# Unique Clinical Features of Imaging-Stage I Peripheral Lung Squamous Cell Carcinoma: A Retrospective Study

## TL;DR

This study identifies unique clinical features of early-stage peripheral lung squamous cell carcinoma, helping clinicians recognize it before diagnosis and suggesting potential for personalized treatment.

## Contribution

The study reveals distinct clinical and imaging features of early-stage peripheral lung squamous cell carcinoma compared to adenocarcinoma.

## Key findings

- p-LUSC tumors appear as solid nodules and are associated with male sex, older age, smoking, and shorter volume doubling time.
- p-LUSC tumors in the 2.0 to 3.0 cm range show lower lymph node metastasis rates compared to p-LUAD tumors of similar size.
- Tumor size and lymph node metastasis are independent risk factors for recurrence in p-LUSC.

## Abstract

Although the incidence of peripheral lung squamous cell carcinoma (p-LUSC) has increased in recent years, the clinical features of early-stage p-LUSC remain unclear. We conducted a retrospective analysis of 103 cases of p-LUSC and 600 cases of peripheral lung adenocarcinoma, revealing that p-LUSC exhibited distinct characteristics in terms of patient demographics, imaging presentation, clinicopathological features, and tumor volume doubling time. A systematic summary of these unique clinical features in early-stage p-LUSC fosters heightened clinician vigilance before pathological confirmation. Additionally, the relatively low malignant invasiveness observed in >2.0 to ≤3.0 cm p-LUSC tumors offered promising directions for future research on personalized treatment strategies.

The incidence of peripheral lung squamous cell carcinoma (p-LUSC) has increased in recent years, but the clinical features of early-stage p-LUSC remain unclear. In the present study, we aim to elucidate the general clinical features of p-LUSC by comparing it with peripheral lung adenocarcinoma (p-LUAD). Patients with p-LUSC or p-LUAD who were at an early imaging stage and underwent complete lobectomy with systematic lymph node dissection were included. The clinical characteristics of p-LUSC were elucidated through comparative analysis with p-LUAD, and independent prognostic factors for recurrence-free survival were identified. A total of 103 patients with p-LUSC and 600 patients with p-LUAD were included. Compared with p-LUAD, all p-LUSC cases appeared as solid nodules (SDNs) on imaging, and p-LUSC was associated with the male sex, older age, smoking history, lobulation sign, interstitial pneumonia, and a shorter volume doubling time. In terms of malignant aggressiveness, p-LUSC demonstrated a significantly lower lymph node metastasis rate than SDNs of p-LUAD in the >2.0 to ≤3.0 cm group, while no statistically significant difference was observed between the two groups in the 0–2.0 cm group. As for prognosis, tumor size and lymph node metastasis were found as independent risk factors for tumor recurrence.