Chakrabarti, Sakti

393 Background: Clinicopathological features and the outcomes of patients with fibrolamellar hepatocellular carcinoma (FLHCC) are not clearly defined. Methods: Data were collected by retrospective chart review on 42 patients with FLHCC treated between 1990 and 2017 at the Mayo Clinic. Clinicopathological characteristics, response to treatment, recurrence pattern and survival were analyzed. Results: Of 42 patients (17 males and 25 females; median age at diagnosis 22 years, range 15 to 39), 10 patients (23%) had stage I disease and 32 patients (77%) had stage II to IVB disease. All 10 patients with stage I disease and 21 of 32 patients with stage II-IVB disease underwent resection at presentation. In stage I patient group, 6 patients experienced recurrence with a median time to recurrence of 30.5 months, resulting in a 5 year overall survival (OS) of 86%. Patients with stage II to IVB disease who underwent resection (n=21) at presentation had a median OS of 32.5 months and 5 year OS of 44%. In the upfront surgery group, 71% of the patients experienced recurrent disease. The median OS of patients with unresectable disease (n=11) was 10 months. Systemic therapy was given to 17 patients which included sorafenib, FOLFOX (5-fluorouracil/leucovorin and oxaliplatin), gemcitabine plus oxaliplatin, single agent adriamycin or gemcitabine, capecitabine plus interferon alfa, gemcitabine plus cisplatin, cisplatin plus adriamycin and nivolumab . Sorafenib was given to 9 patients and 4 patients achieved stable disease (SD) with duration ranging from 5 months to 5 years. One programmed cell death receptor positive-1 patient had a durable complete response after 2 months of therapy with nivolumab. Conclusions: In FLHCC, surgical resection was associated with prolonged OS. However, recurrences were common after the surgery. Limited benefit was derived from the systemic treatment. In rare cases, therapy with a checkpoint inhibitor may provide a viable treatment option.

864 Background: Definitive chemoradiotherapy (CRT) is the standard of care for localized or locally advanced ACSCC, while surgery is typically reserved for salvage therapy. Outcome of treatment with local excision alone is unknown and is currently not recommended by NCCN. We retrospectively analyzed outcome of the patients with small (T1 lesion) incidentally found ACSCC who were treated with local excision alone. Methods: On retrospective analysis, a cohort of 12 patients with pathologically confirmed stage I ACSCC treated at Mayo Clinic between 1994 and 2014 was identified who were managed with local excision alone. Baseline as well as followup data were obtained by electronic chart review. Results: Median age of the patients at diagnosis was 68 years (range: 36-81 years) and majority were females (76.9%). Median follow-up duration was 7.5 years. Of the 12 patients, 2 patients did not receive standard CRT due to co-morbid conditions and other 10 patients chose surveillance over CRT. There was only one patient with disease recurrence at 3 years which was salvaged by abdominoperineal resection (APR). This subject remains alive and disease free at the time of data collection (4 years out from APR). There were 4 deaths, all unrelated to ACSCC. Of 12 patients, 10 patients (83%) remained disease free at 5 years and beyond, 1 patient had recurrence and 1 patient was lost to follow up at 5 months from diagnosis. Conclusions: Local excision as a single modality of treatment may be safe and effective for highly selected small stage I ACSCC. Further clinical study is warranted to accurately define the patient population who can be treated with local excision alone, potentially sparing them long term toxicities.

Abstract Checkpoint inhibitors targeted at programmed cell death-1 receptor (PD-1) and its ligand (PD-L1) can result in significant benefit to a small proportion of patients with cancer, including those with tumors of the stomach and gastroesophageal junction. These drugs are now approved for several solid tumors, including the recent accelerated approval of pembrolizumab for gastroesophageal adenocarcinomas in the third-line setting and beyond based on the KEYNOTE-059 phase II trial. Data are lacking on the efficacy of chemotherapy after progression on PD-1 blockade in metastatic gastroesophageal adenocarcinoma. This report describes the exceptional response of two patients who received ramucirumab plus paclitaxel after progressive disease on pembrolizumab. This early clinical observation suggests that the sequence of administration of PD-1 blockade and chemotherapy may be important in this disease.