Comprehensive compartmental model and calibration algorithm for the study of clinical implications of the population-level spread of COVID-19: a study protocol.

INTRODUCTION: The complex dynamics of the coronavirus disease 2019 (COVID-19) pandemic has made obtaining reliable long-term forecasts of the disease progression difficult. Simple mechanistic models with deterministic parameters are useful for short-term predictions but have ultimately been unsuccessful in extrapolating the trajectory of the pandemic because of unmodelled dynamics and the unrealistic level of certainty that is assumed in the predictions. METHODS AND ANALYSIS: We propose a 22-compartment epidemiological model that includes compartments not previously considered concurrently, to account for the effects of vaccination, asymptomatic individuals, inadequate access to hospital care, post-acute COVID-19 and recovery with long-term health complications. Additionally, new connections between compartments introduce new dynamics to the system and provide a framework to study the sensitivity of model outputs to several concurrent effects, including temporary immunity, vaccination rate and vaccine effectiveness. Subject to data availability for a given region, we discuss a means by which population demographics (age, comorbidity, socioeconomic status, sex and geographical location) and clinically relevant information (different variants, different vaccines) can be incorporated within the 22-compartment framework. Considering a probabilistic interpretation of the parameters allows the model's predictions to reflect the current state of uncertainty about the model parameters and model states. We propose the use of a sparse Bayesian learning algorithm for parameter calibration and model selection. This methodology considers a combination of prescribed parameter prior distributions for parameters that are known to be essential to the modelled dynamics and automatic relevance determination priors for parameters whose relevance is questionable. This is useful as it helps prevent overfitting the available epidemiological data when calibrating the parameters of the proposed model. Population-level administrative health data will serve as partial observations of the model states. ETHICS AND DISSEMINATION: Approved by Carleton University's Research Ethics Board-B (clearance ID: 114596). Results will be made available through future publication.

Does the false-negative rate for 1 or 2 negative sentinel nodes after neo-adjuvant chemotherapy translate into a high local recurrence rate?

Prospective trials demonstrate that sentinel node (SN) biopsy after neo-adjuvant chemotherapy (NACT) has a significant false-negative rate (FNR) when only 1 or 2 SNs are removed. It is unknown whether this increased FNR correlates with an elevated risk of recurrence. Tumor Registry data at an NCI-Designated Comprehensive Cancer Center were reviewed from 2004 to 2018 for patients having a negative SN biopsy after NACT. Among 190 patients with histologically negative nodes after NACT having 1 (n = 42), 2 (n = 46), and ≥3 (n = 102) SNs, axillary recurrences occurred in 7.14%, 0%, and 1.96% (p = 0.09), breast recurrences occurred in 2.38%, 6.52%, and 0.98% (p = 0.12), and distance recurrences occurred in 16.67%, 8.70%, and 7.84% (p = 0.27), respectively. Time to first recurrence did not differ by SN count (p = 0.41). After adjustment for age, race, clinical stage, and receptor status, there were no differences in the rates of axillary (p = 0.26), breast (p = 0.44), or distance recurrence (p = 0.24) by numbers of SNs harvested. Median follow-up was 46.8 months. Despite higher post-NACT FNRs reported in randomized trials for patients having <3 sentinel nodes, recurrence rates were not significantly different for 1 versus 2 versus ≥3 SNs. This suggests that patients having 1 or 2 post-NACT SNs identified may not necessitate axillary dissection.

Treatment times in breast cancer patients receiving neoadjuvant vs adjuvant chemotherapy: Is efficiency a benefit of preoperative chemotherapy?

