Squamous Cell/Adenosquamous Carcinomas and Adenocarcinomas of the Gallbladder: An Immunohistochemistry Study of Prognostic Markers

Tissue proteome analysis for profiling proteins associated with lymph node metastasis in gallbladder cancer

Lymph node (LN) metastasis is the earliest sign of metastatic spread and an established predictor of poor outcome in gallbladder cancer (GBC). Patients with LN positive GBC have a significantly worse survival (median survival- 7 months) than patients with LN negative disease (median survival- ~ 23 months) in spite of standard treatment which includes extended surgery followed by chemotherapy, radiotherapy and targeted therapy. This study aims at understanding the underlying molecular processes associated with LN metastasis in GBC. Here, we used iTRAQ-based quantitative proteomic analysis using tissue cohort comprising of primary tumor of LN negative GBC (n = 3), LN positive GBC (n = 4) and non-tumor controls (Gallstone disease, n = 4), to identify proteins associated with LN metastasis. A total of 58 differentially expressed proteins (DEPs) were found to be specifically associated with LN positive GBC based on the criteria of p value ≤ 0.05, fold change ≥ 2 and unique peptides ≥ 2. These include the cytoskeleton and associated proteins such as keratin, type II cytoskeletal 7 (KRT7), keratin type I cytoskeletal 19 (KRT19), vimentin (VIM), sorcin (SRI) and nuclear proteins such as nucleophosmin Isoform 1 (NPM1), heterogeneous nuclear ribonucleoproteins A2/B1 isoform X1 (HNRNPA2B1). Some of them are reported to be involved in promoting cell invasion and metastasis. Bioinformatic analysis of the deregulated proteins in LN positive GBC using STRING database identified 'neutrophil degranulation' and 'HIF1 activation' to be among the top deregulated pathways. Western blot and IHC analysis showed a significant overexpression of KRT7 and SRI in LN positive GBC in comparison to LN negative GBC. KRT7, SRI and other proteins may be further explored for their diagnostics and therapeutic applications in LN positive GBC.

Comparative Outcomes of Adenosquamous Carcinoma of the Gallbladder: an Analysis of the National Cancer Database

BACKGROUND

A paucity of data exists regarding adenosquamous carcinoma of the gallbladder, a histology comprising under 10% of gallbladder cancer diagnoses. The aim of this study is to characterize the clinicopathological features of these tumors utilizing a population-based dataset compared with gallbladder adenocarcinoma.

METHODS

We identified patients with gallbladder adenosquamous and adenocarcinoma from the National Cancer Database from 2004 to 2015. Patient demographics, tumor characteristics, treatment regimens, and overall survival were analyzed between the groups.

RESULTS

We identified 13,158 patients: 12,455 (95%) with a diagnosis of gallbladder adenocarcinoma and 703 (5%) with adenosquamous carcinoma. Adenosquamous tumors were larger, poorly differentiated, and presented with Stage III/IV disease (75% vs 69%, p < 0.001). Overall 1-, 3-, and 5-year survival for adenosquamous and adenocarcinoma were 24%, 11%, and 9% vs 37%, 16%, and 11%, respectively (p < 0.001). Following surgical resection, adenosquamous carcinoma had more positive margins (31% vs 25%, p < 0.001), and median overall survival was 10.3 months vs 20.5 months for adenocarcinoma (p < 0.001). Overall survival at 1-, 3-, and 5-years for surgically resected adenosquamous and adenocarcinoma were 43%, 23%, and 18% versus 63%, 35%, and 25%, respectively (p < 0.001). In resected adenosquamous carcinoma, positive lymph nodes and margins were associated with worse survival, while adjuvant chemoradiation (HR 0.457, 95% CI 0.31-0.69, p < 0.001) was associated with improved survival.

CONCLUSION

Adenosquamous gallbladder cancer presented with larger tumors at advanced clinical stages when compared with adenocarcinoma. Overall survival was worse for adenosquamous tumors both overall, and following curative intent resection. Adjuvant chemoradiation was associated with improved survival in adenosquamous tumors.

Diagnostic and prognostic impact of cytokeratin 19 expression analysis in human tumors: a tissue microarray study of 13,172 tumors

To evaluate cytokeratin 19 (CK19) expression in normal and cancerous tissues, 15,977 samples from 122 tumor types and 608 samples of 76 normal tissue types were analyzed by immunohistochemistry (IHC). In normal tissues, CK19 expression occurred in epithelial cells of most glandular organs but was strictly limited to the basal cell layer of nonkeratinizing squamous epithelium and absent in the skin. CK19 expression in ≥90% of cases was seen in 34% of the tumor entities including the adenocarcinomas of the pancreas (99.4%), colorectum (99.8%), esophagus (98.7%), and stomach (97.7%), as well as breast cancer (90.0%-100%), high-grade serous (99.1%) or endometrioid (97.8%) ovarian cancer, and urothelial carcinoma (92.6%-100%). A low CK19 positivity rate (0.1-10%) was seen in 5 of 122 tumor entities including hepatocellular carcinoma and seminoma. A comparison of tumor versus normal tissue findings demonstrated that upregulation and downregulation of CK19 can occur in cancer and that both alterations can be linked to unfavorable phenotypes. CK19 downregulation was linked to high grade (p = 0.0017) and loss of estrogen receptor- and progesterone receptor-expression (p < 0.0001 each) in invasive breast carcinoma of no special type. CK19 upregulation was linked to nodal metastases in neuroendocrine tumors and papillary thyroid carcinomas (p < 0.05 each) and to poor grade in clear cell renal cell carcinoma (p < 0.05). CK19 upregulation was particularly common in squamous cell carcinomas. We concluded that CK19 IHC might separate primary liver cell carcinoma from liver metastases, seminoma from other testicular tumors, and helps in the detection of early neoplastic transformation in squamous epithelium.

Adenosquamous gallbladder carcinoma: Multigene hotspot mutational profiling reveals a monoclonal origin of the two components

Adenosquamous carcinoma (ASC) of the gallbladder is a rare malignant tumor that is characterized by a coexisting of glandular and squamous components. In a case of ASC, we performed hotspot multigene mutational profiling of 164 hotspot regions of eleven cancer-associated genes (AKT1, APC, BRAF, CTNNB1, KIT, KRAS, NRAS, PDGFRA, PIK3CA, PTEN and TP53) in the two microdissected components. Both tumor phenotypes resulted characterized by a p.E542K point mutation in the PIK3CA gene, whereas adenocarcinoma component revealed also a TP53 Q331* homozygous stop mutation. Of note, coexisting high-grade dysplastic epithelium was characterized by a mixed cell population, with an upper part featuring a glandular differentiation and a basal layer of p63 positive (squamous committed) cells. Overall these data provide evidence of an early squamous differentiation of the lesion with a common genetic landscape of the two components.