Validation of Immunotherapy Response Score as Predictive of Pan-solid Tumor Anti-PD-1/PD-L1 Benefit

Immunotherapy response score (IRS) integrates tumor mutation burden (TMB) and quantitative expression biomarkers to predict anti-PD-1/PD-L1 [PD-(L)1] monotherapy benefit. Here, we evaluated IRS in additional cohorts. Patients from an observational trial (NCT03061305) treated with anti-PD-(L)1 monotherapy were included and assigned to IRS-High (-H) versus -Low (-L) groups. Associations with real-world progression-free survival (rwPFS) and overall survival (OS) were determined by Cox proportional hazards (CPH) modeling. Those with available PD-L1 IHC treated with anti-PD-(L)1 with or without chemotherapy were separately assessed. Patients treated with PD-(L)1 and/or chemotherapy (five relevant tumor types) were assigned to three IRS groups [IRS-L divided into IRS-Ultra-Low (-UL) and Intermediate-Low (-IL), and similarly assessed]. In the 352 patient anti-PD-(L)1 monotherapy validation cohort (31 tumor types), IRS-H versus IRS-L patients had significantly longer rwPFS and OS. IRS significantly improved CPH associations with rwPFS and OS beyond microsatellite instability (MSI)/TMB alone. In a 189 patient (10 tumor types) PD-L1 IHC comparison cohort, IRS, but not PD-L1 IHC nor TMB, was significantly associated with anti-PD-L1 rwPFS. In a 1,103-patient cohort (from five relevant tumor types), rwPFS did not significantly differ in IRS-UL patients treated with chemotherapy versus chemotherapy plus anti-PD-(L)1, nor in IRS-H patients treated with anti-PD-(L)1 versus anti-PD-(L)1 + chemotherapy. IRS associations were consistent across subgroups, including both Europeans and non-Europeans. These results confirm the utility of IRS utility for predicting pan-solid tumor PD-(L)1 monotherapy benefit beyond available biomarkers and demonstrate utility for informing on anti-PD-(L)1 and/or chemotherapy treatment.

Significance

This study confirms the utility of the integrative IRS biomarker for predicting anti-PD-L1/PD-1 benefit. IRS significantly improved upon currently available biomarkers, including PD-L1 IHC, TMB, and MSI status. Additional utility for informing on chemotherapy, anti-PD-L1/PD-1, and anti-PD-L1/PD-1 plus chemotherapy treatments decisions is shown.

Abstract 2171: A multivariate biomarker predicts sacituzumab govitecan response in solid tumors

Despite the recent clinical success of antibody drug conjugates (ADC) in oncology, predictive biomarkers are lacking, potentially limiting their impact. Herein, we evaluated the ability of candidate biomarkers alone and in combination to predict objective response rates observed in solid tumor patients treated with the TROP2-targeted ADC, sacituzumab govitecan (SG), as determined in the IMMU-12-01 basket trial. We leveraged available next generation sequencing (NGS)-based molecular profiling data from an independent advanced solid tumor cohort (n = 23,968) and developed a multivariate biomarker algorithm that produced biomarker positive rates correlating with the objective response rates (ORR) observed in IMMU-12-01. Candidate biomarkers evaluated included TROP2 gene expression, proliferation (by gene expression) and tumor cellularity. Notably, while TROP2 gene expression was highly correlated with protein expression across 45 tumor types (r = 0.93), TROP2 gene expression alone did not significantly predict ORR across 9 tumor types (r = 0.40, p = 0.29). In contrast, a biomarker algorithm combining TROP2 and proliferation by gene expression with tumor cellularity strongly predicted response both when using tumor type-specific biomarker rates in a discovery cohort (r = 0.83, p = 0.006) and in an independent validation cohort (r = 0.82, p = 0.007). These results indicate that the multivariate biomarker accounts for 67% of the variability observed in response rates and may thus identify patients likely to benefit from SG. Among tumor types with objective responses in IMMU-12-01, biomarker positive rates ranged from 9.9% in colorectal cancer to 57.4% in bladder cancer. Additional tumor types with biomarker positive rates >30% included cancers of the head and neck, cervix, salivary gland, skin (non-melanoma) and ovary, all with positive biomarker rates >30%. Interestingly, most tumor types had biomarker positive rates >5%, suggesting the potential for a tumor type-agnostic approach to patient selection. Considering SG and other ADC’s mechanism of action, a plausible model for response is that (1) higher target expression increases ADC drug delivery, (2) higher tumor cellularity increases ADC bystander effect and (3) higher tumor cell proliferation increases tumor cell death. In summary, we uncovered a novel biomarker algorithm capable of predicting SG response across solid tumors that may be generalizable to ADCs as a class, with the potential to further optimize use and maximize benefit.

Citation Format: Nickolay A. Khazanov, Laura E. Lamb, Daniel H. Hovelson, Kat Kwiatkowski, D. Bryan Johnson, Daniel R. Rhodes, Scott A. Tomlins. A multivariate biomarker predicts sacituzumab govitecan response in solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2171.

Abstract 968: Evaluation of Her2 RNA expression as a potential predictive biomarker for anti-Her2 therapy

Trastuzumab deruxtecan (Enhertu) is effective in "HER2 Low" breast cancer, defined by 1+ or 2+ expression by immunohistochemistry (IHC). Interest has now turned toward defining a sub-population of IHC 0+ tumors that may have HER2 expression below the limit of IHC detection/quantification and may thus also be responsive. We previously validated a high dynamic range HER2 RNA expression assay run as part of our comprehensive genomic profiling test, StrataNGS.

