Elective neck dissection versus observation for early-stage oral squamous cell carcinoma: Systematic review and meta-analysis

INTRODUCTION

Oral squamous cell carcinoma (OSCC) is the seventh most common cancer globally, and has been identified as a growing health concern. This study aims to evaluate the current literature comparing elective neck dissection to observation in the treatment of early-stage tongue SCC, focusing on nodal recurrence, overall survival, disease specific survival statistics from randomised controlled trials comparing the two interventions.

METHODS

Systematic review and meta-analysis was conducted according to PRISMA guidelines. The odds ratio (OR) was used as a summary statistic.

RESULTS

From 8 studies, there was a total of 372 cases of recurrence, 98 (15.1%) in END group and 274 (41.5%) in the Observation group. There was a significantly lower rate of recurrence in the END group compared to observation (OR 0.25, 95% CI 0.16-0.39, I² = 54%, P < 0.00001). END was associated with higher overall survival rates when compared with observation (OR 1.95, 95% CI 1.40-2.73, I² = 14%, P < 0.0001). END was also associated with higher disease-specific survival compared with observation (OR 1.88, 95% CI 1.21-2.93), I² = 47%, P = 0.005), with no significant heterogeneity noted.

CONCLUSIONS

END was associated with significantly lower recurrence rates and higher overall and disease-specific survival compared to a conservative observation approach in early-stage oral SCC with clinically N0 neck.

Impact of resident involvement on cervical and lumbar spine surgery outcomes

BACKGROUND CONTEXT

Resident involvement in the operating room is a vital component of their medical education. Conflicting and limited research exists regarding the effects of surgical resident participation on spine surgery patient outcomes.

PURPOSE

To determine the effect of resident involvement on surgery duration, length of hospital stay and 30-day postoperative complication rates in common spinal surgery using the American College of Surgeons' National Surgical Quality Improvement Program (ACS-NSQIP) database.

STUDY DESIGN

Multicenter retrospective cohort study.

PATIENT SAMPLE

A total of 1,441 patients met the inclusion criteria: 1,142 patients had surgeries with an attending physician alone and 299 patients had surgeries with trainee involvement. All anterior cervical or posterior lumbar surgery patients were identified. Patients who had missing trainee involvement information, surgery for cancer, preoperative infection or dirty wound classification, spine fractures, traumatic spinal cord injury, intradural surgery, thoracic surgery, and emergency surgery were excluded.

OUTCOME MEASURES

The main outcomes of interest analyzed from the ACS-NSQIP database included surgical complications, medical complications, length of hospital stay, and surgery duration.

METHODS

Propensity score for risk of any complication was calculated to account for baseline characteristic differences between the attending alone and trainee present group. Multivariate logistic regression was used to investigate the impact of resident involvement on surgery duration, length of hospital stay, and 30-day postoperative complication rates.

RESULTS

After adjusting using the calculated propensity score, the multivariate analysis demonstrated that there was no significant difference in any complication rates between surgeries involving trainees compared to surgeries with attending surgeons alone. Surgery times were found to be significantly longer for surgeries involving trainees. To further explore this relationship, separate analyses were performed for tertiles of predicted surgery duration, cervical or lumbar surgery, fusion or nonfusion, and inpatient or outpatient surgery. The effect of trainee involvement on increasing surgery time remained significant for medium predicted surgery duration, longer predicted surgery duration, cervical surgery, lumbar surgery, fusion surgery, and inpatient surgery. There were no significant differences reported for any other factors.

CONCLUSIONS

After adjusting for confounding, we demonstrated in a national database that resident involvement in surgeries did not increase complication rates. We demonstrated that surgeries with more complex features may lead to an increase in operative time when trainees are involved. Further study is required to determine how to efficiently integrate resident involvement in surgeries without affecting their medical education.

