Detection of circulating tumor cells (CTC) using a non-EpCAM-based, high-definition, single-cell assay in advanced hepatocellular carcinoma (HCC) for patients enrolled on phase I and II trials of sorafenib plus temsirolimus

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Background: Noninvasive biomarkers are needed for diagnosis, prognosis, and molecular profiling of HCC due to scarcity of tumor tissue and heterogeneous tumor biology. CTC are detectable in metastatic HCC using methods which enrich for expression of the cell adhesion molecule, EpCAM. Because a subset of HCC does not express EpCAM, however, non-EpCAM enrichment methods are needed for CTC studies in HCC. Methods: This CTC cohort was derived from patients enrolled on multicenter phase 1 and 2 trials of the combination of sorafenib plus temsirolimus in advanced HCC (NCT01008917, NCT01687673) with approval and funding from the National Comprehensive Cancer Network (NCCN) Oncology Research Program. Eligibility required histologic diagnosis of incurable HCC with no prior systemic therapy. All patients in the cohort were treated at the recommended phase 2 dose of sorafenib 200 mg PO BID and temsirolimus 10 mg IV weekly. Whole blood samples were collected at baseline and on treatment. CTC were enumerated and analyzed cytomorphologically using a high-definition, single cell assay without EpCAM enrichment and blinded to clinical outcomes. Results: The CTC cohort was comprised of 36 patients (phase 1 n = 9, phase 2 n = 27). Characteristics: male 89%; white 64%, Asian/PI 28%, black 6%; HBsAg+ 31%, HCV+ 44%; Child Pugh A 92%, B7 8%; BCLC C 83%; tumor vascular invasion 47%; median AFP 74 ng/mL. Median OS from start of treatment was 392 days (95% CI: 214, 569). CTC ≥ 1/mL were detectable at baseline in 23/36 (64%) overall (95% CI: 47%, 80%), with similar findings in the phase 1 (56%) and phase 2 (67%) subsets. There was no significant relationship between baseline CTC values ≥ 1, 2, or 5/mL and overall survival (OS) on univariate analysis. Analyses of CTC relationship to clinical characteristics and time to progression, changes on treatment, and multivariable analysis for relationship to OS will be presented. Conclusions: CTC were detected in over 60% of patients in this advanced HCC clinical trial cohort using a non-EpCAM, high-definition single cell assay, suggesting future potential for noninvasive molecular profiling of HCC.

Clinical features and tumor mutational profile of younger versus older patients with cholangiocarcinoma (CCA)

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Background: As seen in lung cancer, young patients with cancer can have different risk factors, presentation, and tumor genotype than older patients with the same disease. The clinical and molecular features of young patients with CCA have yet to be well characterized. Methods: Retrospective chart review was performed on patients with intrahepatic (ICC) or extrahepatic cholangiocarcinoma (ECC) across 5 institutions. Data on demographics, risk factors, treatments, pathology, and overall survival (OS) were collected. Tumor genotyping results from MGH SNaPShot and Foundation Medicine were analyzed. Log-rank tests and Kaplan-Meier survival curves were used for statistical analysis. Results: Of 567 patients analyzed, 134 (23.6%) were < 50 years old (yo) and 455 (80.2%) had ICC. When assessed for risk factors, younger patients ( < 50yo) were more likely to have primary sclerosing cholangitis (PSC) (p < 0.001) and less likely to have diabetes (p = 0.05), compared to older patients ( ≥ 50yo). Surgical resection rates were similar in younger vs older patients (41.9 vs 42.6%, p = 0.890), but younger patients had larger tumors (median size 7.1 vs 5.3cm p = 0.012). Younger patients were also more likely to receive palliative systemic chemotherapy (p < 0.001) and more lines of therapy (median, 2 vs 1 line, p < 0.001). Frequency of treatment with liver directed therapy did not differ between the two groups. Molecular testing was performed on 222/567 (39.1%) patients of which 84/134 (62.7%) were younger patients and 138/433 (31.9%) were older patients. FGFR aberrations were more common in younger patients versus older patients (17.6 vs. 5.7%, p = 0.002). Targeted therapy was given to 15/84 (17.9%) younger and 28/138 (20.3%) older patients based on results of mutational profiling. Finally, no significant difference was seen in OS between younger and older patients (22.9 vs 22.7 months, p = 0.89). Conclusions: Younger patients with CCA may have different risk factors, tumor biology, and tolerance of systemic therapy compared to older patients. Further study is needed as referral patterns to tertiary care centers and motivation of younger patients to seek tertiary care may impact these results.

Phase II trial of temsirolimus (TEM) plus sorafenib (SOR) in hepatocellular carcinoma (HCC)

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Background: The multikinase inhibitor SOR prolongs survival in patients with HCC not amenable to curative therapies. In HCC preclinical models, the combination of SOR with an inhibitor of the mammalian target of rapamycin (mTOR) pathway is synergistic, though single-agent mTOR inhibition did not improve survival in HCC patients after failure of SOR in a phase III trial. We previously completed a phase I study of the mTOR inhibitor TEM combined with SOR in 25 HCC patients which identified the maximum tolerated dose as TEM 10 mg IV weekly and SOR 200 mg PO BID. This two-center, phase II study was developed to examine the efficacy of the combination and to explore candidate biomarkers. The study was approved and funded by the National Comprehensive Cancer Network (NCCN) Oncology Research Program from general research support, with activation October 2012. Methods: The study is registered on ClinicalTrials.gov (NCT01687673). Design: Single-arm, one stage phase II trial. Primary endpoint: Time to progression (TTP) by RECIST 1.1. Other endpoints: Progression-free survival, response rate, overall survival, proportion with alpha fetoprotein decline ≥ 50%, toxicity, hepatitis B virus reactivation rate, and exploratory biomarkers including mTOR pathway protein expression in tumor, circulating tumor cells, and blood and tumor micro-RNA profiles. Sample size: 25 evaluable patients are required to detect a difference between the null hypothesis of median TTP < 3 months versus alternate hypothesis of median TTP ≥ 6 months (a clinically-meaningful outcome in advanced HCC), with 1-sided significance level of 10% and power 88% under the exact test. Main eligibility criteria: HCC not amenable to curative therapies, histologically-confirmed, ≥ 1 untreated, radiographically-measurable site of disease. No prior systemic therapy. ECOG ≤ 1. Child-Pugh score ≤ 7 with bilirubin ≤ 2 mg/dL. Treatment and procedures: TEM 10 mg IVweekly plus SOR 200 mg PO BID in 28-day cycles, with collection of archival tumor samples and blood samples at baseline, on treatment, and at progression. Accrual:Sixteen of 25 planned evaluable patients have enrolled. An interim analysis for safety after 30% enrollment met pre-specified target to continue. Clinical trial information: NCT01687673.