Prognostic significance of micronest in cancer stroma in resected lung squamous cell carcinoma.

Tumor budding in the cancer stroma has been reported to be a prognostic factor in non-small cell lung cancer. Micronest in cancer stroma (MICS) is often observed as a formation that is larger and more conspicuous than budding, but its clinicopathologic significance is unclear. In this study, we aimed to examine the clinicopathological significance of MICS in lung squamous cell carcinoma (LSqCC). A total of 198 consecutive patients with pathologically diagnosed LSqCC (anyT N0-1M0) were enrolled in this study. MICS were defined as those that met the following criteria: (1) consisting of 5-200 tumor cells or less than 200 µm in diameter and (2) more than 200 µm away from the adjacent main lesion. The prognostic impact of the presence or absence of MICS and the characteristics of MICS-forming cancer cells were evaluated by immunohistochemistry (IHC). MICS was observed in 57 patients (28.8%), and overall survival (OS) and recurrence-free survival (RFS) were significantly shorter in the MICS-positive group (OS: 44.4% vs. 84.4%, p < 0.001; RFS: 30.0% vs. 82.6%, p < 0.001). Univariate and multivariate analyses revealed that the presence of MICS was an independent poor prognostic factor for OS (hazard ratio [HR] 3.54, p < 0.001) and RFS (HR 4.99, p < 0.001). Immunohistochemistry showed that the expression levels of the cell-cell adhesion molecule E-cadherin and hypoxia-induced protein GLUT-1 were significantly decreased in cancer cells forming MICS lesions compared to the tumor component excluding MICS within the same tumor (non-MICS lesions). Our data show that MICS is a distinct morphological feature with important biological and prognostic significance.

EGFR mutation impacts recurrence in high-risk early-stage lung adenocarcinoma in the IASLC grading system.

INTRODUCTION: The developments of perioperative treatments for patients with high-risk early-stage lung cancer are ongoing, however, real-world data and evidence of clinical significance of genetic aberration are lacking in this population. This study aimed to identify patients with early-stage lung adenocarcinoma at high risk for recurrence based on pathological indicators of poor prognosis, including the International Association for the Study of Lung Cancer (IASLC) grade, and elucidate the prognostic impact of epidermal growth factor receptor mutation (EGFRm) status. METHODS: This retrospective study included 494 consecutive patients who underwent complete resection for pathological stage I lung adenocarcinoma between 2011 and 2016. The patients were evaluated for EGFRm and IASLC grade. Multivariable analysis was used to identify pathological factors for poor prognosis associated with recurrence-free survival (RFS) and overall survival (OS). Patients with any one of these factors were classified into the high-risk group. The prognostic impact of EGFRm was evaluated using RFS, OS, and cumulative recurrence proportion. RESULTS: Multivariable analysis for RFS and OS revealed that IASLC grade 3, pathological invasion size>2 cm, and presence of lymphovascular invasion were indicators of poor prognosis. EGFRm-positive patients had a higher incidence of all types of recurrence, including central nervous system (CNS) metastasis and distant metastasis in high-risk group, but not in low-risk group. CONCLUSIONS: This study provides evidence that patients with EGFRm-positive stage I lung adenocarcinoma in the high-risk group have an increased risk of recurrence, including CNS metastasis. These findings highlight the need for development of adjuvant treatment in this population.

Ten-year follow-up outcomes of limited resection trial for radiologically less-invasive lung cancer.

BACKGROUND: The JCOG0804/WJOG4507L single-arm confirmatory trial indicated a satisfactory 10-year prognosis for patients who underwent limited resection for radiologically less-invasive lung cancer. However, only one prospective trial has reported a 10-year prognosis. METHODS: We conducted a multicenter prospective study coordinated by the National Cancer Center Hospital East and Kanagawa Cancer Center. We analyzed the long-term prognosis of 100 patients who underwent limited resection of a radiologically less-invasive lung cancer in the peripheral lung field. We defined radiologically less-invasive lung cancer as lung adenocarcinoma with a maximum tumor diameter of ≤2 cm, tumor disappearance ratio of ≥0.5 and cN0. The primary endpoint was the 10-year local recurrence-free survival. RESULTS: Our patients, with a median age of 62 years, included 39 males. A total of 58 patients were non-smokers; 87 had undergone wide wedge resection and 9 underwent segmentectomy. A total of four cases were converted to lobectomy because of the presence of poorly differentiated components in the frozen specimen or insufficient margin with segmentectomy. The median follow-up duration was 120.9 months. The 10-year recurrence-free survival and overall survival rates of patients with lung cancer were both 96.0%. Following the 10-year long-term follow-up, two patients experienced recurrences at resection ends after wedge resection. CONCLUSIONS: Limited resection imparted a satisfactory prognosis for patients with radiologically less-invasive lung cancer, except two cases of local recurrence >5 years after surgery. These findings suggest that patients with this condition who underwent limited resection may require continued follow-up >5 years after surgery.