Herein, we evaluated the HER2 RNA expression data together with copy number and clinical outcome data from the Strata Clinical Molecular Database (SCMD) in advanced breast cancer (n = 3,063) and other advanced solid tumors (n = 26,715). As expected, HER2 gene expression was significantly higher in tumors with DNA amplification (>=6 copies; median: 13.9 vs. 10.0 in log2 units; p < 1e-100). Despite similar copy number levels in amplified breast vs. other cancers (median: 21.8 vs. 19.8 copies), HER2 expression levels were ~2-fold higher (median: 14.5 vs. 13.5; p = 1.3e-10). Similarly, HER2 expression levels were higher in non-amplified breast vs. other cancers (median: 10.7 vs. 9.9; p<1e-100), suggesting that DNA amplification and cell lineage affect HER2 expression. Using our previously validated HER2 threshold, among 75 eligible SCMD breast cancer patients treated with 1st or 2nd line systemic trastuzumab or pertuzumab containing therapy, HER2 RNA High patients (n=46, 59%) had significantly longer time to next therapy (TTNT) compared to HER2 RNA Not High patients (median TTNT 26.9 vs. 5.6 months, adjusted hazard ratio 0.31, p=0.005 when adjusted for 1st vs. 2nd line, pertuzumab inclusion, and inclusion of chemotherapy or hormonal therapy).

In patients with available IHC data (n = 388), HER2 RNA expression trended with IHC across the 0-3+ range, however, while 3+ tumors had distinctly high RNA expression (median: 14.4), 0-2+ tumors had lower expression with overlapping distributions (median: 10.5, 10.9, 11.5, respectively), suggesting that 0-2+ tumors do not represent distinct biological groups, but rather a continuum of low expression. We defined a HER2 RNA Low threshold (>10.6), corresponding to the top 75% of IHC 1-2+ breast cancers. Importantly, at this threshold, nearly half (44.1%) of 0+ breast cancers were also classified as HER2 RNA Low. Additionally, 25.8% of all non-breast solid tumors were classified as HER2 RNA Low. Given that HER2 RNA High predicted benefit from 1st generation anti-HER2 therapies, future studies should consider HER2 RNA Low as an alternative biomarker to Her2 IHC Low, with the opportunity to further expand trastuzumab deruxtecan use into the IHC 0+ breast cancer population and potentially to additional solid tumors.

Citation Format: Laura E. Lamb, Nickolay A. Khazanov, Daniel H. Hovelson, Kat Kwiatkowski, D. Bryan Johnson, Daniel R. Rhodes, Scott A. Tomlins. Evaluation of Her2 RNA expression as a potential predictive biomarker for anti-Her2 therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 968.

Single-agent anti-PD-1 or combined with ipilimumab in patients with mucosal melanoma: an international, retrospective, cohort study

BACKGROUND

Mucosal melanoma (MM) is a rare melanoma subtype with distinct biology and poor prognosis. Data on the efficacy of immune checkpoint inhibitors (ICIs) is limited. We determined the efficacy of ICIs in MM, analysed by primary site and ethnicity/race.

PATIENTS AND METHODS

Retrospective cohort study from 25 cancer centres in Australia, Europe, USA and Asia. Patients with histologically confirmed MM were treated with anti-PD1+/-ipilimumab. Primary endpoints were response rate (RR), progression-free survival (PFS), overall survival (OS) by primary site (naso-oral, urogenital, anorectal, other), ethnicity/race (Caucasian, Asian, Other) and treatment. Univariate and multivariate Cox proportional hazard model analyses were conducted.

RESULTS

In total, 545 patients were included: 331 (63%) Caucasian, 176 (33%) Asian and 20 (4%) Other. Primary sites included 113 (21%) anorectal, 178 (32%) urogenital, 206 (38%) naso-oral and 45 (8%) other. 348 (64%) received anti-PD1 and 197 (36%) anti-PD1/ipilimumab. RR, PFS and OS did not differ by primary site, ethnicity/race or treatment. RR for naso-oral was numerically higher for anti-PD1/ipilimumab (40%, 95% CI 29-54%) compared with anti-PD1 (29%, 95% CI 21-37%). 35% of patients that initially responded progressed. Median duration of response (mDOR) was 26 months (95% CI 18-NR [Not Reached]). Factors associated with short PFS were ECOG PS ≥3 (p<0.01), LDH >ULN (p=0.01), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01). Factors associated with short OS were ECOG PS ≥1 (p<0.01), LDH >ULN (p=0.03), lung metastases (p<0.01) and ≥1 previous treatments (p<0.01).

CONCLUSIONS

MM has poor prognosis. Treatment efficacy of anti-PD1+/-ipilimumab was similar and did not differ by ethnicity/race. Naso-oral primaries had numerically higher response to anti-PD1/ipilimumab, without difference in survival. The addition of ipilimumab did not show greater benefit over anti-PD1 for other primary sites. In responders, mDOR was short and acquired resistance was common. Other factors, including site and number of metastases were associated with survival.

Development and Validation of StrataNGS, a Multiplex PCR, Semiconductor Sequencing-Based Comprehensive Genomic Profiling Test

Despite widespread use in targeted tumor testing, multiplex PCR/semiconductor (Ion Torrent) sequencing-based assessment of all comprehensive genomic profiling (CGP) variant classes has been limited. Herein, we describe the development and validation of StrataNGS, a 429-gene, multiplex PCR/semiconductor sequencing-based CGP laboratory-developed test performed on co-isolated DNA and RNA from formalin-fixed, paraffin-embedded tumor specimens with ≥2 mm² tumor surface area. Validation was performed in accordance with MolDX CGP validation guidelines using 1986 clinical formalin-fixed, paraffin-embedded samples and an in-house developed optimized bioinformatics pipeline. Across CGP variant classes, accuracy ranged from 0.945 for tumor mutational burden (TMB) status to >0.999 for mutations and gene fusions, positive predictive value ranged from 0.915 for TMB status to 1.00 for gene fusions, and reproducibility ranged from 0.998 for copy number alterations to 1.00 for splice variants and insertions/deletions. StrataNGS TMB estimates were highly correlated to those from whole exome- or FoundationOne CDx-determined TMB (Pearson r = 0.998 and 0.960, respectively); TMB reproducibility was 0.996 (concordance correlation coefficient). Limit of detection for all variant classes was <20% tumor content. Together, we demonstrate that multiplex PCR/semiconductor sequencing-based tumor tissue CGP is feasible using optimized bioinformatic approaches described herein.

