Genomic Predictors of Recurrence Patterns After Complete Resection of Colorectal Liver Metastases and Adjuvant Hepatic Artery Infusion Chemotherapy

BACKGROUND

Despite curative hepatectomy, most colorectal liver metastasis (CRLM) patients relapse locally within 2 years. Genomic predictors for hepatic recurrence are poorly understood. This study was designed to identify genomic signatures for recurrence in resected CRLM patients treated with adjuvant hepatic artery infusion (HAI) and/or systemic (SYS) chemotherapy.

METHODS

Patients undergoing curative hepatectomy and adjuvant HAI+SYS or SYS between January 2000 and October 2017 with next-generation sequencing data were catalogued. Gene and signaling-level alterations were checked for association with time to any (AR), liver (LR), and extrahepatic recurrence (ER) by using Kaplan-Meier analysis.

RESULTS

Of 172 receiving HAI+SYS, 100 patients recurred, with 69 LR and 83 ER. Five- and ten-year LR-free rates were 57% (95% confidence interval [CI] 48-65%) and 51% (95% CI 41-60%), respectively. Five- and 10-year ER-free, rates were 51% (95% CI 43-58%) and 45% (95% CI 36-54%), respectively. More ER was observed with tumors harboring altered KRAS (38% [95% CI 25-50%] vs. 63% [95% CI 53-71%], p-adj = 0.003) and RAS/RAF (36% [95% CI 25-48%] vs. 66% [95% CI 56-74%], p-adj < 0.001) than wild-type. Co-altered RAS/RAF-TP53 was associated with worse AR (26% [95% CI 14-40%] vs. 48% [95% CI 39-57%], p-unadj < 0.001), ER (30% [95% CI 17-45%] vs. 62% [95% CI 53-70%], p-unadj < 0.001), and LR rate (40% [95% CI 24-57%] vs. 70% [95% CI 60-77%], p-unadj = 0.002). On multivariable analysis, controlling for clinical risk score, ablation, margin status, and primary T-stage, co-altered RAS/RAF-TP53 was associated with increased risk for AR (HR = 2.14, 95% CI 1.38-3.31, p-unadj < 0.001), LR (HR = 1.79, 95% CI 1.06-3.02, p-unadj = 0.029), and ER (HR = 2.81, 95% CI 1.78-4.44, p-unadj < 0.001).

CONCLUSIONS

Altered KRAS, RAS/RAF, and RAS/RAF-TP53 associated with earlier local and distant recurrence in resected CRLM patients receiving adjuvant HAI+SYS. Co-altered RAS/RAF-TP53 was a novel predictor of LR warranting investigation of whether genomic cooperativity is associated with this relapsing phenotype. Systemic therapies tailored to high-risk tumor biology are needed to reduce distant relapse after hepatectomy.

Recurrence of Hepatocellular Carcinoma After Complete Radiologic Response to Trans-Arterial Embolization: A Retrospective Study on Patterns, Treatments, and Prognoses

BACKGROUND

There is limited information about the long-term outcomes and patterns of progression in patients who have unresectable, liver-confined hepatocellular carcinoma (HCC) with complete response (CR) to transarterial embolization and do not undergo resection or transplantation (LT).

METHODS

A retrospective review analyzed participants in a randomized trial comparing hepatic artery embolization (HAE) and drug-eluting bead transarterial chemoembolization (DEB-TACE) with doxorubicin who had CR according to modified response evaluation criteria in solid tumors (mRECIST). The overall survival (OS), incidence and patterns of progression, and factors associated with progression were assessed.

RESULTS

Of the 101 patients in the trial, 37 with CR were included in this study. This cohort had 17 patients treated with HAE (46 %), and 20 patients managed with DEB-TACE (54 %). The median age was 67 years (range, 42-82 years). Most of the cohort were male (86.5 %) and Caucasian (78 %). The median pre-treatment Model for End-Stage Liver Disease (MELD) score was 10, and 70 % of the cohort had Barcelona Clinic Liver Cancer (BCLC) stage B or C. The median follow-up period was 49 months (95 % confidence interval [CI], 9-108 months), and the median OS was 25 months (95 % CI, 18.9-30.9 months). The 3- and 5-year survival rates were respectively 31 % (95 % CI, 16.7-45.9 %) and 18 % (95 % CI, 6.8-32.1 %). The 1- and 2-year cumulative incidences of progression were respectively 76 % (95 % CI, 57.7-86.8 %) and 92 % (95 % CI, 74.5-97.6 %). The most common first site of progression was the previously treated hepatic site or local site (32 %, 12/37). The 3-year cumulative incidence of progression was 65 % (95 % CI, 46.4-78.4 %) for the local site.

