This study objectively determined the optimal time for surgery after completion of nCRT for rectal cancer based on completeness of resection and tumor downstaging. Eight weeks appears to be the critical threshold for optimal tumor response.

Surgery, radiation and chemotherapy remain the mainstay of current cancer therapy. However, treatment failure persists due to the inability to achieve complete local control of the tumor and curtail metastatic spread. Vascular disrupting agents (VDAs) are a class of promising systemic agents that are known to synergistically enhance radiation, chemotherapy or thermal treatments of solid tumors. Unfortunately, there is still an unmet need for VDAs with more favorable safety profiles and fewer side effects. Recent work has demonstrated that conjugating VDAs to other molecules (polyethylene glycol, CNGRCG peptide) or nanoparticles (liposomes, gold) can reduce toxicity of one prominent VDA (tumor necrosis factor alpha, TNF-α). In this report, we show the potential of a gold conjugated TNF-α nanoparticle (NP-TNF) to improve multimodal cancer therapies with VDAs. In a dorsal skin fold and hindlimb murine xenograft model of prostate cancer, we found that NP-TNF disrupts endothelial barrier function and induces a significant increase in vascular permeability within the first 1–2 hours followed by a dramatic 80% drop in perfusion 2–6 hours after systemic administration. We also demonstrate that the tumor response to the nanoparticle can be verified using dynamic contrast-enhanced magnetic resonance imaging (MRI), a technique in clinical use. Additionally, multimodal treatment with thermal therapies at the perfusion nadir in the sub- and supra- physiological temperature regimes increases tumor volumetric destruction by over 60% and leads to significant tumor growth delays compared to thermal therapy alone. Lastly, NP-TNF was found to enhance thermal therapy in the absence of neutrophil recruitment, suggesting that immune/inflammatory regulation is not central to its power as part of a multimodal approach. Our data demonstrate the potential of nanoparticle-conjugated VDAs to significantly improve cancer therapy by preconditioning tumor vasculature to a secondary insult in a targeted manner. We anticipate our work to direct investigations into more potent tumor vasculature specific combinations of VDAs and nanoparticles with the goal of transitioning optimal regimens into clinical trials.

Nanoparticles show tremendous promise in the safe and effective delivery of molecular adjuvants to enhance local cancer therapy. One important form of local cancer treatment that suffers from local recurrence and distant metastases is thermal therapy. Here we review a new concept involving the use of nanoparticle delivered adjuvants to “pre-condition” or alter the vascular and immunological biology of the tumor to enhance its susceptibility to thermal therapy. To this end, a number of opportunities to combine nanoparticles with vascular and immunologically active agents are reviewed. One specific example of pre-conditioning involves a gold nanoparticle tagged with a vascular targeting agent (i.e. TNF-α). This nanoparticle embodiment demonstrates pre-conditioning through a dramatic reduction in tumor blood flow and induction of vascular damage which recruits a strong and sustained inflammatory infiltrate in the tumor. The ability of this nanoparticle pre-conditioning to enhance subsequent heat or cold thermal therapy in a variety of tumor models is reviewed. Finally, the potential for future clinical imaging to judge the extent of pre-conditioning and thus the optimal timing and extent of combinatorial thermal therapy is discussed.

