Activated FGFR2 signalling as a biomarker for selection of intrahepatic cholangiocarcinoma patients candidate to FGFR targeted therapies

FGFR inhibitors have been developed to inhibit FGFR activation and signal transduction; notwithstanding, currently the selection of intrahepatic cholangiocarcinoma (iCCA) patients for these drugs only relies on the detection of FGFR2 genetic alterations (GAs) in tumor tissues or circulating tumor DNAs, without concomitant assessment of FGFR2 signalling status. Accordingly, we performed multi-omic analyses of FGFR2 genes and FGFR2 signalling molecules in the tissue samples from 36 iCCA naïve patients. Gain-of-function FGFR2 GAs were detected in 7 patients, including missense mutations (n = 3; p.F276C, p.C382R and p.Y375C), translocations (n = 1) and copy number gain (n = 4; CNV ≥ 4). In contrast, among 29 patients with wild-type FGFR2, 4 cases showed activation of FGFR2 signalling, as they expressed the FGFR2 ligand FGF10 and phosphorylated FGFR2/FRS2α proteins; the remaining 25 cases resulted negative for activated FGFR2 signalling, as they lacked FGFR2 (n = 8) or phosphorylated FRS2α (n = 17) expression. Overall, we found that activation of FGFR2 signalling occurs not only in iCCA naïve patients with FGFR2 GAs, but also in a subgroup carrying wild-type FGFR2. This last finding entails that also this setting of patients could benefit from FGFR targeted therapies, widening indication of these drugs for iCCA patients beyond current approval. Future clinical studies are therefore encouraged to confirm this hypothesis.

Asbestos exposure as an additional risk factor for small duct intrahepatic cholangiocarcinoma: a pilot study

Intrahepatic cholangiocarcinoma (iCCA) is a rare malignancy, recently classified in small duct and large duct morphological subtypes. Growing evidence suggests asbestos as a putative risk factor for iCCA, albeit no correlation between asbestos and iCCA morphology has been investigated so far. The aim of the present study was to assess the relationship between asbestos exposure and iCCA morphological subtype. Forty patients with surgically removed iCCA were prospectively enrolled: asbestos exposure was assessed according to the Italian National Mesothelioma Register questionnaire. From the surgical iCCA specimens the main histopathological variables were collected, including the small duct (sd-iCCA, 32 patients) and large duct subtypes (ld-iCCA, 8 patients). Five sd-iCCA cases had a definite/probable occupational exposure to asbestos, while no cases of ld-iCCA were classified as being occupationally exposed (definite/probable). Other kind of asbestos exposure (i.e. possible occupational, familial, environmental) were recorded in 16 sd-iCCA and 3 ld-iCCA. Cases with unlikely exposure to asbestos were 11 sd-iCCA (35.5%) and 5 ld-iCCA (62.5%). In conclusion, these findings seem to indicate that sd-iCCA might be more frequently associated to asbestos exposure rather than ld-iCCA, suggesting that asbestos fibres might represent a parenchymal, rather than a ductal risk factor for iCCA. This pilot study must be confirmed by further case-control studies or large independent cohorts.

Anti-EGFR Monoclonal Antibodies in Advanced Biliary Tract Cancer: A Systematic Review and Meta-analysis

BACKGROUND

Despite several clinical trials and advances in understanding the genetic basis of biliary tract cancer (BTC), the addition of epidermal growth factor receptor (EGFR) targeted therapy does not seem to enhance the activity of first-line chemotherapy (CHT).

MATERIALS AND METHODS

We carried out a meta-analysis of available randomized clinical trials to assess the efficacy and safety of gemcitabine-based first-line CHT plus monoclonal antibodies against EGFR (EGFR-mAbs) in advanced or metastatic BTC.

RESULTS

In the overall population, the pooled hazard ratio for overall (OS) and progression-free (PFS) survival were 0.82 (95% confidence interval=0.64-1.06) and 0.88 (95% confidence intervaI=0.73-1.08), respectively. No differences were detected in objective response rate between the two groups. Patients treated with gemcitabine-based CHT plus EGFR-mAbs showed a statistically significant increased risk of grade 3-4 neutropenia, grade 3-4 thrombocytopenia and especially grade 3-4 skin rash.

CONCLUSION

The addition of EGFR-mAbs to gemcitabine-based first-line CHT does not significantly improve overall and progression-free survival, nor the objective response rate in patients with advanced BTC and increases the risk of hematological and cutaneous adverse drug events.

Wilson disease, ABCC2 c.3972C > T polymorphism and primary liver cancers: suggestions from a familial cluster

BACKGROUND

Polymorphisms in genes modulating xenobiotics metabolism, in particular the ABCC2 c.3972C > T single nucleotide polymorphism (SNP) at exon 28, have been suggested to increase primary liver cancer (PLC) risk. Conversely, the occurrence of PLCs in Wilson disease patients is a rare event, in contrast with the occurrence observed in other chronic liver diseases. Here we report the clinical case of five siblings carrying the ABCC2 c.3972C > T SNP; three of them were affected by Wilson disease and two brothers with Wilson disease also developed PLCs.