CONCLUSION

Patients with advanced-stage HCC and CR to embolization do not have durable responses and experience inevitable disease progression. Most patients with progression have liver-confined disease and should be evaluated for additional consolidative treatments.

Association of genomic profiles and survival in early onset and screening‐age colorectal cancer patients with liver metastases resected over 15 years

BACKGROUND

This study explores whether genomic profiles of colorectal liver metastasis (CRLM) patients with early onset (EO, < 50 years old) and screening age (SA) primary diagnosis are associated with overall survival (OS).

METHODS

All patients undergoing hepatectomy between 2002 and 2017 were identified and tumor specimens with next-generation sequencing data were cataloged. Gene and signaling-level alterations were checked for association with OS from primary diagnosis accommodating for left-truncated survival.

RESULTS

Of 1822 patients, 333 were sequenced-127 (38%) EO-CRLM and 206 (62%) SA-CRLM patients. More aggressive features presented in EO-CRLM patients-synchronous metastatic presentation (83% vs. 75%, p < 0.001) and primary node-positive disease (71% vs. 61%, p < 0.001). The median OS from primary diagnosis was 11.8 years (95% confidence interval = 7.94-NA). Five-year OS did not differ by age (p = 0.702). On multivariable analysis, altered APC (EO-CRLM: [hazard ratio [HR] = 0.37, p = 0.018] vs. SA-CRLM:[HR = 0.61, p = 0.260]), BRAF (EO-CRLM:[HR = 4.38, p = 0.007] vs. SA-CRLM:[HR = 4.78, p = 0.032]), and RAS-TP53 (EO-CRLM:[HR = 2.82, p = 0.011] vs. SA-CRLM:[HR = 2.35, p = 0.003]) associated with OS.

CONCLUSIONS

Despite bearing more aggressive features, EO-CRLM patients had similar genomic profiles and survival as SA-CRLM patients. Better performance status in younger patients leading to increased treatment tolerance may partly explain this. As screening and treatment strategies from older patients are applied to younger patients, genomic predictors of biology identified historically in older cohorts could apply to EO patients.

Genome-Derived Classification Signature for Ampullary Adenocarcinoma to Improve Clinical Cancer Care

PURPOSE

The clinical behavior of ampullary adenocarcinoma varies widely. Targeted tumor sequencing may better define biologically distinct subtypes to improve diagnosis and management.

EXPERIMENTAL DESIGN

The hidden-genome algorithm, a multilevel meta-feature regression model, was trained on a prospectively sequenced cohort of 3,411 patients (1,001 pancreatic adenocarcinoma, 165 distal bile-duct adenocarcinoma, 2,245 colorectal adenocarcinoma) and subsequently applied to targeted panel DNA-sequencing data from ampullary adenocarcinomas. Genomic classification (i.e., colorectal vs. pancreatic) was correlated with standard histologic classification [i.e., intestinal (INT) vs. pancreatobiliary (PB)] and clinical outcome.

RESULTS

Colorectal genomic subtype prediction was primarily influenced by mutations in APC and PIK3CA, tumor mutational burden, and DNA mismatch repair (MMR)-deficiency signature. Pancreatic genomic-subtype prediction was dictated by KRAS gene alterations, particularly KRAS G12D, KRAS G12R, and KRAS G12V. Distal bile-duct adenocarcinoma genomic subtype was most influenced by copy-number gains in the MDM2 gene. Despite high (73%) concordance between immunomorphologic subtype and genomic category, there was significant genomic heterogeneity within both histologic subtypes. Genomic scores with higher colorectal probability were associated with greater survival compared with those with a higher pancreatic probability.

CONCLUSIONS

The genomic classifier provides insight into the heterogeneity of ampullary adenocarcinoma and improves stratification, which is dictated by the proportion of colorectal and pancreatic genomic alterations. This approach is reproducible with available molecular testing and obviates subjective histologic interpretation.

Lending a hand for laparoscopic distal pancreatectomy: the optimal approach?

BACKGROUND

Both minimally invasive surgery (MIS) and open approaches for distal pancreatectomy are acceptable. MIS options include total laparoscopic/robotic (TLR) and hand-assist laparoscopy (HAL). When considering safety profile and specimen quality, the optimal approach is unknown.

