A Step Toward Personalized Surgical Decision Making: Machine Learning Predicts 1 Versus Numerous Melanoma Lymph Node Metastases Using RNA-sequencing

OBJECTIVE

Develop a predictive model to identify patients with 1 pathologic lymph node (pLN) versus >1 pLN using machine learning applied to gene expression profiles and clinical data as input variables.

BACKGROUND

Standard management for clinically detected melanoma lymph node metastases is complete therapeutic LN dissection (TLND). However, >40% of patients with a clinically detected melanoma lymph node will only have 1 pLN on final review. Recent data suggest that targeted excision of just the single enlarged LN may provide excellent regional control, with less morbidity than TLND. The selection of patients for less morbid surgery requires accurate identification of those with only 1 pLN.

METHODS

The Cancer Genome Atlas database was used to identify patients who underwent TLND for melanoma. Pathology reports in The Cancer Genome Atlas were reviewed to identify the number of pLNs. Patients were included for machine learning analyses if RNA sequencing data were available from a pLN. After feature selection, the top 20 gene expression and clinical input features were used to train a ridge logistic regression model to predict patients with 1 pLN versus >1 pLN using 10-fold cross-validation on 80% of samples. The model was then tested on the remaining holdout samples.

RESULTS

A total of 153 patients met inclusion criteria: 64 with one pLN (42%) and 89 with >1 pLNs (58%). Feature selection identified 1 clinical (extranodal extension) and 19 gene expression variables used to predict patients with 1 pLN versus >1 pLN. The ridge logistic regression model identified patient groups with an accuracy of 90% and an area under the receiver operating characteristic curve of 0.97.

CONCLUSIONS

Gene expression profiles together with clinical variables can distinguish melanoma metastasis patients with 1 pLN versus >1 pLN. Future models trained using positron emission tomography/computed tomography imaging, gene expression, and relevant clinical variables may further improve accuracy and may predict patients who can be managed with a targeted LN excision rather than a complete TLND.

Associations of Race, Ethnicity, and Social Determinants of Health With Colorectal Cancer Screening

BACKGROUND

Racial and ethnic disparities in receipt of recommended colorectal cancer screening exist; however, the impact of social determinants of health on such disparities has not been recently studied in a national cohort.

OBJECTIVE

This study aimed to determine whether social determinants of health attenuate racial disparities in receipt of colorectal cancer screening.

DESIGN

This was a cross-sectional telephone survey of self-reported race and ethnicity and up-to-date colorectal cancer screening. Associations between race/ethnicity and colorectal cancer screening were tested before and after adjustment for demographics, behavioral factors, and social determinants of health.

SETTING

This was a nationally representative telephone survey of US residents in 2018.

PATIENTS

The patients included were US residents aged 50 to 75 years.

MAIN OUTCOME MEASURES

The primary outcome was up-to-date colorectal cancer screening status, according to 2008 US Preventive Services Task Force recommendations.

RESULTS

This study included 226,106 respondents aged 50 to 75 years. Before adjustment, all minority racial and ethnic groups demonstrated a significantly lower odds of screening than those of non-Hispanic white respondents. After adjustment for demographics, behavioral factors, and social determinants of health, compared to non-Hispanic white respondents, odds of screening were found to be increased among non-Hispanic black respondents (OR, 1.10; p = 0.02); lower but attenuated among Hispanic respondents (OR, 0.73; p < 0.001), non-Hispanic American Indian/Alaskan Native respondents (OR, 0.85; p = 0.048), and non-Hispanic respondents of other races (OR, 0.82; p = 0.01); and lower but not attenuated among non-Hispanic Asian respondents (OR, 0.68; p < 0.001).

LIMITATIONS

Recall bias, participant bias, and residual confounding.

CONCLUSIONS

Adjustment for social determinants of health reduced racial and ethnic disparities in colorectal cancer screening among all minority racial and ethnic groups except non-Hispanic Asian individuals; however, other unmeasured confounders likely exist. See Video Abstract at http://links.lww.com/DCR/B977 .

