Achievement of Cure with Gefitinib in Advanced Lung Adenocarcinoma Harboring an Activating EGFR Mutation: A Case Report

Adaptive therapy to circumvent drug resistance to tyrosine kinase inhibitors in cancer: is it clinically relevant?

INTRODUCTION

Cancer is highly adaptable and is constantly evolving against current targeted therapies such as tyrosine kinase inhibitors. Despite advances in recent decades, the emergence of drug resistance to tyrosine kinase inhibitors constantly hampers therapeutic efficacy of cancer treatment. Continuous therapy versus intermittent clinical regimen has been a debate in drug administration of cancer patients. An ecologically-inspired shift in cancer treatment known as 'adaptive therapy' intends to improve the drug administration of drugs to cancer patients that can delay emergence of drug resistance.

AREAS COVERED

We discuss improved understanding of the concept of drug resistance, the basis of continuous therapy, intermittent clinical regimens, and adaptive therapy will be reviewed. In addition, we discuss how adaptive therapy provides guidance for future cancer treatment.

EXPERT OPINION

The current understanding of drug resistance in cancer leads to poor prognosis and limited treatment options in patients. Fighting drug resistance mutants is constantly followed by new forms of resistance. In most reported cases, continuous therapy leads to drug resistance and an intermittent clinical regimen vaguely delays it. However, adaptive therapy, conceptually, exploits multiple parameters that can suppress the growth of drug resistance and provides safe treatment for cancer patients in the future.

Long-term complete response to gefitinib after treatment termination in a patient with recurrent post-operative EGFR-mutated lung adenocarcinoma: case report and literature review

Non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations is highly sensitive to EGFR-tyrosine kinase inhibitor (EGFR-TKI). However, few cases of advanced NSCLC completely cured by EGFR-TKIs have been reported. We present an extremely rare case of lung adenocarcinoma that was completely cured by gefitinib administration. A 36-year-old Japanese woman was diagnosed with clinical Stage IIIB (T2N3M0) lung adenocarcinoma originating from the left upper lobe in April 2006. After the two cycles of chemotherapy, it was down-staged to ycStage IA (T1N0M0). She underwent a thoracotomy with left upper lobectomy, pulmonary angioplasty, and mediastinal nodal dissection in July 2006 [ypStage IIIA (T3N1M0)]. Eighteen months later, she was found to have lymphadenopathy of the right supraclavicular nodes. Fine needle aspiration cytology of the lymph node indicated adenocarcinoma. She started gefitinib therapy for recurrent lung cancer with EGFR mutation (exon 19 deletion) in January 2008. Four months afterward, computed tomography (CT) showed her right supraclavicular nodes had shrunk dramatically. Treatment with gefitinib was continued. Thereafter, no disease progression was observed throughout her approximately 8-year gefitinib treatment, and gefitinib was terminated in November 2016. Although the patient received no other treatment, she has suffered no recurrence in the 4 years since. A review of the literature, including our case, is also presented.

Factors Associated With Distant Metastasis in EGFR-mutated Non-small Cell Lung Cancer Patients: Logistic Analysis

BACKGROUND/AIM

The aim of this retrospective study was to identify, using logistic analysis, the factors associated with distant metastasis in non-small cell lung cancer patients carrying mutations in epidermal growth factor receptor.

PATIENTS AND METHODS

Patients who were diagnosed with distant metastasis at the time of diagnosis up to their death and during the period from April 2009 to March 2019, were included in this study. Clinical charts and imaging studies were reviewed.

RESULTS

A total of 64 patients during the research period. The factors associated with pleural metastasis were "female" and "no bone metastasis". The factor associated with brain metastasis was "lung metastasis". The factors associated with liver metastasis were "age under 70" and "Exon 19 deletion".

CONCLUSION

Knowing the factors associated with distant metastasis will provide useful information to conduct targeted and efficient imaging studies.

Long-lasting response to afatinib that persisted after treatment discontinuation in a case of EGFR-mutated lung adenocarcinoma

It is unknown whether tyrosine kinase inhibitors targeting epidermal growth factor receptor (EGFR) can be discontinued in patients in whom EGFR-mutated lung cancer has well stabilised. We present a case of a 73-year-old Japanese woman with no history of smoking. Right pulmonary lower lobectomy, lymph node dissection and segmental resection of the right middle lobe were performed. Additionally, she underwent adjuvant chemotherapy for stage IIIB adenocarcinoma harbouring an EGFR exon 19 deletion. Afatinib was administered for liver metastases after 15 months. A complete response of metastatic disease was achieved for 2 years. However, afatinib was unavoidably discontinued due to splenectomy for the treatment of idiopathic thrombocytopenic purpura. Although afatinib was not resumed, due to the abscess formation as surgery complication, a drug-free complete response was sustained for over 18 months. The present case suggests that exceptional and durable responses to afatinib can be achieved in individual cases.