JAK inhibitors for alopecia areata: a systematic review and meta-analysis

There have been a number of case reports and small clinical trials reporting promising outcomes of Janus Kinase (JAK) inhibitors tofacitinib, ruxolitinib and baricitinib for alopecia areata (AA). The majority of the literature to date is based on small volume data, with a lack of definitive evidence or guidelines. To determine the expected response of AA to JAK inhibitor therapy and factors which influence response and recurrence rates. A systematic review and meta-analysis was performed according to PRISMA guidelines. From 30 studies and 289 cases, there were 72.4% responders, good responders 45.7% and partial responders 21.4%. Mean time to initial hair growth was 2.2 ± 6.7 months, and time to complete hair regrowth was 6.7 ± 2.2 months. All 37 recurrences occurred when treatment was ceased after 2.7 months. Oral route was significantly associated with response to treatment compared to topical therapy. No difference was found between paediatric and adult cases in proportion of responses. There is promising low-quality evidence regarding the effectiveness of JAK inhibitors in AA. Future large-sized randomized studies are required to confirm findings.

On Flow Diversion: The Changing Landscape of Intracerebral Aneurysm Management

Uptake of flow-diverting technology is rapidly outpacing the availability of clinical evidence. Most current usage is off-label, and the endovascular community is nearer the beginning than the end of the learning curve, given the number of devices in development. A comprehensive overview of technical specifications alongside key outcome data is essential both for clinical decision-making and to direct further investigations. Most-studied has been the Pipeline Embolization Device, which has undergone a transition to the Pipeline Flex for which outcome data are sparse or heterogeneous. Alternative endoluminal devices do not appear to be outperforming the Pipeline Embolization Device to date, though prospective studies and long-term data mostly are lacking, and between-study comparisons must be treated with caution. Nominal technical specifications may be unrelated to in situ performance, emphasizing the importance of correct radiologic sizing and device placement. Devices designed specifically for bifurcation aneurysms also lack long-term outcome data or have only recently become available for clinical use. There are no major studies directly comparing a flow-diverting device with standard coiling or microsurgical clipping. Data on flow-diverting stents are too limited in terms of long-term outcomes to reliably inform clinical decision-making. The best available evidence supports using a single endoluminal device for most indications. Recommendations on the suitability and choice of a device for bifurcation or ruptured aneurysms or for anatomically complex lesions cannot be made on the basis of current evidence. The appropriateness of flow-diverting treatment must be decided on a case-by-case basis, considering experience and the relative risks against standard approaches or observation.

Hidradenitis suppurativa and diabetes mellitus: updated systematic review and adjusted meta-analysis

BACKGROUND

Hidradenitis suppurativa (HS) is a debilitating and distressing chronic inflammatory skin disease. There is also evolving evidence supporting the association between HS and cardiovascular risk factors, including smoking, obesity, hyperlipidaemia and metabolic syndrome. Notably, these are clinical features and risk factors that are closely associated with type 2 diabetes mellitus (DM).

AIMS

We performed a pooled adjusted meta-analysis of comparative studies to investigate the relationship between HS and DM.

METHODS

A systematic review and meta-analysis was performed according to recommended Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. OR was used as the summary effect size.

RESULTS

From pooled analysis of unadjusted data from 12 studies, we found a significantly higher proportion of DM in HS cases compared with non-HS healthy controls (16.1% vs. 15.7%; OR = 2.17; 95% CI 1.85-2.55; P < 0.001). Adjusted effect sizes from five studies were also pooled. A significantly higher proportion of DM was found for HS compared with healthy controls, although the effect size was attenuated compared with unadjusted analyses (OR 1.69; 95% CI 1.50-1.91; P < 0.001).

CONCLUSIONS

To our knowledge, our systematic review and meta-analysis is the first to pool adjusted effect sizes. We found that HS was associated with a 1.69-fold increased odds of diabetes; however, the absolute risk difference was small (16.1% vs. 15.7%) and is probably not clinically relevant. Treating clinicians should be aware of this association, but there may not be an urgent need to perform screening for impaired glucose tolerance or diabetes.

Laparoscopic vs. robotic rectal cancer surgery and the effect on conversion rates: a meta-analysis of randomized controlled trials and propensity-score-matched studies

BACKGROUND

The usage of robotic surgery in rectal cancer is increasing, but there is an ongoing debate as to whether it provides any benefit. The aim of the present study was to determine if robotic surgery results in less conversion to an open operation than laparoscopic rectal cancer surgery.

