Cervical Small Cell Neuroendocrine Cancer: PD-L1 Expression and NTRK Gene Fusion
Posted: Monday, December 6, 2021
According to findings presented in Frontiers in Oncology, PD-L1 inhibitors may be an effective therapeutic target when treating patients with cervical small cell neuroendocrine carcinoma (SCNC). Zhiyong Liang, MD, PhD, of Peking Union Medical College, Beijing, and colleagues emphasized that immune checkpoint inhibitors could be a promising targeted therapy option for this rare type of tumor.
“Cervical SCNC is a mismatch repair–stable tumor and lacks NTRK gene fusion,” the authors concluded. “The pan-Trk immunohistochemistry method showed a high false-positive rate of NTRK gene fusion, which questions the use of this method in the detection of NTRK fusion in small cell neuroendocrine tumors.”
In this trial, the authors enrolled 46 patients, all of whom had surgery or a biopsy at Union Medical College Hospital in Beijing. The physicians used immunohistochemistry as the main detection method, and any NTRK-positive cases were submitted for evaluation by fluorescence in situ hybridization (FISH) and real-time polymerase chain reaction (RT-PCR) methods.
The authors discovered positive PD-L1 expression in 22 of the 43 patients, with an average combined positive score of 6.82. They found that patients with PD-L1–positive disease were more likely to have a higher proliferation rate in the tumor and a lower rate of recurrence and death, compared with those patients with PD-L1–negative expression.
However, the authors noted, in the multivariate analysis, none of the clinical parameters were associated with the expression of PD-L1. There was no association between PD-L1 expression and disease recurrence or overall survival in the Kaplan-Meier analysis, and all cases were DNA mismatch repair-–table and lacked ˆgene fusion. Pan-Trk expression occurred in 14 of the 43 cases, but FISH and RT-PCR analyses did not confirm any positive fusion signals in those patients with immunohistochemical-positive cases.
Disclosure: The authors reported no conflicts of interest.