To examine the impact of alvimopan on outcomes and costs in a rigorous enhanced recovery colorect... more To examine the impact of alvimopan on outcomes and costs in a rigorous enhanced recovery colorectal surgery protocol. Postoperative ileus remains a major source of morbidity and costs in colorectal surgery. Alvimopan has been shown to reduce incidence of postoperative ileus in enhanced recovery colorectal surgery; however, data are equivocal regarding its benefit in reducing length of stay and costs. Patients undergoing major elective enhanced recovery colorectal surgery were identified from a prospectively-collected database (2010-2013). Multivariable analyses were employed to compare outcomes and hospital costs among patients who had alvimopan versus no alvimopan by adjusting for demographic, clinical, and treatment characteristics. A total of 660 patients were included; 197 patients received alvimopan and 463 patients had no alvimopan. In unadjusted analysis, the alvimopan group had a faster return of bowel function, shorter length of stay, and lower rates of ileus, Foley re-insertion, and urinary tract infection (all P < 0.01). After adjustment, alvimopan was associated with a faster return of bowel function by 0.6 day (P = 0.0006), and lower incidence of postoperative ileus (odds ratio 0.23, P = 0.0002). With adjustment, alvimopan was associated with a shorter length of stay by 1.6 days (P = 0.002), and a hospital cost savings of $1492 per patient (P = 0.01). Alvimopan administration as an element of enhanced recovery colorectal surgery is associated with faster return of bowel function, lower incidence of postoperative ileus, shorter hospitalization, and a significant cost savings. These results suggest that alvimopan is cost-effective in the setting of enhanced recovery colorectal surgery protocols, and should therefore be considered in these programs.
Feeding tube placement is common among patients undergoing gastrectomy, and national guidelines c... more 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. 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. 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. 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.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2009
Thermal therapies such as hyperthermia, radiofrequency ablation, cryoablation, etc. have shown gr... more Thermal therapies such as hyperthermia, radiofrequency ablation, cryoablation, etc. have shown great potential and are gaining increasing clinical acceptance in the treatment of solid tumors. However, these treatment modalities are limited by the size of tumor that can be treated, incomplete tumor kill, and damage to adjacent normal tissues. To address these limitations, the concept of adjuvant-assisted thermal therapies has been proposed and tested to enhance the tumor destructive effects of thermal therapies. CYT-6091, a pegylated colloidal gold nanoparticle containing TNF-alpha bound to its surface, has been extensively investigated in our lab as an adjuvant to enhance thermal therapies. This paper describes our investigations of nanoparticle enhanced thermal therapies in various preclinical and translational models of solid tumors.
TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference, 2007
We present a label-free CMOS DNA sensor with a new sensing-pixel architecture and background nois... more We present a label-free CMOS DNA sensor with a new sensing-pixel architecture and background noise reduction scheme. The proposed sensor generates a differential signal between bio-samples and reference buffer solution with significant reduction in offset and gain fixed pattern noise by employing on-chip correlated double sampling circuits. Non-surface-binding detection technique allows to quantify DNA molecules continuously and sequentially and to
The outcome of systemic and local therapies (e.g. chemotherapy, radiotherapy, surgery, focal abla... more The outcome of systemic and local therapies (e.g. chemotherapy, radiotherapy, surgery, focal ablation) for prostate cancer can be significantly improved by using tumor-specific adjuvants prior to treatment ("preconditioning"). We propose to use dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to monitor the in vivo response of a mouse model of prostate cancer treated with a vascular disruptive agent, TNF-α, delivered on a gold nanoparticle (NP-TNF). Six male nude mice bearing 4-5 week old LNCaP tumors were scanned at 9.4 T. DCE-MRI was performed two days before and 4-5 h after treatment with NP-TNF. An intraperitoneal (i.p.) bolus of gadolinium-DTPA (Gd) was administered and contrast enhancement was measured for 90 min. Concentration-time curves of Gd were calculated and the area under the Gd curve (AUGC) was determined pre- and post-treatment. NP-TNF treatment caused an increase in contrast uptake in tumors. Interestingly, the early concentration (10 min post Gd bolus i.p.) was similar in both untreated and treated conditions; however, 90 min after injection, [Gd] was 3.4 times higher than before treatment. AUGC doubled from (11 ± 6) [Gd] × min before treatment to (22 ± 9) [Gd] × min after treatment. An increase in signal enhancement was also observed in the muscle but to a lesser degree. We also evaluated the kinetics of intravenous Gd administration in mice bearing a jugular vein catheter to mimic the delivery method used in clinical trials. The overall treatment effects were independent of the delivery pathway of the contrast agent. In conclusion, we show that DCE-MRI is suitable to detect changes associated with a vascular disruptive agent in a mouse model of prostate cancer. The ability to characterize the effects of nanoparticle therapy in vivo with non-destructive methods is important, as such compounds, in combination with treatment strategies, are progressing towards clinical trials.
