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

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.

Monitoring of the presence of EGFR-mutated DNA during EGFR-targeted therapy may assist in the prediction of treatment outcome

The aim of our trial was to evaluate the prognostic significance of qualitative ctDNA analysis on different stages of EGFR mutated non-small cell lung cancer (NSCLC) treatment. We included 99 patients amendable for the first line treatment with either gefitinib/erlotinib (n = 87), afatinib (n = 10) or osimertinib (n = 2). Sequential qualitative analysis of ctDNA with cobas® EGFR Mutation Test v2 were performed before first dose, after 2 and 4 months of treatment, and on progression. Our analysis showed clinically significant heterogeneity of EGFR-mutated NSCLC treated with 1st line tyrosine kinase inhibitors (TKIs) in terms of progression-free and overall survival. When treated with conventional approach, i.e. monotherapy with TKIs, the patients falls into three subgroups based on ctDNA analysis before and after 2 months of treatment. Patients without detectable ctDNA at baseline (N = 32) possess the best prognosis on duration of treatment (PFS: 24.07 [16.8-31.3] and OS: 56.2 [21.8-90.7] months). Those who achieve clearance after two months of TKI (N = 42) have indistinguishably good PFS (19.0 [13.7 - 24.2]). Individuals who retain ctDNA after 2 months (N = 25) have the worst prognosis (PFS: 10.3 [7.0 - 13.5], p = 0.000). 9/25 patients did not develop ctDNA clearance at 4 months with no statistical difference in PFS from those without clearance at 2 months. Prognostic heterogeneity of EGFR-mutated NSCLC should be taken into consideration in planning further clinical trials and optimizing the outcome of patients.

Pathological complete response after afatinib treatment of stage IV oligometastatic adenocarcinoma of the lung: the role of pulmonary surgery

BACKGROUND

Some oligometastatic lung cancer patients, after induction systemic chemotherapy or tyrosine kinases inhibitor treatment, followed by aggressive radical consolidative treatment, have improved overall survival. Unfortunately, clinical criteria cannot assess such patients.

CASE PRESENTATION

We hereby reported the case of a 55-year-old female with lower back pain and bilateral lower leg numbness for months and who had an osteolytic bone lesion over the third lumbar vertebra. In February 2017, a third lumbar vertebra biopsy showed metastatic adenocarcinoma, compatible with lung origin (thyroid transcription factor-1 positive [TTF-1], L858R mutation positive). Complete imaging of the right lower lobe (RLL) showed a spiculated mass of about 3.4 × 2.2 cm, and a trans-bronchoscopic lung biopsy revealed non-small cell carcinoma of lung origin (positive for TTF-1 and negative for p40). Tentative diagnosis was RLL adenocarcinoma, cT2aN0M1b, with bone metastasis at L3. The epidermal growth factor receptor-tyrosine kinase inhibitor afatinib was prescribed beginning April 2017. A November 2018 follow-up CT scan showed regression in the RLL lung mass. A whole-body positron emission tomography-computed tomography showed RLL lung nodule with faint uptake and mildly increased uptake in the L3 vertebra. After providing informed consent, the patient received uniportal video-assisted thoracoscopic RLL lobectomy and radical mediastinal lymph node dissection on December 25, 2018. The final pathology report was fibrotic scar with no residual tumor cells, compatible with post-treatment status, ypT0N0. Curative intent radiotherapy was also applied to the L3 vertebra after the operation. The patient is still alive for more than 32 months after initially diagnosed with metastatic lung adenocarcinoma.

CONCLUSIONS

Our case provides additional data to support that tissue assessment through primary lung tumor resection after systemic treatment of oligometastic lung cancer by minimally invasive surgery can reveal the treatment effect and potentially provide a surrogate endpoint in further clinical trials.