Perioperative nivolumab monotherapy versus nivolumab plus ipilimumab in resectable hepatocellular carcinoma: a randomised, open-label, phase 2 trial

BACKGROUND

Hepatocellular carcinoma has high recurrence rates after surgery; however, there are no approved standard-of-care neoadjuvant or adjuvant therapies. Immunotherapy has been shown to improve survival in advanced hepatocellular carcinoma; we therefore aimed to evaluate the safety and tolerability of perioperative immunotherapy in resectable hepatocellular carcinoma.

METHODS

In this single-centre, randomised, open-label, phase 2 trial, patients with resectable hepatocellular carcinoma were randomly assigned (1:1) to receive 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery at 6 weeks) followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for 2 years, or 240 mg of nivolumab intravenously every 2 weeks (for up to three doses before surgery) plus one dose of 1 mg/kg of ipilimumab intravenously concurrently with the first preoperative dose of nivolumab, followed in the adjuvant phase by 480 mg of nivolumab intravenously every 4 weeks for up to 2 years plus 1 mg/kg of ipilimumab intravenously every 6 weeks for up to four cycles. Patients were randomly assigned to the treatment groups by use of block randomisation with a random block size. The primary endpoint was the safety and tolerability of nivolumab with or without ipilimumab. Secondary endpoints were the proportion of patients with an overall response, time to progression, and progression-free survival. This trial is registered with ClinicalTrials.gov (NCT03222076) and is completed.

FINDINGS

Between Oct 30, 2017, and Dec 3, 2019, 30 patients were enrolled and 27 were randomly assigned: 13 to nivolumab and 14 to nivolumab plus ipilimumab. Grade 3-4 adverse events were higher with nivolumab plus ipilimumab (six [43%] of 14 patients) than with nivolumab alone (three [23%] of 13). The most common treatment-related adverse events of any grade were increased alanine aminotransferase (three [23%] of 13 patients on nivolumab vs seven [50%] of 14 patients on nivolumab plus ipilimumab) and increased aspartate aminotransferase (three [23%] vs seven [50%]). No patients in either group had their surgery delayed due to grade 3 or worse adverse events. Seven of 27 patients had surgical cancellations, but none was due to treatment-related adverse events. Estimated median progression-free survival was 9·4 months (95% CI 1·47-not estimable [NE]) with nivolumab and 19·53 months (2·33-NE) with nivolumab plus ipilimumab (hazard ratio [HR] 0·99, 95% CI 0·31-2·54); median time to progression was 9·4 months (95% CI 1·47-NE) in the nivolumab group and 19·53 months (2·33-NE) in the nivolumab plus ipilimumab group (HR 0·89, 95% CI 0·31-2·54). In an exploratory analysis, three (23%) of 13 patients had an overall response with nivolumab monotherapy, versus none with nivolumab plus ipilimumab. Three (33%) of nine patients had a major pathological response (ie, ≥70% necrosis in the resected tumour area) with nivolumab monotherapy compared with three (27%) of 11 with nivolumab plus ipilimumab.

INTERPRETATION

Perioperative nivolumab alone and nivolumab plus ipilimumab appears to be safe and feasible in patients with resectable hepatocellular carcinoma. Our findings support further studies of immunotherapy in the perioperative setting in hepatocellular carcinoma.

FUNDING

Bristol Myers Squibb and the US National Institutes of Health.

Clinical outcomes analysis of TP53-mutated advanced and metastatic biliary tract cancers

4106

Background: Advanced biliary tract cancers (BTC) are lethal cancers with limited treatment options and short survival. Median progression-free survival (mPFS) in the ABC-02 trial was 8.0 months with gemcitabine-cisplatin (GC) and 5.0 m with gemcitabine alone in the front-line setting. The ABC-06 trial showed mPFS of 4.0 m with second-line FOLFOX. TP53 mutation is known to be associated with poor prognosis in other cancers, but its impact on survival in advanced or metastatic BTC has not been detailed. Methods: Mutational profiles were obtained from a retrospective database collected via an institutional DNA/RNA sequencing panel, FoundationOne, or Guardant360. Out of 149 patients with TP53 mutations in BTC, 90 had advanced or metastatic BTC treated at a single institution between 2015 and 2021. These patients were not candidates for surgery, radiation, or liver-directed therapy. Results: Intrahepatic, hilar, distal, and gallbladder cancer diagnoses were confirmed in 66, 11, 10, and 3 patients. Median age was 63, with a male:female ratio of 1:1. Poorly, moderately, and well-differentiated adenocarcinomas were found in 62, 20, and 1 (not available in 7 patients). The most common TP53 mutations were R175H (n = 5) and R248Q (n = 4). Common co-mutated genes included KRAS (n = 15), ARID1A (n = 15), FGFR2 fusion (n = 14), IDH1 (n = 13), BAP1 (n = 10), CDKN2A (n = 9), and HER2 amplification (n = 8). Microsatellite unstable (MSI-H) tumors were found in 3 patients. The median tumor mutational burden was 2.5/Mb. Patients received front-line GC (n = 54), GC-nab-paclitaxel (GAP, n = 14), FOLFIRINOX (n = 3), and GC with targeted or trial therapy (n = 11, e.g. trastuzumab). mPFS with front-line therapy was 5.0 m (n = 90); it was 4.7 m with GC and 5.1 m with GAP. Patients who had co-mutated IDH1 or FGFR2 fusion had longer mPFS (9.5 and 6.9 m, respectively) than those who did not (n = 63, 3.7 m, p < 0.05) from front-line chemotherapy. mPFS after second-line FOLFOX (n = 17) and FOLFIRI (n = 10) was 2.1 and 1.9 m, respectively, and mPFS after third-line FOLFOX/FOLFIRI was 1.8 m (n = 8). The median overall survival (OS) of patients with co-mutated FGFR2, IDH1, or neither was 34.5, 22.0, and 13.1 m, respectively (p < 0.05). TP53-mutated BTC with mutations other than FGFR2/IDH1 did not show statistically significant difference in PFS or OS. Conclusions: Patients with TP53-mutated advanced BTC have shorter PFS than those without TP53 mutation in front and further-line settings. The presence of co-mutated FGFR2 or IDH1 is associated with improved PFS with chemotherapy (not FGFR/IDH1 inhibitors) and longer OS. Other co-mutations do not appear to have a survival benefit. It is crucial for clinicians to take into account the worse prognosis with TP53 mutation before starting front-line therapy in patients with advanced BTC and consider early clinical trial options.

