Can PAK6 Transform Small Cell Lung Cancer Diagnosis?
P21 Activated Kinase 6 outperforms CEA and CA19-9 for small cell lung cancer diagnosis and may predict treatment response and prognosis
TOPLINE: Serum P21 Activated Kinase 6 (PAK6) demonstrated diagnostic accuracy comparable to pro-gastrin-releasing peptide (ProGRP) for small cell lung cancer (SCLC), with area under the curve (AUC) values of 0.892 and 0.935, respectively, in a study of 109 patients with SCLC. Combining PAK6, ProGRP, and neuron-specific enolase (NSE) achieved diagnostic efficiency of 0.98. Elevated baseline PAK6 levels correlated with shorter progression-free survival and increased risk for disease progression.
METHODOLOGY:
Participants included 380 people in China: 109 with SCLC, 92 with non–small cell lung cancer (NSCLC), 85 with benign pulmonary nodules, and 94 healthy controls who received routine physical examinations.
Laboratory testing measured serum PAK6 by ELISA, while NSE, carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and ProGRP were quantified by chemiluminescence.
Pretreatment and posttreatment serum samples from 56 patients with SCLC were analyzed to evaluate changes in biomarker levels following 3 months of treatment.
Progression-free survival data were collected through case review and follow-up, defined as time from treatment initiation to radiographic disease progression per RECIST 1.1 criteria or death from any cause.
TAKEAWAY:
Median serum PAK6 is reported as 56.44 ng/L in SCLC vs 41.06 ng/L in NSCLC, 37.82 ng/L in pulmonary nodules, and 34.75 ng/L in healthy controls (P < .01).
PAK6 demonstrated diagnostic efficacy with and AUC of 0.892 (95% CI, 0.857-0.927), sensitivity of 0.82, and specificity of 0.86 at optimal cut-off value of 47.30 ng/L, comparable to ProGRP (AUC, 0.935) and superior to CEA (AUC, 0.676) and CA19-9 (AUC, 0.611).
In 56 paired SCLC samples, PAK6, NSE, and ProGRP decrease after 3 months of treatment (P < .001), while CEA and CA19-9 display no meaningful change.
Elevated baseline PAK6 expression correlated with shorter progression-free survival, with high-expression patients demonstrating median survival of 92 days vs 194 days in low-expression patients (HR, 2.02; 95% CI, 1.33-3.07; P = .001).
IN PRACTICE: “We identify PAK6 as a multi-faceted biomarker for SCLC with diagnostic, prognostic, and therapeutic monitoring value. Its cost-effective ELISA quantification facilitates clinical translation,” wrote the authors of the study. “Integrating PAK6 with emerging technologies could further refine SCLC management paradigms.”
SOURCE:The study was led by Simei Chen, Department of Blood Transfusion, the Second Affiliated Hospital, Jiangxi Medical College, Nanchang University in Nanchang, China. It was published online in PeerJ.
LIMITATIONS: A single-center design and modest sample size may limit generalizability of the diagnostic and prognostic estimates. The authors also note the absence of immunohistochemical validation, leaving tissue-level correlation of PAK6 unaddressed. Finally, insufficient overall survival data were reported, which constrains interpretation beyond PFS and supports the need for prospective follow-up and larger multi-center validation.
DISCLOSURES: Grant support came from the Science and Technology Program Project of Jiangxi Provincial Administration of Traditional Chinese Medicine (Grant 2024B1433). The authors stated the funders had no role in study design, data collection and analysis, the decision to publish, or manuscript preparation. No competing interests were disclosed.
This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.