METHODS

A meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using Ovid Medline, PubMed, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, ACP Journal Club and Database of Abstracts of Review of Effectiveness. Included were randomized controlled trials (RCTs) and propensity-score-matched (PSM) studies comparing a robotic vs. laparoscopic approach to rectal cancer surgery. The primary endpoint was conversion to open. All statistical analyses and data synthesis were conducted using STATA/IC version 14·2, Windows 64 bit (StataCorp LP, College Station, TX, USA) RESULTS: Six hundred and twenty-one studies were identified through electronic database search. After application of selection criteria as per PRISMA and MOOSE criteria, six RCTs and five PSM articles were analyzed. From the six RCTs, 512 robotic and 519 laparoscopic cases were evaluated. There was a significantly lower rate of conversion for the robotic surgery arm (4.1% vs. 8.1%, OR 0.28; 95% CI 0.00-0.57). Of the five PSM studies, 2097 robotic and 3053 laparoscopic cases were evaluated. There was a significantly lower conversion to open rate found in the robotic surgery cohort (7.4% vs. 15.6%; OR 0.39; 95% CI 0.30-0.47). Pooled RCT and PSM data demonstrated significantly lower conversion rates for robotic surgery (6.7% vs. 14.5%; OR 0.38; 95% CI 0.30-0.46).

CONCLUSIONS

Robotic surgery for rectal cancer is associated with reduced conversion to open surgery compared to a laparoscopic approach.

Abstract B32: A tumor microenvironment specific EGFR targeting antibody-drug conjugate promotes regression in KRAS or BRAF mutant tumors

The epidermal growth factor (EGF) signaling pathway relies on recognition by its receptor, EGFR, and subsequent downstream signaling by the KRAS and BRAF proteins to relay proper proliferative, migratory, and angiogenic functions. Cancers with activating KRAS or BRAF mutations are resistant to EGFR targeting agents and correspond to a significant unmet medical need. We hypothesized that an anti-EGFR antibody-drug conjugate (ADC) could be active against KRAS or BRAF mutated tumors, due to the cytotoxic mechanism of the ADC warhead. In an effort to eliminate the known dermal toxicity associated with anti-EGFR therapy, and to mitigate potential toxicities associated with treatment by an anti-EGFR ADC, we wished to engineer an antibody with enhanced specificity towards EGFR in the tumor microenvironment (TME) and attenuated binding to EGFR in normal tissue. This was achieved by screening a library of antibody variants (based on cetuximab) in a spatially addressed manner for binding to a recombinant version of the EGFR extracellular domain (EGFRECD) in two separate ELISA reaction conditions. High affinity binding to the EGFRECD was desired in the first condition, which approximated the physicochemical properties of the TME (acidic pH, high lactic acid concentration, 25% human serum). In the second assay condition, which approximated mAb binding to EGFRECD in normal tissue (neutral pH, low lactic acid concentration, 25% human serum), attenuated binding affinity was desired. We identified a lead mAb variant, cMab-1501, which possessed several fold reduced binding to EGFRECD in the neutral pH, low lactic acid condition, when compared to EGFRECD binding in the low-pH, high lactic acid, assay condition. To evaluate enhanced specificity for binding to EGFR in vivo, cMab-1501 was compared to cetuximab for binding to both human donor foreskin xenografts and human A431 tumor xenografts, using a DyLight 755 conjugated version of each antibody, and subsequent fluorescence detection with a Caliper IVIS system. cMab-1501 and cetuximab demonstrated relatively comparable binding towards human A431 tumor xenografts in vivo. In addition, cetuximab bound relatively equally between human tumor xenografts and human skin grafts. However, no binding to EGFR in the human skin graft was detected for cMab-1501 over all days measured; suggesting that cMab-1501 was highly specific for binding to EGFR in the TME. We next generated an cMab-1501 based ADC (antibody-drug conjugate), via maleimide chemistry carrying a protease cleavable valine-citrulline-p-aminobenzyloxycarbonyl monomethylauristatin E (vcPAB-MMAE) cytotoxic moiety, forming a cMab-1501-vcPAB-MMAE conjugate. Both the conjugated and un-conjugated versions of cMab-1501 were rapidly internalized by EGFR positive MDA-MB-231M tumor cells over several hours. In tumor xenograft models, the TME-specific anti-EGFR ADC demonstrated complete tumor regressions against two human EGFR overexpressing tumor types, MDA-MB-231M (TNBC, KRAS G13D) and HT-29 (CRC, BRAF V600E). In both in vivo models, tumors were resistant to treatment by cetuximab. These data suggest that it is possible to engineer a monoclonal antibody with enhanced specificity for its target within the TME and that an ADC-based approach could be utilized as potential treatment of EGFR overexpressing tumors with KRAS or BRAF mutations.

