Controversies on lung cancers manifesting as part-solid nodules

Abstract

Purpose Summarise survival of patients with resected lung cancers manifesting as part-solid nodules (PSNs). Methods PubMed/MEDLINE and EMBASE databases were searched for all studies/clinical trials on CT-detected lung cancer in English before 21 December 2015 to identify surgically resected lung cancers manifesting as PSNs. Outcome measures were lung cancer-specific survival (LCS), overall survival (OS), or disease-free survival (DFS). All PSNs were classified by the percentage of solid component to the entire nodule diameter into category PSNs <80% or category PSNs ≥80%. Results Twenty studies reported on PSNs <80%: 7 reported DFS and 2 OS of 100%, 6 DFS 96.3-98.7%, and 11 OS 94.7-98.9% (median DFS 100% and OS 97.5%). Twenty-seven studies reported on PSNs ≥80%: 1 DFS and 2 OS of 100%, 19 DFS 48.0%-98.0% (median 82.6%), and 16 reported OS 43.0%-98.0% (median DFS 82.6%, OS 85.5%). Both DFS and OS were always higher for PSNs <80%. Conclusion A clear definition of the upper limit of solid component of a PSN is needed to avoid misclassification because cell-types and outcomes are different for PSN and solid nodules. The workup should be based on the size of the solid component.

Long-Term Active Surveillance of Screening Detected Subsolid Nodules is a Safe Strategy to Reduce Overtreatment

“…34,35,38 In fact, delayed resection of SSN until signs of growth did not increase mortality in our series, validating the retrospective evidence from previous studies. 8,30,31,35,39 The conservative management of SSNs preserved the lung function in subjects that subsequently required resection of more aggressive cancer in other pulmonary sites. Early SSN resection could have caused deterioration of pulmonary function and quality of life, potentially hampering resectability of a second more aggressive lung cancer.…”

“…34 A systematic review of the literature on slow-growing adenocarcinoma derived from SSNs showed that the proportion of the solid component, but not the total size of the SSN, correlates with outcome measures, supporting a conservative management of slow growing tumors. 35 The long-term outcome of subjects with SSNs from the MILD trial shows that it is a safe option to manage SSNs conservatively until signs of growth of the solid component. Although only a minority of SSNs were resected under the MILD protocol (8 of 389 including one protocol violation), none of the unresected persistent SSNs developed into a clinically perceivable cancer within the follow-up period of almost 10 years.…”

Lung Adenocarcinomas Manifesting as Radiological Part-Solid Nodules Define a Special Clinical Subtype

“…The authors suggested a clear definition of the upper limit of the solid component of PSNs. 6 In 2017, Matsunaga et al divided part-solid lung cancers into ground glass-predominant and consolidation-predominant tumors, with a cutoff value 0.5 for the consolidation-to-tumor (CTR) ratio. They found that PSNs with a CTR of 0.5 or higher had a higher prevalence of lymphatic invasion and worse 5-year recurrence-free survival (RFS) than those with a CTR less than 0.5.…”

ESR/ERS statement paper on lung cancer screening

“…Extremely rare lymph node metastasis and 100% 5-year survival have been reported for NSNs [101]. For NSNs, size of the solid component (>5 mm), its ratio to total nodule size (⩾80%) and its evolution can be used to minimise the rate of overdiagnosis [67,102].…”