171 Elastin in pulmonary pathology Survival After the first H&E scoring according to the WHO classification, the 5-year overall survival (OS) rate for patients with a non-invasive pattern (n=2) versus invasive pattern (n=31) was respectively 100% and 48% (p=0.18). When surgical/iatrogenic collapse was considered, 5 invasive cases were downgraded to non-invasive AIS. The 5-year OS rate for all those non-invasive cases (n=7) remained 100% and for the invasive cases (n=26) became 39% (p=0.019) (Figure 2). After CK7 staining the same 7 cases were scored as non-invasive. The CK7 reading was perceived as an easy tool. Discussion In this ‘proof of principle study’ we used surgical/iatrogenic collapse morphology to recognize non-invasive areas, while these can also according to the WHO be interpreted as invasive acinar or papillary patterns. The overall survival of the patients with in-situ reclassified adenocarcinomas remained 100%. The assessment of invasion as acknowledged by the WHO and as borne out in numerous studies, may be challenging in more than occasional cases of resected adenocarcinoma 14,309–311. CK7 regularity clearly aids in understanding the folded architecture of surgical collapse. Boland and colleagues show for assessment of pulmonary early adenocarcinomas a difference in survival curves between readings of two pathologists312 . One has 100% probability of overall survival for AIS compared to 80% for the other. Moreover, they suggested that “tumors with disagreement between ‘minimal invasive adenocarcinoma’ and ‘invasive adenocarcinoma’ had survival similar to agreed ‘minimal invasive adenocarcinoma’, and thus, borderline cases can be confidently classified as ‘minimal invasive adenocarcinoma’.” Although with the recognition of surgical collapsed adenocarcinoma in situ ‘minimal invasive adenocarcinoma’ should not be used, their findings are in line with our study. Limitations of this study are i) the raked together sample set from a larger cohort collected for another purpose (mutation analysis in a period with only focal availability of mutation testing); ii) the sample size, which was reduced by limited availability of follow-up. Conclusion In this proof of principle study recognition of surgical/iatrogenic collapse with the aid of CK7-IHC are supportive in the assessment of (non)invasive adenocarcinoma. Further study on this topic is needed. 13
RkJQdWJsaXNoZXIy MTk4NDMw