Real-World Performance of a Comprehensive Genomic Profiling Test Optimized for Small Tumor Samples

PURPOSE

Tissue-based comprehensive genomic profiling (CGP) is increasingly used for treatment selection in patients with advanced cancer; however, tissue availability may limit widespread implementation. Here, we established real-world CGP tissue availability and assessed CGP performance on consecutively received samples.

MATERIALS AND METHODS

We conducted a post hoc, nonprespecified analysis of 32,048 consecutive tumor tissue samples received for StrataNGS, a multiplex polymerase chain reaction (PCR)-based comprehensive genomic profiling (PCR-CGP) test, as part of an ongoing observational trial (NCT03061305). Sample characteristics and PCR-CGP performance were assessed across all tested samples, including exception samples not meeting minimum input quality control (QC) requirements (< 20% tumor content [TC], < 2 mm2 tumor surface area [TSA], DNA or RNA yield < 1 ng/µL, or specimen age > 5 years). Tests reporting ≥ 1 prioritized alteration or meeting TC and sequencing QC were considered successful. For prostate carcinoma and lung adenocarcinoma, tests reporting ≥ 1 actionable or informative alteration or meeting TC and sequencing QC were considered actionable.

RESULTS

Among 31,165 (97.2%) samples where PCR-CGP was attempted, 10.7% had < 20% TC and 59.2% were small (< 25 mm2 tumor surface area). Of 31,101 samples evaluable for input requirements, 8,089 (26.0%) were exceptions not meeting requirements. However, 94.2% of the 31,101 tested samples were successfully reported, including 80.5% of exception samples. Positive predictive value of PCR-CGP for ERBB2 amplification in exceptions and/or sequencing QC-failure breast cancer samples was 96.7%. Importantly, 84.0% of tested prostate carcinomas and 87.9% of lung adenocarcinomas yielded results informing treatment selection.

CONCLUSION

Most real-world tissue samples from patients with advanced cancer desiring CGP are limited, requiring optimized CGP approaches to produce meaningful results. An optimized PCR-CGP test, coupled with an inclusive exception testing policy, delivered reportable results for > 94% of samples, potentially expanding the proportion of CGP-testable patients and impact of biomarker-guided therapies.

Association of clinical factors and recent anticancer therapy with COVID-19 severity among patients with cancer: a report from the COVID-19 and Cancer Consortium

BACKGROUND

Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies.

PATIENTS AND METHODS

Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients).

RESULTS

A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality.

CONCLUSIONS

Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies.

CLINICAL TRIAL IDENTIFIER

NCT04354701.

Delayed immune-related adverse events with anti-PD-1-based immunotherapy in melanoma

BACKGROUND

Immune-related adverse events (irAEs) typically occur within 4 months of starting anti-programmed cell death protein 1 (PD-1)-based therapy [anti-PD-1 ± anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA4)], but delayed irAEs (onset >12 months after commencement) can also occur. This study describes the incidence, nature and management of delayed irAEs in patients receiving anti-PD-1-based immunotherapy.

PATIENTS AND METHODS

Patients with delayed irAEs from 20 centres were studied. The incidence of delayed irAEs was estimated as a proportion of melanoma patients treated with anti-PD-1-based therapy and surviving >1 year. Onset, clinical features, management and outcomes of irAEs were examined.

RESULTS

One hundred and eighteen patients developed a total of 140 delayed irAEs (20 after initial combination with anti-CTLA4), with an estimated incidence of 5.3% (95% confidence interval 4.0-6.9, 53/999 patients at sites with available data). The median onset of delayed irAE was 16 months (range 12-53 months). Eighty-seven patients (74%) were on anti-PD-1 at irAE onset, 15 patients (12%) were <3 months from the last dose and 16 patients (14%) were >3 months from the last dose of anti-PD-1. The most common delayed irAEs were colitis, rash and pneumonitis; 55 of all irAEs (39%) were ≥grade 3. Steroids were required in 80 patients (68%), as well as an additional immunosuppressive agent in 27 patients (23%). There were two irAE-related deaths: encephalitis with onset during anti-PD-1 and a multiple-organ irAE with onset 11 months after ceasing anti-PD-1. Early irAEs (<12 months) had also occurred in 69 patients (58%), affecting a different organ from the delayed irAE in 59 patients (86%).

CONCLUSIONS

Delayed irAEs occur in a small but relevant subset of patients. Delayed irAEs are often different from previous irAEs, may be high grade and can lead to death. They mostly occur in patients still receiving anti-PD-1. The risk of delayed irAE should be considered when deciding the duration of treatment in responding patients. However, patients who stop treatment may also rarely develop delayed irAE.

Management of early melanoma recurrence despite adjuvant anti-PD-1 antibody therapy☆

BACKGROUND

Anti-programmed cell death protein 1 (PD-1) antibodies (PD1) prolong recurrence-free survival in high-risk resected melanoma; however, approximately 25%-30% of patients recur within 1 year. This study describes the pattern of recurrence, management and outcomes of patients who recur with adjuvant PD1 therapy.

PATIENTS AND METHODS

Consecutive patients from 16 centres who recurred having received adjuvant PD1 therapy for resected stage III/IV melanoma were studied. Recurrence characteristics, management and outcomes were examined; patients with mucosal melanoma were analysed separately.