Citation Format: Bob Veneziale, Lei Huang, Xiaoming Li, Qiping Zhao, Chunmei Zhao, Ryan Osgood, Jessica Cowell, Sanna Rosengren, Jason Parise, Ge Wei, Kim Phan, Robert Connor, Steve Rowe, Gilbert Keller, Gregory Frost, Dan Maneval, Curtis Thompson, Michael Shepard, Christopher Thanos. A tumor microenvironment specific EGFR targeting antibody-drug conjugate promotes regression in KRAS or BRAF mutant tumors. [abstract]. In: Proceedings of the AACR Special Conference: Function of Tumor Microenvironment in Cancer Progression; 2016 Jan 7–10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2016;76(15 Suppl):Abstract nr B32.

Abstract 1472: Enzymatic depletion of adenosine by pegylated, engineered adenosine deaminase 2 (PEG-ADA2): A novel immunotherapeutic approach to treat solid tumors

Adenosine is an endogenous immunosuppressant that binds to adenosine receptor checkpoints and protects tissue from immune-mediated rejection. Abnormally high adenosine levels (up to 100-fold greater than other tissues) contribute to a highly immunosuppressive tumor microenvironment (TME). We hypothesized that adenosine deaminase 2 (ADA2), a human enzyme that catalyzes the deamination of adenosine, could be administered at therapeutic levels to deplete high levels of TME adenosine and stimulate anti-tumor immune activity. Recombinant wild-type ADA2 (wtADA2) was cleared extremely rapidly from circulation (t1/2 = 69 min, 7.5 mg/kg iv, n = 9 mice), rendering it unsuitable for therapeutic testing. Therefore, a series of variants was designed to attenuate the heparin binding properties of ADA2 to improve bio-distribution and conjugated with 20K PEG to improve pharmacokinetics (PK). The variant PEG-ADA2-K374D displayed 94% less binding to heparin compared to wtADA2, enzymatic activity comparable to wtADA2, and 33-fold improved PK (t1/2 = 2,256 min); and consistently induced at least 60% (p&lt;0.0001) tumor growth inhibition (TGI) of established subcutaneous syngeneic CT26 tumors (b.i.w., 0.3mg/kg, n = 8). Treatment with PEG-ADA2-K374D resulted in a 5-fold increase in tumor infiltrating CD3+ T-cells (p&lt;0.0001, 6 hours post dose), as assessed by histology. We hypothesized that CD73, which catalyzes the turnover of AMP to adenosine, could be used as a biomarker to identify tumors with elevated adenosine levels. Gene expression studies against a panel of syngeneic tumors revealed that lung KLN205 and pancreatic MH194/PSC4 tumors had high CD73 levels. PEG-ADA2-K374D inhibited the growth of established MH194/PSC4 and KLN205 tumors, with TGI reaching 47% (p&lt;0.0001) and 78% (p&lt;0.0001) after 2 weeks of treatment (b.i.w, 0.3 mg/kg, n = 8). A second series of variants was generated based on structure-based design to have significantly improved kcat/km for adenosine deaminase activity. ADA2-R222Q/S265N had the highest improvement, with a 15-fold greater kcat/km than wtADA2. After pegylation, the circulating half-life of PEG-ADA2-R222Q-S265N in mice was extended from 69 min to 2,790 min (&gt;40-fold increase). This variant induced a maximum TGI of 69% (p&lt;0.05) in the MH194/PSC4 model at 0.003 mg/kg, a 100-fold lower dose than PEG-ADA2-K374D (n = 8). A third variant, PEG-ADA2-E182T lacked detectable enzymatic activity and displayed no tumor growth inhibition, suggesting that ADA2 enzyme activity is required for efficacy. These data

suggest that engineered PEG-ADA2 variants induce significant tumor growth inhibition activity in several syngeneic solid tumor models, validating enzymatic depletion of high TME adenosine levels as novel immunotherapeutic approach to treat solid tumors.

