Changes in surgical mortality during COVID-19 pandemic by patients' race, ethnicity and socioeconomic status among US older adults: a quasi-experimental event study model.

OBJECTIVES: To examine changes in the 30-day surgical mortality rate after common surgical procedures during the COVID-19 pandemic and investigate whether its impact varies by urgency of surgery or patient race, ethnicity and socioeconomic status. DESIGN: We used a quasi-experimental event study design to examine the effect of the COVID-19 pandemic on surgical mortality rate, using patients who received the same procedure in the prepandemic years (2016-2019) as the control, adjusting for patient characteristics and hospital fixed effects (effectively comparing patients treated at the same hospital). We conducted stratified analyses by procedure urgency, patient race, ethnicity and socioeconomic status (dual-Medicaid status and median household income). SETTING: Acute care hospitals in the USA. PARTICIPANTS: Medicare fee-for-service beneficiaries aged 65-99 years who underwent one of 14 common surgical procedures from 1 January 2016 to 31 December 2020. MAIN OUTCOME MEASURES: 30-day postoperative mortality rate. RESULTS: Our sample included 3 620 689 patients. Surgical mortality was higher during the pandemic, with peak mortality observed in April 2020 (adjusted risk difference (aRD) +0.95 percentage points (pp); 95% CI +0.76 to +1.26 pp; p<0.001) and mortality remained elevated through 2020. The effect of the pandemic on mortality was larger for non-elective (vs elective) procedures (April 2020: aRD +0.44 pp (+0.16 to +0.72 pp); p=0.002 for elective; aRD +1.65 pp (+1.00, +2.30 pp); p<0.001 for non-elective). We found no evidence that the pandemic mortality varied by patients' race and ethnicity (p for interaction=0.29), or socioeconomic status (p for interaction=0.49). CONCLUSIONS: 30-day surgical mortality during the COVID-19 pandemic peaked in April 2020 and remained elevated until the end of the year. The influence of the pandemic on surgical mortality did not vary by patient race and ethnicity or socioeconomic status, indicating that once patients were able to access care and undergo surgery, surgical mortality was similar across groups.

Tofacitinib Is Associated With Increased Risk of Postoperative Venous Thromboembolism in Patients With Ulcerative Colitis.