ASOCIACIN DE RAZA, ETNICIDAD Y DETERMINANTES SOCIALES DE LA SALUD CON LA DETECCIN DEL CNCER COLORRECTAL

ANTECEDENTES: Existen disparidades raciales y étnicas en la recepción de las pruebas recomendadas de detección de cáncer colorrectal; sin embargo, el impacto de los determinantes sociales de la salud en dichas disparidades no se ha estudiado recientemente en una cohorte nacional.OBJETIVO: El objetivo de este estudio fue determinar si los determinantes sociales de la salud atenúan las disparidades raciales en la recepción de pruebas de detección del cáncer colorrectal.DISEÑO: Encuesta telefónica transversal de raza y etnia autoinformada y detección actualizada de cáncer colorrectal. Las asociaciones entre la raza/etnicidad y la detección del cáncer colorrectal se probaron antes y después del ajuste por demografía, factores conductuales y determinantes sociales de la salud.ESCENARIO: Esta fue una encuesta telefónica representativa a nivel nacional de los residentes de EE. UU. en 2018.PACIENTES: Los pacientes eran residentes de EE. UU. de 50 a 75 años.PRINCIPALES MEDIDAS DE RESULTADO: Estado actualizado de detección de cáncer colorrectal, según las recomendaciones del Grupo de Trabajo de Servicios Preventivos de EE. UU. de 2008.RESULTADOS: Este estudio incluyó a 226.106 encuestados de 50 a 75 años. Antes del ajuste, todos los grupos étnicos y raciales minoritarios demostraron probabilidades significativamente más bajas de detección en comparación con los encuestados blancos no hispanos. Después del ajuste por demografía, factores conductuales y determinantes sociales de la salud, en comparación con los encuestados blancos no hispanos, las probabilidades de detección aumentaron entre los encuestados negros no hispanos (OR 1,10, p = 0,02); más bajo pero atenuado entre los encuestados hispanos (OR 0,73, p < 0,001), los encuestados indios americanos/nativos de Alaska no hispanos (OR 0,85, p = 0,048) y los encuestados no hispanos de otras razas (OR 0,82, p = 0,01); y menor pero no atenuado entre los encuestados asiáticos no hispanos (OR 0,68, p < 0,001).LIMITACIONES: Sesgo de recuerdo y sesgo de participante, así como confusión residual.CONCLUSIONES: El ajuste para los determinantes sociales de la salud redujo las disparidades raciales y étnicas en la detección del cáncer colorrectal entre todos los grupos étnicos y raciales minoritarios, excepto las personas asiáticas no hispanas; sin embargo, es probable que existan otros factores de confusión no medidos. Consulte Video Resumen en http://links.lww.com/DCR/B977 . (Traducción-Dr. Felipe Bellolio ).

Preoperative Identification and Management of Anemia in the Colorectal Surgery Patient

Preoperative anemia is a common finding in patients undergoing colorectal surgery, particularly those with cancer. While often multifactorial, iron deficiency anemia remains the most common cause of anemia in this patient population. Although seemingly innocuous, preoperative anemia is associated with an increased risk of perioperative complications and need for allogenic blood transfusions, both of which may worsen cancer-specific survival. Preoperative correction of anemia and iron deficiency is thus necessary to diminish these risks. Current literature supports preoperative screening for anemia and iron deficiency in patients slated to undergo colorectal surgery for malignancy or for benign conditions with associated patient- or procedure-related risk factors. Accepted treatment regimens include iron supplementation-either oral or intravenous-as well as erythropoietin therapy. Autologous blood transfusion should not be utilized as a treatment for preoperative anemia when there is time to implement other corrective strategies. Additional study is still needed to better standardize preoperative screening and optimize treatment regimens.

Intratumoral IFN-γ or topical TLR7 agonist promotes infiltration of melanoma metastases by T lymphocytes expanded in the blood after cancer vaccine

BACKGROUND

Immune-mediated melanoma regression relies on melanoma-reactive T cells infiltrating tumor. Cancer vaccines increase circulating melanoma-reactive T cells, but little is known about vaccine-induced circulating lymphocytes (viCLs) homing to tumor or whether interventions are needed to enhance infiltration. We hypothesized that viCLs infiltrate melanoma metastases, and intratumoral interferon (IFN)-γ or Toll-like receptor 7 (TLR7) agonism enhances infiltration.

