Citations

672 Background: Rectal squamous cell carcinoma (RSCC) is a rare form of gastrointestinal malignancy. Using the NCDB, we determined the prognostic factors and survival outcomes of RSCC in the United States. Methods: We identified histologically confirmed cases of RSCC from the National Cancer Data Base (2004-2015). Univariate and multivariable methods were used to assess factors associated with survival. Kaplan-Meier method and log-rank test were used to perform overall survival (OS) analysis. Results: Of the 5,527 cases included in our analysis, 67% were female. Median age at diagnosis was 61 years and did not differ by sex. The proportion of patients with stage 1, 2, 3 and 4 diseases were 22%, 16%, 20%, and 11%, respectively (30% unknown stage). Among the ones who received surgical resection of primary tumor, 41%, 30%, 20% and 8% are of stages 1, 2, 3 and 4 respectively. The rate of R0 resection was 54%, 63%, 55% and 38% in stage 1, 2, 3 and 4, respectively. The R0 resection rate was much higher in patients who received neoadjuvant chemo or radiation therapy or both (87%, 78%, 74%, and 57% in stages I, 2, 3 and 4, respectively) as compared to that of their counterparts. On stage wise sub-group OS analysis, stage 1-3 patients had OS benefit from surgery (as compared to no-surgery) (145 vs 90 months, p<0.001) as opposed to 4 disease (16 vs 11 months, p=0.06). Adjuvant radiation therapy improved the median OS in stage 1-3 patients (as compared to no-adjuvant radiation) in patients with positive surgical margins (not reached vs 40 months, p<0.0001). Patients with stage 4 disease treated with radiation therapy had a better median OS than those without (16 vs 6 months, p<0.0001). On therapy wise sub-group analysis, the patients who received surgery only had a median OS of 145 months; surgery + chemoradiation (adjuvant and neoadjuvant) = not reached; whereas patients with chemoradiation only had median OS of 80 months. Conclusions: This is the largest registry-based study on RSCC to date. RSCC had a diverse OS varied significantly according to stage of the disease at presentation and therapy received. Surgical resection of primary tumor was associated with improved OS as compared to that of patients who received chemoradiation.

399 Background: PSCC is a rare form of exocrine pancreatic malignancy with a dismal prognosis. Using the NCDB, we determined the prognostic factors and survival outcomes of PSCC in the United States. Methods: We performed a retrospective analysis of patients with histologically confirmed PSCC from 2004-2015 using NCDB. Kaplan-Meier method and log-rank test were used to perform overall survival (OS) analysis. Hazard Ratios were calculated using the Cox-proportional hazard method. Results: Of the 654 cases included in our analysis, 46% were female. Median age at diagnosis was 70 years and did not differ by sex (p = 0.19). The proportion of patients with stage I, II, III and IV diseases were 5%, 18%, 12%, and 54%, respectively (10%, unknown stage). Among these, 23% (35 of 150) of stage I and II disease, 10% (8 of 78) of stage III, and 2% (7 of 353) received surgical resection of the primary tumor. The rate of R0 resection was 74% in stage I and II; 38% in stage III; 29% in stage IV disease. Median OS for the entire cohort was 4 months and was significantly higher in patients who received surgical resection of the primary tumor (17 vs. 4 months, p < 0.001). On stage wise sub-group analysis, stage I-II patients had OS benefit from surgery (21 vs. 5 months, p < 0.001) as opposed to stage III (7 vs. 6 months, p = 0.31) and IV disease (5 vs. 3 months, p = 0.17). Adjuvant chemotherapy had no role in prolonging survival in stage I-II disease (20 vs 24 months, p = 0.6). Stage IV patients treated with chemotherapy had a better median OS than those without (5 vs. 2 months, p < 0.0001). On Cox multivariable analysis, stage IV disease (HR: 1.92 CI: 1.46-2.52, p < 0.001) and advanced patient age (HR: 1.02; CI:1.01-1.03, p < 0.001 were associated with poor OS, whereas OS was not dependent on the sex, race, grade, insurance status, surgery, and chemotherapy. Conclusions: This is the largest registry-based study on PSCC to date. PSCC had a diverse OS varied significantly according to increasing age and stage of the disease at presentation. Surgical resection of primary tumor was associated with improved OS in stages I-II, whereas chemotherapy improved OS in stage IV disease. The results of our study may aid the prognostication of patients and in treatment decision making.

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.

Pancreatic cancer is the third most common cause of cancer deaths in the United States. Surgical resection with negative margins still constitutes the cornerstone of potentially curative therapy, but is possible only in 15–20% of patients at the time of initial diagnosis. Accumulating evidence suggests that the neoadjuvant approach may improve R0 resection rate in localized resectable and borderline resectable diseases, and potentially downstage locally advanced disease to achieve surgical resection, though the impact on survival is to be determined. Despite advancements in the last decade in developing effective combinational chemo-radio therapeutic options, preoperative treatment strategies, and better peri-operative care, pancreatic cancer continues to carry a dismal prognosis in the majority. Prodigious efforts are currently being made in optimizing the neoadjuvant therapy with a better toxicity profile, developing novel agents, imaging techniques, and identification of biomarkers for the disease. Advancement in our understanding of the tumor microenvironment and molecular pathology is urgently needed to facilitate the development of novel targeted and immunotherapies for this setting. In this review, we detail the current literature on contemporary management of resectable, borderline resectable and locally advanced pancreatic cancer with a focus on future directions in the field.