BACKGROUND: In 2019, the Food and Drug Administration issued a black box warning for increased risk of venous thromboembolism in patients with rheumatoid arthritis exposed to tofacitinib. There are limited data regarding postoperative venous thromboembolism risk in patients with ulcerative colitis exposed to tofacitinib. OBJECTIVE: To assess whether preoperative exposure to tofacitinib is associated with increased odds of postoperative venous thromboembolism. DESIGN: Retrospective review. SETTINGS: Tertiary academic medical center. PATIENTS: Consecutive patients exposed to tofacitinib within 4 weeks before total abdominal colectomy or total proctocolectomy, with or without ileostomy, from 2014 to 2021, matched 1:2 for tofacitinib exposure or no exposure. INTERVENTION: Tofacitinib exposure versus no exposure. MAIN OUTCOME MEASURES: Ninety-day postoperative venous thromboembolism rate. RESULTS: Forty-two patients with tofacitinib exposure and 84 case-matched patients without tofacitinib exposure underwent surgery for medically refractory ulcerative colitis. Nine (22.0%) tofacitinib-exposed patients and 7 (8.5%) unexposed patients were diagnosed with venous thromboembolism within 90 days of surgery. In univariate logistic regression, patients exposed to tofacitinib had 3.01 times increased odds of developing venous thromboembolism within 90 days after surgery compared to unexposed patients ( p = 0.04; 95% CI, 1.03-8.79). Other venous thromboembolism risk factors were not significantly associated with venous thromboembolisms. Venous thromboembolisms in both groups were most commonly portomesenteric vein thromboses (66.7% in the tofacitinib-exposed group and 42.9% in the unexposed group) and were diagnosed at a mean of 23.2 days (range, 3-90 days) postoperatively in the tofacitinib-exposed group and 7.9 days (1-19 days) in the unexposed group. There were no statistically significant differences in location or timing between the 2 groups. LIMITATIONS: Retrospective nature of the study and associated biases. Reliance on clinically diagnosed venous thromboembolisms may underreport the true incidence rate. CONCLUSIONS: Tofacitinib exposure before surgery for medically refractory ulcerative colitis is associated with 3 times increased odds of venous thromboembolism compared with patients without tofacitinib exposure. See Video Abstract . TOFACITINIB SE ASOCIA CON UN MAYOR RIESGO DE TROMBOEMBOLISMO VENOSO POSTOPERATORIO EN PACIENTES CON COLITIS ULCEROSA: ANTECEDENTES:En 2019, la FDA emitió una advertencia de recuadro negro sobre un mayor riesgo de tromboembolismo venoso en pacientes con artritis reumatoide expuestos a tofacitinib. Hay datos limitados sobre el riesgo de tromboembolismo venoso postoperatorio en pacientes con colitis ulcerosa expuestos a tofacitinib.OBJETIVO:Evaluar si la exposición preoperatoria a tofacitinib se asocia con mayores probabilidades de tromboembolismo venoso postoperatorio.DISEÑO:Revisión retrospectiva.LUGARES:Centro médico académico terciario.PACIENTES:Pacientes consecutivos expuestos a tofacitinib dentro de las 4 semanas previas a la colectomía abdominal total o proctocolectomía total, con o sin ileostomía, entre 2014 y 2021, emparejados 1:2 para exposición a tofacitinib o ninguna exposición.INTERVENCIÓN(S):Exposición a tofacitinib versus ninguna exposición.PRINCIPALES MEDIDAS DE RESULTADO:Tasa de tromboembolismo venoso posoperatorio a los 90 días.RESULTADOS:Cuarenta y dos pacientes con exposición a tofacitinib y 84 pacientes de casos similares sin exposición a tofacitinib se sometieron a cirugía por colitis ulcerosa médicamente refractaria. Nueve (22,0%) pacientes expuestos a tofacitinib y 7 (8,5%) pacientes no expuestos fueron diagnosticados con tromboembolismo venoso dentro de los 90 días posteriores a la cirugía. En la regresión logística univariada, los pacientes expuestos a tofacitinib tuvieron 3,01 veces más probabilidades de desarrollar un tromboembolismo venoso dentro de los 90 días posteriores a la cirugía en comparación con los no expuestos ( p = 0,04, IC del 95 %: 1,03-8,79). Otros factores de riesgo de tromboembolismo venoso no se asociaron significativamente con el tromboembolismo venoso. Los tromboembolismos venosos en ambos grupos fueron más comúnmente trombosis de la vena portomesentérica (66,7% en los expuestos a tofacitinib y 42,9% en los no expuestos) y se diagnosticaron en una media de 23,2 días (rango, 3-90 días) después de la operación en los expuestos a tofacitinib y 7,9 días. (1-19 días) en los grupos no expuestos, respectivamente. No hubo diferencias estadísticamente significativas en la ubicación o el momento entre los dos grupos.LIMITACIONES:Carácter retrospectivo del estudio y sesgos asociados. La dependencia de tromboembolismos venosos diagnosticados clínicamente puede subestimar la tasa de incidencia real.CONCLUSIONES:La exposición a tofacitinib antes de la cirugía para la colitis ulcerosa médicamente refractaria se asocia con probabilidades 3 veces mayores de tromboembolismo venoso en comparación con los pacientes sin exposición a tofacitinib. (Traducción-Dr. Mauricio Santamaria ).

History and Role of Quality Accreditation.

Accreditation has played a major role in the evolution of health care quality as well as the structure and organization of American medicine. In its earliest iterations, accreditation aimed to set a minimum standard of care, and now more prominently sets standards for high quality, optimal patient care. There are several institutions that provide accreditations that are relevant to colorectal surgery including the American College of Surgeons (ACS) Commission on Cancer, National Cancer Institute Cancer Center Designation, National Accreditation Program for Rectal Cancer, and the ACS Geriatrics Verification Program. While each program has unique criteria, the aim of accreditation is to assure high-quality evidenced-based care. In addition to these benchmarks, these programs provide avenues for collaboration and research between centers and programs.