BACKGROUND/OBJECTIVE: Delays in times to surgery, chemotherapy, and radiotherapy impair survival in breast cancer patients. Neoadjuvant chemotherapy (NAC) confers equivalent survival to adjuvant chemotherapy (AC), but it remains unknown which approach facilitates faster initiation and completion of treatment. METHODS: Women ≥18 years old with nonrecurrent, noninflammatory, clinical stage I-III breast cancer diagnosed between 2004 and 2015 who underwent both surgery and chemotherapy were reviewed from the National Cancer Database. RESULTS: Among 155 606 women overall, 28 241 patients received NAC and 127 365 patients received AC. NAC patients had higher clinical T and N stages (35.8% T3/4 vs 4.9% T3/4; 14.4% N2/3 vs 3.7% N2/3). After adjusting for stage and other factors, NAC patients had longer times to begin treatment (36.1 vs 35.4 days adjusted, P = .15), and took significantly longer to start radiotherapy (240.8 vs 218.2 days adjusted, P < .0001), and endocrine therapy (301.6 vs 275.7 days adjusted, P < .0001). Unplanned readmissions (1.2% vs 1.7%), 30-day mortality (0.04% vs 0.01%), and 90-day mortality (0.30% vs 0.08%) were all low and clinically insignificant between NAC and AC. CONCLUSION: Compared to patients receiving AC, those receiving NAC do not start treatment sooner. In addition, patients receiving NAC do not complete treatment faster. Although there are clear indications for administering NAC vs AC, rapidity of treatment should not be considered a benefit of giving chemotherapy preoperatively.

Preoperative Delays in the Treatment of DCIS and the Associated Incidence of Invasive Breast Cancer.

BACKGROUND: Although treatment delays have been associated with survival impairment for invasive breast cancer, this has not been thoroughly investigated for ductal carcinoma in situ (DCIS). With trials underway to assess whether DCIS can remain unresected, this study was performed to determine whether longer times to surgery are associated with survival impairment or increased invasion. METHODS: A population-based study of prospectively collected national data derived from women with a clinical diagnosis of DCIS between 2004 and 2014 was conducted using the National Cancer Database. Overall survival (OS) and presence of invasion were assessed as functions of time by evaluating five intervals (≤ 30, 31-60, 61-90, 91-120, 121-365 days) between diagnosis and surgery. Subset analyses assessed those having pathologic DCIS versus invasive cancer on final pathology. RESULTS: Among 140,615 clinical DCIS patients, 123,947 had pathologic diagnosis of DCIS and 16,668 had invasive ductal carcinoma. For all patients, 5-year OS was 95.8% and unadjusted median delay from diagnosis to surgery was 38 days. With each delay interval increase, added relative risk of death was 7.4% (HR 1.07; 95% CI 1.05-1.10; P < 0.001). On final pathology, 5-year OS for noninvasive patients was 96.0% (95% CI 95.9-96.1%) versus 94.9% (95% CI 94.6-95.3%) for invasive patients. Increasing delay to surgery was an independent predictor of invasion (OR 1.13; 95% CI 1.11-1.15; P < 0.001). CONCLUSIONS: Despite excellent OS for invasive and noninvasive cohorts, invasion was seen more frequently as delay increased. This suggests that DCIS trials evaluating nonoperative management, which represents infinite delay, require long term follow up to ensure outcomes are not compromised.

Time to Surgery and the Impact of Delay in the Non-Neoadjuvant Setting on Triple-Negative Breast Cancers and Other Phenotypes.

BACKGROUND: Characterization of breast cancer phenotypes has improved our ability to predict breast cancer behavior. Triple-negative (TN) breast cancers have higher and earlier rates of distant events. It has been suggested that this behavior necessitates treating TNs faster than others, including use of neoadjuvant chemotherapy (NACT) if time to surgery is not rapid. METHODS: A review of women diagnosed with non-inflammatory, invasive breast cancer was conducted using the National Cancer Database for patients not having NACT, diagnosed between 2010 and 2014. Changes in overall survival due to delay were measured by phenotype. RESULTS: Overall, 351,087 patients met the inclusion criteria, including 36,505 (10.4%) TNs, 77.9% hormone receptor-positive (HR+) and 11.7% human epidermal growth factor receptor 2 (HER2)-enriched (HER2+). Phenotype, among other factors, was predictive of treatment delays. Adjusted median days from diagnosis to surgery and chemotherapy were 29.9, 31.6 and 31.5 (p< 0.001), and 72.7, 78.0 and 74.4 (p< 0.001) for TNs, HR+ and HER2+ cancers, respectively. After diagnosis, OS declined for all patients per month of preoperative delay (hazard ratio 1.104; p< 0.001). In models separating or combining surgery and chemotherapy, this survival decline did not vary by breast cancer phenotype (p > 0.3). CONCLUSIONS: Delays cause small but measurable effects overall, but the effect on survival does not differ among breast cancer phenotypes. Our data suggest that urgency between diagnosis and surgery or chemotherapy is similar for breast cancers of different subtypes. Although NACT is sometimes advocated solely to avoid treatment delays, this study does not suggest a greater surgical urgency for TNs compared with other breast cancer phenotypes.