Adaptive dose optimization trial of stereotactic body radiation therapy (SBRT) with or without GC4419 (avasopasem manganese) in pancreatic cancer

TPS4670

Background: Local progression causes up to 30% of deaths from pancreatic cancer (PC) and is also a significant source of morbidity. Stereotactic body radiotherapy (SBRT) offers the potential for improved therapeutic index over standard fractionation, but current regimens of 5 fractions of 5-7 Gy/fraction are constrained by nearby organ tolerance and offer only palliation without improving survival. Safe dose escalation may be necessary to improve SBRT efficacy. Avasopasem, a superoxide dismutase mimetic, selectively converts superoxide (O2•-) to hydrogen peroxide (H2O2) and oxygen. O2•-initiates normal tissue damage due to RT. Avasopasem is in a Phase 3 trial (NCT03689712) to reduce RT-induced oral mucositis in head and neck cancer, based on positive results in a randomized Phase 2 trial for that indication (Anderson, JCO 2019). Avasopasem improved the survival of mice receiving 8.5 Gy x 5 to the upper abdomen. Cancer cells are less tolerant to elevated H2O2, and more tolerant to elevated O2•-, than normal cells, and avasopasem demonstrated mechanism-dependent synergy with high dose-fraction RT in a human tumor xenograft with inducible expression of catalase (Sishc, AACR 2018). Thus, adding avasopasem to SBRT may increase both the efficacy and the safety of the latter. Methods: 48 patients with locally advanced PC, who have completed medically-indicated induction chemotherapy, are randomized 1:1 to placebo or avasopasem, 90 mg IV, prior to each of 5 consecutive daily (M-F) SBRT fractions. A phase I/II Late Onset Efficacy/ Toxicity tradeoff (LO-ET) based adaptive design adaptive model drives assignment of SBRT dose escalation in each arm based on a dual endpoint (Gr 3-4 GI toxicity or death; local stable disease or better) by 90 days post SBRT. The planned dose levels are 10, 11 and 12Gy x 5 fractions (BED10 = 100,112.5 and 132Gy, respectively) as an integrated boost to the gross tumor volume (GTV). Primary endpoint: Maximum tolerated dose of SBRT with avasopasem or placebo. Secondary endpoints progression-free survival, response rate, and acute (90 day) and late (12 month) radiation toxicity with avasopasem vs placebo. Exploratory correlative studies include ctDNA, tumor exome/transcriptome sequencing, and immune profiling. Clinical trial information: NCT03340974 .

Final results of a randomized, open label, perioperative phase II study evaluating nivolumab alone or nivolumab plus ipilimumab in patients with resectable HCC

4599

Background: In resectable hepatocellular carcinoma (HCC) surgical resection is associated with high recurrence rates. However, there is no approved neoadjuvant or adjuvant therapies yet. Neoadjuvant immunotherapy effect has never been reported in this setting in HCC. Methods: This is a randomized phase II trial of nivolumab (Arm A) or nivolumab + ipilimumab (Arm B) as peri-operative treatment for patients (pts) with HCC who are eligible for surgical resection. Pts in Arm A are given nivolumab 240 mg iv, every 2 weeks (wks) for a total of 3 doses followed by surgery on week 6. Pts in Arm B are treated with nivolumab per same schedule as arm A plus concurrent ipilimumab 1 mg/kg on day 1. Adjuvant part of study starts 4 weeks after surgery, with Nivolumab at 480 mg iv every 4 weeks for 2 years in arm A. Pts in Arm B are treated with nivolumab per same schedule as arm A plus concurrent ipilimumab 1 mg/kg every 6 weeks times 4 doses after resection. The primary objective was the safety/tolerability of nivolumab +/- ipilimumab. Secondary objectives include overall response rate, pathologic complete response (pCR) rate and time to progression. Exploratory objectives include evaluating the pre- and post-treatment immunological changes in tumor tissues and peripheral blood. Results: 30 patients were enrolled, 2 patients withdrew consent, one patient was not eligible at time of therapy, and 27 randomized (13 to Arm A and 14 to Arm B). 21 patients proceeded with resection as planned and surgery was aborted for 6 patients; 1 for frozen abdomen due to old surgery, 2 for small residual volume, and 3 for progressive disease. Pts age ranged between 32-83 yo, 75 % were males, 7 pts had HCV, 7 had HBV and 7 had no hepatitis. Pathologic complete response (pCR) was observed in 5/21 pts (24% pCR rate) – 2 in Arm A and 3 Arm B, and 3/21 pts (16%) – 1 in Arm A, 2 in Arm B, achieved major pathologic response (necrosis effect of 50-99%). 5 patients in Arm B and 1 in Arm A experienced grade 3 or higher toxicity prior to surgery. No grade 4 or higher toxicity were observed and surgery was not delayed or cancelled due to oxicity. Conclusions: Our study reached its primary endpoint of safety. Importantly, we report a 40% pathologic response rate = pCR rate of 24%, and major necrosis rate of 16% for resectable HCC after preoperative immunotherapy in a randomized phase II pilot trial. After future validation, these promising results may contribute to a paradigm shift in the perioperative treatment of resectable HCC. Clinical trial information: NCT03222076 .