Oncologic Accuracy of Image-guided Percutaneous Core-Needle Biopsy of Peripheral Nerve Sheath Tumors at a High-volume Sarcoma Center.

OBJECTIVES: Peripheral nerve sheath tumors (PNSTs) are clinically heterogenous, comprising benign (BPNST) and malignant (MPNST) variants. BPNSTs can be managed with nerve-sparing excision or observation. MPNSTs require radical resection and multidisciplinary oncologic management (1, 15). Image-guided core-needle biopsy (IGCNBx) is the well-established standard to obtain preoperative tissue diagnosis of soft tissue tumors. However, there has been resistance to performing IGCNBx of PNSTs because of the presumed risk of nerve injury and unknown accuracy in determining malignancy. We sought to define the accuracy and safety of IGCNBx in PNSTs. MATERIALS AND METHODS: All patients that underwent both IGCNBx and surgical resection of a PNST at our institution between 2002 and 2016 were analyzed. The accuracy of IGCNBx in determining malignancy was calculated, including subgroup analyses by histologic subtype and neurofibromatosis 1 status. Complication data were collected and analyzed. RESULTS: Among the 78 PNSTs with IGCNBx and postresection surgical pathology, 76% (n=59) had BPNST and 24% (n=19) had MPNST on postresection surgical pathology. IGCNBx accurately determined malignancy in 94% of cases. IGCNBx demonstrating schwannoma or MPNST were 100% accurate in determining malignancy. IGCNBx demonstrating neurofibroma or indeterminate results were 33% and 57% malignant on postresection surgical pathology, respectively. There were no long-term complications, including sensory or motor deficits, from IGCNBx. CONCLUSIONS: Percutaneous IGCNBx demonstrates 94% accuracy in differentiating benign from malignant PNSTs. IGCNBx demonstrating neurofibroma or indeterminate pathology should be interpreted with caution because of risk of malignant reclassification on surgical pathology. Our results reaffirm the safety of IGCNBx, as no patients experienced long-term complications.

Pazopanib regresses a doxorubicin-resistant synovial sarcoma in a patient-derived orthotopic xenograft mouse model.

Synovial sarcoma (SS) is an aggressive subgroup of soft tissue sarcoma (STS) with high grade and high risk of metastasis. However, there are no systemic therapies available that target SS. Therefore, transformative therapy is needed for SS. To establish a patient-derived orthotopic xenograft (PDOX) model, a patient tumor with high grade SS from a lower extremity was grown orthotopically in the right biceps femoris muscle of mice. To test the efficacy of drugs, the PDOX models were randomized into five groups: Group 1 (G1), control-without treatment; Group 2 (G2), doxorubicin (DOX); Group 3 (G3), temozolomide (TEM); Group 4 (G4), gemcitabine (GEM) combined with docetaxel (DOC); and Group 5 (G5), pazopanib (PAZ). Tumor size and body weight were measured twice a week for each treatment group. A significant growth inhibition was found on day 14 in each treatment group compared to the untreated control, except for DOX. However, PAZ was significantly more effective than both TEM and GEM + DOC. In addition, PAZ significantly regressed the tumor volume on day 14 compared to day 0. No change was found in body weight on day 14 compared to day 0 in any treatment group. The present study demonstrated the precision of the SS PDOX models for individualizing SS therapy.

Assessment of Anastomotic Biliary Complications in Adult Patients Undergoing High-Acuity Liver Transplant.