METHODS

The presence of the ABCC2 c.3972C > T SNP was assessed by Sanger sequencing and the exposure of PLC risk factors by standardized questionnaires.

RESULTS

Notably, PLCs occurred only in the two brothers with the ABCC2 c.3972C > T SNP and Wilson disease who resulted exposed to asbestos and cigarette smoking, but not in the other siblings with the ABCC2 c.3972C > T SNP, alone or in association with Wilson disease, not exposed to these carcinogens and/or to other known risk factors for PLCs.

CONCLUSIONS

These findings suggest that ABCC2 c.3972C > T SNP and WD, also in association, may not represent a sufficient condition for PLC development, but that co-occurrence of further host/exogenous risk factors are needed to drive this process, reinforcing the notion that liver carcinogenesis is the result of a complex interplay between environmental and host genetic determinants. Due to the sporadic cases of this study and the paucity of data currently available in literature on this issue, future investigations in a larger population are needed to confirm our findings.

PARP Inhibitors in Biliary Tract Cancer: A New Kid on the Block?

Poly adenosine diphosphate-ribose polymerase inhibitors (PARPi) represent an effective therapeutic strategy for cancer patients harboring germline and somatic aberrations in DNA damage repair (DDR) genes. BRCA1/2 mutations occur at 1–7% across biliary tract cancers (BTCs), but a broader spectrum of DDR gene alterations is reported in 28.9–63.5% of newly diagnosed BTC patients. The open question is whether alterations in genes that are well established to have a role in DDR could be considered as emerging predictive biomarkers of response to platinum compounds and PARPi. Currently, data regarding PARPi in BTC patients harboring BRCA and DDR mutations are sparse and anecdotal; nevertheless, a variety of clinical trials are testing PARPi as monotherapy or in combination with other anticancer agents. In this review, we provide a comprehensive overview regarding the genetic landscape of DDR pathway deficiency, state of the art and future therapeutic implications of PARPi in BTC, looking at combination strategies with immune-checkpoint inhibitors and other anticancer agents in order to improve survival and quality of life in BTC patients.

Adjuvant treatment in biliary tract cancer

Biliary tract cancers (BTCs) are a heterogeneous group of malignancies with a dismal prognosis. Despite radical surgery, the five-year overall survival (OS) does not exceed 40% in the best series. Adjuvant treatments are widely used even though they have mainly been investigated in small retrospective series until recently. Available data suggest that chemotherapy with 5-fluorouracil (and relative prodrugs) or gemcitabine can reduce the risk of relapse and potentially improve patients’ long-term outcome. The role of adjuvant radiotherapy seems to be confined to patients with positive surgical margins. In addition, patients with high-risk factors for relapse (nodal involvement and non-radical resection) benefit most from chemotherapy. Recent results from large randomized trials have clarified the benefit of adjuvant treatments and probably defined a new standard of care.

Membrane human equilibrative nucleoside transporter 1 is associated with a high proliferation rate and worse survival in resected intrahepatic cholangiocarcinoma patients not receiving adjuvant treatments

Human equilibrative nucleoside transporter 1 (hENT-1) is a membrane nucleoside transporter mediating the intracellular uptake of nucleosides and their analogues. hENT-1 was recently reported to have a predictive role in intrahepatic cholangiocarcinoma (iCC) patients receiving adjuvant gemcitabine-based chemotherapy, but its biological and clinical significance in iCC remains unsettled. This study investigated the role of hENT-1 in regulating tumour growth and predicting the survival of 40 resected iCC patients not receiving adjuvant treatments. hENT-1 expression was found to be significantly higher in iCC than in the matched non-tumoural liver. Patients harbouring hENT-1 localised on the tumour cell membrane had a worse overall survival than membrane hENT-1-negative patients (median 21.2 months vs 30.3 months, p = 0.031), with an adjusted hazard ratio of 2.8 (95% confidence interval 1.01-7.76). Moreover, membrane hENT-1-positive patients had a higher percentage of Ki67-positive cells in tumour tissue than membrane hENT-1-negative patients (median 23% vs 5%, p < 0.0001). Functional analyses in iCC cell lines revealed that hENT-1 silencing inhibited cell proliferation and induced apoptosis in HUH-28 cells expressing hENT-1 on the cell membrane, but not in SNU-1079 cells expressing the transporter only in the cytoplasm. Overall, these findings suggest that membrane hENT-1 is involved in iCC proliferation and associated with worse survival in resected iCC patients. Further prospective studies on larger cohorts are required to confirm these results and better define the potential prognostic role of membrane hENT-1 in this setting of patients.

In Reply

Brandi et al. clarify data about the localization of human equilibrative nucleoside transporter 1 in cancer patients receiving gemcitabine-based chemotherapy. They discuss methodology, differences between antibodies, and recommendations for further study.