RESULTS

Melanoma recurrence occurred in 147 (17%) of ∼850 patients treated with adjuvant PD1. In those with cutaneous melanoma (n = 136), median time to recurrence was 4.6 months (range 0.3-35.7); 104 (76%) recurred during (ON) adjuvant PD1 after a median 3.2 months and 32 (24%) following (OFF) treatment cessation after a median 12.5 months, including in 21 (15%) who ceased early for toxicity. Fifty-nine (43%) recurred with locoregional disease only and 77 (57%) with distant disease. Of those who recurred locally, 22/59 (37%) subsequently recurred distantly. Eighty-nine (65%) patients received systemic therapy after recurrence. Of those who recurred ON adjuvant PD1, none (0/6) responded to PD1 alone; 8/33 assessable patients (24%) responded to ipilimumab (alone or in combination with PD1) and 18/23 (78%) responded to BRAF/MEK inhibitors. Of those who recurred OFF adjuvant PD1, two out of five (40%) responded to PD1 monotherapy, two out of five (40%) responded to ipilimumab-based therapy and 9/10 (90%) responded to BRAF/MEK inhibitors.

CONCLUSIONS

Most patients who recur early despite adjuvant PD1 develop distant metastases. In those who recur ON adjuvant PD1, there is minimal activity of further PD1 monotherapy, but ipilimumab (alone or in combination with PD1) and BRAF/MEK inhibitors have clinical utility. Retreatment with PD1 may have activity in select patients who recur OFF PD1.

P1591Cardiovascular toxicity of ibrutinib: a pharmacovigilance study

Importance

Ibrutinib, a first in class Bruton tyrosine kinase inhibitor, has revolutionized treatment for several B-cell malignancies. However, early data suggested that ibrutinib was associated with supra-ventricular arrhythmias (SVA) and bleeding. Other types of cardiovascular adverse drug reactions (CV-ADR) induced by ibrutinib have been sporadically reported.

Objective

To determine the full spectrum of CV-ADR associated with ibrutinib and provide data concerning their clinical characteristics.

Design

An observational, retrospective, pharmacovigilance study

Setting

VigiBase, the World Health Organization's pharmacovigilance database.

Main outcomes and measures

A disproportionality analysis using reporting odds-ratios (ROR) and information component (IC). IC compares observed and expected values to find associations between drugs and ADR using disproportionate Bayesian reporting; IC025 (lower end of the IC 95% credibility interval) >0 is considered statistically significant.

Exposures

Exposure to ibrutinib versus entire database.

Results

Ibrutinib was associated with higher reporting of supraventricular arrhythmias (SVA; ROR: 23.1 [21.6–24.7]; IC025:3.97), central nervous system (CNS) hemorrhagic events (ROR: 3.7 [3.4–4.1]; IC025:1.63), heart failure (HF; ROR: 3.5 [3.1–3.8]; IC025:1.46), ventricular arrhythmias (VA; ROR: 4.7 [3.7–5.9]; IC025:0.96), conduction disorders (CD; ROR: 3.5 [2.7–4.6]; IC025:0.76), CNS ischemic events (ROR: 2.2 [2.0–2.5]; IC025:0.73) and hypertension (ROR: 1.7 [1.5–1.9]; IC025:0.4). CV-ADR occurred early after ibrutinib administration, as soon as after the first dose, with a shorter median time to onset of 27.5 days (IQR: 1–138.5 days) for CD (p<0.01, Kruskal-Wallis), as compared to CNS ischemic events (51 days; IQR: 17.5–160 days, p: 0.05 vs. CD), CNS hemorrhagic events (53.5 days; IQR: 20.3–183.3 days, p: 0.03 vs. CD), HF (54 days; IQR: 20–142.8 days, p: 0.05 vs. CD), VA (70 days; IQR: 28.5–152.5 days, p: 0.03 vs. CD), SVA (74 days; (IQR: 29.5–196.5 days, p: 0.0004 vs. CD) and hypertension (164 days; IQR: 20–274 days, p: 0.04 vs. CD). CV-ADR were associated with fatalities, with rates ranging from ∼10% (SVA and VA) to ∼20% (CNS events, HF and CD). More deaths occurred when SVA cases were associated with CNS hemorrhagic and/or ischemic events compared to their absence (15/52, 28.8% vs. 88/907, 9.7%, p<0.0001, respectively).

Conclusions

Severe and occasionally fatal cardiac events related to cardiac SVA, VA, CD, HF, hypertension, CNS hemorrhagic and ischemic events occur in patients exposed to ibrutinib. These events should be considered in patient care and in clinical trial designs.

Microbial diversity and biomarker analysis of modern freshwater microbialites from Laguna Bacalar, Mexico

Laguna Bacalar is a sulfate-rich freshwater lake on the Yucatan Peninsula that hosts large microbialites. High sulfate concentrations distinguish Laguna Bacalar from other freshwater microbialite sites such as Pavilion Lake and Alchichica, Mexico, as well as from other aqueous features on the Yucatan Peninsula. While cyanobacterial populations have been described here previously, this study offers a more complete characterization of the microbial populations and corresponding biogeochemical cycling using a three-pronged geobiological approach of microscopy, high-throughput DNA sequencing, and lipid biomarker analyses. We identify and compare diverse microbial communities of Alphaproteobacteria, Deltaproteobacteria, and Gammaproteobacteria that vary with location along a bank-to-bank transect across the lake, within microbialites, and within a neighboring mangrove root agglomeration. In particular, sulfate-reducing bacteria are extremely common and diverse, constituting 7%-19% of phylogenetic diversity within the microbialites, and are hypothesized to significantly influence carbonate precipitation. In contrast, Cyanobacteria account for less than 1% of phylogenetic diversity. The distribution of lipid biomarkers reflects these changes in microbial ecology, providing meaningful biosignatures for the microbes in this system. Polysaturated short-chain fatty acids characteristic of cyanobacteria account for <3% of total abundance in Laguna Bacalar microbialites. By contrast, even short-chain and monounsaturated short-chain fatty acids attributable to both Cyanobacteria and many other organisms including types of Alphaproteobacteria and Gammaproteobacteria constitute 43%-69% and 17%-25%, respectively, of total abundance in microbialites. While cyanobacteria are the largest and most visible microbes within these microbialites and dominate the mangrove root agglomeration, it is clear that their smaller, metabolically diverse associates are responsible for significant biogeochemical cycling in this microbialite system.