Novel targeted and sustained drug delivery therapy for localized pancreatic cancer: Validation in porcine models and minimally invasive surgical feasibility in human cadavers

e16747

Background: As systemic therapy improves, control of localized pancreatic adenocarcinoma (PDAC) remains a major challenge. Up to 40% of patients present with locally advanced and borderline resectable tumors, for whom enhanced local downsizing of disease could improve resection rates and survival. PanTher is developing a locally targeted drug delivery product (PTM-101) to treat localized PDAC by directly delivering chemotherapy to the primary tumor. PTM-101 is a bioresorbable polymeric patch containing paclitaxel surgically placed onto the tumor. It biodegrades, resulting in sustained localized release of drug. In murine orthotopic patient-derived xenograft models a 60% increase in OS and inhibition of metastasis was achieved after single treatment. Here we validate and de-risk PTM-101 implantation in standard OR settings in large animals and human cadavers to prepare for a phase 1 study. Methods: We conducted two 30-day studies in porcine models to assess safety, toxicity and biodistribution. Parameters included body weights, hematology, urinalyses, drug levels in the blood and at the implantation site and histomorphologic evaluation. To validate the feasibility of minimally invasive surgical insertion, we conducted a follow-up study in three human cadavers. In each case, PTM-101 was laparoscopically placed directly on the pancreas. Results: We surgically implanted PTM-101 without complications and our approach ensures localized drug delivery with extreme control of drug biodistribution. Importantly, no detectable levels of drug were present in the blood any time during the 30-day treatment, confirming our targeted delivery. PTM-101 was consistently and effectively placed during a minimally invasive surgery without substantial increase in procedure time. PTM-101 conforms fully to pancreatic tissue, allowing for close contact with the intended tissue for drug delivery, and can cover the areas of the pancreas where critical involvements of tumors with vasculature are commonly found. Conclusions: By changing the route of administration to target just the area of interest, PTM-101 can increase the amount of drug reaching the tumor with the aim to enhance therapeutic efficacy. This could open the door to clinically relevant applications in PDAC patients: (i)pre-operatively as neoadjuvant treatment to control progression and downsize locally advanced and borderline anatomy to improve resectability; or (ii)post-resection to reduce the rate of local recurrence.

Randomized, open-label, perioperative phase II study evaluating nivolumab alone or nivolumab plus ipilimumab in patients with resectable HCC

486

Background: In HCC, surgical resection is associated with high recurrence rates, and no effective neoadjuvant or adjuvant therapies currently exist. Immunotherapy using anti-PD-1 antibodies has shown promised but limited increase in survival in advanced disease. To maximize the benefit, we are studying the efficacy and safety of anti–PD-1 (nivolumab) and anti–CTLA-4 (ipilimumab) antibodies against HCC for resectable HCC. Methods: This is a randomized phase II trial of nivolumab (Arm A) or nivolumab + ipilimumab (Arm B) as pre-operative treatment for patients with HCC who are eligible for surgical resection. Pts are given nivolumab 240 mg every 2 weeks (wks) for a total of 6 wks. Pt in Arm B are treated concurrently with ipilimumab 1 mg/kg every 6 wks. Surgical resection occurs within 4 wks after last cycle of therapy. Pts continue adjuvant immunotherapy for up to 2 years after resection. The primary objective is the safety/tolerability of nivolumab +/- ipilimumab. Secondary objectives include overall response rate, complete response rate and time to progression. Exploratory objectives include evaluating the pre- and post-treatment immunological changes in tumor tissues and peripheral blood. Results: Twenty-six patients were enrolled at the time of this interim analysis, of which 20 have evaluable data. Most pts (55%) were between 60-70yo and male (75%). Four pts were HCV-positive, 6 had HBV and 10 had no hepatitis. 20 patients proceeded with resection as planned, surgery was aborted for 5 patients (1 for frozen abdomen and 2 development of contralateral liver nodule). Three are still receiving preoperative therapy. Pathologic complete response (pCR) was observed in 5/20 evaluable patients – 2 in Arm A and 3 Arm B (25% pCR rate). Five patients in Arm B and 1 in Arm A experienced grade 3 or higher toxicity prior to surgery. No grade 4 or higher toxicity were observed. Conclusions: We report a pCR rate of 25% for resectable HCC after preoperative immunotherapy in a randomized phase II pilot trial. Treatment was safe and surgical resection was not delayed. The study is ongoing. These promising results may contribute to a paradigm shift in the perioperative treatment of resectable HCC. Clinical trial information: NCT03510871.

Pattern of recurrence after curative resection of stage I-III duodenal adenocarcinoma

794

Background: Duodenal adenocarcinoma (DA) is a rare cancer with limited data regarding the pattern of disease recurrence following resection. Methods: A retrospective review of 115 patients with Stage I-III DA from 3/1994 to 6/2018, at a single high-volume cancer center was conducted. Only patients (pts) who underwent a potentially curative surgical resection (R0/R1 margins) and had a postoperative follow-up radiographic evaluation were included. Periampullary adenocarcinomas were excluded. Clinicopathologic features and patterns of recurrence were compared across cohorts. Results: Of 76 patients who met inclusion criteria, 7 (9%) were stage I, 25 (33%) stage II, and 44 (57%) stage III. Histologic grade was moderate in 58% and poor in 38%. Median age was 63 years (range, 29-84), 38% were female, and R0 resection was 97%. Neoadjuvant therapy was given to 14% and adjuvant therapy to 61%. Radiation therapy (XRT) as either adjuvant/neoadjuvant therapy was used in 27%. Median follow-up was 44 (6-293) months. Median time to recurrence was 11mo, with 84% of recurrences occurring within 2 years. Median time to local recurrence (LR) vs. distant recurrence (DR) was 11mo vs. 12mo, respectively, p = 0.42. Stage impacted recurrence rate: 0% in stage 1 vs. 50% stage 2 vs. 71% stage 3 (p = 0.002). Median time to recurrence was 16mo for stage II and 11mo for stage III (p = 0.04). In total, 4 (5%) pts had LR only, 8 (10%) had LR concurrent with DR, and 32 (42%) had DR only. Recurrence distribution was similar across stage II (LR 8%, LR+DR 15%, DR 77%) and stage III (LR 10%, LR+DR 19%, DR 71%). LR was similar in patients that received XRT (10%) compared to those who did not (9%). Most common sites of DR were peritoneal (38%), liver (33%), distant lymph nodes (12%), and lung (10%). Conclusions: The recurrence pattern for resected DA is predominantly distant metastatic disease with the majority of recurrences occurring within the first two years. Future therapies should focus on improved systemic therapy, and surveillance should be most intensive in the first two years.