Importance: Anastomotic biliary complications (ABCs) constitute the most common technical complications in liver transplant (LT). Given the ever-increasing acuity of LT, identification of factors contributing to ABCs is essential to minimize morbidity and optimize outcomes. A detailed analysis in a patient population undergoing high-acuity LT is lacking. Objective: To evaluate the rate of, risk factors for, and outcomes of ABCs and acuity level in LT recipients. Design, Setting, and Participants: This retrospective cohort study included adult LT recipients from January 1, 2013, through June 30, 2016, at a single large urban transplant center. Patients were followed up for at least 12 months after LT until June 30, 2017. Of 520 consecutive adult patients undergoing LT, 509 LTs in 503 patients were included. Data were analyzed from May 1 through September 13, 2017. Exposure: Liver transplant. Main Outcomes and Measures: Any complications occurring at the level of the biliary reconstruction. Results: Among the 503 transplant recipients undergoing 509 LTs included in the analysis (62.3% male; median age, 58 years [interquartile range {IQR}, 50-63 years), median follow-up was 24 months (IQR, 16-34 months). Overall patient and graft survival at 1 year were 91.1% and 90.3%, respectively. The median Model for End-stage Liver Disease (MELD) score was 35 (IQR, 15-40) for the entire cohort. T tubes were used in 199 LTs (39.1%) during initial bile duct reconstruction. Overall incidence of ABCs included 103 LTs (20.2%). Anastomotic leak occurred in 25 LTs (4.9%) and stricture, 77 (15.1%). Exit-site leak in T tubes occurred in 36 (7.1%) and T tube obstruction in 16 (3.1%). Seventeen patients with ABCs required surgical revision of bile duct reconstruction. Multivariate analysis revealed the following 7 independent risk factors for ABCs: recipient hepatic artery thrombosis (odds ratio [OR], 12.41; 95% CI, 2.37-64.87; P = .003), second LT (OR, 4.05; 95% CI, 1.13-14.50; P = .03), recipient hepatic artery stenosis (OR, 3.81; 95% CI, 1.30-11.17; P = .02), donor hypertension (OR, 2.79; 95% CI, 1.27-6.11; P = .01), recipients with hepatocellular carcinoma (OR, 2.66; 95% CI, 1.23-5.74; P = .01), donor death due to anoxia (OR, 2.61; 95% CI, 1.13-6.03; P = .03), and use of nonabsorbable suture material for biliary reconstruction (OR, 2.45; 95% CI, 1.09-5.54; P = .03). Conclusions and Relevance: This large, single-center series identified physiologic and anatomical independent risk factors contributing to ABCs after high-acuity LT. Careful consideration of these factors could guide perioperative management and mitigate potentially preventable ABCs.

Patterns of sensitivity to a panel of drugs are highly individualised for undifferentiated/unclassified soft tissue sarcoma (USTS) in patient-derived orthotopic xenograft (PDOX) nude-mouse models.

Undifferentiated/unclassified soft tissue sarcoma (USTS) is a recalcitrant disease; therefore, precise individualised therapy is needed. Toward this goal, we previously established patient-derived orthotopic xenograft (PDOX) models of USTS in nude mice. Here, we determined the extent of uniqueness of drug response in a panel on USTS PDOX models from 5 different patients. We previously showed that 3 of the 5 patients were resistant to doxorubicin (DOX) despite DOX being first-line therapy. Two weeks after orthotopic tumour implantation, PDOX mouse models were randomised into five groups: untreated control, DOX, gem-citabine/docetaxel (GEM/DOC), pazopanib (PAZ), temozolomide (TEM). Three PDOX cases were completely resistant to DOX. TEM had high efficacy for 4 USTS PDOX models, including DOX-resistant cases. GEM/DOC and PAZ were effective in three USTS PDOX. One case was completely resistant to TEM. Two cases were completely resistant to PAZ. The results showed the drug sensitivity pattern for each USTS PDOX was highly individualised and that at least one effective drug could be found for each. The PDOX model could be effective in precise individualised drug sensitivity testing which is especially important for heterogeneous cancers such as USTS, and can give the patient a greater chance to be treated with an effective drug.

Minimizing central line-associated bloodstream infections in a high-acuity liver transplant intensive care unit.

