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

Abstract

Background/aim: 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.

Patients and methods: 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.

Results: 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.

Conclusion: The radiographical consolidation tumor size may affect overall survival and possibly reflect tumor growth activity, being consistent with 8^th edition of the TNM classification in that larger consolidation tumor size significantly correlates with poor survival.