Randomized, open-label, perioperative phase II study evaluating nivolumab alone or nivolumab plus ipilimumab in patients with resectable HCC

4098

Background: In HCC, surgical resection is associated with high recurrence rate, and no effective neoadjuvant or adjuvant therapies currently exist. On the basis of of previous reports on the efficacy and safety of anti–PD-1 (nivolumab) and anti–CTLA-4 (ipilimumab) antibodies against HCC, we initiated a randomized pilot trial of perioperative immunotherapy for resectable HCC. Methods: This is a randomized, phase II pilot trial of nivolumab (Arm A) or nivolumab + ipilimumab (Arm B) as pre-operative treatment for patients (pt) with HCC who are eligible for surgical resection. Pt are given nivolumab 240 mg every 2 weeks (wk) for a total of 6 wk. Pt in Arm B are treated concurrently with ipilimumab 1 mg/kg every 6 wk. Surgical resection occurs within 4 weeks after last cycle of therapy. Pt continue adjuvant immunotherapy for up to 2 years after resection. Primary objective is the safety and tolerability of nivolumab +/- ipilimumab. Secondary objectives include overall response rate, complete response rate and time to progression. Exploratory objectives include evaluating the pre- and post-treatment immunological changes in tumor tissues and peripheral blood. Results: 17 pt were enrolled at the time of interim analysis (8 in Arm A, 9 in Arm B) and 14 were evaluable. Most pt (53%) were 60-70yo, and males (70%). 6 pt were HCV-positive and 4 had chronic hepatitis B. 14 pt proceeded with resection as planned; surgery was aborted for 2 pt (1 for frozen abdomen and 1 for development of contralateral liver nodule). One is still receiving preoperative therapy. Pathologic complete response (pCR) was observed in 4/14 evaluable pt – 2 in Arm A and 2 Arm B (29% pCR rate). 4 pt in Arm B and 1 in Arm A experienced grade 3 or higher toxicity prior to surgery. Conclusions: We report a pCR rate of 29% in an interim analysis of a phase II pilot trial of perioperative immunotherapy for resectable HCC. Treatment was safe and surgical resection was not delayed. The study is ongoing and results may contribute to a paradigm shift in the perioperative treatment of HCC. Clinical trial information: NCT03222076.

Outcomes and patterns of failures after hypofractionated radiation therapy for intrahepatic cholangiocarcinoma

e15609

Background: Locally advanced unresectable intrahepatic cholangiocarcinoma (IHCC) remains incurable. Prior data has shown the effectiveness of hypofractionated radiation therapy (HRT) with biological equivalent doses (BED) greater than 80.5 Gy in improving local control and survival for this patient population. This is an updated report of our IHCC experience with HRT in 15 or 25 fractions using a simultaneous integrated boost technique. Methods: A retrospective analysis of 63 patients (median age 64, range 29-87) diagnosed between 2007-2016 who received HRT was performed. RT dose ranged from 58-90 Gy in 15 fractions and 62.5-100 Gy in 25 fractions, translating to a median BED of 97.5 (range 78.1-144 Gy). Median primary tumor size at diagnosis was 7.8 cm (2.4-17cm). Forty-eight (76%) patients received gemcitabine-based therapy prior to HRT. Results: Median follow up was 31 months (4-110). The 2 year overall-survival (OS), local-progression-free-survival (LPFS), intrahepatic-distant-metastasis-free-survival (IH-DMFS) and extraheptic-distant-metastasis-free-survival (EH-DMFS) were 71% (95% CI 58-82), 67% (95% CI 50-80), 40% (95% CI 28-54) and 40% (95% CI 27-54) respectively. Pattern of failure analysis revealed 16 patients with local failure after HRT, of which only 5 (8% of total) progressed within the high iso-dose field line (BED > 80.5). After HRT, 41 (65%) patients had intrahepatic metastasis that occurred outside the radiation field, and 34 (54%) patients developed extrahepatic metastasis. On multi-variate analysis, T-stage was an independent predictor of OS, LPFS, IH-DMFS, and EH-DMFS. Larger normal liver volume and 15 fraction treatments were independently associated with better LPFS and IH-MFS respectively. There were no significant HRT-related toxicities. Conclusions: HRT demonstrates safety and efficacy for durable local control and prolonged overall survival in patients with unresectable IHCC. Dominant modes of failure are outside the HRT field. Improvements in systemic therapies could further improve outcomes for this patient population.

Adoptive transfer of tumor-infiltrating lymphocytes in patients with sarcomas, ovarian, and pancreatic cancers

TPS2650

Background: Adoptive cell therapy (ACT) with tumor-infiltrating lymphocytes (TIL) has a long history of efficacy in metastatic melanoma, and is being increasingly considered across other solid tumors. Preclinical data generated at MD Anderson Cancer Center has demonstrated the ability to grow TIL from a variety of tumor types including various types of sarcomas, ovarian and pancreas cancers. We are testing the efficacy of TIL across multiple tumor types using two different manufacturing protocols. Methods: We are conducting two ongoing investigator initiated basket TIL therapy trials. The first (NCT03449108) includes cohorts with poorly differentiated soft tissue and bone sarcomas, osteosarcoma, and platinum resistant ovarian cancer. The TIL product used in this trial is an investigational cell product (LN-145, Iovance Biotherapeutics, Inc.). The second trial (NCT03610490) includes cohorts of osteosarcoma, platinum resistant ovarian cancer, and pancreatic cancer (who have progressed on, or received maximal benefit from, front-line therapy). For this trial, TIL are manufactured at MD Anderson Cancer Center using a protocol that includes the use of urelumab (an agonistic anti-CD137 antibody) combined with T cell receptor activation during TIL expansion. In both trials eligible subjects undergo tumor harvest using a surgical excisional biopsy of the tumor for TIL manufacturing, receive a modified cyclophosphamide and fludarabaine lymphodepletion regimen and up to six doses of IL-2 (600,000 IU/kg) following TIL infusion. No intervening therapy is allowed between tumor harvest and initiation of lymphodepletion. The primary endpoint for each cohort is ORR as assessed by investigators using RECIST 1.1 criteria. The Simon’s two stage design is used to monitor the efficacy of each cohort independently. In the first stage, 10 patients will be treated per cohort. If there is no confirmed response in these 10 evaluable patients, the cohort will be terminated. If the cohort moves forward to Stage II, an additional 8 patients will be treated leading to a total of 18 patients. Three or more responders out of 18 treated patients for the cohort will be considered clinically relevant to justify further investigation. Enrollment is ongoing in all cohorts in both trials. An accrual update will be provided at the annual meeting. Clinical trial information: NCT03449108, NCT03610490.

