphoma kinase (ALK) inhibitors has been described and is associated with a poor prognosis. We describe the first reported case of accelerated NSCLC tumor extension throughout the entire spinal epidural space.

CASE DESCRIPTION

A 68-year-old woman with stage IV ALK-positive metastatic NSCLC presented with acute neck pain, urinary retention, and lower extremity weakness 15 days post discontinuation of alectinib. Magnetic resonance imaging (MRI) with contrast was significant for a new compressive lesion spanning the entire cervical, thoracic, and lumbar spine, which was new compared with MRI obtained 20 days before and was suspicious for infection. Cervical (C3-C7), thoracic (T9-T12), and lumbar (L3-L5) decompression were performed with collection of culture and pathology specimens. Repeat MRI obtained for acute neurologic deterioration on postoperative day 2 noted further progression of disease and continued thoracic cord compression. After urgent T1-9 laminectomy, specimens were again sent for pathology, cultures, and cytology. No evidence of infection was noted, and all pathologic specimens evaluated were consistent with metastatic adenocarcinoma. Despite operative intervention, the patient continued to decline, suffering from recurrent pleural effusions, and eventual cardiopulmonary arrest 11 days after admission.

CONCLUSIONS

The differential diagnosis when evaluating presumed spine epidural abscess should include tumor and metastatic disease, even in cases of rapid development. Recent termination of tyrosine kinase inhibitors or ALK inhibitors may result in severe disease flares, and a history of such should raise clinical suspicion for metastatic progression. In addition to cultures, biopsy for pathologic diagnosis should be collected during decompressive surgery.