High-risk pathological features at the time of salvage surgery predict poor survival after definitive therapy in patients with head and neck squamous cell carcinoma.

OBJECTIVES: Salvage surgical resection is the preferred treatment for head and neck squamous cell carcinoma (HNSCC) patients who develop locally recurrent disease after failing primary therapy. However, salvage surgical resection is not always feasible, and survival outcomes for those that do undergo salvage remain poor. It is well known that patients with adverse pathological features (extracapsular extension (ECE) of lymph nodes (LN), positive margins, perineural invasion (PNI), lymphovascular invasion (LVI), and multiple LN metastases) at the time of primary surgical resection are likely to have relatively poor outcomes. However, the impact of adverse pathological features on outcomes in the salvage setting remains controversial. MATERIALS AND METHODS: We retrospectively analyzed 73 patients at a single institution from 2008 to 2017 who developed recurrence and subsequently underwent salvage surgery (SS) after definitive curative-intent therapy including radiation. Demographic and disease control outcomes were reviewed. Kaplan-Meier curves were used to estimate relapse free survival (RFS) and overall survival (OS). RESULTS: Median age at diagnosis was 61 years (range 40-86), 49/73 (67%) were male, and 55/73 (75%) had smoked. Patients with any adverse pathological features at SS had worse RFS (HR 3.15 p = 0.0008) and worse OS (3.97 p = 0.0008). Patients who relapsed <6 months after initial therapy had worse OS (HR 2.96 p = 0.004). CONCLUSIONS: Patients with adverse pathological features at time of salvage surgery as well as those who have an early recurrence after definitive treatment and salvage surgery have worse outcomes. Prospective studies are necessary to clarify which patients should receive more intense treatment at salvage.

Histidine-tryptophan-ketoglutarate and University of Wisconsin solution demonstrate equal effectiveness in the preservation of human pancreata intended for islet isolation: a large-scale, single-center experience.

We previously reported a small-scale study on the efficacy of histidine-tryptophan-ketoglutarate (HTK) solution versus University of Wisconsin (UW) solution on pancreas preservation for islet isolation. In this large-scale, retrospective analysis (n = 252), we extend our initial description of the impact of HTK on islet isolation outcomes and include pancreatic digestion efficacy, purification outcomes, and islet size distribution. Multivariable linear regression analysis, adjusted for donor age, sex, BMI, cold ischemia time, and enzyme, demonstrated similar results for the HTK group (n = 95) and the UW group (n = 157), including postpurification islet yields (HTK: 289,702 IEQ vs. UW: 283,036 IEQ; p = 0.76), percentage of digested pancreatic tissue (HTK: 66.9% vs. UW: 64.1%; p = 0.18), and islet loss from postdigestion to postpurification (HTK: 24,972 IEQ vs. UW: 39,551 IEQ; p = 0.38). Changes in islet size between the postdigestion and postpurification stages were comparable within each islet size category for HTK and UW (p = 0.14-0.99). Tissue volume distribution across purification fractions and islet purity in the top fractions were similar between the groups; however, the HTK group had significantly higher islet purity in the middle fractions (p = 0.003-0.008). Islet viability and stimulation indices were also similar between the HTK and the UW groups. In addition, we analyzed a small sample of patients transplanted either with HTK (n = 7) or UW (n = 8) preserved islets and found no significant differences in posttransplant HbA1c, ß-score, and frequency of insulin independence. This study demonstrates that HTK and UW solutions offer comparable pancreas preservation for islet transplantation. More in vivo islet outcome data are needed for a complete analysis of the effects of HTK on islet transplantation.

Systematic prevention of bubble formation and accumulation for long-term culture of pancreatic islet cells in microfluidic device.

Reliable long-term cell culture in microfluidic system is limited by air bubble formation and accumulation. In this study, we developed a bubble removal system capable of both trapping and discharging air bubbles in a consistent and reliable manner. Combined with PDMS (Polydimethylsiloxane) hydrophilic surface treatment and vacuum filling, a microfluidic perifusion system equipped with the bubble trap was successfully applied for long-term culture of mouse pancreatic islets with no bubble formation and no flow interruption. In addition to demonstrating normal cell viability and islet morphology, post-cultured islets exhibited normal insulin secretion kinetics, intracellular calcium signaling, and changes in mitochondrial potentials in response to glucose challenge. This design could be easily adapted by other microfluidic systems due to its simple design, ease of fabrication, and portability.