Membrane Localization of Human Equilibrative Nucleoside Transporter 1 in Tumor Cells May Predict Response to Adjuvant Gemcitabine in Resected Cholangiocarcinoma Patients

BACKGROUND

The use of gemcitabine as an adjuvant modality for cholangiocarcinoma (CC) is increasing, but limited data are available on predictive biomarkers of response. Human equilibrative nucleoside transporter 1 (hENT-1) is the major transporter involved in gemcitabine intracellular uptake. This study investigated the putative predictive role of hENT-1 localization in tumor cells of CC patients undergoing treatment with adjuvant gemcitabine.

METHODS

Seventy-one consecutive patients with resected CC receiving adjuvant gemcitabine at our center were retrospectively analyzed by immunohistochemistry for hENT-1 localization in tumor cells. The main outcome measure was disease-free survival (DFS). Hazard ratios (HRs) of relapse and associated 95% confidence intervals (CIs) were obtained from proportional hazards regression models stratified on quintiles of propensity score.

RESULTS

Twenty-three (32.4%) cases were negative for hENT-1, 22 (31.0%) were positive in the cytoplasm only, and 26 (36.6%) showed concomitant cytoplasm/membrane staining. Patients with membrane hENT-1 had a longer DFS (HR 0.49, 95% CI 0.24-0.99, p = .046) than those who were negative or positive only in the cytoplasm of tumor cells. Notably, the association between DFS and membrane hENT-1 was dependent on the number of gemcitabine cycles (one to two cycles: HR 0.96, 95% CI 0.34-2.68; three to four cycles: HR 0.99, 95% CI 0.34-2.90; five to six cycles: HR 0.27, 95% CI 0.10-0.77).

CONCLUSION

hENT-1 localization on tumor cell membrane may predict response to adjuvant gemcitabine in CC patients receiving more than four cycles of chemotherapy. Further prospective randomized trials on larger populations are required to confirm these preliminary results, so that optimal gemcitabine-based chemotherapy may be tailored for CC patients in the adjuvant setting.

IMPLICATIONS FOR PRACTICE

Gemcitabine is becoming an increasingly used adjuvant modality in cholangiocarcinoma (CC), but limited data are available on predictive biomarkers of response. In this study, patients receiving more than four cycles of adjuvant gemcitabine and harboring Human equilibrative nucleoside transporter 1 (hENT-1, the major transporter involved in gemcitabine intracellular uptake) on tumor cell membrane had a longer disease-free survival compared with patients negative or positive for hENT-1 only in the cytoplasm of tumor cells. Overall these results may lay the basis for further prospective randomized trials based on a larger population of patients and may prove useful for tailoring appropriate gemcitabine-based chemotherapy for CC patients in the adjuvant setting.

Plasma membrane localization of human equilibrative nucleoside transporter 1 (hENT-1) to predict better outcome of adjuvant gemcitabine in cholangiocarcinoma (CC) patients

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Background: The role of adjuvant chemotherapy in CC is controversial and, to date, no standard treatment has been established in this setting. Some institutions offer gemcitabine (GEM) as adjuvant strategy to radically resected CC patients. The efficient uptake of this drug into cells requires the expression and plasma membrane localization of hENT-1. A recent study showed that a high hENT-1 expression closely associated with better survivals in macroscopically (R0 + R1) resected CC patients treated with adjuvant GEM plus S-1. In the present study, we analyzed the relationship between hENT-1 expression/localization and disease free survival (DFS) in CC patients undergone surgery and treated with adjuvant GEM. Methods: A total of 71 CC patients (44 intra-hepatic and 27 extra-hepatic) operated between 2002 and 2011 (46 R0 and 25 R1) and treated with adjuvant GEM (1000 mg/m2, 1-8-15/21 days planned for 6 months) in our institution were enrolled and retrospectively analyzed for hENT-1 expression/localization by immunohistochemistry. Main outcome measure was DFS. Hazard ratios (HR) of relapse and associated 95% confidence intervals (95% CIs) were obtained from proportional hazards regression models stratified on quintiles of propensity score (estimated from baseline covariates). Results: 26/71 patients (36.6%) showed a high hENT-1 plasma membrane expression. During a median follow-up of 18.1 months (IQR 9.1–36.2) 49 relapses were observed. Patients with a high expression of hENT-1 showed a reduced risk of relapse (HR 0.50, 95%CI 0.26–0.99, p=0.047). Noteworthy, the effect of hENT-1 appeared to increase across tertiles of duration of gemcitabine-based adjuvant chemotherapy (lower tertile, ≤102 days: HR 0.87, 95%CI 0.30–2.53; middle tertile, 103–170 days: HR 0.68, 95%CI 0.22–2.06; higher tertile, ≥171 days: 0.20, 95%CI 0.04–0.94). Conclusions: High plasma membrane hENT-1 expression was associated with a longer DFS among CC patients. The interaction between hENT-1 expression and duration of chemotherapy deserves further investigations, as it could be useful to tailor optimal GEM-based adjuvant chemotherapies.