Published online Jul 6, 2020. doi: 10.12998/wjcc.v8.i13.2833
Peer-review started: February 14, 2020
First decision: May 26, 2020
Revised: May 29, 2020
Accepted: June 17, 2020
Article in press: June 17, 2020
Published online: July 6, 2020
Processing time: 143 Days and 11.6 Hours
Pembrolizumab is a highly selective IgG4 kappa isotype monoclonal antibody against the programmed cell death-1 (PD-1) molecule. In the treatment of non-small cell lung cancer (NSCLC), pembrolizumab has demonstrated significant efficacy, significant survival outcomes, long-lasting responses, and a good safety profile compared with cytotoxic chemotherapy.
A 79-year-old Korean male presented with a left side palpable neck mass. An ultrasound-guided core-needle biopsy of the largest neck mass was performed, and squamous cell carcinoma was confirmed based on the histological and immunohistochemical findings. He was diagnosed with squamous cell carcinoma of the lung with multiple lymph nodes and rib metastases (T1N3M1b, Stage IVA) using enhanced chest computed tomography and 18F-fluorodeoxyglucose positron emission/computed tomography. After 4 cycles of gemcitabine and carboplatin, we clinically judged the disease as progressive. Owing to the high PD-1 expression demonstrated by the patient, pembrolizumab was initiated (200 mg every 3 wk). After 3 cycles of pembrolizumab, a complete response was achieved. At the 4th cycle of pembrolizumab, the white blood cell count was markedly elevated. Peripheral blood smear analysis and bone marrow biopsy were performed. The patient was diagnosed with acute myelomonocytic leukemia.
We present the first report of acute myelomonocytic leukemia during pembrolizumab treatment in an NSCLC patient; the mechanism remains unknown.
Core tip: In the treatment of non-small cell lung cancer (NSCLC), pembrolizumab has demonstrated significant efficacy, significant survival outcomes, long-lasting responses, and good safety profile. To the best of our knowledge, this is the first report of acute myelomonocytic leukemia during pembrolizumab in a patient with NSCLC. However, the precise underlying mechanism remains unknown.