Patterns of Care and Efficacy of Chemotherapy and Radiotherapy in Skin-Involved Breast Cancers of All Sizes.

BACKGROUND: The management of small skin-involved (SI) invasive breast cancers is controversial because although they are considered unresectable, their prognosis is far better than their stage III classification. This study was undertaken to determine how SI lesions are treated in the United States and to discern the benefit of systemic therapy. PATIENTS AND METHODS: Data of patients diagnosed with stage I-III breast cancer in the National Cancer Data Base between 2004 and 2011 were reviewed. Treatment patterns were examined and overall survival assessed. RESULTS: A total of 3485 patients had SI and 456,287 patients had non-SI breast cancers. Chemotherapy was administered to 68.5% of SI and 45.9% of non-SI tumors (P < .001), including 77.2% of SI and 33% of non-SI tumors < 2 cm (P < .001). After adjusting for patient and tumor characteristics, SI patients were 19.4% more likely to receive chemotherapy than non-SI patients. Radiotherapy was provided to 61.1% of SI and 64.3% of non-SI tumors (P < .001), including 65.5% of SI and 66.5% non-SI tumors < 2 cm (P = .711). After adjusting for patient and tumor characteristics, SI patients were 76.6% more likely to receive radiotherapy than non-SI patients. Chemotherapy and radiotherapy provided an overall survival benefit for stage II and III SI and non-SI tumors. CONCLUSION: Despite controversy regarding staging and prognosis of SI tumors, the majority of patients are provided systemic therapy and radiotherapy. Varied patterns of chemotherapy administration for SI tumors suggests that further treatment guidance and standardization are required, especially because chemotherapy and radiotherapy are equally efficacious in SI and non-SI tumors alike.

Breast conservation versus mastectomy in patients with T3 breast cancers (> 5 cm): an analysis of 37,268 patients from the National Cancer Database.

PURPOSE: Breast conservation therapy (BCT) is standard for T1-T2 tumors, but early trials excluded breast cancers > 5 cm. This study was performed to assess patterns and outcomes of BCT for T3 tumors. METHODS: We reviewed the National Cancer Database (NCDB) for noninflammatory breast cancers > 5 cm, between 2004 and 2011 who underwent BCT or mastectomy (Mtx) with nodal evaluation. Patients with skin or chest wall involvement were excluded. Patients having clinical T3 tumors were analyzed to determine outcomes based upon presentation, with those having pathologic T3 tumors, subsequently assessed, irrespective of presentation. Overall survival (OS) was analyzed using multivariable Cox proportional hazards models, with adjusted survival curves estimated using inverse probability weighting. RESULTS: After exclusions, 37,268 patients remained. Median age and tumor size for BCT versus Mtx were 53 versus 54 years (p < 0.001) and 6.0 versus 6.7 cm (p < 0.001), respectively. Predictors of BCT included age, race, location, facility type, year of diagnosis, tumor size, grade, histology, nodes examined and positive, and administration of chemotherapy and radiotherapy. OS was similar between Mtx and BCT (p = 0.36). This held true when neoadjuvant chemotherapy patients were excluded (p = 0.39). BCT percentages declined over time (p < 0.001), while tumor sizes remained the same (p = 0.77). Median follow-up was 51.4 months. CONCLUSIONS: OS for patients with T3 breast cancers is similar whether patients received Mtx or BCT, confirming that tumor size should not be an absolute BCT exclusion. Declining use of BCT for tumors > 5 cm in younger patients may be accounted for by recent trends toward mastectomy.

Breast conservation versus mastectomy for patients with T3 primary tumors (>5 cm): A review of 5685 medicare patients.