BACKGROUND: Increases in liver transplant patient perioperative acuity have resulted in frail immunosuppressed patients at elevated risk for nosocomial infections. Avoiding central line-associated bloodstream infections (CLABSIs) is paramount to facilitate transplantation and post-transplant recovery. In 2015, our liver transplant intensive care unit (ICU) CLABSIs accounted for more than 25% of all CLABSI at our institution. We therefore undertook a multidisciplinary collaborative among clinical epidemiology, nursing, transplant surgery, and critical care to eliminate CLABSI events. METHODS: From 2014-2016, using Lean methodology and plan-do-study-act (PDSA) cycles, 14 interventions were implemented in the liver transplant ICU. Interventions were aimed at infection prevention, care standardization, and team-based monitoring. Implementation used quality improvement methodology including audit and feedback, education, standardization, multidisciplinary stakeholder involvement, and PDSA cycles. Process measures were monitored and audited. CLABSI rates per 1,000 central venous catheter (CVC) days were tracked by clinical epidemiology. RESULTS: During the intervention, 901 CVC catheter audits were completed. Improvements were seen on all process measures, and complete compliance increased from 25%-67%. CLABSI infection rates dropped from 4.2 to 1.8 in 1,000 CVC days, with an average of less than 1 CLABSI per month. This marked a 61.2% annual reduction, which correlated with an estimated $935,000 annual savings. CONCLUSION: Concerted ongoing multidisciplinary collaboratives are essential to minimize CLABSI and optimize value and quality in a challenging, high-acuity patient population.

Quantitative Measure of Intestinal Permeability Using Blue Food Coloring.

BACKGROUND: Loss of intestinal barrier integrity plays a fundamental role in the pathogenesis of various gastrointestinal diseases and is implicated in the onset of sepsis and multiple organ failure. An array of methods to assess different aspects of intestinal barrier function suffers from lack of sensitivity, prolonged periods of specimen collection, or high expense. We have developed a technique to measure the concentration of the food dye FD&C Blue #1 from blood and sought to assess its utility in measuring intestinal barrier function in humans. MATERIALS AND METHODS: Four healthy volunteers and 10 critically ill subjects in the intensive care unit were recruited in accordance with an institutional review board approved protocol. Subjects were given 0.5 mg/kg Blue #1 enterally as an aqueous solution of diluted food coloring. Five blood specimens were drawn per subject: 0 h (before dose), 1, 2, 4, and 8 h. After plasma isolation, organic extracts were analyzed by high-performance liquid chromatography/mass spectrometry detecting the presence of unmodified dye. RESULTS: We found no baseline detectable absorption in healthy volunteers. After including the subjects in the intensive care unit, we compared dye absorption in the six subjects who met criteria for septic shock with the eight who did not. Septic patients demonstrated significantly greater absorption of Blue #1 after 2 h. CONCLUSIONS: We have developed a novel, easy-to-use method to measure intestinal barrier integrity using a food grade dye detectable by mass spectrometry analysis of patient blood following oral administration.

Metabolic targeting with recombinant methioninase combined with palbociclib regresses a doxorubicin-resistant dedifferentiated liposarcoma.

Liposarcoma is the most common type of soft tissue sarcoma. Among the subtypes of liposarcoma, dedifferentiated liposarcoma (DDLPS) is recalcitrant and has the lowest survival rate. The aim of the present study is to determine the efficacy of metabolic targeting with recombinant methioninase (rMETase) combined with palbociclib (PAL) against a doxorubicin (DOX)-resistant DDLPS in a patient-derived orthotopic xenograft (PDOX) model. A resected tumor from a patient with recurrent high-grade DDLPS in the right retroperitoneum was grown orthotopically in the right retroperitoneum of nude mice to establish a PDOX model. The PDOX models were randomized into the following groups when tumor volume reached 100 mm3: G1, control without treatment; G2, DOX; G3, PAL; G4, recombinant methioninase (rMETase); G5, PAL combined with rMETase. Tumor length and width were measured both pre- and post-treatment. On day 14 after initiation, all treatments significantly inhibited tumor growth compared to the untreated control except DOX. PAL combined with rMETase was significantly more effective than both DOX, rMETase alone, and PAL alone. Combining PAL and rMETase significantly regressed tumor volume on day 14 after initiation of treatment and was the only treatment to do so. The relative body weight on day 14 compared with day 0 did not significantly differ between each treatment group. The results of the present study indicate the powerful combination of rMETase and PAL should be tested clinically against DDLPS in the near future.

A combination of irinotecan/cisplatinum and irinotecan/temozolomide or tumor-targeting Salmonella typhimurium A1-R arrest doxorubicin- and temozolomide-resistant myxofibrosarcoma in a PDOX mouse model.

