Early Progression Patterns of Lung Squamous Cell Carcinoma on Computed Tomography Images

A study found that lung squamous cell carcinoma (SqCC) initiated with various image patterns on computed tomography (CT). Additionally, initial CT image patterns differed between the hilar and peripheral zones, indicating a difference in progression scheme. Variances in volume doubling time (VDT) supported these findings.

“Because little is known about the early progression patterns of lung [squamous cell carcinoma], particularly lesions that develop in the peripheral lungs, the findings of this study provide insights into the carcinogenesis of lung [squamous cell carcinoma] and an important clue for the radiological diagnosis of early squamous lesions,” wrote Haruto Sugawara, MD, National Cancer Center Hospital, Tokyo, Japan, and colleagues.

The study enrolled 65 patients with SqCC who underwent surgical resection and 2 CT scans separated by an interval of at least 6 months. Findings were characterized by the initial and at-diagnosis CT images, then sorted into 5 previously reported patterns, with VDT calculated for measurable lesions.

The most common CT image at diagnosis was the single nodule pattern, occurring in 56 (86.2%) patients, which aligned with previous practical clinical findings. The patterns, however, were more diverse in the initial images. CT scans for 28 (43.1%) patients displayed atypical findings, such as multiple nodules (3.1%), endobronchial lesions (20%), subsolid nodules (10.8 %), and cyst wall thickening (9.2 %).

The study found all endobronchial lesions occurred in the central/middle zone of the lung field, while lesions presented as multiple nodules, subsolid nodules, and cyst wall thickening were detected in the peripheral zone. These differences in the developed zones were reflected in the median VDT, with tumors that presented an initial endobronchial pattern exhibiting a significantly shorter VDT than subsolid nodule-patterned tumors (140 days vs 276 days, respectively; P < .001).

“As suggested by the differences in VDT estimates, there may be some patterns in early development, particularly in the peripheral origin of squamous cell carcinoma,” Dr Sugawara et al noted before concluding, “The difference in doubling time suggested that the initial CT patterns represented biological differences between hilar and peripheral SqCCs.”

Source:

Sugawara H, Yatabe Y, Watanabe H, et al. Radiological precursor lesions of lung squamous cell carcinoma: Early progression patterns and divergent volume doubling time between hilar and peripheral zones. Lung Cancer. Published online: December 19, 2022. doi:10.1016/j.lungcan.2022.12.007