The “histological replacement growth pattern” represents aggressive invasive behavior in liver metastasis from pancreatic cancer

• Published in: Cancer medicine (Malden, MA) MA), 2020-05, Vol.9 (9), p.3130-3141
• Main Authors: Watanabe, Kazuo, Mitsunaga, Shuichi, Kojima, Motohiro, Suzuki, Hidetaka, Irisawa, Ai, Takahashi, Hideaki, Sasaki, Mitsuhito, Hashimoto, Yusuke, Imaoka, Hiroshi, Ohno, Izumi, Ikeda, Masafumi, Akimoto, Tetsuo, Ochiai, Atsushi
• Format: Article
• Language: English
• Subjects: Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Automation; Biopsy; Cancer Biology; Cancer therapies; CD8 antigen; Cell Proliferation; Chemotherapy; Female; Follow-Up Studies; Growth patterns; Hepatocytes; Humans; Inflammation; Invasiveness; Liver; Liver cancer; liver metastasis; Liver Neoplasms - drug therapy; Liver Neoplasms - secondary; Male; Medical prognosis; Metastases; Metastasis; Middle Aged; Multivariate analysis; Neoplasm Invasiveness; Original Research; Pancreatic cancer; Pancreatic Neoplasms - drug therapy; Pancreatic Neoplasms - pathology; Prognosis; prognostic factor; replacement growth pattern; Retrospective Studies; Survival Rate; tumor microenvironment; Tumors
• ISSN: 2045-7634; 2045-7634
• DOI: 10.1002/cam4.2954

Background In the case of liver metastasis (LM), tumors showing the replacement growth pattern (RGP), in which metastatic cells infiltrate and replace hepatocytes with minimal desmoplastic reaction and inflammatory cell infiltration, associate with a poor prognosis. The heterogeneity, frequency, and prognostic value of the RGP in LM from pancreatic cancer (PCa) are not well known. Methods In the circumference of treatment‐naïve resected LMs from patients with PCa, the heterogeneity of the GP was assessed. Next, the clinicopathological features of LMs showing the RGP in needle biopsy specimens were investigated in patients with treatment‐naïve advanced PCa. Results Thirteen of the 14 (93%) in all resected LMs and 7 of the 9 (78%) in RGP component GP in resected LMs showed homogeneous GP. A RGP was found in 50% of the needle biopsy specimens of LMs obtained from 107 patients. The median overall survival times in the RGP group and non‐RGP group were 3.6 and 10.4 months. Multivariate analysis identified RGP as an independent poor prognostic factor. Median value of CD8 positive percentage in RGP was lower than that in non‐RGP (0.75 vs 1.46, P = .04). Median overall survival times in low CD8 groups tend to be shorter than those in high CD8 group (8.2 vs 4.2 months). Conclusion Most LMs from PCa show a homogeneous GP. The RGP was observed in about a half of the LMs from PCa patients, and was identified as a poor prognostic factor. Morphological aspects of the tumor‐liver interface of liver metastasis, which was called growth pattern have been carefully studied in various cancers but not in pancreatic cancer. The RGP was observed in about a half of the LMs from PCa patients, and was identified as a poor prognostic factor.