Myxofibrosarcoma (MFS) is the most common sarcomas in elderly patients and is either chemo-resistant or recurs with metastasis after chemotherapy. This recalcitrant cancer in need of improved treatment. We have established a patient-derived orthotopic xenograft (PDOX) of MFS. The MFS PDOX model was established in the biceps femoris of nude mice and randomized into 7 groups of 7 mice each: control; doxorubicin (DOX); pazopanib (PAZ); temozolomide (TEM); Irinotecan (IRN); IRN combined with TEM; IRN combined with cisplatinum (CDDP) and Salmonella typhimurium A1-R (S. typhimurium A1-R). Treatment was evaluated by relative tumor volume and relative body weight. The MFS PDOX models were DOX, PAZ, and TEM resistant. IRN combined with TEM and IRN combined with CDDP were most effective on the MFS PDOX. S. typhimurium A1-R arrested the MFS PDOX tumor. There was no significant body weight loss in any group. The present study suggests that the combination of IRN with either TEM or CDDP, and S. typhimurium have clinical potential for MFS.

Combination therapy of tumor-targeting Salmonella typhimurium A1-R and oral recombinant methioninase regresses a BRAF-V600E-negative melanoma.

Melanoma is a recalcitrant cancer. To improve and individualize treatment for this disease, we previously developed a patient-derived orthotopic xenograft (PDOX) model for melanoma. We previously reported the individual efficacy of tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R) and recombinant methioninase (rMETase) for melanoma in the PDOX models of this disease. In the present study, we evaluated the efficacy of the combination of S. typhimurium A1-R with orally-administered rMETase (o-rMETase) for BRAF-V600E-negative melanoma in a PDOX model. Three weeks after implantation, 60 PDOX mouse models were randomized into six groups of 10 mice each: untreated control, temozolomide (TEM); o-rMETase; S. typhimurium A1-R; TEM + rMETase, S. typhimurium A1-R + rMETase. All treatments inhibited tumor growth compared to untreated control (TEM: p < 0.0001, rMETase: p < 0.0001, S. typhimurium A1-R: p < 0.0001, TEM + rMETase: p < 0.0001, S. typhimurium A1-R + rMETase: p < 0.0001). The most effective was the combination of S. typhimurium A1-R + o-rMETase which regressed this melanoma PDOX, thereby indicating a new paradigm for treatment of metastatic melanoma.

Doxorubicin-resistant pleomorphic liposarcoma with PDGFRA gene amplification is targeted and regressed by pazopanib in a patient-derived orthotopic xenograft mouse model.

Pleomorphic liposarcoma (PLPS) is a heterogeneous resistant group of tumors. Complete surgical resection is the only known way to treat PLPS. PLPS is reristant to both radiation and chemotherapy. Therefore, precise individualized therapy is needed to improve outcome of advanced PLPS patients. In this study, a patient-derived orthotopic xenograft (PDOX) model of a PDGFRA-amplified PLPS was established in the biceps femoris of nude mice by surgical orthotopic implantation (SOI) in order to match the patient. The PLPS PDOX was treated with pazopanib (PAZ) which targets PDGFRA, as well as with temozolomide (TEM) and first-line therapy doxorubicin (DOX). The PLPS PDOX was resistant to DOX and responded very well to PAZ as well as TEM. The tumor volume on treatment day-14 relative to day-1 was as follows: DOX (4.50 ±â€¯2.6, p = 0.8087); PAZ (1.29 ±â€¯0.9, p = 0.0008 compared to the control, p = 0.0167 compared to DOX); TEM (1.07 ±â€¯0.8, p = 0.0079 compared to the control, p = 0.0079 compared to DOX). There was no significant difference in body weight between any treated group or control. The PAZ- and TEM-treated tumors showed extensive necrosis compared to the DOX-treated and untreated PDOX tumors. The present study showed that PDGFRA amplification could be effectively targeted by PAZ. The PLPS PDOX model also identified the efficacy of TEM which does not target PDGFRA, indicating that the PDOX model can identify effective targeted therapy as well as standard therapy and at the same time, identify ineffective drugs, even if they are first-line.

Trabectedin arrests a doxorubicin-resistant PDGFRA-activated liposarcoma patient-derived orthotopic xenograft (PDOX) nude mouse model.

