TOPLINE

An observational study found that among lung cancers detected through low-dose CT (LDCT) screening, adenocarcinomas (ADCs) were smaller, more often found in the upper lobes, and more frequently attached to the pleura than other histologic subtypes. After adjustment, lower- and middle-lobe tumours had lower odds of being ADCs, whereas pleural attachment was linked to more than sixfold higher odds, although the CI was wide.

METHODOLOGY

• Researchers conducted a retrospective, observational cohort study within NELSON-POP, an extension of the Dutch-Belgian NELSON randomised controlled trial, analysing histologically confirmed screen-detected cancers from three Dutch sites.
• The analysis included 213 participants (mean age, 64 years; 81.7% men), of whom 67.5% had ADCs and 32.5% had other subtypes, such as squamous cell carcinoma and small cell lung cancer (SCLC). A total of 73.7% had stage I-II, 12.2% had stage III, and 7.5% had stage IV disease.
• Thoracic radiologists trained in screening and blinded to histology measured the location, margins, nodule type, diameter, volume, and pleural distance of each lesion using standardised NELSON protocols; volume doubling time (VDT) was calculated from serial scans.
• The researchers examined associations between these features and ADCs vs other subtypes, adjusting for age, sex, smoking status, and stage.

TAKEAWAY

• In the final multivariable model, the odds of ADC fell as maximum diameter increased (odds ratio [OR], 0.92 per 1-mm increase; 95% CI, 0.85-0.99); however, lesion attachment to the pleura, compared with the central location, was associated with higher odds of ADCs (OR, 6.67; 95% CI, 1.20-33.33).
• Compared with tumours in the right upper lobe, those in the left lower lobe (OR, 0.28; 95% CI, 0.10-0.78), right lower lobe (OR, 0.24; 95% CI, 0.09-0.65), and right middle lobe (OR, 0.17; 95% CI, 0.04-0.74) were associated with lower odds of being ADCs.
• The discrimination of the final model was acceptable (area under the curve [AUC], 0.75; 95% CI, 0.67-0.84), with a sensitivity of 96% but a specificity of only 29%.
• In the sensitivity analysis of 80 participants with serial scans, a longer VDT was associated with higher odds of ADC (OR, 5.65; 95% CI, 1.67-19.07), and discrimination improved (AUC, 0.89) compared with the model without VDT, although the models were fitted in different samples.

IN PRACTICE

"The exploratory multivariable model showed acceptable discrimination; however, imaging characteristics alone are insufficient for histologic prediction and should be considered hypothesis-generating until externally validated," the authors wrote.

"External validation and integration with clinical and molecular data are required before clinical use," they added.

SOURCE

The study was led by Erick Suazo-Zepeda, University Medical Center Groningen, University of Groningen, Groningen, Netherlands. It was published online on October 07, 2026, in European Radiology.

LIMITATIONS

The smaller subtype groups limited the analysis, especially for the less common cancers such as SCLC. VDT data were available for only a subset of participants, which introduced selection bias. Women were underrepresented in the sample, limiting generalisability. Because LDCT screening tends to detect slower-growing tumours, some of the patterns could partly reflect selection. Additionally, the exploratory model was not validated.

DISCLOSURES

The study received funding from the Dutch Cancer Society, Siemens Healthineers, and the Ministry of Economic Affairs and Climate Policy through the public-private partnerships allowance of the Top Sector Life Sciences & Health. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.