Abstract P1-08-02: Breast tumor-specific MHC-II expression drives a unique pattern of adaptive resistance to antitumor immunity through MHC-II receptor checkpoint engagement

Background: We have previously shown that some breast cancers express major histocompatibility complex II (MHC-II), correlating with enhanced immune infiltration. In other tumor types, we have shown that MHC-II expression on tumor cells predicts clinical response to checkpoint inhibition. We sought to determine the direct effects of MHC-II on anti-tumor immunity and characterize mechanisms of immune escape in this breast cancer subset.

Methods: To determine the functional effects of MHC-II on tumor cells, we generated isogenic mouse breast tumor cells with enforced MHC-II expression and determined their ability to generate tumors in syngeneic mice, the impact on immunity, and their response to checkpoint inhibition. In a series of molecularly-characterized HER2+ (n=8) and triple-negative breast cancers (TNBC; n=103), we performed immunohistochemistry (IHC) and quantitative immunofluorescence (QIF) for Lag-3, PD-L1, CD4, CD8, FCRL6, and granzyme B.

Results: Following injection in syngeneic immunocompetent mice, MHC-II+ mouse breast tumors were more frequently rejected (p=0.04) and recruited greater numbers of CD4+ TILs. When MHC-II+ tumors escaped rejection, they expressed higher degrees of PD-1 and Lag-3 in the tumor and in the draining lymph node. Since Lag-3 is a checkpoint that specifically targets MHC-II, we hypothesized that MHC-II+ breast cancers escape anti-tumor immunity through suppressing MHC-II-mediated antigen presentation. Combinations of anti-Lag-3 and anti-Pd-1 antibodies inhibited growth of MHC-II+ tumors. These findings led us to also explore Fc receptor-like 6 (FCRL6), a previously reported MHC-II receptor expressed on NK and cytotoxic T cells. Residual MHC-II+ TNBC post-neoadjuvant chemotherapy (NAC) recruited greater numbers of CD4+ and CD8+ TILs (p=0.0001 and p=0.0002), suggesting enhanced immune recognition. However, MHC-II+ TNBCs also demonstrated a greater frequency of Lag-3+ and FCRL6+ TILs (p&lt;0.001 and p=0.01, respectively) which frequently co-occurred (p=0.003). Thus, our data suggest that MHC-II expression in breast tumors supports recruitment of MHC-II-specific checkpoint-positive TILs. In line with this concept, QIF analysis demonstrated that the presence of Lag3+ and/or FCRL6+ TILs was strongly associated with suppression of T cell cytotoxicity as assessed by granzyme-B+ CD8+ T cells (p=0.0001 and p=0.002, respectively). Functional analyses of FCRL6 on human NK cell lines and peripheral blood mononuclear cells (PBMCs) demonstrated that like Lag3, FCRL6 is a checkpoint which engages MHC-II and suppresses cytotoxic NK and T cell activity.

Conclusions: These data suggest that MHC-II+ breast tumors are immunologically active and circumvent anti-tumor immunity by targeting MHC-II antigen presentation through recruitment of Lag-3+ and FCRL6+ TILs. We describe herein FCRL6 as a novel bona fide immune checkpoint which targets MHC-II, which may impact a variety of cancers. MHC-II expression status may be a useful biomarker for patient stratification on anti-PD-1/anti-Lag-3 combination, and eventually, anti-PD-1/anti-FCRL6 combinations in patients with breast cancer.

Citation Format: Balko JM, Johnson DB, Ericsson-Gonzalez P, Nixon MJ, Salgado R, Sanchez V, Shreeder DM, Rimm DL, Loi S, Kim JY, Bordeaux J, Sanders ME, Davis RS. Breast tumor-specific MHC-II expression drives a unique pattern of adaptive resistance to antitumor immunity through MHC-II receptor checkpoint engagement [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-08-02.

Safety of resuming anti-PD-1 in patients with immune-related adverse events (irAEs) during combined anti-CTLA-4 and anti-PD1 in metastatic melanoma

Background

Combined cytotoxic T-lymphocyte antigen 4 (CTLA-4) and programmed death 1 (PD-1) blockade induces high rates of immune-related adverse events (irAEs). The safety of resuming anti-PD-1 in patients who discontinue combination therapy due to irAEs is not known.

Patients and methods

We assessed patients who experienced clinically significant irAEs from combined CTLA-4 and PD-1 blockade leading to treatment discontinuation at four academic centers. We assessed the safety of resuming anti-PD-1 in terms of recurrent and distinct irAEs.

Results

Eighty patients discontinued combination therapy due to irAEs, including colitis (41%), hepatitis (36%), and pneumonitis (4%). Of these, 96% received corticosteroids and 21% received additional immunosuppression (e.g. infliximab). All were rechallenged with anti-PD-1, and 14 (18%) had recurrent irAEs at a median of 14 days after therapy resumption (six grade 1-2, seven grade 3-4, and one grade 5 Steven-Johnson Syndrome). Colitis was less likely to recur than other irAEs (6% versus 28%, P = 0.01). Clinically significant but distinct toxicities occurred in an additional 17 (21%) patients (11 grade 1-2 and 6 grade 3-4). Duration of steroid taper, severity of initial irAEs and use of additional immunosuppressants did not predict for toxicity on rechallenge, although patients remaining on steroid therapy at anti-PD-1 resumption had higher rates of toxicities (55% versus 31%, P = 0.03).