BACKGROUND: Pleomorphic liposarcoma (PLPS) is a rare, heterogeneous and an aggressive variant of liposarcoma. Therefore, individualized therapy is urgently needed. Our recent reports suggest that trabectedin (TRAB) is effective against several patient-derived orthotopic xenograft (PDOX) mouse models. Here, we compared the efficacy of first-line therapy, doxorubicin (DOX), and TRAB in a platelet-derived growth factor receptor-α (PDGFRA)-amplified PLPS. METHODS: We used a fresh sample of PLPS tumor derived from a 68-year-old male patient diagnosed with a recurrent PLPS. Subcutaneous implantation of tumor tissue was performed in a nude mouse. After three weeks of implantation, tumor tissues were isolated and cut into small pieces. To match the patient a PDGFRA-amplified PLPS PDOX was created in the biceps femoris of nude mice. Mice were randomized into three groups: Group 1 (G1), control (untreated); Group 2 (G2), DOX-treated; Group 3 (G3), TRAB-treated. Measurement was done twice a week for tumor width, length, and mouse body weight. RESULTS: The PLPS PDOX showed resistance towards DOX. However, TRAB could arrest the PLPS (p < 0.05 compared to control; p < 0.05 compared to DOX) without any significant changes in body-weight. CONCLUSIONS: The data presented here suggest that for the individual patient the PLPS PDOX model could specifically distinguish both effective and ineffective drugs. This is especially crucial for PLPS because effective first-line therapy is harder to establish if it is not individualized.

Tumor-targeting Salmonella typhimurium A1-R suppressed an imatinib-resistant gastrointestinal stromal tumor with c-kit exon 11 and 17 mutations.

Gastrointestinal stromal tumor (GIST) is a refractory disease in need of novel efficacious therapy. The aim of our study was to evaluate the effectiveness of tumor-targeting Salmonella typhimurium A1-R (S. typhimurium A1-R) using on a patient derived orthotopic xenograft (PDOX) model of imatinib-resistant GIST. The GIST was obtained from a patient with regional recurrence, and implanted in the anterior gastric wall of nude mice. The GIST PDOX mice were randomized into 3 groups of 6 mice each when the tumor volume reached 60 mm3: G1, control group; G2, imatinib group (oral administration [p.o.], daily, for 3 weeks); G3, S. typhimurium A1-R group (intravenous [i.v.] injection, weekly, for 3 weeks). All mice from each group were sacrificed on day 22. Relative tumor volume was estimated by laparotomy on day 0 and day 22. Body weight of the mouse was evaluated 2 times per week. We found that S. typhimurium A1-R significantly reduced tumor growth in contrast to the untreated group (P = 0.001). In addition, we found that S. typhimurium A1-R was more effective compared to imatinib (P = 0.013). Furthermore, Imatinib was not significantly effective compared to the control group (P = 0.462). These results indicate that S. typhimurium A1-R may be new effective therapy for imatinib-resistant GIST and therefore a good candidate for clinical development of this disease.

Tumor-targeting Salmonella typhimurium A1-R arrests a doxorubicin-resistant PDGFRA-amplified patient-derived orthotopic xenograft mouse model of pleomorphic liposarcoma.

Pleomorphic liposarcoma (PLPS) is a recalcitrant soft-tissue sarcoma (STS) subtype in need of transformative therapy. We have previously established a patient-derived orthotopic xenograft (PDOX) model, of PLPS with PDGFRA amplification, using surgical orthotopic implantation. In the current study, the PLPS PDOX model was randomized into 3 groups of 7 mice each: untreated control; doxorubicin (DOX)-treated; and treated with Salmonella typhimurium A1-R (S. typhimurium A1-R) expressing green fluorescent protein (GFP). Tumor volume and body weight were monitored during the treatment period. The PLPS PDOX was resistant to DOX. In contrast, the PLPS PDOX was highly sensitive to S. typhimurium A1-R. There was no significant body-weight loss among these 3 groups. Fluorescence imaging demonstrated that S. typhimurium A1-R-GFP was very effective to target the PLPS PDOX tumor. The current study demonstrates that a PLPS PDOX, resistant to first-line therapy DOX, was highly sensitive to tumor targeting S. typhimurium A1-R.

