Comprehensive clinicopathological and genomic profiling of gallbladder cancer reveals actionable targets in half of patients

Gallbladder cancer (GBC) is a rare, highly aggressive malignancy with a 5-year survival rate of 5–10% in advanced cases, highlighting the need for more effective therapies. The aim of this study was to identify potentially actionable therapeutic targets for GBC. Specimens and clinicopathological data of 642 GBC patients, diagnosed between 2000 and 2019 were collected using the Dutch Pathology Registry (PALGA) and the Netherlands Cancer Registry. All cases were histologically reviewed and a subset was subjected to a comprehensive next generation sequencing panel. We assessed mutations and gene amplifications in a panel of 54 actionable genes, tumor-mutational burden (TMB), and microsatellite instability (MSI). Additionally, the entire cohort was screened for HER2, PD-L1, pan-TRK, and p53 expression with immunohistochemistry. Histopathological subtypes comprised biliary-type adenocarcinoma (AC, 69.6%), intestinal-type AC (20.1%) and other subtypes (10.3%). The median total TMB was 5.5 mutations/Mb (range: 0–161.1) and 17.7% of evaluable cases had a TMB of >10 mutations/Mb. MSI was observed in two cases. Apart from mutations in TP53 (64%), tumors were molecularly highly heterogeneous. Half of the tumors (50%) carried at least one molecular alteration that is targetable in other tumor types, including alterations in CDKN2A (6.0% biallelically inactivated), ERBB2 (9.3%) and PIK3CA (10%). Immunohistochemistry results correlated well with NGS results for HER2 and p53: Pearson r = 0.82 and 0.83, respectively. As half of GBC patients carry at least one potentially actionable molecular alteration, molecular testing may open the way to explore targeted therapy options for GBC patients.

Comparative kinase and cancer cell panel profiling of kinase inhibitors approved for clinical use from 2018 to 2020

During the last two decades, kinase inhibitors have become the major drug class for targeted cancer therapy. Although the number of approved kinase inhibitors increases rapidly, comprehensive in vitro profiling and comparison of inhibitor activities is often lacking in the public domain. Here we report the extensive profiling and comparison of 21 kinase inhibitors approved by the FDA for oncology indications since June 2018 and 13 previously approved comparators on panels of 255 biochemical kinase assays and 134 cancer cell line viability assays. Comparison of the cellular inhibition profiles of the EGFR inhibitors gefitinib, dacomitinib, and osimertinib identified the uncommon EGFR p.G719S mutation as a common response marker for EGFR inhibitors. Additionally, the FGFR inhibitors erdafitinib, infigratinib, and pemigatinib potently inhibited the viability of cell lines which harbored oncogenic alterations in FGFR1-3, irrespective of the specific clinical indications of the FGFR inhibitors. These results underscore the utility of in vitro kinase inhibitor profiling in cells for identifying new potential stratification markers for patient selection. Furthermore, comparison of the in vitro inhibition profiles of the RET inhibitors pralsetinib and selpercatinib revealed they had very similar biochemical and cellular selectivity. As an exception, an NTRK3 fusion-positive cell line was potently inhibited by pralsetinib but not by selpercatinib, which could be explained by the targeting of TRK kinases in biochemical assays by pralsetinib but not selpercatinib. This illustrates that unexpected differences in cellular activities between inhibitors that act through the same primary target can be explained by subtle differences in biochemical targeting. Lastly, FLT3-mutant cell lines were responsive to both FLT3 inhibitors gilteritinib and midostaurin, and the PI3K inhibitor duvelisib. Biochemical profiling revealed that the FLT3 and PI3K inhibitors targeted distinct kinases, indicating that unique dependencies can be identified by combined biochemical and cellular profiling of kinase inhibitors. This study provides the first large scale kinase assay or cell panel profiling study for newly approved kinase inhibitors, and shows that comprehensive in vitro profiling of kinase inhibitors can provide rationales for therapy selection and indication expansion of approved kinase inhibitors.

Metastasis in the gallbladder: does literature reflect reality?

BACKGROUND

Metastases to the gallbladder (GBm) are rare and pose a unique diagnostic challenge because they can mimic a second primary tumor. This study aimed to gain insight into the clinicopathological and epidemiological characteristics of GBm.

METHODS

A comprehensive literature review was performed (literature cohort) and compared with a nationwide cohort of GBm patients diagnosed between 1999 and 2015 in the Netherlands, collected via two linked registries (population cohort). Overall survival (OS) was estimated by Kaplan-Meier. Hazard ratios were determined by a Cox proportional hazard model.