Conclusions

Patients who discontinued CTLA-4/PD-1 blockade for severe irAEs had relatively high rates of recurrent or distinct toxicities with anti-PD-1 resumption. However, many patients, particularly with combination-induced colitis, tolerated anti-PD-1 rechallenge well, and this approach can be considered in selected patients.

Anti-PD-1 therapy in patients with advanced melanoma and preexisting autoimmune disorders or major toxicity with ipilimumab

Background

Anti-PD-1 antibodies (anti-PD-1) have clinical activity in a number of malignancies. All clinical trials have excluded patients with significant preexisting autoimmune disorders (ADs) and only one has included patients with immune-related adverse events (irAEs) with ipilimumab. We sought to explore the safety and efficacy of anti-PD-1 in such patients.

Patients and methods

Patients with advanced melanoma and preexisting ADs and/or major immune-related adverse events (irAEs) with ipilimumab (requiring systemic immunosuppression) that were treated with anti-PD-1 between 1 July 2012 and 30 September 2015 were retrospectively identified.

Results

One hundred and nineteen patients from 13 academic tertiary referral centers were treated with anti-PD-1. In patients with preexisting AD (N = 52), the response rate was 33%. 20 (38%) patients had a flare of AD requiring immunosuppression, including 7/13 with rheumatoid arthritis, 3/3 with polymyalgia rheumatica, 2/2 with Sjogren's syndrome, 2/2 with immune thrombocytopaenic purpura and 3/8 with psoriasis. No patients with gastrointestinal (N = 6) or neurological disorders (N = 5) flared. Only 2 (4%) patients discontinued treatment due to flare, but 15 (29%) developed other irAEs and 4 (8%) discontinued treatment. In patients with prior ipilimumab irAEs requiring immunosuppression (N = 67) the response rate was 40%. Two (3%) patients had a recurrence of the same ipilimumab irAEs, but 23 (34%) developed new irAEs (14, 21% grade 3-4) and 8 (12%) discontinued treatment. There were no treatment-related deaths.

Conclusions

In melanoma patients with preexisting ADs or major irAEs with ipilimumab, anti-PD-1 induced relatively frequent immune toxicities, but these were often mild, easily managed and did not necessitate discontinuation of therapy, and a significant proportion of patients achieved clinical responses. The results support that anti-PD-1 can be administered safely and can achieve clinical benefit in patients with preexisting ADs or prior major irAEs with ipilimumab.

Abstract P6-10-02: MHC-II positive breast tumors are more immunogenic and may preferentially select for LAG-3-positive tumor immune infiltrates

Background: Lymphocyte-activation gene 3 (LAG-3) is a T-cell checkpoint regulator and a current target in immunotherapy trials. LAG-3's main ligand is MHC class II (MHC-II), to which it binds with higher affinity than CD4. Binding of LAG3 to MHC-II antigen-presenting cells negatively regulates cellular proliferation, activation, and homeostasis of T cells, similarly to CTLA-4 and PD-1, suggesting that antibodies targeting LAG-3 may demonstrate similar anti-tumor immune effects.

Hypothesis: We recently reported an association of MHC-II on tumor cells and its involvement in mediating sensitivity to PD-1/PD-L1 monoclonal antibodies. MHC-II demonstrates a strong bimodal expression pattern on tumor cells from a variety of tissues, including those of the breast. In breast cancer patients, tumor-specific MHC-II expression on TNBCs is correlated with a 'hot' immune environment. We hypothesized that 1) MHC-II expression may drive potent anti-tumor immune responses and 2) MHC-II-positive tumors that generate immunotolerance may develop a specific immune checkpoint dependency on LAG-3, since LAG-3 is the inhibitory receptor for MHC-II-mediated antigen presentation.

Methods: To determine the functionality of MHC-II in driving anti-tumor immune responses, we constitutively expressed the MHC-II master regulator CIITA in MMTV-neu mouse tumor cells and determined their ability to form tumors in immunocompetent syngeneic hosts. To evaluate the association of MHC-II+ tumors with LAG-3 expression, we evaluated LAG-3-positivity by immunohistochemistry (IHC) in lymphocytic infiltrates in a series of 111 post-NAC TNBC specimens from patients with residual disease remaining after presurgical chemotherapy. Tumor-infiltrating lymphocytes (TILs) were scored by H&E, PD-L1 and MHC-II (HLA-DR) were scored in the stroma and tumor compartments using automated quantitative immunofluorescence (AQUA).

Results: Enforced expression of MHC-II via constitutive expression of CIITA caused rejection in 60% of mice, while only 11% of mice rejected MMTV-neu tumors expressing the vector control (Fisher's exact p=0.04). All rejecting mice were immune to rechallenge with parental (non-CIITA-expressing) MMTV-neu cells, suggesting a memory effector response.

Clinically, 11/102 patients (10.8%) had LAG-3+ immune cells in their tumor. LAG-3+ tumors were strongly correlated with MHC-II positivity in tumor cells (p&lt;0.0001). Presence of LAG-3+ cells also correlated strongly with overall TILs (p&lt;0.0001), and PD-L1 expression on TILs (p&lt;0.02). Since the likelihood of identifying LAG3+ lymphocytes is confounded by the inclusion of poorly-infiltrated tumors, we performed a subset analysis on only those tumors with substantial TILs (&gt;20%). When this subset was analyzed, LAG-3 positivity retained its association with tumor MHC-II expression (p=0.0001), while the association of LAG-3 with stromal PD-L1 was reduced below the level of significance (p=0.052).

Conclusions: MHC-II expression causes increased immune activation in breast cancers, consistent with our previous findings. MHC-II positivity in breast tumors may identify a population with preferential dependence on the LAG-3 checkpoint, which may be important for future immunotherapy trials.