Patient-derived orthotopic xenograft models for cancer of unknown primary precisely distinguish chemotherapy, and tumor-targeting S. typhimurium A1-R is superior to first-line chemotherapy.

Cancer of unknown primary (CUP) is a recalcitrant disease with poor prognosis because it lacks standard first-line therapy. CUP consists of diverse malignancy groups, making personalized precision therapy essential. The present study aimed to identify an effective therapy for a CUP patient using a patient-derived orthotopic xenograft (PDOX) model. This paper reports the usefulness of the PDOX model to precisely identify effective and ineffective chemotherapy and to compare the efficacy of S. typhimurium A1-R with first-line chemotherapy using the CUP PDOX model. The present study is the first to use a CUP PDOX model, which was able to precisely distinguish the chemotherapeutic course. We found that a carboplatinum (CAR)-based regimen was effective for this CUP patient. We also demonstrated that S. typhimurium A1-R was more effective against the CUP tumor than first-line chemotherapy. Our results indicate that S. typhimurium A1-R has clinical potential for CUP, a resistant disease that requires effective therapy.

Recombinant methioninase combined with doxorubicin (DOX) regresses a DOX-resistant synovial sarcoma in a patient-derived orthotopic xenograft (PDOX) mouse model.

Synovial sarcoma (SS) is a recalcitrant subgroup of soft tissue sarcoma (STS). A tumor from a patient with high grade SS from a lower extremity was grown orthotopically in the right biceps femoris muscle of nude mice to establish a patient-derived orthotopic xenograft (PDOX) mouse model. The PDOX mice were randomized into the following groups when tumor volume reached approximately 100 mm3: G1, control without treatment; G2, doxorubicin (DOX) (3 mg/kg, intraperitoneal [i.p.] injection, weekly, for 2 weeks; G3, rMETase (100 unit/mouse, i.p., daily, for 2 weeks); G4 DOX (3mg/kg), i.p. weekly, for 2 weeks) combined with rMETase (100 unit/mouse, i.p., daily, for 2 weeks). On day 14 after treatment initiation, all therapies significantly inhibited tumor growth compared to untreated control, except DOX: (DOX: p = 0.48; rMETase: p < 0.005; DOX combined with rMETase < 0.0001). DOX combined with rMETase was significantly more effective than both DOX alone (p < 0.001) and rMETase alone (p < 0.05). The relative body weight on day 14 compared with day 0 did not significantly differ between any treatment group or untreated control. The results indicate that r-METase can overcome DOX-resistance in this recalcitrant disease.

Temozolomide regresses a doxorubicin-resistant undifferentiated spindle-cell sarcoma patient-derived orthotopic xenograft (PDOX): precision-oncology nude-mouse model matching the patient with effective therapy.

Undifferentiated spindle-cell sarcoma (USCS) is a recalcitrant cancer, resistant to conventional chemotherapy. A patient with high-grade USCS from a striated muscle was implanted orthotopically in the right biceps femoris muscle of mice to establish a patient-derived orthotopic xenograft (PDOX) model. The PDOX models were randomized into the following groups when tumor volume reached 100 mm3 : G1, control without treatment; G2, doxorubicin (DOX) (3 mg/kg, intraperitoneal [i.p.] injection, weekly, for 2 weeks); G3, temozolomide (TEM) (25 mg/kg, p.o., daily, for 14 days). Tumor size and body weight were measured with calipers and a digital balance twice a week. TEM significantly inhibited tumor volume growth compared to the untreated control and the DOX-treated group on day 14 after treatment initiation: control (G1): 343 ± 78 mm3 ; DOX (G2): 308 ± 31 mm3 , P = 0.272; TEM (G3): 85 ± 21 mm3 , P < 0.0001. TEM significantly regressed the tumor volume compared to day 0 (P = 0.019). There were no animal deaths in any group. The body weight of treated mice was not significantly different in any group. Tumors treated with DOX were comprised of spindle-shaped viable cells without apparent necrosis or inflammatory changes. In contrast, tumors treated with TEM showed extensive tumor necrosis. The present study demonstrates the potential power of matching the patient with an effective drug and saving the patient needless toxicity from ineffective drugs.