J Cancer 2020; 11(10):2845-2851. doi:10.7150/jca.35027

Research Paper

Novel Imprint Cytological Classification for Small Pulmonary Adenocarcinoma Using Surgical Specimens: Comparison with the 8th Lung Cancer Staging System and Histopathological Classification

Tomoyuki Nakagiri1, Tomio Nakayama2, Toshiteru Tokunaga1, Akemi Takenaka3, Hidenori Kunoh1, Hiroto Ishida1, Yasuhiko Tomita4, Shin-ichi Nakatsuka4, Harumi Nakamura4, Jiro Okami1, Masahiko Higashiyama1✉

1. Department of General Thoracic Surgery, Osaka International Cancer Institute, Osaka, Japan
2. Cancer Control and Statistics, Osaka International Cancer Institute Osaka, Japan
3. Department of Cytology, Osaka International Cancer Institute, Osaka, Japan
4. Department of Pathology, Osaka International Cancer Institute, Osaka, Japan

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Citation:
Nakagiri T, Nakayama T, Tokunaga T, Takenaka A, Kunoh H, Ishida H, Tomita Y, Nakatsuka Si, Nakamura H, Okami J, Higashiyama M. Novel Imprint Cytological Classification for Small Pulmonary Adenocarcinoma Using Surgical Specimens: Comparison with the 8th Lung Cancer Staging System and Histopathological Classification. J Cancer 2020; 11(10):2845-2851. doi:10.7150/jca.35027. Available from http://www.jcancer.org/v11p2845.htm

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Abstract

Objectives: Small-size lung lesions suspected of being cancer are now often being identified on computed tomography. Correspondingly, a new lung cancer staging system has been proposed by the International Association for the Study of Lung Cancer (IASLC), in which the T1 factor and adenocarcinoma are re-subclassified. Previously, we proposed an intraoperative cytological diagnosis and its classification of small-size lung adenocarcinoma, which correlated significantly with clinical malignancy, to be used for selecting the surgical strategy. In the current study, the correlation of our intraoperative cytological classification with the new 8th IASLC classification was investigated.

Materials and Methods: A total of 139 consecutive small-size lung adenocarcinoma cases were surgically resected from 2000 to 2006 and included in this study. Intraoperative stump imprint cytology using these specimens was performed, and the cases were classified into 5 groups based on our classification. The cytological classification was compared with the IASLC classification and the WHO histopathological grading.

Results: According to our classification, 32 patients were in Group I, 38 in Group II, 24 in Group III, 27 in Group IV, and 18 in Group V. Compared with the IASLC classification, most of Group I was pTis or pT1mi, and most of Group II was pT1mi or pT1a (p<0.001). There was also a significant relationship between lymph node metastasis and our cytological classification (p<0.001). The histological patterns according to the WHO classification also had a significant relationship with our classification (p<0.001).

Conclusion: Our cytological classification correlated not only with the T classification, but also with the adenocarcinoma subclassification of the 8th IASLC classification.

Keywords: imprint cytology, lung small adenocarcinoma, intraoperative diagnosis, cytological classification, 8th IASLC classification