Faster Return to Intended Oncologic Treatment (RIOT) After Trisectionectomy Does Not Translate to Better Outcomes

BACKGROUND

Resection with trisectionectomy may necessitate liver molding for adequate future liver remnant (FLR), and subsequent complications can impact return to intended oncologic therapy (RIOT). This study evaluated whether a difference in RIOT exists with the use of molding and between liver molding techniques (associating liver partition and portal vein ligation for staged hepatectomy [ALPPS] and portal vein embolization [PVE]) with trisectionectomy.

METHODS

A retrospective review evaluated trisectionectomies for malignancy. Outcomes were compared with and without molding, and RIOT was determined.

RESULTS

Fifty-one patients underwent trisectionectomy: 11 ALPPS, 14 PVE, 26 without molding. 73% of ALPPS, 64% of PVE, and 58% without molding achieved RIOT (P = .971). There were no differences found in baseline characteristics, R0 rate, length of stay, readmission, complications, or mortality. Time to RIOT was significantly different (ALPPS: 3.3 months; PVE: 5.2 months; none: 2.4 months, P = .0203). There were no differences in recurrence or survival.

CONCLUSIONS

Liver molding should not cause apprehension as there are no differences in achieving RIOT. Although technique alters time to RIOT, this does not translate into improved outcomes, implicating disease biology, and regeneration stimulus.

Oncologic Outcomes of Robotic Left Pancreatectomy for Pancreatic Adenocarcinoma: A Single-Center Comparison to Laparoscopic Resection

BACKGROUND

Feasibility and safety of robotic surgery for pancreatic disease has been well demonstrated; however, there is scarce literature on long-term oncologic outcomes. We compared perioperative and oncologic outcomes between robotic left pancreatectomy (RLP) and laparoscopic left pancreatectomy (LLP) for pancreatic adenocarcinoma.

METHODS

A retrospective review evaluated left pancreatectomies performed for pancreatic adenocarcinoma from 2009 to 2019 in a tertiary institution. Baseline characteristics, operative and oncologic outcomes were compared between RLP and LLP.

RESULTS

There were 75 minimally invasive left pancreatectomy cases for pancreatic adenocarcinoma identified of which 33 cases were done robotically and 42 laparoscopically. Baseline characteristics demonstrated no difference in gender, age, BMI, T stage, N stage, neoadjuvant, or adjuvant chemotherapy. An analysis of operative variables demonstrated no difference in blood loss, increased duration, and higher lymph node yield with RLP (20 vs 12; P = .0029). Postoperatively, both cohorts had 30% pancreatic fistulas and no difference in complications. There were no differences in length of stay (LOS), 30- or 90-day readmission rates, or 90-day mortality. The analysis of oncologic outcomes demonstrated similar R0 resections (RLP: 72% vs OLP: 67%), recurrence rates (RLP: 36% vs OLP: 41%), and time to recurrence (RLP: 324 vs OLP 218 days). There was increased survival in the RLP cohort that was not significant (32 vs 19 months).

CONCLUSION

This analysis demonstrates RLP is at least equivalent to LLP in perioperative and oncologic outcomes. The significantly higher lymph node yield and trend toward an improved survival suggests oncologic advantage. Randomized controlled studies are needed to clarify benefit.

Pathologic response translates to improved patient survival after locoregional treatment for hepatocellular carcinoma: the importance of minimally invasive microwave ablation

BACKGROUND

Hepatectomy or transplantation can serve as curative treatment for early-stage hepatocellular carcinoma (HCC). Unfortunately, as progression remains a reality, locoregional therapies (LRT) for curative or bridging intent have become common. Efficacy on viability, outcomes, and accuracy of imaging should be defined to guide treatment.

METHODS

Patients with HCC who underwent minimally invasive (MIS) microwave ablation (MWA), transarterial chemoembolization (TACE), or both (MIS-MWA-TACE) prior to hepatectomy or transplantation were identified. Tumor response and preoperative computed tomography (CT) accuracy were assessed and compared to pathology. Clinical and oncologic outcomes were compared between MIS-MWA, TACE, and MIS-MWA-TACE.

RESULTS

Ninety-one patients, with tumors from all stages of the Barcelona Clinic Liver Cancer (BCLC) staging, were identified who underwent LRT prior to resection or transplant. Fourteen patients underwent MIS-MWA, 46 underwent TACE, and 31 underwent both neoadjuvantly. TACE population was older; otherwise, there were no differences in demographics. Fifty-seven percent of MIS-MWA patients had no viable tumor on pathology whereas only 13% of TACE patients and 29% of MIS-MWA-TACE patients had complete destruction (p = 0.004). The amount of remaining viable tumor in the explant was also significantly different between groups (MIS-MWA: 17.2%, TACE: 48.7%, MIS-MWA-TACE: 18.6%; p ≤ 0.0001). Compared with TACE, the MIS-MWA and MIS-MWA-TACE groups had significantly improved overall survival (MIS-MWA: 99.94 months, TACE: 75.35 months, MIS-MWA-TACE: 140 months; p = 0.017). This survival remained significant with stratification by tumor size. CT accuracy was found to be 50% sensitive and 86% specific for MIS-MWA. For TACE, CT had an 82% sensitivity and 33% specificity and for MIS-MWA-TACE, there was a 42% sensitivity and 78% specificity.