The effect of antibiotic use on survival of patients with resected pancreatic ductal adenocarcinoma

e15773

Background: Recent studies showed that gut microbial dysbiosis can affect carcinogenesis and tumor responses to therapies. Antibiotics, key pharmacologic agents that modulate microbiota diversity and bacterial strains, can lead to dysbiosis. Recent studies have postulated a tumor promoting effect for some pancreatic ductal adenocarcinoma (PDAC)-associated gut bacteria. However, the effects of antibiotic use on PDAC patients outcome is yet to be discovered. Methods: We examined a total of 342 patients who were diagnosed with PDAC between 2003-2015 and underwent primary tumor resection. Antibiotic exposure was defined as the use of antibiotics for ≥7 days between diagnosis and surgery. We collected data on patient demographics, presurgical antibiotic use, duration, type and reason, disease and therapy characteristics, and prognostic parameters. We analyzed and compared the objective responses, progression free survival (PFS) and overall survival (OS). Results: From a total 342 patients with resected PDAC, 147 patients (43%) used antibiotics for ≥7 days duration during the presurgical period. The most frequently used antibiotics were quinolones (80.4%), beta-lactams (38.2%), nitroimidazoles (23%), glycopeptides (15.3%), tetracyclines (8.6%), and macrolides (6.7%). The median OS for patients with antibiotic use was 1007 vs. 940 days for those without antibiotic use (p = 0.57). The median PFS was 374 for patients with antibiotic use and 313 days for those without antibiotic use (p = 0.51). The effect of individual antibiotics was examined and statistical analysis was done for possible confounding factors including disease stage, treatment type, and the reason for antibiotic use. Tetracyclines use was found to be significantly associated with worse survival on resected PDAC patients and was not affected by confounding factors such as skin infections. The median OS of patients who had tetracycline for ≥7 days was 687 vs. 1004 days for those not exposed to this antibiotic (HR 1.836; p = 0.015). Although not statistically significant, PFS was shorter with tetracycline use. Conclusions: We conducted the first retrospective, single-center cohort study on resected PDAC patients examining the potential influence of antibiotic use on survival. Tetracycline use in resectable PDAC patients is associated with clinically significant decreased PFS and statistically significant worse OS. Further multicenter studies with larger population would be necessary to confirm these findings that could help clinical practice for infectious treatment in PDAC patients.

First line gemcitabine and nab-paclitaxel chemotherapy for localized pancreatic ductal adenocarcinoma

369

Background: Chemotherapy is widely used as a component of treatment of localized pancreatic ductal adenocarcinoma (PDAC). Pre-operative chemotherapy is associated with early treatment of micro-metastases and guaranteed delivery of all components of multimodality therapy. For locally advanced (LA) PDAC, induction chemotherapy is standard of care. We evaluated the use of gemcitabine and nab-paclitaxel (Gem/nab-P) as first-line therapy in localized PDAC. Methods: Records of pts with localized PDAC who initiated Gem/nab-P at a single institution from 2013-2015 were retrospectively reviewed. Clinicopathologic features, dose and outcomes were evaluated. Pts were staged using our previously published criteria: potentially resectable (PR), borderline type A (BR-A) (anatomy amenable to vascular resection), BR-B (biology suspicious for metastatic disease including high CA19-9), BR-C (co-morbidities requiring medical optimization), and LA. Co-morbidities were classified using adult comorbidity evaluation-27 score. Overall survival (OS) was analyzed using Kaplan Meier method. Results:99 pts [M/F: 50/49; median age: 70 yrs (range 30-85); PR/BR/LA: 45/14/40] were treated with Gem/nab-P. Clinical staging showed PR+BR-A/BR-B+C: 20/39. BR-B+C included one or more of the following factors: age ≥80 yrs [13%], ECOG PS ≥2 [13%], moderate/severe co-morbidities [55%], CA19-9≥1000 [28%], suspicion for metastatic disease [21%]. Majority of pts received biweekly Gem/nab-P dosing [standard/biweekly/other: 10/80/9] with minimal grade 4 toxicity. 45/99 pts received chemoradiation after Gem/nab-P [30Gy/50.4Gy: 15/30]. 12/20 (60%) PR+BR-A, 2/39 (5%) BR-B+C and 1/40 (3%) LA pts underwent pancreatectomy. 13/15 resected pts received adjuvant chemotherapy. At median follow-up of 26 mo, median OS was 18 (95% CI: 15.6-20.5) mo for all, 17 (95% CI: 14.6-19.5) mo for unresected and not reached for resected pts (p = 0.03). Conclusions: A significant number of pts with resectable PDAC albeit aggressive biology (BR-B) and/or medically inoperable disease (BR-C) received first-line Gem/nab-P; resection rates were lower compared to PR/BR-A pts. Biweekly dosing is being used in localized PDAC and is well tolerated.

LUNA: A randomized phase II trial of liver resection plus chemotherapy or chemotherapy alone in patients with unresectable lung and resectable liver metastases from colorectal adenocarcinoma

TPS3625

Background: Liver resection for metastatic colorectal cancer is associated with 5-year overall survival (OS) of 58% and accepted as standard of care. However, the role of liver resection with unresectable low-volume lung metastases is unknown. A recent retrospective study showed that resection of liver metastases was associated with statistically improved OS compared to a matched group of patients treated with systemic therapy alone for lung and liver metastases (3-year OS 43% vs. 14%; Mise Y, Ann Surg Oncol 2015). LUNA is a single-institution phase 2 randomized trial designed to determine the overall survival benefit of liver resection in patients with unresectable lung metastases and to integrate biological surrogates to risk stratify patients and optimize patient selection for hepatectomy. Methods: Eligibility criteria include resectable liver metastases, defined as sufficient liver remnant volume, adequate vascular inflow and outflow, and preservation of 2 contiguous liver segments. Low-volume lung metastases are defined as solid pulmonary nodules < 2 cm in size and < 15 in number. Chest computed tomography is reviewed by an attending thoracic surgeon, and lung metastases are deemed unresectable due to anatomic location, distribution, or patients’ comorbidities. Previous treatment with systemic chemotherapy and/or biologic agents is permitted. After stratification by KRAS status and primary tumor location in the colon vs. rectum, patients are randomized 1:1 to liver resection plus chemotherapy or no liver resection with chemotherapy at the discretion of the treating oncologist as routine standard of care. Patients are restaged every 3‒6 months until 3 years after randomization or death. The primary endpoint is OS. Secondary endpoints include quality of life and identification of biological surrogates in blood and resected liver tissue associated with response to chemotherapy, time to tumor progression, and survival. Targeting an effect size of extending median OS from 17 to 34 months will provide 80% power with 0.05 one-sided alpha with a sample size of 80 patients. Clinical trial information: NCT02738606.