To explore the effects of volume and concentration in thermochemical ablation using an in vivo po... more To explore the effects of volume and concentration in thermochemical ablation using an in vivo porcine model. Twelve swine 60-75 kg were used in this institutionally approved study. A needle design prototype coaxial device for reagent injections and a thermocouple were inserted into surgically exposed liver. Simultaneously, an acid and base (acetic acid and NaOH) were injected at 4 mL/min based on a 3 × 3 matrix with concentration (5, 10, and 15 mol/L) and volume on the axes (total volumes of 1, 2, and 4 mL). Three animals (centre grid position) strengthened the statistical analysis. Each animal received four identical injections (total 48). Temperatures and heart rate were recorded. Livers were formalin-fixed after sacrifice. After sectioning, coagulation zones were analysed by two observers. Area and slice thickness were used to calculate the volume, surface area, and sphericity for each treatment. Coagulation volumes ranged from 2.95 ± 0.29 to 14.72 ± 1.42 mL with a maximum of 18.3 mL. Highest peak temperature was 105°C with temperatures ranging 43.5 ± 2.6°C to 91.0 ± 6.5°C. There was no association between conditions and sphericity or heart rate. The method can be used successfully to ablate tissue in vivo. By neutralising acid in situ and releasing heat and a salt, this technique improves considerably upon the use of acetic acid used alone. Peak temperatures exceeded accepted coagulation thresholds even if the only mechanism operating was hyperthermia. Reagent concentrations and volumes increased the amount of the coagulum but not in a linear fashion.
To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, ... more To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.
ABSTRACT Surgery, radiation and chemotherapy remain the mainstay of current cancer therapy. Howev... more ABSTRACT 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 (PEG, NGR) or nanoparticles (liposomes, gold) can greatly 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 h followed by a dramatic 80% drop in perfusion 2–6 h 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 demonstrates the potential of nanoparticle-conjugated VDAs to significantly improve cancer therapy by preconditioning tumor vasculature to a secondary insult in a targeted manner with limited systemic toxicity or inflammatory response. 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.
Neoadjuvant chemoradiotherapy (nCRT) has demonstrated proven benefit in tumor regression and impr... more Neoadjuvant chemoradiotherapy (nCRT) has demonstrated proven benefit in tumor regression and improved long-term local control for patients with locally advanced rectal cancer. However, precise analysis of the optimal waiting time that maximizes oncologic benefits of nCRT has not been established. The 2006-2012 National Cancer Data Base was queried for patients with stage II and III rectal adenocarcinoma who underwent nCRT followed by surgical resection. Time to surgery was defined as the difference between last date of radiotherapy and date of surgery. Primary study endpoints included resection margin positivity and pathologic downstaging. Multivariable regression modeling with restricted cubic splines was used to evaluate the adjusted association between time to surgery and our study endpoints, and to establish an optimal time threshold for surgery. A total of 11,760 patients were included. Median time to surgery was 53 days (interquartile range [IQR] 43 to 63 days). After adjusting for patient demographic, clinical, tumor, and treatment characteristics, our model determined an inflection point at 56 days after end of radiotherapy associated with the highest likelihood of complete resection and pathologic downstaging. With adjustment, the risk of margin positivity was increased in those who underwent surgery after 56 days from end of radiotherapy (odds ratio [OR] 1.40, 95% CI 1.21 to 1.61, p < 0.001). The likelihood of downstaging was increasing up to 56 days after radiotherapy (≥56 days vs <56 days, OR 1.2, 95% CI 1.02 to 1.23, p = 0.01). 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.