METHODS

Patients on two clinical trials (Mel51 (NCT00977145), Mel53 (NCT01264731)) received vaccines containing 12 class I major histocompatibility complex-restricted melanoma peptides (12MP). In Mel51, tumor was injected with IFN-γ on day 22, and biopsied on days 1, 22, and 24. In Mel53, dermal metastases were treated with topical imiquimod, a TLR7 agonist, for 12 weeks, and biopsied on days 1, 22, and 43. For patients with circulating T-cell responses to 12MP by IFN-γ ELISpot assays, DNA was extracted from peripheral blood mononuclear cells (PBMCs) pre-vaccination and at peak T-cell response, and from tumor biopsies, which underwent T-cell receptor sequencing. This enabled identification of clonotypes induced in PBMCs post-vaccination (viCLs) and present in tumor post-vaccination, but not pre-vaccination.

RESULTS

Six patients with T-cell responses post-vaccination (Mel51 n = 4, Mel53 n = 2) were evaluated for viCLs and vaccine-induced tumor infiltrating lymphocytes (viTILs). All six patients had viCLs, five of whom were evaluable for viTILs in tumor post-vaccination alone. Mel51 patients had viTILs identified in day 22 tumors, post-vaccination and before IFN-γ (median = 2, range = 0-24). This increased in day 24 tumors after IFN-γ (median = 30, range = 4-74). Mel53 patients had viTILs identified in day 22 tumors, post-vaccination plus imiquimod (median = 33, range = 2-64). Three of five evaluable patients across both trials had viTILs with vaccination alone. All five had enhancement of viTILs with tumor-directed therapy. viTILs represented 0.0-2.9% of total T cells after vaccination alone, which increased to 0.6-8.7% after tumor-directed therapy.

CONCLUSION

Cancer vaccines induce expansion of new viCLs, which infiltrate melanoma metastases in some patients. Our findings identify opportunities to combine vaccines with tumor-directed therapies to enhance T-cell infiltration and T cell-mediated tumor control. These combinations hold promise in improving the therapeutic efficacy of antigen-specific therapies for solid malignancies.

Tertiary lymphoid structures in desmoplastic melanoma have increased lymphocyte density, lymphocyte proliferation, and immune cross talk with tumor when compared to non-desmoplastic melanomas

Tertiary lymphoid structures (TLS) are ectopic lymphoid structures that can arise in human cancers and are associated with improved overall survival (OS) and response to immune checkpoint blockade (ICB) in several cancers, including non-desmoplastic metastatic melanoma (NDMM). Desmoplastic melanoma (DM) has one of the highest response rates to ICB, and we previously identified that primary DM (PDM) contains TLS. Despite the association of TLS with survival and ICB response, it is unknown whether TLS or associated markers of immune activity can differ between PDM and NDMM. We hypothesized that PDM would contain higher frequencies of TLS than NDMM, that T and B-cell densities and proliferation would be greater in TLS of PDM than TLS of NDMM, and that proliferation rates of T and B-cells in PDM TLS would be concordant with those of intratumoral lymphocytes. We found that four features of TLS in PDM distinguish them from TLS in NDMM. TLS were peritumoral in NDMM but intratumoral in PDM. CD8⁺ T-cell and CD20⁺ B-cell densities and proliferative fractions were higher in PDM TLS than NDMM TLS. Additionally, the proliferative fractions of T- and B-cells were concordant between the TLS and tumor site in PDM and discordant in NDMM. Collectively, these data suggest that TLS and associated immune markers can differ across melanoma subsets and suggest that PDM TLS may be more immunologically active and have enhanced immune cell trafficking between tumor and TLS compared to NDMM.

The vaccine-site microenvironment: impacts of antigen, adjuvant, and same-site vaccination on antigen presentation and immune signaling

Background

A goal of cancer vaccines is to induce strong T cell responses to tumor antigens, but the delivery method, schedule, and formulation of cancer vaccines have not yet been optimized. Adjuvants serve to increase the immune response against vaccine antigens. However, little is known about the impact of adjuvants plus antigen and their delivery schedule on the immunologic milieu in the vaccine-site microenvironment (VSME). We hypothesized that antigen processing and presentation may occur directly in the VSME, that adding the toll-like receptor 3 (TLR3) agonist polyICLC (pICLC) would enhance markers of immune activation, and that the immune signatures would be enhanced further by repeated vaccination in the same skin site rather than after multiple vaccines in different skin locations.

