Impact of Radiographical Consolidation of Tumor Size of Part-solid Adenocarcinomas on Survival – A Propensity Score-matching Analysis

Recent evidence indicates that the radiographical consolidation tumor size of part-solid adenocarcinomas does not have prognostic value unlike that of pure-solid adenocarcinomas. We analyzed the impact of consolidation tumor size on postoperative survival in patients with part-solid adenocarcinoma. This retrospective study analyzed data of 375 patients with part-solid adenocarcinomas who underwent surgery at our Institute between 2006 and 2021. The consolidation-to-tumor ratio (CTR) was determined using preoperative computed tomography and the patients were grouped into groups with low (0-≤0.5, n=187) or high (>0.5 to <1, n=188) CTR. Clinical characteristics and survival were analyzed using propensity score-matching for radiographical consolidation tumor size. A larger radiographical consolidation tumor size significantly correlated with higher CTR (r2=0.56, p<0.0001) and larger pathological invasive size (r2=0.41, p<0.0001). Male sex and high radiographical consolidation tumor size were significant negative risk factors for overall survival in the unmatched cohort. The 5-year overall survival rates in the low- and high-CTR groups were 95.2% versus 85.2% (p=0.008) in the unmatched cohort, and 93.0% versus 83.2% (p=0.10) in the matched cohort. Competing-risk analysis showed 5-year cumulative incidence of cancer-specific death were 0% [95% confidence interval (CI)=not estimable] and 5.57% (95% CI=2.10-11.70%) in the low- and high-CTR groups, respectively (p=0.01), in contrast, the corresponding rates of non-cancer-related death were 4.72% (95% CI=1.40-11.10%) and 9.44% (95% CI=4.50-16.50%), respectively (p=0.18). These results indicate that survival of patients with consolidation-dominant part-solid adenocarcinoma is poor due to a higher rate of lung cancer death. The radiographical consolidation tumor size may affect overall survival and possibly reflect tumor growth activity, being consistent with 8th edition of the TNM classification in that larger consolidation tumor size significantly correlates with poor survival.