Citation Format: Balko JM, Loi S, Giltnane JM, Combs S, Estrada MV, Sanchez V, Rimm D, Sanders ME, Salgado R, Gomez H, Johnson DB. MHC-II positive breast tumors are more immunogenic and may preferentially select for LAG-3-positive tumor immune infiltrates [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-10-02.

Abstract P2-19-02: Do older women benefit from post-mastectomy breast reconstruction?

Purpose: Despite evidence that post-mastectomy breast reconstruction (PMBR) decreases psychological morbidity and improves body image, older women (aged 65 and above) receive it six times less often than younger women. It is unclear whether this difference represents a disparity or reflects informed patient choices since the outcomes of PMBR in older women have never been rigorously studied. We hypothesized that in older women, the use of PMBR is associated with greater psychosocial well-being and breast satisfaction than mastectomy alone.

Patients and Methods: The Dillman method was used to survey 299 older women with stage 0-III breast cancer who underwent a mastectomy from 2006-2011. The response rate was 75.3%. The survey incorporated demographic questions and measured satisfaction and health-related quality of life outcomes using the Duke health profile and the BREAST-Q mastectomy module. Patients who underwent PMBR were compared to those who did not (no-PMBR) to determine differences in patient characteristics, satisfaction, and quality-of-life outcomes between groups. Satisfaction and outcome results were risk adjusted using multivariable logistic regression to account for differences between PMBR and no-PMBR groups.

Results: The median age of respondents was 72. Of these, 77/214 (36%) elected to undergo PMBR. Marital status, education level, race, and tumor stage were similar in PMBR and no-PMBR groups. Those in the PMBR group were generally younger and more affluent than those in the no-PMBR group (p&lt;0.001 and p&lt;0.05, respectively). There were no significant differences in age-adjusted physical health, anxiety, or depression scores between PMBR and no-PMBR groups. Both groups reported high levels of decisional satisfaction. However, after adjusting for age and income, PMBR was associated with greater breast satisfaction (BREAST-Q score 69 vs. 57, p&lt;0.001) and greater psychosocial well-being (BREAST-Q score 83 vs. 76, p&lt;0.001). These differences in scores compared favorably to those seen in younger women.

Conclusions: This is the first study to compare psychosocial outcomes and breast satisfaction between older women who undergo PMBR and those who do not. These findings show that older women have the potential to benefit from PMBR at least as much as younger women do. PMBR can be performed in a significant proportion of older women with high levels of satisfaction. Older women who are appropriate candidates should be encouraged to consider breast reconstruction, and efforts should be made to narrow the disparity in the delivery of PMBR between older and younger women.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-02.

Circumferential mucosectomy with stapled proctopexy is a safe, effective outpatient alternative for the treatment of symptomatic prolapsing hemorrhoids in the elderly

BACKGROUND

Circumferential mucosectomy with stapled proctopexy (CMSP) was first introduced in 1993 as a less painful and highly effective alternative to traditional operative hemorrhoidectomy. Although CMSP has many advantages over traditional hemorrhoidectomy, some authorities and insurers continue to regard it as an inpatient procedure and others have been slow to adopt this progressive technique. This study documents the safe and effective outpatient nature of this procedure.

METHODS

From December 2001 through August 2002, 33 patients with mucosal prolapse and prolapsing internal hemorrhoids were treated using circumferential mucosectomy with stapled proctopexy as outpatients at an ambulatory surgery center. Fourteen (42%) patients were treated using local anesthesia with intravenous sedation, 18 (55%) chose spinal anesthesia, and general anesthesia was used in one patient. Patients were evaluated postoperatively by telephone at 1 and 2 weeks, and seen in clinic at 4 weeks.

RESULTS

One patient (3%) required an emergency department visit for minor postoperative bleeding. None of our elderly patients required emergency department evaluation and none reported significant complications. Four patients (13%) required urinary catheter placement prior to discharge from the surgery center due to urinary retention. One patient (3%) developed an uncomplicated urinary tract infection, which resolved with antibiotic treatment. Two patients were seen earlier than 4 weeks at the surgeon's request; one was immunocompromised from chemotherapy for metastatic carcinoid, and one reported persistent pain during initial telephone follow-up. No complications were identified in either patient, and no additional complications have been noted to date.

CONCLUSIONS

CMSP is a safe, effective, time-efficient procedure for patients with mucosal prolapse and prolapsing hemorrhoids that can be performed safely in the ambulatory surgery center setting. Age is not a limiting factor in selecting patients for this safe outpatient procedure.

Formation of iodinin by a strain of Acidithiobacillus ferrooxidans grown on elemental sulfur

The presence of the pigment iodinin, an Acidithiobacillus ferrooxidans culture metabolite, was demonstrated after growth of bacteria on elemental sulfur. The structure of iodinin was confirmed by X-ray structure analysis; its physiological role is discussed.

Reduction of ferric iron by acidophilic heterotrophic bacteria: evidence for constitutive and inducible enzyme systems in Acidiphilium spp

AIMS

To compare the abilities of two obligately acidophilic heterotrophic bacteria, Acidiphilium acidophilum and Acidiphilium SJH, to reduce ferric iron to ferrous when grown under different culture conditions.

METHODS AND RESULTS

Bacteria were grown in batch culture, under different aeration status, and in the presence of either ferrous or ferric iron. The specific rates of ferric iron reduction by fermenter-grown Acidiphilium SJH were unaffected by dissolved oxygen (DO) concentrations, while iron reduction by A. acidophilum was highly dependent on DO concentrations in the growth media. The ionic form of iron present (ferrous or ferric) had a minimal effect on the abilities of harvested cells to reduce ferric iron. Whole cell protein profiles of Acidiphilium SJH were very similar, regardless of the DO status of the growth medium, while additional proteins were present in A. acidophilum grown microaerobically compared with aerobically-grown cells.