Methods

Using RNA sequencing, we evaluated VSME biopsies from patients undergoing subcutaneous/intradermal peptide vaccination against melanoma, with incomplete Freund’s adjuvant (IFA) with or without pICLC. Differential gene expression analyses and gene set enrichment analyses were performed using R. False discovery rate corrected p values <0.05 were considered significant.

Results

We found that addition of peptide antigens to IFA enhanced antigen presentation pathways and a tertiary lymphoid structure gene-signature locally at the VSME. Addition of pICLC to IFA + peptide induced an immunologically favorable VSME 1 week after injection but had little impact on the VSME after three injections, compared with IFA + peptide alone. Repeated same-site injection of IFA + peptide antigens induced a VSME with more dendritic cell activation, Th1 dominance, and TLR adaptor protein gene expression than that induced by injections at different, rotating skin locations.

Conclusions

These data suggest that the vaccine-site itself may be a critically important location contributing to vaccine immunity rather than just the draining lymph node, that IFA induces a favorable VSME with TLR agonist being most beneficial early in the vaccine course, and that same-site injections lead to persistent stimulation of immune pathways that may be beneficial in eliciting antigen specific T cell expansion.

Factors Associated with Receipt of Oral Antibiotic Agents and Mechanical Bowel Preparation before Elective Colectomy

Background: Pre-operative administration of combined oral antibiotic agents and mechanical bowel preparation has been demonstrated to improve post-operative outcomes after elective colectomy, however, many patients do not receive combined preparation. Patient and procedural determinants of combined preparation receipt remain understudied. Patients and Methods: All patients undergoing elective colectomy within the 2018 American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Participant Use File and Targeted Colectomy datasets were included. Univariable and multivariable logistic regression analyses were performed to identify factors associated with receipt of combined preparation. Results: A total of 21,889 patients were included, of whom 13,848 (63.2%) received combined preparation pre-operatively. Patients who received combined preparation tended to be younger, male, of white race, and of non-Hispanic ethnicity (all p < 0.05). After multivariable adjustment, male gender, body mass index (BMI) 30-39 kg/m², independent functional status, and laparoscopic and robotic surgical approaches were associated with receipt of combined preparation (all p < 0.05), whereas Asian race, hypertension, disseminated cancer, and inflammatory bowel disease were associated with omission of combined preparation (all p < 0.05). Conclusions: Patients with risk factors for infectious complications-including a poor functional status, comorbid conditions, and undergoing an open procedure-are less likely to receive combined preparation before elective colectomy. Similarly, female and Asian patients are less likely to receive combined preparation, emphasizing the need for equitable administration of combined preparation.

Residents as Leaders: Using a Delphi Process to Conduct an Institutional Preoperative Patient Optimization Quality Improvement Initiative

BACKGROUND

Many residency programs struggle to meet the ACGME requirement for resident participation in quality improvement initiatives.

STUDY DESIGN

As part of an institutional quality improvement effort, trainees from the Departments of Surgery and Anesthesiology at a single academic medical center were teamed with institutional content experts in 7 key risk factor areas within preoperative patient optimization. A systematic review of each subject matter area was performed using the MEDLINE database. Institutional recommendations for the screening and management of each risk factor were developed and approved using modified Delphi consensus methodology. Upon project completion, an electronic survey was administered to all individuals who participated in the process to assess the perceived value of participation.

RESULTS

Fifty-one perioperative stakeholders participated in recommendation development: 26 trainees and 25 content experts. Residents led 6 out of 7 groups specific to a subject area within preoperative optimization. A total of 4,649 abstracts were identified, of which 456 full-text articles were selected for inclusion in recommendation development. Seventeen out of 26 (65.4%) trainees completed the survey. The vast majority of trainees reported increased understanding of their preoperative optimization subject area (15/17 [88.2%]) as well as the Delphi consensus method (14/17 [82.4%]) after participation in the project. Fourteen out of 17 (82.4%) trainees stated that they would participate in a similar quality improvement initiative again.

CONCLUSIONS

We demonstrate a novel way to involve trainees in an institutional quality initiative that served to educate trainees in quality improvement, the systematic review process, Delphi methodology, and preoperative optimization. This study provides a framework that other residency programs can use to engage residents in institutional quality improvement efforts.