To examine the impact of alvimopan on outcomes and costs in a rigorous enhanced recovery colorect... more To examine the impact of alvimopan on outcomes and costs in a rigorous enhanced recovery colorectal surgery protocol. Postoperative ileus remains a major source of morbidity and costs in colorectal surgery. Alvimopan has been shown to reduce incidence of postoperative ileus in enhanced recovery colorectal surgery; however, data are equivocal regarding its benefit in reducing length of stay and costs. Patients undergoing major elective enhanced recovery colorectal surgery were identified from a prospectively-collected database (2010-2013). Multivariable analyses were employed to compare outcomes and hospital costs among patients who had alvimopan versus no alvimopan by adjusting for demographic, clinical, and treatment characteristics. A total of 660 patients were included; 197 patients received alvimopan and 463 patients had no alvimopan. In unadjusted analysis, the alvimopan group had a faster return of bowel function, shorter length of stay, and lower rates of ileus, Foley re-insertion, and urinary tract infection (all P < 0.01). After adjustment, alvimopan was associated with a faster return of bowel function by 0.6 day (P = 0.0006), and lower incidence of postoperative ileus (odds ratio 0.23, P = 0.0002). With adjustment, alvimopan was associated with a shorter length of stay by 1.6 days (P = 0.002), and a hospital cost savings of $1492 per patient (P = 0.01). Alvimopan administration as an element of enhanced recovery colorectal surgery is associated with faster return of bowel function, lower incidence of postoperative ileus, shorter hospitalization, and a significant cost savings. These results suggest that alvimopan is cost-effective in the setting of enhanced recovery colorectal surgery protocols, and should therefore be considered in these programs.
Feeding tube placement is common among patients undergoing gastrectomy, and national guidelines c... more 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. 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. 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. 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.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Annual Conference, 2009
Thermal therapies such as hyperthermia, radiofrequency ablation, cryoablation, etc. have shown gr... more Thermal therapies such as hyperthermia, radiofrequency ablation, cryoablation, etc. have shown great potential and are gaining increasing clinical acceptance in the treatment of solid tumors. However, these treatment modalities are limited by the size of tumor that can be treated, incomplete tumor kill, and damage to adjacent normal tissues. To address these limitations, the concept of adjuvant-assisted thermal therapies has been proposed and tested to enhance the tumor destructive effects of thermal therapies. CYT-6091, a pegylated colloidal gold nanoparticle containing TNF-alpha bound to its surface, has been extensively investigated in our lab as an adjuvant to enhance thermal therapies. This paper describes our investigations of nanoparticle enhanced thermal therapies in various preclinical and translational models of solid tumors.
TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference, 2007
We present a label-free CMOS DNA sensor with a new sensing-pixel architecture and background nois... more We present a label-free CMOS DNA sensor with a new sensing-pixel architecture and background noise reduction scheme. The proposed sensor generates a differential signal between bio-samples and reference buffer solution with significant reduction in offset and gain fixed pattern noise by employing on-chip correlated double sampling circuits. Non-surface-binding detection technique allows to quantify DNA molecules continuously and sequentially and to
The outcome of systemic and local therapies (e.g. chemotherapy, radiotherapy, surgery, focal abla... more The outcome of systemic and local therapies (e.g. chemotherapy, radiotherapy, surgery, focal ablation) for prostate cancer can be significantly improved by using tumor-specific adjuvants prior to treatment ("preconditioning"). We propose to use dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) to monitor the in vivo response of a mouse model of prostate cancer treated with a vascular disruptive agent, TNF-α, delivered on a gold nanoparticle (NP-TNF). Six male nude mice bearing 4-5 week old LNCaP tumors were scanned at 9.4 T. DCE-MRI was performed two days before and 4-5 h after treatment with NP-TNF. An intraperitoneal (i.p.) bolus of gadolinium-DTPA (Gd) was administered and contrast enhancement was measured for 90 min. Concentration-time curves of Gd were calculated and the area under the Gd curve (AUGC) was determined pre- and post-treatment. NP-TNF treatment caused an increase in contrast uptake in tumors. Interestingly, the early concentration (10 min post Gd bolus i.p.) was similar in both untreated and treated conditions; however, 90 min after injection, [Gd] was 3.4 times higher than before treatment. AUGC doubled from (11 ± 6) [Gd] × min before treatment to (22 ± 9) [Gd] × min after treatment. An increase in signal enhancement was also observed in the muscle but to a lesser degree. We also evaluated the kinetics of intravenous Gd administration in mice bearing a jugular vein catheter to mimic the delivery method used in clinical trials. The overall treatment effects were independent of the delivery pathway of the contrast agent. In conclusion, we show that DCE-MRI is suitable to detect changes associated with a vascular disruptive agent in a mouse model of prostate cancer. The ability to characterize the effects of nanoparticle therapy in vivo with non-destructive methods is important, as such compounds, in combination with treatment strategies, are progressing towards clinical trials.
