Clinical implication of minimal presence of solid or micropapillary subtype in early‐stage lung adenocarcinoma

Abstract

Background: We investigated the clinical features and surgical outcomes of lung adenocarcinoma with minimal solid or micropapillary (S/MP) components, with a focus on stage IA. Methods: We enrolled 506 patients with lung adenocarcinoma who underwent curative resection in this study. Clinical features and surgical outcomes were compared between the groups with and without the S/MP subtype (S/MP+ and S/MP−, respectively), and between the group with an S/MP proportion of ≤5% (S/MP5) and the S/MP−. Results: The S/MP subtype was present in 247 patients (48.8%); 129 (25.5%) were grouped as the S/MP5 group. The S/MP+ and S/MP5 groups had larger tumors, higher frequency of lymph node metastasis, and more advanced stages of disease than the S/MP− group (P < 0.001, all comparisons). Pleural, lymphatic, and vascular invasions occurred more frequently in the S/MP+ and S/MP5 groups (P < 0.001, all comparisons for S/MP+ vs. S/MP−; P ≤ 0.01, all comparisons for S/MP5 vs. S/MP−). The S/MP+ and S/MP5 groups showed a shorter time to recurrence and cancer-related death than the S/MP− group(P < 0.001, both comparisons). For stage I, the presence or absence of the S/MP subtype defined prognostic subgroups better than the stage IA/IB classification. Notably, in the multivariate analysis, the minimal S/MP component was a significant predictor of recurrence, even in stage IA. Conclusions: The presence of the minimal S/MP component was a significant predictor of poor prognosis after surgery, even in stage IA patients. Clinical trials to evaluate the advantages of adjuvant chemotherapy for this subset of patients and further investigations to understand underlying biological mechanisms of poor prognosis are needed. Key points: Significant findings of the study: We demonstrated that only minimal presence of solid or micropapillary component was profoundly associated with aggressive clinicopathological features and poor prognosis after complete resection even in stage IA lung adenocarcinoma. What this study adds: Our results

Genomics Analysis and Nomogram Risk Prediction of Occult Lymph Node Metastasis in Non-Predominant Micropapillary Component of Lung Adenocarcinoma Measuring ≤ 3 cm

“…In our retrospective cohort, the clinical features of each patient were systematically analyzed; 717 (11.17%) patients were confirmed to have a micropapillary component, and OLNM was observed in 20.13% of patients with an NP-MCP of lung adenocarcinoma measuring ≤ 3 cm. Our data demonstrated that tumor size, young age of onset, and solidand micropapillary-components were independent risk factors for OLNM, which is consistent with previous studies (21)(22)(23)(24)(25).…”

A prognostic nomogram based on a new classification of combined micropapillary and solid components for stage IA invasive lung adenocarcinoma

“…According to the new pathological classification of lung adenocarcinoma proposed by IASLC/ATS/ERS, the patients with micropapillary and solid subtypes were considered to have poor prognosis. Several studies have reported that micropapillary/solid subtypes, including predominant and non‐predominant patterns, were associated with poor prognosis 4–7,9–12 . Lung adenocarcinomas are usually heterogeneous and contain a mixture of multiple subtypes.…”

“…Since a new histological classification of LUAD was proposed by IASLC/ATS/ERS, the impact of micropapillary or solid components on the survival of early lung cancer had attracted more attention. According to 384 patients with stage I lung adenocarcinoma, Choi et al 9 found that the presence or absence of micropapillary/solid patterns had a greater advantage over the stage IA/IB classification in distinguishing prognosis, indicating that the micropapillary/solid components may be a preferable prognostic factor compared with tumor size in stage I LUAD. Due to the importance of micropapillary and solid components in affecting the survival of patients with LUAD, the combination of two components is necessary to comprehensively evaluate the prognosis of patient.…”

“…This study revealed that the SMPM group had poorer survival than the SMPN group, and the survival of SMPP group was worse compared with the SMPM group. Choi et al 9 showed that a subtype component occupying not less than 1% of the entire tumor was considered to be present. The tumors with present solid (S) or micropapillary (MP) were grouped as S/MP+, whereas those without both S and MP were categorized as S/MP−.…”

Preoperative Folate Receptor-Positive Circulating Tumor Cell Level Is a Prognostic Factor of Long Term Outcome in Non-Small Cell Lung Cancer Patients

“…Clinicopathological characteristics including age, sex, tumor size, pathological type, tumor differentiation, adenocarcinoma subtype, and TNM stages were collected. According to the degree of invasion and adenocarcinoma subtype, patients were divided into two groups (Low Risk Group: AIS, MIA, lepidic, and acinar; High Risk Group: mucinous, micropapillary, and solid) ( 23 , 24 ).…”