Citation Format: Lin Wang, Jessica Cowell, Sanna Rosengren, Lei Huang, Xiaoming Li, Qiping Zhao, Jennifer Souratha, Mathieu Marella, Barbara Blouw, Keri Cannon, Chunmei Zhao, Kim Phan, Curtis Thompson, Michael Shepard, Christopher Thanos. Enzymatic depletion of adenosine by pegylated, engineered adenosine deaminase 2 (PEG-ADA2): A novel immunotherapeutic approach to treat solid tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1472.

Abstract 1217: Preclinical evaluation of a next-generation, EGFR targeting ADC that promotes regression in KRAS or BRAF mutant tumors

Cancers with downstream activating KRAS or BRAF mutations in the EGFR pathway are resistant to EGFR targeting agents such as cetuximab and correspond to a significant unmet need. We hypothesized that an anti-EGFR ADC could be effective against KRAS or BRAF mutated tumors due to the cytotoxic mechanism of the ADC warhead. In an effort to eliminate the known dermal toxicity associated with anti-EGFR therapy, and to mitigate potential toxicities associated with treatment by an anti-EGFR ADC, a mAb was engineered with increased tumor microenvironment (TME) specificity for EGFR. The lead mAb demonstrated undetectable in vivo binding to human donor foreskins grafted onto nude mice, while binding to human A431 tumor xenografts with similar intensity to cetuximab (P &lt; 0.005, detected using DyLight-755 conjugated versions of each mAb, measured with a Caliper IVIS system). The lead mAb was further optimized and conjugated to the potent cytotoxic drug MMAE using a novel bis-alkylating conjugation linker, which covalently re-bridged the inter-chain disulfide bonds, creating a stable and defined ADC. The resulting ADC, HTI-1511, incorporated a vc-PAB cleavable moiety and a short linear PEG (24 ethylene glycol units) in a side-chain configuration. Analytical HIC revealed that HTI-1511 possessed a nearly homogenous drug:antibody ratio (DAR) of 4 (&gt;99.7%). Approximately 70% of this compound was rapidly internalized by human tumor cells grown in vitro over 4 hours, overlapping the internalization kinetics of the unconjugated mAb. HTI-1511 was evaluated for efficacy against two human EGFR overexpressing tumor models, MDA-MB-231M (triple-negative breast cancer, KRAS-G13D) and HT-29 (colorectal cancer, BRAF-V600E), and dosed at 5, 10, and 15 mg/kg, (qw, IV). A clear dose dependent anti-tumor response was observed with complete tumor regressions observed at the 15 mg/kg dose in both models, which were resistant to treatment by cetuximab. In addition, HTI-1511 was well-tolerated at 2 and 8 mg/kg in a cynomolgus monkey toxicity study (n = 3 per group), with limited dermal findings that were comparable with the vehicle control group. No adverse findings were observed at either dose. HTI-1511 showed a high degree of circulating stability in cynomolgus monkeys, and lacked in vivo degradation and instability that was observed in a control ADC conjugated using maleimide chemistry. HTI-1511 demonstrated significantly attenuated binding to FcγRIIa, FcγIIb, FcγIIIa 158V, and FcγIIIa 158F receptors, but not attenuated binding to FcγR1, in a FACS based assay format specific for each receptor, suggesting that HTI-1511 might have improved tolerability due to lack of binding by FcγRII-III receptors, possibly due steric hindrance from the PEG side chain. Thus, HTI-1511 holds promise as a potentially safe and effective treatment of EGFR overexpressing tumors with KRAS or BRAF mutations.

Citation Format: Lei Huang, Bob Veneziale, Mark Frigerio, George Badescu, Xiaoming Li, Qiping Zhao, Jesse Bahn, Jennifer Souratha, Ryan Osgood, Chunmei Zhao, Kim Phan, Jessica Cowell, Sanna Rosengren, Jason Parise, Martin Pabst, Mathew Bird, William McDowell, Gina Wei, Curtis Thompson, Antony Godwin, Michael Shepard, Christopher Thanos. Preclinical evaluation of a next-generation, EGFR targeting ADC that promotes regression in KRAS or BRAF mutant tumors. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1217.