A pilot trial of vaccination with Carcinoembryonic antigen and Her2/neu peptides in advanced colorectal cancer

Checkpoint-blockade therapy (CBT) is approved for select colorectal cancer (CRC) patents, but additional immunotherapeutic options are needed. We hypothesized that vaccination with carcinoembryonic antigen (CEA) and Her2/neu (Her2) peptides would be immunogenic and well tolerated by participants with advanced CRC. A pilot clinical trial (NCT00091286) was conducted in HLA-A2⁺ or -A3⁺ Stage IIIC-IV CRC patients. Participants were vaccinated weekly with CEA and Her2 peptides plus tetanus peptide and GM-CSF emulsified in Montanide ISA-51 adjuvant for 3 weeks. Adverse events (AEs) were recorded per NIH Common Terminology Criteria for Adverse Events version 3. Immunogenicity was evaluated by interferon-gamma ELISpot assay of in vitro sensitized peripheral blood mononuclear cells and lymphocytes from the sentinel immunized node. Eleven participants were enrolled and treated; one was retrospectively found to be ineligible due to HLA type. All 11 participants were included in AEs and survival analyses, and the 10 eligible participants were evaluated for immunogenicity. All participants reported AEs: 82% were Grade 1-2, most commonly fatigue or injection site reactions. Two participants (18%) experienced treatment-related dose-limiting Grade 3 AEs; both were self-limiting. Immune responses to Her2 or CEA peptides were detected in 70% of participants. Median overall survival (OS) was 16 months; among those enrolled with no evidence of disease (n = 3), median OS was not reached after 10 years of follow-up. These data demonstrate that vaccination with CEA or Her2 peptides is well tolerated and immunogenic. Further study is warranted to assess potential clinical benefits of vaccination in advanced CRC either alone or in combination with CBT.

Heterogeneity in tertiary lymphoid structure B-cells correlates with patient survival in metastatic melanoma

BACKGROUND

Tertiary lymphoid structures (TLSs) are immune aggregates in peripheral tissues that may support adaptive immune responses. Their presence has been associated with clinical response to checkpoint blockade therapy (CBT), but it is unknown whether TLS have prognostic significance independent of CBT in melanoma. We hypothesized that TLS in melanoma metastases would be associated with increased intratumoral lymphocyte infiltration, but that the intra-TLS immunological milieu would be distinct from the intratumoral immunological milieu. We also hypothesized that the presence of TLS would be associated with improved survival, and that TLS maturation or intra-TLS lymphocyte activity would also correlate with survival.

METHODS

Cutaneous melanoma metastases (CMM) from 64 patients were evaluated by multiplex immunofluorescence for the presence and maturation status of TLS. Intra-TLS lymphocyte density, proliferation and B-cell Ig somatic hypermutation (AID+) were analyzed, as were markers of T-cell exhaustion and Th1/Tc1 differentiation. Associations between TLS maturation and intra-TLS immunologic activity were assessed, as well as associations with intratumoral immune cell infiltration. Independent associations with overall survival (OS) were assessed using log-rank tests and Cox proportional hazards models.

RESULTS

TLS were identified in 30 (47%) of 64 CMM (TLS+) and were associated with increased intratumoral lymphocyte infiltration. However, proliferation of intra-TLS lymphocytes did not correlate with intratumoral lymphocyte proliferation. Most were early TLS; however, subsets of primary or secondary follicle-like TLS were also present. TLS+ lesions were associated with lower risk of tumor recurrence after metastasectomy and with improved OS in multivariate analyses (HR 0.51, p=0.04). OS was longer for TLS with low fractions of CD21+ B-cells (HR 0.29, p=0.02) and shorter for those with low AID+ fraction of B-cells (HR 2.74, p=0.03).

CONCLUSIONS

The presence of TLS in CMMs is associated with improved OS in patients treated with surgery before CBT, but TLS vary widely in maturation state, in proportions of proliferating T and B cells, and in markers of B cell function, including AID and CD21. Importantly, these features have additional prognostic significance, which suggest that some TLS may have regulatory function, while others functioning to support antigen-driven immune responses, depending on the cellular composition and activation status.