RESULTS

The literature cohort and population cohort consisted of 225 and 291 patients, respectively. In the literature cohort, melanoma was the most frequent origin (33.8%), while colorectal cancer was the most frequent origin in the population cohort (23.7%). Prognosis was poor with median OS ranging from 6.0 to 22.5 months in the literature and population cohorts, respectively. Age, timing of GBm (synchronous/metachronous) and primary tumor origin were independent prognostic factors for OS.

DISCUSSION

Metastases to the gallbladder are rare and carry a poor prognosis. Differences between both cohorts can be attributable to the biased reporting of tumor types that are more easily recognized as GBm because of distinct histological features.

Clinical, Pathology, Genetic, and Molecular Features of Colorectal Tumors in Adolescents and Adults 25 Years or Younger

BACKGROUND & AIMS

Colorectal cancers (CRCs) are rare in adolescents and adults ages 25 years or younger. We analyzed clinical, pathology, and molecular features of colorectal tumors from adolescents and young adults in an effort to improve genetic counseling, surveillance, and, ultimately, treatment and outcomes.

METHODS

We analyzed clinical data and molecular and genetic features of colorectal tumor tissues from 139 adolescents or young adults (age, ≤25 y; median age, 23 y; 58% male), collected from 2000 through 2017; tumor tissues and clinical data were obtained from the nationwide network and registry of histopathology and cytopathology and The Netherlands Cancer Registry, respectively. DNA samples from tumors were analyzed for microsatellite instability, mutations in 56 genes, and genome-wide somatic copy number aberrations.

RESULTS

Mucinous and/or signet ring cell components were observed in 33% of tumor samples. A genetic tumor risk syndrome was confirmed for 39% of cases. Factors associated with shorter survival time included younger age at diagnosis, signet ring cell carcinoma, the absence of a genetic tumor risk syndrome, and diagnosis at an advanced stage of disease. Compared with colorectal tumors from patients ages 60 years or older in the Cancer Genome Atlas, higher proportions of tumors from adolescents or young adults were microsatellite stable with nearly diploid genomes, or contained somatic mutations in TP53 and POLE, whereas lower proportions contained mutations in APC.

CONCLUSIONS

We found clinical, molecular, and genetic features of CRCs in adolescents or young adults to differ from those of patients older than age 60 years. In 39% of patients a genetic tumor risk syndrome was identified. These findings provide insight into the pathogenesis of CRC in young patients and suggest new strategies for clinical management. Performing genetic and molecular analyses for every individual diagnosed with CRC at age 25 years or younger would aid in this optimization.

Quality Assessment of Gallbladder Cancer Pathology Reports: A Dutch Nationwide Study

Simple Summary

Appropriate reporting of pathological findings is required for optimal patient care and to perform high-quality research. The aim of our study was to assess the completeness of pathology reports of gallbladder cancer (GBC) in a large nation-wide patient cohort from the Netherlands. Results showed that reports were often incomplete; information on essential items that can predict prognosis were often missing. Whereas certain items were often missing in the report, they could be retrospectively detected in a large proportion of patients during pathology review. Our findings showed that significant improvements could be made in the reporting of gallbladder cancer in the Netherlands. To this end, the added value of standardized (synoptic) reporting should be explored, of which the beneficial effects have already been demonstrated in other tumor types.

Abstract

Adequate reporting of pathological findings is essential for optimal patient management and to perform high-quality research. The aim of this study was to assess the completeness of pathology reports of gallbladder cancer (GBC) at the nationwide level to assess guideline adherence and make recommendations for improvement. A retrospective population-based cohort of GBC patients diagnosed in the Netherlands from 2000 to 2019 was collected using data from the Dutch Cancer Registry and the nationwide network and registry of histology. Pathology reports were scored on the presence and content of essential and optional items according to the Dutch consensus-based guideline on biliary tract cancer. By histopathological review of cases, we compared findings with the conclusion of the corresponding pathology report. All pathology reports (n = 849) had a narrative, nonstructured format. Overall completeness was low. Information on key prognostic factors, such as tumor side (hepatic vs. serosal), status of cystic duct and liver surgical margins and venous and perineural invasion, was frequently lacking (80%, 23%, 59%, 74% and 74% missing, respectively). Whereas certain items were often missing from the report, they could be retrospectively detected in a substantial proportion of cases during pathology review (n = 738). In conclusion, significant improvements could be made in the reporting of GBC in the Netherlands. Synoptic reporting could greatly enhance the completeness of reports, as already demonstrated for tumor types.

Unraveling Neuroendocrine Gallbladder Cancer: Comprehensive Clinicopathologic and Molecular Characterization

PURPOSE

Neuroendocrine carcinomas and mixed neuroendocrine non-neuroendocrine neoplasms of the gallbladder (NE GBC) are rare and highly aggressive entities. The cell of origin of NE GBC has been a matter of controversy. Here, we performed a comparative histopathologic and molecular analysis of NE GBC cases and, if present, associated precancerous lesions.