Neoadjuvant nab-paclitaxel and gemcitabine (AG) in borderline resectable (BR) or unresectable (UR) locally advanced pancreatic adenocarcinoma (LAPC) in patients ineligible for FOLFIRINOX

328

Background: AG is superior to gemcitabine in patients with advanced pancreas cancer. There are limited data on the use of AG in BR or UR LAPC. Although FOLFIRINOX (5-fluorouracil, leucovorin, irinotecan and oxaliplatin) is an option for such patients, many are not eligible due to age, poor performance status (PS) or comorbidities. Herein, we report our experience with neoadjuvant AG for BR/UR LAPC in patients ineligible for FOLFIRINOX. Methods: In this retrospective series, we included patients with BR/UR LAPC who received neoadjuvant AG. The treatment algorithm included AG for 3-4 months followed by radiation, then re-evaluation for surgery. The published AG regimen doses were modified based on patient tolerance. The primary outcome measure was R0 resection rate. Secondary outcomes were response rate, tolerability, and overall survival (OS). Results: Between 10/2013-9/2015, 20 patients (14 BR, 6 UR) at two institutions were treated with this approach. Median age was 69 years (range 44-90); 11/20 were female; PS ranged from 0-3; 14 patients have completed therapy and 6 remain on treatment. Five were converted to resectability by imaging and subsequently underwent operation; 4 had R0 resections (29% of patients who have finished therapy). To date, 6 patients died from progressive disease (PD), 2 are alive with PD and 12 remain alive on therapy or surveillance. All patients who achieved R0 resections are alive and disease free. The best response to AG was a partial response in 4 patients (20%), stable disease in 11, and progression in 2 with 3 patients still pending re-evaluation. Mean dose intensity was 77% for AG. Toxicities were similar to the published AG regimen. Conclusions: In this small series, both the R0 resection rate and the response rate were at least 20%, despite frequent dose reductions and relatively low dose intensity. Elderly and/or poor PS patients with LAPC have been historically excluded from curative-intent strategies. Our data suggest that these patients may now have a possibility for cure with the use of neoadjuvant AG.

Defining the optimal timing of adjuvant therapy for resected pancreatic cancer: A statewide cancer registry analysis

406

Background: Recent long-term results from the ESPAC-3 trial suggest that while completing adjuvant therapy (AT) is necessary after resection of pancreatic adenocarcinoma (PDAC), early initiation of AT before 8 weeks may not be associated with improved overall survival (OS). The primary aim of this study was to evaluate the impact of early vs. late AT initiation on OS in a statewide population-based analysis. Methods: Among all patients with stage I-III PDAC in the Surveillance Epidemiology and End Results (SEER) - Kentucky Cancer Registry (KCR) from 2004-2012, those undergoing pancreatectomy were stratified by postoperative chemotherapy/radiotherapy delivery and timing. Patients with preoperative therapy, no AT, or postoperative therapy beyond 16 weeks, were excluded. Remaining patients were stratified into 2 groups defined as “early” (<8 weeks) and “late” AT (8-16 weeks). A Cox regression model was created to analyze the impact of AT timing, adjusting for clinicopathologic variables. Results: Of the 4,882 total patients with PDAC, 1,193 (24%) underwent pancreatectomy. Of these, only 364 (30%) received AT within 16 weeks. With median age 65 years (range 20-101), 86% patients were stage II and 76% were node-positive. Median time to AT initiation was 52 days (range 5-111). Timing of AT did not affect OS (median OS: early AT, 19.5 vs. 19.7 mo, late AT, p=0.63). Median OS for stages I, II, and III were 46.1, 19.3, and 8.6 mo, respectively (p<0.001). Poorly/undifferentiated tumors were associated with worse median OS 17.6 vs. 21.3 mo for well/moderately differentiated tumors (p<0.001). Lymph node positivity was associated with worse median OS 18.1 vs. 25.8 mo for node negativity (p<0.001). On multivariate analysis, factors that affected OS included stage (II, HR 2.54, p=0.022; III, HR 5.16, p<0.001), node positivity (HR 1.57, p=0.008), poorly/undifferentiated grade (HR 1.50; p=0.002), but not AT timing. Conclusions: In this SEER-KCR analysis, there was no difference in OS between early and late AT initiation. Despite its proven value, the ideal window for AT initiation remains unknown as tumor biology continues to trump current treatment regimens.

Paclitaxel, carboplatin, and capecitabine (TCX) with and without radiation in locally advanced and metastatic distal esophageal and esophagogastric junction cancer: A single-center retrospective review

197

Background: Toxicities of the active triple-drug DCF regimen (docetaxel, cisplatin and 5-FU) in gastric cancer limit its broad use and general acceptance as first-line therapy. To improve the toxicity profile of triple-drug therapy, distal esophageal and esophagogastric junction (DE-EGJ) poorly differentiated and moderately differentiated adenocarcinoma patients were treated with TCX. This single-center retrospective review is reported for patients treated between 2005 and 2013. Methods: Patients with DE-EGJ adenocarcinoma were treated with capecitabine (850 mg/m2 5 out of 7 or 14 out of 21 days), carboplatin (AUC 5) and paclitaxel (175 mg/m2) every 3 weeks. Those with locally advanced disease received concomitant radiation therapy (50.4 Gy using 3D approach) during the first 2 cycles. Dose reductions (25-50%), delay of therapy and hospitalizations for disease and treatment-related Grades 3/4 toxicities were recorded. Growth factors were prescribed reactively. Kaplan-Meier statistics were used for survival analyses. The institutional tumor registry data provided the historical median survival. Results: Thirty-one males and 3 females (median age 56, range 37-82) with locally advanced (N=17) and metastatic (N=17) disease were included. Median overall survivals are shown below. Two patients were admitted for neutropenic fever and 7 total hospitalizations occurred. Conclusions: A triple-drug combination first-line regimen (TCX) with and without radiation in DE-EGJ cancer is active, and associated with a manageable toxicity profile. The median survival of 15.8 months in patients with metastatic disease treated with TCX compares favorably with the DCF regimen (9.2 mos), the EOX regimen (11.2 mos) as well as institutional historical controls. Our data suggests that future prospective trials evaluating triple-drug regimens in combination with targeted therapy may be feasible in patients with esophageal and gastric adenocarcinoma. [Table: see text]