BACKGROUND: Although breast conservation therapy (BCT) is standard for breast cancer treatment, patients with tumors measuring >5 cm have been excluded from clinical trials. Nevertheless, only a few small retrospective series to date have compared BCT with mastectomy for tumors measuring >5 cm. The current study was performed to determine whether survival is equivalent for BCT versus mastectomy using a large national data set. METHODS: Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked cases were identified for patients aged ≥ 66 years undergoing breast conservation for invasive, noninflammatory, nonmetastatic breast cancer between 1992 and 2009. Propensity score-based adjustment was used to account for demographics and tumor and treatment factors. RESULTS: A total of 5685 patients with tumors measuring >5.0 cm underwent breast surgery, with 15.6% receiving BCT. Mean ages of the patients and tumor sizes were similar. Predictors of BCT included neoadjuvant chemotherapy and postoperative radiotherapy use, higher income, breast cancer as a first malignancy, and a higher Charlson Comorbidity Index. Predictors of mastectomy included younger age, nonductal histology, higher grade, numbers of lymph nodes examined and found to be positive, American Joint Committee on Cancer stage III disease, postoperative chemotherapy use, and residential region of the country. Adjusted overall and breast cancer-specific survival were not different between patients treated with BCT and mastectomy (hazard ratio, 0.934; 95% confidence interval, 0.791-1.103 [P = .419] for overall survival; and subdistribution hazard ratio, 1.042; 95% confidence interval, 0.793-1.369 [P = .769] for breast cancer-specific survival), with each improving over time. The median follow-up was 7.0 years. CONCLUSIONS: For Medicare patients with tumors measuring >5 cm, survival is similar between those treated with BCT and mastectomy as for patients with smaller primary tumors. Despite exclusion from randomized trials, BCT may remain an option for patients with larger tumors when deemed clinically and cosmetically amenable to surgical resection.

Morphine, but not trauma, sensitizes to systemic Acinetobacter baumannii infection.

Acinetobacter baumannii is an important nosocomial pathogen in civilian intensive care units. Recently the incidence has increased in wounded military personnel. Morphine is documented in numerous animal studies to be immunosuppressive and to sensitize to infection. The hypotheses were tested that morphine, administered for analgesia in the battlefield, predisposes to Acinetobacter infection, and that the opioid may have an additive or synergistic effect with trauma. To test these hypotheses, an intraperitoneal infection model was established in mice using several Acinetobacter strains. Morphine administered for 48 h by implantation of a slow-release morphine pellet increased mortality compared to animals receiving a placebo pellet, an effect that was blocked by the mu-opioid receptor antagonist, naltrexone. Acinetobacter burdens in the blood, spleens, livers, and lungs of morphine-treated mice, were significantly higher than those in placebo-treated animals, confirming that mortality was due to potentiated growth of the bacteria. There were also elevated levels of pro-inflammatory cytokines in morphine-treated versus placebo-treated mice. Morphine caused a reduction in the total number of cells in the peritoneal cavity, a decrease in the percentage and total numbers of neutrophils, and a decrease in the total number of macrophages. Morphine treatment also suppressed levels of the neutrophil-inducing molecules, IL-17A and KC/CXCL1. However, IL-17A(-/-) mice given morphine were not sensitized to Acintobacter infection to a greater degree than similarly treated wild-type mice. Trauma alone did not sensitize to Acinetobacter infection, and there was no additive effect between morphine and trauma. These results support the hypothesis that morphine potentiates Acinetobacter infection.

The relationships of nutrients, routes of delivery, and immunocompetence.

Malnutrition has marked consequences on surgical outcomes. Adequate nutrition is important for the proper functioning of all organ systems, particularly the immune system. Determination of the type and amount of nutrient supplementation and the appropriate route of nutrient delivery is essential to bolster the immune system and enhance the host's response to stress. Correct administration of immunonutrients could lead to reductions in patient morbidity following major surgery, trauma, and critical illness.

Anti-proliferative effect of LXR agonist T0901317 in ovarian carcinoma cells.