PATIENTS AND METHODS

We selected cases diagnosed between 2000 and 2019 in the Netherlands. Precursors and carcinomas were immunohistochemically compared and analyzed for mutations, gene amplifications, microsatellite instability, and tumor mutational burden using an next-generation sequencing panel containing 523 cancer-related genes. In addition, presence of fusion genes was analyzed using a panel of 55 genes.

RESULTS

Sixty percent of neuroendocrine cases (6/10) presented with a precursor lesion, either intracholecystic papillary neoplasm (n = 3) or biliary intraepithelial neoplasia (n = 3). Immunohistochemically, neuroendocrine components were different from the epithelial precursor lesions. Molecular profiling, however, revealed TP53 mutations shared between different components in five of six cases, indicating a clonal relation. Furthermore, 40% of cases (4/10) harbored at least one potentially actionable alteration. This included (likely) pathogenic mutations in RAD54L, ATM, and BRCA2; amplifications of ERBB2 and MDM2; and a gene fusion involving FGFR3-TACC3. All cases were microsatellite-stable and had a tumor mutational burden of < 10 mutations/Mb.

CONCLUSION

Our data provide insight into the development of NE GBC and suggest a common origin of precancerous epithelial lesions and invasive neuroendocrine components, favoring the hypothesis of lineage transformation. Moreover, nearly half of the NE GBCs carried at least one potentially actionable molecular alteration, highlighting the importance of molecular testing in this highly lethal cancer.

Re-resection in Incidental Gallbladder Cancer: Survival and the Incidence of Residual Disease

Background

Re-resection for incidental gallbladder cancer (iGBC) is associated with improved survival but little is known about residual disease (RD) and prognostic factors. In this study, survival after re-resection, RD, and prognostic factors are analyzed.

Methods

Patients with iGBC were identified from the Netherlands Cancer Registry, and pathology reports of re-resected patients were reviewed. Survival and prognostic factors were analyzed.

Results

Overall, 463 patients were included; 24% (n = 110) underwent re-resection after a median interval of 66 days. RD was present in 35% of patients and was most frequently found in the lymph nodes (23%). R0 resection was achieved in 93 patients (92%). Median overall survival (OS) of patients without re-resection was 13.7 (95% confidence interval [CI] 11.6–15.6), compared with 52.6 months (95% CI 36.3–68.8) in re-resected patients (p < 0.001). After re-resection, median OS was superior in patients without RD versus patients with RD (not reached vs. 23.1 months; p < 0.001). In patients who underwent re-resection, RD in the liver (hazard ratio [HR] 5.54; p < 0.001) and lymph nodes (HR 2.35; p = 0.005) were the only significant prognostic factors in multivariable analysis. Predictive factors for the presence of RD were pT3 stage (HR 25.3; p = 0.003) and pN1 stage (HR 23.0; p = 0.022).

Conclusion

Re-resection for iGBC is associated with improved survival but remains infrequently used and is often performed after the optimal timing interval. RD is the only significant prognostic factor for survival after re-resection and can be predicted by pT and pN stages.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-08074-4) contains supplementary material, which is available to authorized users.

Colorectal metastasis to the gallbladder mimicking a primary gallbladder malignancy: histopathological and molecular characteristics

AIMS

Outcomes of colorectal cancer (CRC) treatment and survival have steadily improved during the past decades, accompanied by an increased risk of developing second primary tumours and metastatic tumours at unusual sites. Metastatic CRC can show mucosal colonisation, thereby mimicking a second primary tumour. This potential confusion could lead to incorrect diagnosis and consequently inadequate treatment of the patient. The aim of this study was to differentiate between metastatic CRC and a second primary (gallbladder cancer, GBC) using a combination of standard histopathology and molecular techniques.

METHODS AND RESULTS

Ten consecutive patients with both CRC and GBC were identified in our region using the Dutch National Pathology Archive (PALGA). Two patients served as negative controls. Histology of GBC was reviewed by nine pathologists. A combination of immunohistochemistry, microsatellite analysis, genomewide DNA copy number analysis and targeted somatic mutation analysis was used to aid in differential diagnosis. In two patients, CRC and GBC were clonally related, as confirmed by somatic mutation analysis. For one case, this was confirmed by genomewide DNA copy number analysis. However, in both cases, pathologists initially considered the GBC as a second primary tumour.

CONCLUSIONS

Metastatic CRC displaying mucosal colonisation is often misinterpreted as a second primary tumour. A combination of traditional histopathology and molecular techniques improves this interpretation, and lowers the risk of inadequate treatment.