To explore the effects of volume and concentration in thermochemical ablation using an in vivo po... more To explore the effects of volume and concentration in thermochemical ablation using an in vivo porcine model. Twelve swine 60-75 kg were used in this institutionally approved study. A needle design prototype coaxial device for reagent injections and a thermocouple were inserted into surgically exposed liver. Simultaneously, an acid and base (acetic acid and NaOH) were injected at 4 mL/min based on a 3 × 3 matrix with concentration (5, 10, and 15 mol/L) and volume on the axes (total volumes of 1, 2, and 4 mL). Three animals (centre grid position) strengthened the statistical analysis. Each animal received four identical injections (total 48). Temperatures and heart rate were recorded. Livers were formalin-fixed after sacrifice. After sectioning, coagulation zones were analysed by two observers. Area and slice thickness were used to calculate the volume, surface area, and sphericity for each treatment. Coagulation volumes ranged from 2.95 ± 0.29 to 14.72 ± 1.42 mL with a maximum of 18.3 mL. Highest peak temperature was 105°C with temperatures ranging 43.5 ± 2.6°C to 91.0 ± 6.5°C. There was no association between conditions and sphericity or heart rate. The method can be used successfully to ablate tissue in vivo. By neutralising acid in situ and releasing heat and a salt, this technique improves considerably upon the use of acetic acid used alone. Peak temperatures exceeded accepted coagulation thresholds even if the only mechanism operating was hyperthermia. Reagent concentrations and volumes increased the amount of the coagulum but not in a linear fashion.
To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, ... more To investigate simultaneous and sequential injection thermochemical ablation in a porcine model, and compare them to sham and acid-only ablation. This IACUC-approved study involved 11 pigs in an acute setting. Ultrasound was used to guide placement of a thermocouple probe and coaxial device designed for thermochemical ablation. Solutions of 10 M acetic acid and NaOH were used in the study. Four injections per pig were performed in identical order at a total rate of 4 mL/min: saline sham, simultaneous, sequential, and acid only. Volume and sphericity of zones of coagulation were measured. Fixed specimens were examined by H&E stain. Average coagulation volumes were 11.2 mL (simultaneous), 19.0 mL (sequential) and 4.4 mL (acid). The highest temperature, 81.3°C, was obtained with simultaneous injection. Average temperatures were 61.1°C (simultaneous), 47.7°C (sequential) and 39.5°C (acid only). Sphericity coefficients (0.83-0.89) had no statistically significant difference among conditions. Thermochemical ablation produced substantial volumes of coagulated tissues relative to the amounts of reagents injected, considerably greater than acid alone in either technique employed. The largest volumes were obtained with sequential injection, yet this came at a price in one case of cardiac arrest. Simultaneous injection yielded the highest recorded temperatures and may be tolerated as well as or better than acid injection alone. Although this pilot study did not show a clear advantage for either sequential or simultaneous methods, the results indicate that thermochemical ablation is attractive for further investigation with regard to both safety and efficacy.
ABSTRACT Surgery, radiation and chemotherapy remain the mainstay of current cancer therapy. Howev... more ABSTRACT 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 (PEG, NGR) or nanoparticles (liposomes, gold) can greatly 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 h followed by a dramatic 80% drop in perfusion 2–6 h 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 demonstrates the potential of nanoparticle-conjugated VDAs to significantly improve cancer therapy by preconditioning tumor vasculature to a secondary insult in a targeted manner with limited systemic toxicity or inflammatory response. 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.
Neoadjuvant chemoradiotherapy (nCRT) has demonstrated proven benefit in tumor regression and impr... more Neoadjuvant chemoradiotherapy (nCRT) has demonstrated proven benefit in tumor regression and improved long-term local control for patients with locally advanced rectal cancer. However, precise analysis of the optimal waiting time that maximizes oncologic benefits of nCRT has not been established. The 2006-2012 National Cancer Data Base was queried for patients with stage II and III rectal adenocarcinoma who underwent nCRT followed by surgical resection. Time to surgery was defined as the difference between last date of radiotherapy and date of surgery. Primary study endpoints included resection margin positivity and pathologic downstaging. Multivariable regression modeling with restricted cubic splines was used to evaluate the adjusted association between time to surgery and our study endpoints, and to establish an optimal time threshold for surgery. A total of 11,760 patients were included. Median time to surgery was 53 days (interquartile range [IQR] 43 to 63 days). After adjusting for patient demographic, clinical, tumor, and treatment characteristics, our model determined an inflection point at 56 days after end of radiotherapy associated with the highest likelihood of complete resection and pathologic downstaging. With adjustment, the risk of margin positivity was increased in those who underwent surgery after 56 days from end of radiotherapy (odds ratio [OR] 1.40, 95% CI 1.21 to 1.61, p < 0.001). The likelihood of downstaging was increasing up to 56 days after radiotherapy (≥56 days vs <56 days, OR 1.2, 95% CI 1.02 to 1.23, p = 0.01). 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.
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Papers by Mithun Shenoi