IDO1 Expression in Melanoma Metastases Is Low and Associated With Improved Overall Survival

Indoleamine 2-3 dioxygenase 1 (IDO1) expression may contribute to immunologic escape by melanoma metastases. However, a recent clinical trial failed to identify any clinical benefits of IDO1 inhibition in patients with unresectable metastatic melanoma, and prior characterizations of IDO1 expression have predominately studied primary lesions and local metastases, generating uncertainty regarding IDO1 expression in distant metastases. We hypothesized that IDO1 expression in such lesions would be low and correlated with decreased overall survival (OS). Metastases from patients (n=96) with stage IIIb to IV melanoma underwent tissue microarray construction and immunohistochemical staining for IDO1. Th1-related gene expression was determined quantitatively. Associations between OS and IDO1 expression were assessed with multivariate models. Of 96 metastatic lesions, 28% were IDOpos, and 85% exhibited IDO1 expression in <10% of tumor cells. IDOpos lesions were associated with improved OS (28.9 vs. 10.5 mo, P=0.02) and expression of Th1-related genes. OS was not associated with IDO1 expression in a multivariate analysis of all patients; however, IDO1 expression (hazard ratio=0.25, P=0.01) and intratumoral CD8+ T-cell density (hazard ratio=0.99, P<0.01) were correlated with OS in patients who underwent metastasectomy with curative-intent. IDOpos metastases were less likely to recur after metastasectomy (54% vs. 16%, P=0.01). IDO1 expression was low in melanoma metastases and correlated with OS after metastasectomy with curative-intent. Intratumoral CD8+ T cells and Th1-related genes were correlated with IDO1 expression, as was tumor recurrence. These suggest that IDO1 expression may be a marker of immunologic tumor control, and may inform participant selection in future trials of IDO1 inhibitors.

Incomplete Freund's adjuvant reduces arginase and enhances Th1 dominance, TLR signaling and CD40 ligand expression in the vaccine site microenvironment

Background

Immunogenicity of cancer vaccines is impacted by adjuvants and schedule, but systematic assessments of their effects have not been performed. Montanide ISA-51, an incomplete Freund’s adjuvant (IFA), is used in many vaccine trials, but concerns have been raised about negative effects in murine studies. We found in humans that IFA enhances systemic immune responses and that repeat vaccination at one site (same site vaccination (SSV)) creates tertiary lymphoid structures (TLS) in the vaccine site microenvironment (VSME). We hypothesized that vaccination with peptides+IFA+pICLC or SSV×3 with peptides in IFA would create an immunogenic milieu locally at the VSME, with activated dendritic cells (DC), TLS-associated chemokines and a Th1-dominant VSME.

Methods

Biopsies of the VSME were obtained from participants on two clinical trials who were immunized with multiple melanoma peptides (MELITAC 12.1) in adjuvants comprising IFA and/or the TLR3-agonist pICLC. Biopsies were obtained either a week after one vaccine or a week after SSV×3. Controls included normal skin and skin injected with IFA without peptides. Gene expression analysis was performed by RNAseq.

Results

VSME samples were evaluated from 27 patients. One vaccine with peptides in pICLC+IFA enhanced expression of CD80, CD83, CD86 (p<0.01), CD40 and CD40L (p<0.0001) over normal skin; these effects were significantly enhanced for SSV with peptides+IFA. Vaccines containing pICLC increased expression of TBX21 (T-bet) but did not decrease GATA3 over normal skin, whereas SSV with peptides in IFA dramatically enhanced TBX21 and decreased GATA3, with high expression of IFNγ and STAT1. SSV with peptides in IFA also reduced arginase-1 (ARG1) expression and enhanced expression of TLR adapter molecules TICAM-1 (TRIF) and MYD88. Furthermore, SSV with IFA and peptides also enhanced expression of chemokines associated with TLS formation.

Conclusions

These findings suggest that SSV with peptides in IFA enhances CD40L expression by CD4 T cells, supports a Th1 microenvironment, with accumulation of activated and mature DC. Increased expression of TLR adaptor proteins after SSV with peptides in IFA might implicate effects of the skin microbiome. Reduced ARG1 may reflect diminished suppressive myeloid activity in the VSME.

Trial registration number

(NCT00705640, NCT01585350).