Effect of complications after pancreaticoduodenectomy on adjuvant therapy utilization and survival in pancreatic cancer

422

Background: While adjuvant therapy (AT) completion is a necessary component of multimodality therapy for pancreatic adenocarcinoma (PDAC), its timing and utilization can be hindered by complications after pancreaticoduodenectomy (PD). The primary aim of this study was to evaluate the impact of post-PD complications on AT utilization and overall survival (OS). Methods: Patients treated with PD for PDAC at a single institution (2000-2012) were evaluated. Data on 90-day complications were extracted from the electronic medical record with postoperative major complications (PMC) defined as Grade ≥3. Patient records were linked to the Surveillance Epidemiology End Results - Kentucky Cancer Registry for AT and OS data. Early AT required a first dose before 8 weeks, while late was 8-16 weeks. Initiation after 16 weeks was not considered adjuvant. Chi-square statistics, Kaplan-Meier plots, and log-rank tests were used to examine associations among complication status and AT timing, AT utilization, and OS. Results: Of 84 total patients, 54 (64%) received AT (34 [41%] early; 20 [24%] late). Rates of patients with 90-day complications were as follows: 44 (52%) Grade ≥1, 37 (44%) Grade ≥2, and 18 (21%) Grade ≥3. Low-grade (Grades 1-2) complications were not associated with late AT or lack of AT (both p>0.082). However, PMC were associated with lower rates of AT (7/18, 39% with PMC vs. 47/66, 71% without PMC, p=0.011). Even patients who recovered from PMC were less likely to meet the early 8-week window (4/18, 22%, patients with PMC, vs. 30/66, 46%, patients with no PMC, p=0.039). PMC were associated with worse median OS (6.1 mo, 95% confidence interval, CI, 1.6-12.1, vs. 20.8 mo, 95% CI 17.3-23.8, with no PMC, p<0.001), while low-grade complications were not (all p>0.079). Conclusions: In this series,low-grade complications had minimal effects on AT timing, AT utilization, and OS, but PMC were associated with late and decreased AT utilization and negatively impacted OS.These data suggest that strategies to decrease PMC and/or treatment sequencing alternatives to increase multimodality completion rates in high-risk patients may improve oncologic outcomes.

Neoadjuvant radiation therapy and its impact on complications after pancreaticoduodenectomy for pancreatic cancer: analysis of the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP)

OBJECTIVES

This study investigated the impact of neoadjuvant radiation therapy (XRT) on postoperative outcomes following pancreaticoduodenectomy for pancreatic cancer.

METHODS

The American College of Surgeons National Quality Improvement Program database was queried for the period 2005-2010 to assess complication rates following pancreaticoduodenectomy for pancreatic cancer. Two groups of patients were identified, comprising those who received neoadjuvant XRT and those who did not (control group).

RESULTS

A total of 4416 patients were identified, including 200 in the XRT group and 4216 in the control group. There were differences in patient characteristics between the groups, including in age, hypertension and bilirubin level. Despite the fact that weight loss was more common, median operative time was longer (423 min versus 368 min; P < 0.001), and vascular reconstruction was more commonly required (20.5% versus 8.4%; P < 0.001) in the XRT group. In addition, the XRT group had a shorter median hospital stay than the control group (9 days versus 10 days; P = 0.005). Mortality (3.0% versus 2.7%; P = 0.818) and morbidity (40.5% versus 37.6%; P = 0.404) rates were not influenced by neoadjuvant XRT. Blood transfusion rates were increased in the XRT group (13.0% versus 7.4%; P = 0.003). Severe complications were influenced by age >70 years, American Society of Anesthesiologists (ASA) class >2, preoperative sepsis, dyspnoea, weight loss, impaired functional status, peripheral vascular disease and operative time of >8 h.

CONCLUSIONS

Neoadjuvant XRT is not associated with an increase in complications after pancreaticoduodenectomy.

The cost-effectiveness of neoadjuvant chemoradiation is superior to a surgery-first approach in the treatment of pancreatic head adenocarcinoma

BACKGROUND

In treating pancreatic cancer, there is no clearly defined optimal sequence of chemotherapy, radiation therapy and surgery. Therefore, cost-effectiveness should be considered. The objective of this study was to compare cost and outcomes between a surgery-first approach versus neoadjuvant chemoradiation followed by surgery for resectable pancreatic head cancer.

METHODS

A decision analytic model was constructed to compare the 2 approaches. Data from the National Cancer Database, National Surgical Quality Improvement Program, and literature populated the surgery-first arm. Data from our prospectively maintained institutional pancreatic cancer database populated the neoadjuvant arm. Costs were estimated by Medicare payment (2011 U.S. dollars). Survival was reported in quality-adjusted life-months (QALMs).

RESULTS

The neoadjuvant chemoradiation arm consisted of 164 patients who completed preoperative therapy. Of these, 36 (22 %) did not proceed to surgery; 12 (7 %) underwent laparotomy but had unresectable disease; and 116 (71 %) underwent definitive resection. The surgery-first approach cost $46,830 and yielded survival of 8.7 QALMs; the neoadjuvant chemoradiation approach cost $36,583 and yielded survival of 18.8 QALMs. In the neoadjuvant arm, costs and survival times for patients not undergoing surgery, those with unresectable disease at laparotomy, and those completing surgery were $12,401 and 7.7 QALMs, $20,380 and 7.1 QALMs, and $45,673 and 23.4 QALMs, respectively.

CONCLUSIONS

Neoadjuvant chemoradiation for pancreatic cancer identifies patients with early metastases or poor performance status, who can be spared an ineffective or prohibitively morbid operation, and is associated with improved survival at significantly lower cost than a surgery-first approach. Neoadjuvant chemoradiation followed by surgery is a strategy that provides more cost-effective care than a surgery-first approach.