Applications involving freeze-thaw, such as cryoplasty or cryopreservation can significantly alter artery biomechanics including an increase in physiological elastic modulus. Since artery biomechanics plays a significant role in hemodynamics, it is important to understand the mechanisms underlying these changes to be able to help control the biomechanical outcome post-treatments. Understanding of these mechanisms requires investigation of the freeze-thaw effect on arterial components (collagen, smooth muscle cells or SMCs), as well as the components' contribution to the overall artery biomechanics. To do this, isolated fresh swine arteries were subjected to thermal (freeze-thaw to -20 degrees C for 2 min or hyperthermia to 43 degrees C for 2 h) and osmotic (0.1-0.2 M mannitol) treatments; these treatments preferentially altered either the collagen matrix (hydration/stability) or smooth muscle cells (SMCs), respectively. Tissue dehydration, thermal stability and SMC functional changes were assessed from bulk weight measurements, analyses of the thermal denaturation profiles using Fourier transform infrared (FTIR) spectroscopy and in vitro arterial contraction/relaxation responses to norepinephrine (NE) and acetylcholine (AC), respectively. Additionally, Second Harmonic Generation (SHG) microscopy was performed on fresh and frozen-thawed arteries to directly visualize the changes in collagen matrix following freeze-thaw. Finally, the overall artery biomechanics was studied by assessing responses to uniaxial tensile testing. Freeze-thaw of arteries caused: (a) tissue dehydration (15% weight reduction), (b) increase in thermal stability (approximately 6.4 degrees C increase in denaturation onset temperature), (c) altered matrix arrangement observed using SHG and d) complete SMC destruction. While hyperthermia treatment also caused complete SMC destruction, no tissue dehydration was observed. On the other hand, while 0.2 M mannitol treatment significantly increased the thermal stability (approximately 4.8 degrees C increase in denaturation onset), 0.1 M mannitol treatment did not result in any significant change. Both 0.1 and 0.2 M treatments caused no change in SMC function. Finally, freeze-thaw (506+/-159 kPa), hyperthermia (268+/-132 kPa) and 0.2 M mannitol (304+/-125 kPa) treatments all caused significant increase in the physiological elastic modulus (Eartery) compared to control (185+/-92 kPa) with the freeze-thaw resulting in the highest modulus. These studies suggest that changes in collagen matrix arrangement due to dehydration as well as SMC destruction occurring during freeze-thaw are important mechanisms of freeze-thaw induced biomechanical changes.

Background Feeding tube placement is common among patients undergoing gastrectomy, and national guidelines currently recommend consideration of a feeding jejunostomy tube (FJT) for all patients undergoing resection for gastric cancer. However, data are limited regarding the safety of FJT placement at the time of gastrectomy for gastric cancer. Methods The 2005–2011 American College of Surgeons National Surgical Quality Improvement Program Participant User Files were queried to identify patients who underwent gastrectomy for gastric cancer. Subjects were classified by the concomitant placement of an FJT. Groups were then propensity matched using a 1:1 nearest neighbor algorithm, and outcomes were compared between groups. The primary outcomes of interest were overall 30-d overall complications and mortality. Secondary end points included major complications, surgical site infection, and early reoperation. Results In total, 2980 subjects underwent gastrectomy for gastric cancer, among whom 715 (24%) also had an FJT placed. Patients who had an FJT placed were more likely to be male (61.6% versus 56.6%, P = 0.02), have recent weight loss (21.0% versus 14.8%, P < 0.01), and have undergone recent chemotherapy (7.9% versus 4.2%, P < 0.01) and radiation therapy (4.2% versus 1.3%, P < 0.01). They were also more likely to have undergone total (compared with partial) gastrectomy (66.6% versus 28.6%, P < 0.01) and have concomitant resection of an adjacent organ (40.4 versus 24.1%, P < 0.01). After adjustment with propensity matching, however, all baseline characteristics and treatment variables were highly similar. Between groups, there were no statistically significant differences in 30-d overall complications (38.8% versus 36.1%, P =0.32) or mortality (5.8 versus 3.7%, P =0.08). There were also no differences in major complications, surgical site infection, or early reoperation. Operative time was slightly longer among patients with feeding tubes placed (median, 248 versus 233 min, P = 0.01), but otherwise there were no significant differences in any outcomes between groups. Conclusions Concomitant placement of FJT at the time of gastrectomy may result in slightly increased operative times but does not appear to lead to increased perioperative morbidity or mortality. Further investigation is needed to identify the patients most likely to benefit from FJT placement.