BACKGROUND: Ovarian cancer is the most common cause of cancer related death from gynecologic tumors in the United States. The insidious nature of the disease precludes early diagnosis, therefore surgical debulking and chemotherapy are considered as standard treatment modalities for advanced stages. We investigated the effect of the LXR agonist, T0901317, on ovarian cancer cell proliferation and apoptosis as a potential therapeutic agent. RESULTS: T0901317 treatment resulted in a significant (P <0.001) inhibition of cell proliferation in a time- and dose-dependent manner in CaOV3, SKOV3 and A2780 cells. Western blot analysis demonstrated an induction of p21 and p27 with a concominant reduction in phospho-RB protein levels. Cell cycle analysis demonstrated a significant (P <0.001) arrest in the G1 cell cycle phase. Significant induction of Caspase-3 and BAX gene expression occurred with treatment. Induction of apoptosis was confirmed by significant (P < 0.001) elevation of caspase activity on FACS analysis, caspase-glo assay, BAX protein induction and decreased caspase 3 precursor protein expression on Western blot analysis. LXR alpha/beta knockdown experiments did not reverse the anti-proliferative and cytotoxic effects of T0901317. CONCLUSIONS: The LXR agonist, T0901317, significantly suppresses cell proliferation and induces programmed cell death in a dose- and time-dependent manner. Our results indicate that T0901317 induces its anti-proliferative and cytotoxic effects via an LXR-independent mechanism.

beta2 Adrenoreceptor blockade attenuates the hyperinflammatory response induced by traumatic injury.

BACKGROUND: Major operative injury initiates immunologic changes that may result in a systemic inflammatory response, leading to organ dysfunction/sepsis. Catecholamines seem to be key mediators. The effects of beta(2) receptor blockade in vitro and in vivo before and after operative injury were studied to clarify their role. METHODS: In vitro studies were done in RAW 264.7 cells using epinephrine (50 micromol/L) with or without alpha(2)- and beta(2)-receptor blockade. Comparative gene expression analysis on the Toll-like receptor (TLR)-4 receptor signaling pathway was performed between RAW cells pretreated with epinephrine with subsequent lipopolysaccharide (LPS) stimulation versus LPS alone. Confirmatory studies were performed by real-time reverse transcription polymerase chain reaction (RT-PCR). Tumor necrosis factor (TNF)-alpha gene and protein expression were determined via real time RT-PCR and enzyme-linked immunosorbent assay, respectively. In vivo, Balb/C mice received no treatment nor injury (group I). Group II received operative injury and vehicle injection, group III received ICI 118,551 (beta(2)-receptor antagonist) 30 minutes before or in separate studies after operative injury. At 7 days, splenic macrophages were harvested and cytokine production was measured with or without LPS. In separate experiments, cecal ligation and puncture (CLP) was done 7 days after operation and survival determined. RESULTS: In vitro studies demonstrated that epinephrine pretreatment significantly increased TNF-alpha production with LPS stimulation (P < .05). beta(2)-Receptor blockade significantly attenuated (P < .05) LPS stimulated TNF-alpha production. MD-2, an essential coactivator of TLR-4 signaling, gene expression was significantly elevated when cells were pretreated with epinephrine before LPS exposure (P < .001). In vivo studies demonstrated a significant decrease (P < .05) in TNF-alpha and interleukin-6 production in the ICI 118,551 group. Similar findings were demonstrated measuring monocyte chemoattractant protein-1 and interferon-gamma cytokine levels (P < .05) versus no treatment. ICI 118,551 treatment 30 minutes before operation demonstrated a 31% reduction in mortality after CLP (P < .05). CONCLUSION: This study demonstrates that beta(2)-receptor blockade reduces macrophage cytokine production and improves survival showing the critical importance of catecholamines to the immunologic response in surgery.

Analysis of gene expression in the tumor-associated macrophage.

INTRODUCTION: The tumor-associated macrophage (TAM) is at the front line of the host's defense against malignancy and provides an attractive target for immune-modulatory therapy. However, factors present within the tumor microenvironment can alter macrophage phenotype, preventing its cytotoxic activity and reducing its susceptibility to interferon-gamma and lipopolysaccharide-mediated stimulation. METHODS: Macrophages were isolated from subcutaneous B16 melanoma tumors implanted in C57 BL/6 mice. Wound macrophages were harvested from subcutaneously-implanted PVA sponges, and resting peritoneal macrophages were harvested by peritoneal lavage. Gene expression was analyzed using an Atlas cDNA array (Clontech, Mountain View, CA). RESULTS: TAM demonstrated a pattern of gene expression distinct from both wound and peritoneal macrophage. There is an increase in proliferation-associated genes and in genes encoding the ultrastructural proteins cofillin, zyxin, and vimentin more commonly associated with fibroblast-like cells. In addition, an observed decrease in expression of the CD14 gene, and increase in inhibitory pathways including osteopontin and its receptor CD44, the inositol 1,4,5-triphosphate receptor, and the receptors for interleukin-4 and granulocyte monocyte-colony stimulating factor could explain the resistance of TAM to lipopolysaccharide-mediated stimulation. There was also a significant decrease in the expression of the interferon-gamma second messenger, IRF-1. CONCLUSIONS: This study has identified a number of pathways involved in the suppression of TAM function. Targeting of these pathways may allow for the generation of more effective immune-modulatory anti-neoplastic therapy.