Neoadjuvant chemoradiation versus surgery first for resectable pancreatic head adenocarcinoma: An economic and outcome analysis

156

Background: The optimal sequence of treating pancreatic cancer (PC) with chemotherapy, radiation and surgical intervention remains elusive. Thus, cost should be considered. This study was conducted to compare the cost and outcome of a surgery first approach versus neoadjuvant chemoradiation (CRT) followed by surgery.

Methods: A decision model was constructed to contrast the 2 treatment strategies. The NCDB (2003-5), ACS NSQIP (2005-9) and literature populated probabilities and outcomes in the surgery first arm, including operative outcome, complication rate, pathologic stage, adjuvant therapy and stage-specific survival based. Data from a prospectively maintained PC database (2002-8) populated the neoadjuvant arm. Costs were based on Medicare reimbursement (2011$). Survival, discounted when appropriate, was reported in quality-adjusted life months (QALM).

Results: 164 pts completed neoadjuvant CRT. Of these, 36 (22%) did not proceed to surgery. Failure was due to metastases, 18(50%), prohibitive performance status (PS), 17(47%) and pt choice, 1(3%). 12 pts (7%) proceeded to laparotomy but were deemed unresectable. 116 (71%) pts underwent definitive resection. The surgery first approach cost $95,781 to yield survival of 8.7 QALM, while the neoadjuvant strategy cost $71,416 to achieve 18.8 QALM. In the neoadjuvant population, pts not undergoing surgery, those unresectable at laparotomy and those completing surgery demonstrated a cost of $12,401 to yield 7.7 QALM, $39,112 to yield 7.1 QALM and $92,887 to achieve 23.4 QALM, respectively.

Conclusions: Treating pts with neoadjuvant CRT identifies those who develop early metastases or prohibitive PS and can be spared an ineffectual or prohibitively morbid operation. Our data suggest this approach is associated with improved OS at significantly lower cost. Neoadjuvant therapy for resectable PC should be employed more frequently to provide cost-effective care for this lethal disease.

[Table: see text]

Use of operability classifications to predict outcome of patients with anatomically resectable pancreatic adenocarcinoma treated with neoadjuvant therapy

293

Background: We previously introduced a novel classification system for assessing “operability” in patients with localized pancreatic adenocarcinoma (PDAC) that integrates cancer biology, patient physiology, and tumor anatomy. We sought to analyze resection rates, reasons for no resection, and outcomes after neoadjuvant therapy (NT) of patients with both resectable anatomy and either “operable” or “borderline” biology/physiology.

Methods: We evaluated consecutive patients (2002-2007) with radiographically resectable cancers treated with NT prior to potential resection. Borderline resectable anatomy (BR-A) was excluded. We compared clinical factors and outcomes of 217 patients classified by established criteria as “potentially resectable-operable” (PR-OP, no evidence of extrapancreatic disease, performance status [PS] ≤1); “borderline resectable-B” (BR-B, findings suspicious for extrapancreatic disease); or “borderline resectable-C” (BR-C, severe but reversible comorbidities or marginal PS ≥2).

Results: 138 PR-OP, 41 BR-B, and 38 BR-C patients began NT. 62.7% of all patients underwent subsequent pancreatectomy. Resection rates after NT for PR-OP, BR-B, and BR-C were 74.6%, 46.3%, and 36.8%, respectively (p<0.001). Metastases were detected during NT in 23.0% of all patients and were the most common contraindication to resection in PR-OP (15.2%) and BR-B (46.3%) patients. PS rarely precluded surgery except in BR-C patients (31.6%). Factors independently predicting not utilizing surgery after NT were older age, poor PS, new pain medications, and complications on NT (p<0.05). Median OS of all patients was 20.9 (95% CI, 17.1-27.1) mo. Resected and unresected BR-B and BR-C patients had OS similar to that of PR-OP patients (resected medians 33.0, 39.8, 36.0 mo, respectively; unresected medians, 10.1, 12.6, 12.9 mo; p<0.001).

Conclusions: Our operability classification system describes discrete clinical subgroups among PDAC patients with similar, resectable tumor anatomy but vastly heterogeneous physiology and cancer biology. It can be used with NT to predict outcomes, individualize treatment, and optimize survival rates.

Morbidity of staged proctectomy after hepatectomy for colorectal cancer: A matched case-control analysis

629

Background: Proctectomy after hepatectomy, or the “reverse approach,” is an alternative to traditional sequencing for advanced liver metastases with asymptomatic colorectal primaries. However, perioperative morbidity from staged proctectomy remains uncharacterized. We sought to identify risk factors for morbidity in these patients.

Methods: A single-institution colorectal database was queried for patients treated with proctectomy after previous hepatectomy from 2003-2011. Reverse approach patients (31) were matched 1:2 with a cohort of standard proctectomy patients (62), using operation, age, sex, and surgeon. Perioperative factors were analyzed by univariate/multivariate models for associations with complications graded by Dindo-Clavien criteria.

Results: 31 patients with adenocarcinoma ≤20 cm from the anal verge underwent proctectomy after hepatectomy. Median time from hepatectomy to proctectomy was 5.1 mo. Median tumor distance was 8.5 cm from the anal verge. No patients with primary tumors in situ recurred in the liver while awaiting proctectomy after hepatectomy. Prior to proctectomy, there were 28 (90%) major hepatectomies and 7 (22%) portal vein embolizations. Grade ≥2 complications developed in 42% of reverse approach and 27% of standard proctectomies (p=0.17). Grade 3 complications developed in 10% and 8%, respectively (p=1.00). There were no perioperative deaths. Reverse approach patients did not differ from the control cohort in operation, demographics, body mass index (BMI), comorbidities, tumor distance, operative time, estimated blood loss (EBL), length of stay, or complication rates (p>0.05). Independent predictors of Grade ≥2 complications were BMI ≥30 (p=0.007), operative time ≥300 min (p=0.012), intraoperative transfusion (p=0.044), concurrent procedures (p=0.024), and age ≥50 (p=0.030). Independent factors for Grade 3 complications were operative time ≥300 min (p=0.015), intraoperative transfusion (p=0.011), and EBL ≥300 ml (p=0.047).

Conclusions: Risk factors for morbidity of staged proctectomy are similar to those for standard proctectomy. When applied to selected patients, the reverse approach is safe with acceptable morbidity.