Most of the cohort had early-stage disease: 52 of 73 patients, or 71.2%, had stage I disease, comprising 37 classified as stage IA and 15 as stage IB. The other 21 patients, representing 28.8%, had stage II–IV disease. The investigators used definitive histological subtyping and next-generation sequencing data to compare tumor characteristics.

Men accounted for 55.2% of patients whose tumors contained micropapillary/solid components, compared with 22.7% of those whose tumors did not, a difference associated with a P value of 0.006. Patients with a smoking history made up 44.8% of the micropapillary/solid-positive group, versus 20.5% of the negative group, with P = 0.037. Histological combinations further separated the groups by proliferative activity.

Tumors that were micropapillary/solid positive and lepidic negative had the highest Ki-67 expression, at 30%, and differed significantly from tumors that were micropapillary/solid negative and lepidic positive, for which the reported P value was 0.037. Exploratory genomic analyses of this micropapillary/solid-positive, lepidic-negative subgroup also showed numerical enrichment of KRAS, MET, STK11 and CDKN2A alterations, alongside a lower EGFR alteration rate. None of these genomic differences reached statistical significance, so the findings do not establish a mutation-defined subtype.

The study also used individualized tumor-informed ctDNA detection to examine changes around surgery. Detectable ctDNA was found before surgery in 7 of 31 patients and after surgery in 5 of 28 patients with available samples. All detections occurred among patients whose tumors lacked a lepidic component, but this association was not statistically significant.

Overall, the analysis associates micropapillary/solid and lepidic components with distinct clinical and proliferative characteristics, while the possible genomic and ctDNA relationships remain signals that warrant further investigation.

Subject of Research: Histological and molecular correlates of micropapillary/solid and lepidic patterns in invasive non-mucinous lung adenocarcinoma

Article Title: Clinicopathological and molecular correlates of micropapillary/solid and lepidic patterns in lung adenocarcinoma

Article References: Fang, X., Zhang, L., Li, J., Li, S., Wang, H., Zhu, T., Lu, Y., & Xia, H. (2026). Clinicopathological and molecular correlates of micropapillary/solid and lepidic patterns in lung adenocarcinoma. BMC Cancer. https://doi.org/10.1186/s12885-026-16913-3

Image Credits: AI Generated

DOI: 10.1186/s12885-026-16913-3

Keywords: lung adenocarcinoma, micropapillary/solid pattern, lepidic pattern, Ki-67, next-generation sequencing, circulating tumor DNA, tumor genomics, retrospective cohort, proliferation, molecular residual disease, Clinicopathological, molecular