THE PPARgamma ligand 15d-PGJ2 modulates macrophage activation after injury in a murine trauma model.

In macrophages, peroxisome proliferator-activated receptor gamma (PPARgamma) has been shown to be important for differentiation, and it serves as a negative regulator of activation. Major trauma/injury causes a dramatic host response that disrupts cellular immune homeostasis and initiates an inflammatory cascade that predisposes the injured host to subsequent infections. In prior studies using a murine trauma model consisting of femur fracture and hemorrhage, splenic macrophages from traumatized mice had significantly enhanced LPS-induced cyclooxygenase enzyme (subtype 2) and iNOS production as well as elevated levels of inflammatory cytokines at 1 week after injury compared with uninjured controls. These up-regulated cellular responses corresponded to increased mortality when animals were challenged with LPS or Candida. In the current study, we used the injury model to determine the effect of treatment of injured mice with the endogenous PPARgamma ligand 15-deoxy-Delta(12-, 14)-PGJ2 (15d-PGJ2). It was found that in vivo 15d-PGJ2 treatment significantly reduced the levels of inflammatory mediators produced by splenic macrophages 7 days after injury. The mechanism of inhibition is dependent on PPARgamma because concomitant treatment of animals with the PPARgamma antagonist GW9662 reversed the inhibitory effect of 15d-PGJ2. Endogenous PPARgamma modulated activation of LPS-induced p38 mitogen-activated protein kinase. Furthermore, treatment of injured mice with 15d-PGJ2 conferred a significant survival advantage after infectious challenge induced by cecal ligation and puncture. Thus, this PPARgamma ligands significantly attenuate the postinjury inflammatory response and improve survival after infectious challenge.

15-Deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) mediates repression of TNF-alpha by decreasing levels of acetylated histone H3 and H4 at its promoter.

Prostaglandin metabolite 15-Deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2) is known to inhibit a number of pro-inflammatory cytokines as well as being a ligand for nuclear receptor PPARgamma. We investigated the ability of 15d-PGJ2 to inhibit TNF-alpha gene expression through mechanisms that involve histone modification. Pretreatment with 15d-PGJ2 (10 microM) inhibited LPS-stimulated TNF-alpha mRNA in THP-1 monocytes or PMA-differentiated cells to nearly basal levels. A specific PPARgamma ligand, GW1929, failed to inhibit LPS-induced TNF-alpha mRNA expression nor did a PPARgamma antagonist, GW9662, alter the repression of TNF-alpha mRNA in LPS-stimulated cells pretreated with 15d-PGJ2 suggesting a PPARgamma-independent inhibition of TNF-alpha mRNA in THP-1 cells. Transfection studies with a reporter construct and subsequent treatment with 15d-PGJ2 demonstrated a dose-dependent inhibition of the TNF-alpha promoter. Additional studies demonstrated that inhibition of histone deacetylases with trichostatin A (TSA) or overexpression of histone acetyltransferase CBP could overcome 15d-PGJ2-mediated repression of the TNF-alpha promoter, suggesting that an important mechanism whereby 15d-PGJ2 suppresses a cytokine is through factors that regulate histone modifications. To examine the endogenous TNF-alpha promoter, chromatin immunoprecipitations (ChIP) were performed. ChIP assays demonstrated that LPS stimulation induced an increase in histone H3 and H4 acetylation at the TNF-alpha promoter, which was reduced in cells pretreated with 15d-PGJ2. These results highlight the ability of acetylation and deacetylation factors to affect the TNF-alpha promoter and demonstrate that an additional important mechanism whereby 15d-PGJ2 mediates TNF-alpha transcriptional repression by altering levels of acetylated histone H3 and H4 at its promoter.