METHODS

Patients who underwent distal pancreatectomy from 2010-2018 at two major academic institutions were included. Converted procedures were categorized into final approach. Ninety-day perioperative/pathologic outcomes of MIS and open were compared. Subset analyses between TLR vs HAL and HAL vs open were performed. Intent-to-treat analysis was performed.

RESULTS

Among 1006 patients, resection was performed by MIS in 35% (n = 352), open in 65% (n = 654). MIS had similar patient comorbidity profile as open but had increased operative time (183 vs 162 min; p < 0.01), lower estimated-blood-loss (EBL; 131 vs 341 mL; p < 0.01), fewer intraoperative blood transfusions (1.4 vs 5%; p < 0.01), shorter LOS (5.2 vs 7.2 days; p < 0.01). Tumor size was smaller (3.2 vs 4.4 cm; p < 0.01) with lower lymph node (LN) yield (14 vs 16; p < 0.01). When comparing HAL (n = 109) to TLR (n = 243), despite increased prior abdominal operations (60 vs 43%; p = 0.008), HAL had shorter operative time (167 vs 191 min; p < 0.01), similar length-of-stay (LOS; 5.4 vs 5.1 days; p = 0.27), and readmission rate (15 vs 13%; p = 0.47). When comparing HAL to open, the advantages of TLR approach persisted including lower EBL (171 vs 342 mL; p < 0.01), and shorter LOS (5.4 vs 7.2 days; p < 0.01). Although HAL had smaller tumors, it had a similar LN yield (16 vs 16; p = 0.80), and higher R0-rate (97 vs 83%; p < 0.01).

CONCLUSION

Hand-assist laparoscopy is safe and feasible for distal pancreatectomy as operative time, complication profile, lymph node yield, and R0-rates are similar to open procedures, while maintaining the associated the advantages of a total laparoscopic/robotic approach with reduced blood loss and shorter length-of-stay.

Neonatal Fc receptor and IgG-based therapeutics

The majority of potent new biologics today are IgG-based molecules that have demonstrated tissue-targeting specificity with favorable clinical response. Several factors determine the efficacy of these products, including target specificity, serum half-life and effector functions via complement-dependent cytotoxicity, antibody-dependent cell-mediated cytotoxicity or drug conjugates. In this review, we will focus on the interaction between therapeutic antibody and neonatal Fc receptor (FcRn), which is one of the critical factors in determining the circulating antibody half-life. Specifically, we will review the fundamental biology of FcRn, FcRn functions in various organs, Fc mutations designed to modulate binding to FcRn, IgG-based therapeutics that directly exploit FcRn functions and tools and strategies used to study FcRn-IgG interactions. Comprehensive understanding of FcRn-IgG interactions not only allows for development of effective therapeutics, but also avoidance of potential adverse effects.

Neonatal Fc receptor: from immunity to therapeutics

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn.

N-Glycan Moieties in Neonatal Fc Receptor Determine Steady-state Membrane Distribution and Directional Transport of IgG

The neonatal Fc receptor (FcRn) is a major histocompatibility complex class I-related molecule known to protect IgG and albumin from catabolism and transport IgG across polarized epithelial cells in a bidirectional manner. Previous studies have shown species-specific differences in ligand binding, IgG transport direction, and steady-state membrane distribution when expressed in polarized epithelial cells. We hypothesized that these differences may be due to the additional N-glycans expressed on the rat FcRn, because N-glycans have been proposed to function as apical targeting signals, and that two of the N-glycan moieties have been shown to contribute to the IgG binding of rat FcRn. A panel of mutant human FcRn variants was generated to resemble the N-glycan expression of rat FcRn in various combinations and subsequently transfected into Madin-Darby canine kidney II cells together with human beta2-microglobulin. Mutant human FcRn clones that contained additional N-glycan side-chain modifications, including that which was fully rodentized, still exhibited specificity for human IgG and failed to bind to mouse IgG. At steady state, the mutant human FcRn with additional N-glycans redistributed to the apical cell surface similar to that of rat FcRn. Furthermore, the rodentized human FcRn exhibited a reversal of IgG transport with predominant transcytosis from an apical-to-basolateral direction, which resembled that of the rat FcRn isoform. These studies show that the N-glycans in FcRn contribute significantly to the steady-state membrane distribution and direction of IgG transport in polarized epithelia.