Immunogenicity in humans of a transdermal multipeptide melanoma vaccine administered with or without a TLR7 agonist

Background

Experimental cancer vaccines are traditionally administered by injection in subcutaneous tissue or muscle, commonly with adjuvants that create chronic inflammatory depots. Injection of melanoma-derived peptides induces T cell responses; however, the depots that form following injection may inhibit optimization of the immune response. In skin, epidermal Langerhans cells (LC) are a dominant source of professional antigen presenting cells. We hypothesized that: (1) applying melanoma-derived peptides topically, in proximity to LC, could be immunogenic and safe, with low vaccine-site toxicity and (2) topical toll-like receptor 7 (TLR7) agonist would increase immunogenicity of the peptide vaccine.

Methods

Twelve melanoma peptides plus a tetanus helper peptide were combined with granulocyte macrophage colony stimulating factor (GM-CSF) and were administered topically on days 1, 8, and 15, to 28 patients randomized to one of four adjuvant preparations: (1) incomplete Freund’s adjuvant (IFA); (2) IFA plus a TLR7 agonist (imiquimod) administered on days 0, 7, 14; (3) dimethyl sulfoxide (DMSO) or (4) DMSO+ imiquimod administered on day 0, 7, 14. Every 3 weeks thereafter (x 6), the peptides were combined with GM-CSF and were injected into the dermis and subcutis in an emulsion with IFA. Toxicities were recorded and immune responses assayed by ELIspot.

Results

CD8⁺ T cell responses to transdermal vaccination in DMSO occurred in 83% of participants in group 3 and 86% in group 4, and responses to vaccination in IFA were observed in 29% of participants in group 1 and 14% in group 2. Overall, 61% of participants had CD4⁺ T cell immune responses to the tetanus peptide, with large, durable responses in groups 3 and 4. Five of seven participants in group 4 had a severe rash, one that was dose limiting. Ten-year overall survival was 67% and disease-free survival was 44%.

Conclusions

These data provide proof of principle for immunogenicity in humans of transdermal immunization using peptides in DMSO. Further study is warranted into the pharmacokinetics and immunobiology of TLR agonists as vaccine adjuvants during transcutaneous application. Overall survival is high, supporting further investigation of this immunization approach.

Childhood cancer survivors face markedly worse overall survival after diagnosis with breast cancer, melanoma, or colorectal cancer

BACKGROUND

Childhood cancer survivors (CCS) are at elevated risk of secondary malignancies (SM). Enhanced screening for SM is recommended, but compliance is poor. We hypothesized that CCS with adult-onset SM (colorectal cancer [CRC], melanoma, or breast cancer [BC]) would present with more advanced disease and have decreased overall survival (OS).

METHODS

The Surveillance, Epidemiology, and End Results Program was queried for patients diagnosed with cancer at age less than or equal to 18 also diagnosed with adult-onset CRC, melanoma, or BC. A cohort without a history of prior malignancy was likewise identified. Tumor features and clinical outcomes were compared.

RESULTS

CCS with a SM (n = 224) were compared with patients without a childhood cancer history (n = 1,392,670). CCS were diagnosed younger (BC = 37.6 vs. 61.3, p < 0.01, CRC = 35.0 vs. 67.1, p < 0.01, melanoma = 29.6 vs. 61.3 years old, p < 0.01). CCS with BC were more likely to have Stage III or IV disease (25.2% vs. 16.5%, p = 0.01). Hormone-receptor expression also differed; CCS were less likely to develop Luminal A-type tumors (48.6% vs. 66.9%, p = 0.01). After age-adjustment, CCS had worse OS (Hazard ratio: CRC = 2.449, p < 0.01, melanoma = 6.503, p < 0.01, BC = 3.383, p < 0.01).

CONCLUSION

CCS were younger when diagnosed with a SM. After age-adjustment, OS was diminished. Heightened surveillance may be necessary for CCS diagnosed with SM.

A history of Clostridioides difficile infection portends infection recurrence and worse outcomes after stoma reversal

BACKGROUND

Clostridioides difficile infection is reported to occur after 2.2% of colorectal operations and is associated with longer length of hospital stay, greater overall healthcare cost, and significant morbidity and mortality. The incidence of Clostridioides difficile infection is greatest after elective stoma reversal. The purpose of this study was to evaluate the effect of prior Clostridioides difficile infection on patients undergoing stoma reversal. We hypothesized that patients with a history of Clostridioides difficile infection who underwent stoma reversal will be at an increased risk of postoperative Clostridioides difficile infection compared with patients without a history of Clostridioides difficile infection.