CONCLUSION

The impact of locoregional treatments on tumor viability is distinct and superior with MIS-MWA alone and MIS-MWA-TACE offering significant advantage over TACE alone. The extent of this effect may be implicated in the improved overall survival.

Robotic pancreaticoduodenectomy may offer improved oncologic outcomes over open surgery: a propensity-matched single-institution study

BACKGROUND

The robotic platform in pancreatic disease has gained popularity in the hepatobiliary community due to significant advantages it technically offers over conventional open and laparoscopic techniques. Despite promising initial studies, there remains scant literature on operative and oncologic outcomes of robotic pancreaticoduodenectomy (RPD) for pancreatic adenocarcinoma.

METHODS

A retrospective review evaluated all RPD performed for pancreatic adenocarcinoma from 2008 to 2019 in a single tertiary institution. RPD cases were matched to open cases (OPD) by demographic and oncologic characteristics and outcomes compared using Mann-Whitney U test, log rank tests, and Kaplan-Meier methods.

RESULTS

Thirty-eight RPD cases were matched to 38 OPD. RPD had significantly higher lymph node (LN) yield (21.5 vs 13.5; p = 0.0036) and no difference in operative time or estimated blood loss (EBL). RPD had significantly lower rate of delayed gastric emptying (DGE) (3% vs 32%; p = 0.0009) but no difference in leaks, infections, hemorrhage, urinary retention ,or ileus. RPD had significantly shorter length of stay (LOS) (7.5 vs. 9; p = 0.0209). There were no differences in 30- or 90-day readmissions or 90-day mortality. There was an equivalent R0 resection rate and LN positivity ratio. There was a trend towards improved median overall survival in RPD (30.4 vs. 23.0 months; p = 0.1105) and longer time to recurrence (402 vs. 284 days; p = 0.7471). OPD had two times the local recurrent rate (16% vs. 8%) but no difference in distant recurrence.

CONCLUSIONS

While the feasibility and safety of RPD has been demonstrated, the impact on oncologic outcomes had yet to be investigated. We demonstrate that RPD not only offers similar if not superior immediate post-operative benefit by decreasing DGE but more importantly may offer improved oncologic outcomes. The significantly higher LN yield and decreased inflammatory response demonstrated in robotic surgery may improve overall survival.

Abstract A94: Imatinib modulates CD4+ T cells in gastrointestinal stromal tumor (GIST)

Introduction: Imatinib mesylate partially exerts its antitumor effects in GIST by inhibiting tumor production of the immunosuppressive enzyme indoleamine 2,3-dioxygenase (Ido), thereby activating antitumor CD8+ T cells. The role of conventional CD4+ T cells (CD4+FoxP3-) in imatinib therapy is unknown. We examined the effects of imatinib on CD4+ T cells in GIST.

Methods: We injected imatinib or saline intraperitoneally for one week to KitV558-/+ mice that develop spontaneous GISTs. 1-methyl-D-tryptophan (D-1MT), an Ido inhibitor was given via oral gavage. We assessed treatment response by tumor weight and immune cells by flow cytometry. Regulatory T cells (Treg) were defined as CD4+FoxP3+. Matched blood and tumor specimens from GIST patients were freshly analyzed for immune composition. Tumors were classified as untreated, sensitive, or resistant to imatinib based on radiologic assessment just before the time of surgery.

Results: Imatinib increased CD4+ number, activation, and degranulation in the draining lymph node (DLN) but not the spleen of GIST mice (p<0.05). In the tumor, imatinib increased CD4+ number, activation, proliferation, and the intratumoral CD4+/Treg ratio (p<0.05). Conversely, Ido inhibition did not alter CD4+ number, activation, proliferation, or the CD4+/Treg ratio in the DLN or tumor. In untreated human GISTs (n=14), CD4+ T cells demonstrated greater activation and memory phenotype compared to autologous blood CD4+ T cells, but secreted Th2 cytokines on in vitro restimulation (p<0.05). Imatinib treatment altered the intratumoral CD4+/Treg ratio, with a higher ratio in sensitive tumors (n=17) compared to resistant tumors (n=12; p<0.05).

Conclusion: In mouse GIST, imatinib activates CD4+ T cells independently of Ido and increases the intratumoral CD4+/Treg ratio, a hallmark of immunologic outcome. Similarly, imatinib sensitive human GISTs have a higher CD4+/Treg ratio than resistant tumors. Hence, CD4+ T cells may contribute to the antitumor effects of imatinib in GIST. Combination immunotherapy with imatinib and CD4+ T cell modulating agents may be a promising therapy for GIST.

Citation Format: Vinod P. Balachandran, Michael Cavnar, Shan Zeng, Zubin Bamboat, Lee Ocuin, Hebroon Obaid, Eric Sorenson, Teresa Kim, Rachel Popow, Ronald P. DeMatteo. Imatinib modulates CD4+ T cells in gastrointestinal stromal tumor (GIST). [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology: Multidisciplinary Science Driving Basic and Clinical Advances; Dec 2-5, 2012; Miami, FL. Philadelphia (PA): AACR; Cancer Res 2013;73(1 Suppl):Abstract nr A94.