METHODS

This was an observational cohort study of patients undergoing elective stoma reversal surgery by colorectal surgeons at a single academic institution during a 10-year period. A prospectively maintained institutional database was queried to identify 454 patients who underwent stoma reversal surgery between January 1, 2007 and December 31, 2017. The primary outcomes were Clostridioides difficile infection after stoma reversal and time to Clostridioides difficile infection after bowel refunctionalization. Secondary outcomes included postoperative complications, length of hospital stay, discharge destination, and 30-day readmission rate. Univariate and multivariable logistic regression analyses were conducted to identify factors associated with Clostridioides difficile infection after stoma reversal.

RESULTS

A total of 445 patients were identified who underwent elective stoma reversal, 42 of whom had a history of Clostridioides difficile infection before the stoma reversal. There were no significant differences in patient age, number of days diverted, or use of perioperative antibiotics between patients with and without a history of Clostridioides difficile infection. The incidence of postreversal Clostridioides difficile infection was 23.4% in patients with a history of Clostridioides difficile infection compared with 9.6% in patients with no Clostridioides difficile infection history (P = .004); however, time to Clostridioides difficile infection after reversal did not differ. History of Clostridioides difficile infection was also associated with greater risk of postoperative complications (26.2% vs 9.4%, P < .01), increased length of stay (3 vs 5 days postoperatively, P < .01), increased likelihood of discharge to a skilled-care facility (11.9% vs 6.2%, P < .01), and readmission (13.7 vs 31.0%, P < .01) within 30 days. In a multivariable logistic regression model, history of Clostridioides difficile infection, increased length of hospital stay, and discharge to a skilled facility were associated with increased risk of Clostridioides difficile infection after reversal, while proton pump inhibitors use was associated with decreased risk of Clostridioides difficile infection.

CONCLUSION

Patients with a prior history of Clostridioides difficile infection who underwent stoma reversal exhibited higher rates of postoperative Clostridioides difficile infection and were at greater risk of postoperative complications, discharge to a skilled facility, and 30-day readmission. Furthermore, research into interventions aimed at improving outcomes in this unique, high-risk population is needed.

Immunotyping and Quantification of Melanoma Tumor-Infiltrating Lymphocytes

The density of tumour-infiltrating lymphocytes (TILs) in melanoma is correlated with improved clinical prognosis; however, standardized TIL immunotyping and quantification protocols are lacking. Herein, we provide a review of the technologies being utilized for the immunotyping and quantification of melanoma TILs.

Nationwide secondary overtriage in level 3 and level 4 trauma centers: are these transfers necessary?

BACKGROUND

Secondary overtriage (SO) refers to the interfacility transfer of trauma patients who are rapidly discharged home without surgical intervention by the receiving institution. SO imposes a financial hardship on patients and strains trauma center resources. Most studies on SO have been conducted from the perspective of the receiving hospital, which is usually a level 1 trauma center. Having previously studied SO from the referring rural hospital's perspective, we sought to identify variables contributing to SO at the national level.

METHODS

Using data from the 2008-2012 National Trauma Data Bank, we isolated patients transferred to level 1 trauma centers who were: (1) discharged home within 48 h and (2) did not undergo any surgical procedure. This population was subsequently compared with similar patients treated at and discharged directly from level 3 and 4 centers. Multivariate logistic regression analysis was used to isolate variables that independently influenced a patient's risk of undergoing SO. Injury patterns were characterized by use of subspecialty consultants.

RESULTS

A total of 99,114 patients met inclusion criteria, of which 13.2% were discharged directly from level 3 or 4 trauma centers, and 86.8% of them were transferred to a level 1 trauma center before discharge. The mean Injury Severity Score of the nontransfer and transfer groups was 5.4 ± 4.5 and 7.3 ± 5.7, respectively. Multivariate regression analysis showed that Injury Severity Score > 15, alcoholism, smoking, drug use, and certain injury patterns involving the head, vertebra, and face were associated with being transferred. In this minimally injured population, factors protective against transfers were: age > 65 y, female gender, systolic blood pressure <80, a head computed tomography scan and orthopedic injuries.

CONCLUSIONS

SO results from the complex interplay of variables including patient demographics, facility characteristics, and injury type. The inability to exclude a potentially devastating neurologic injury seems to drive SO.