CONCLUSIONS

The dissimilatory reduction of ferric iron is constitutive in Acidiphilium SJH while it is inducible in A. acidophilum.

SIGNIFICANCE AND IMPACT OF THE STUDY

Ferric iron reduction by Acidiphilium spp. may occur in oxygen-containing as well as anoxic acidic environments. This will detract from the effectiveness of bioremediation systems where removal of iron from polluted waters is mediated via oxidation and precipitation of the metal.

Isolation and phylogenetic characterization of acidophilic microorganisms indigenous to acidic drainage waters at an abandoned Norwegian copper mine

The biodiversity of culturable acidophilic microbes in three acidic (pH 2.7-3.7), metal-rich waters at an abandoned subarctic copper mine in central Norway was assessed. Acidophilic bacteria were isolated by plating on selective solid media, and dominant isolates were identified from their physiological characteristics and 16S rRNA gene sequences. The dominant iron-oxidizing acidophile in all three waters was an Acidithiobacillus ferrooxidans-like eubacterium, which shared 98% 16S rDNA identity with the type strain. A strain of Leptospirillum ferrooxidans was obtained from one of the waters after enrichment in pyrite medium, but this iron oxidizer was below detectable levels in the acidic waters themselves. In two sites, there were up to six distinct heterotrophic acidophiles, present at 10(3) ml(-1). These included Acidiphilium-like isolates (one closely related to Acidiphilium rubrum, a second to Acidiphilium cryptum and a third apparently novel isolate), an Acidocella-like isolate (96% 16S rDNA identity to Acidocella facilis) and a bacterium that shared 94.5% 16S rDNA identity to Acidisphaera rubrifaciens. The other numerically significant heterotrophic isolate was not apparently related to any known acidophile, with the closest match (96% 16S rDNA sequence identity) to an acetogen, Frateuria aurantia. The results indicated that the biodiversity of acidophilic bacteria, especially heterotrophs, in acidic mine waters may be much greater than previously recognized.

Cryosurgery and needle ablation of renal lesions

Laparoscopic renal cryoablation is a minimally invasive alternative for treating renal tumors utilizing narrow probes cooled with a compressed gas such as argon or carbon dioxide. At this time, cryotherapy has shown the most promise as an alternative to partial nephrectomy as a nephron-sparing treatment for renal tumors. Radiofrequency ablation employs needle electrodes placed percutaneously directly into renal lesions to deliver energy, creating high temperatures leading to cell death. High-intensity focused ultrasound is a noninvasive technique in which focused ultrasound energy is applied to cause cell death within the focal zone. Microwave thermotherapy uses small applicators to deliver microwave energy to tissues, resulting in the generation of heat. Although RF, HIFU, and microwave thermotherapy show promise as energy sources for tumor ablation, they are in the early stages of development. Little is known about their acute and chronic histologic effects and long-term efficacy as a treatment for malignant disease. Further work is needed to develop cryosurgery and needle ablation in order to delineate what role these techniques will ultimately play in the management of RCC.

A microbiological survey of Montserrat Island hydrothermal biotopes

In March 1996, a survey of hydrothermal sites on the island of Montserrat was carried out. Six sites (Galway's Soufrière. Gages Upper and Lower Soufrières, Hot Water Pond, Hot River, and Tar River Soufrière) were mapped and sampled for chemical, ATP, and microbial analyses. The hydrothermal Soufrière sites on the slopes of the active Chances Peak volcano exhibited temperatures up to almost 100 degrees C and were generally either mildly acidic at pH 5-7 or strongly acidic at pH 1.5-3, but with some hot streams and pools of low redox potential at pH 7-8. Hot Water Pond sites, comprising a series of heated pools near the western shoreline of the island. were neutral and saline, consistent with subsurface heating of entrained seawater. Biological activity shown by ATP analyses was greatest in near-neutral pH samples and generally decreased as acidity increased. A variety of heterotrophic and chemolithotrophic thermophilic organisms were isolated or observed in enrichment cultures. Most of the bacteria that were obtained in pure culture were familiar acidophiles and neutrophiles, but novel, iron-oxidizing species of Sulfobacillus were revealed. These species included the first mesophilic iron-oxidizing Sulfobacillus strains to be isolated and a strain with a higher maximum growth temperature (65 degrees C) than the previously described moderately thermophilic Sulfobacillus species.

Interactive software for generation and visualization of structured findings in radiology reports

OBJECTIVE

Our objectives were to develop a user-friendly graphic interface for a module that integrates traditional radiology reporting, natural language processing, and editing capabilities; to facilitate the structuring of radiology reports as part of routine clinical practice; to use a commercial speech recognition module for online transcription; and to implement the module in a hardware-independent environment.

CONCLUSION

After implementation, the module was tested with 150 chest radiology reports by two radiologists and assessed for ease of use and accuracy. Overall, accuracy was close to 90% and user satisfaction was high. When radiology reports are structured as a part of routine clinical practice, it is possible to accomplish intelligent indexing and retrieval to facilitate teaching and research.

Teleradiology as a foundation for an enterprise-wide health care delivery system

An effective, integrated telemedicine system has been developed that allows (a) teleconsultation between local primary health care providers (primary care physicians and general radiologists) and remote imaging subspecialists and (b) active patient participation related to his or her medical condition and patient education. The initial stage of system development was a traditional teleradiology consultation service between general radiologists and specialists; this established system was expanded to include primary care physicians and patients. The system was developed by using a well-defined process model, resulting in three integrated modules: a patient module, a primary health care provider module, and a specialist module. A middle agent layer enables tailoring and customization of the modules for each specific user type. Implementation by using Java and the Common Object Request Broker Architecture standard facilitates platform independence and interoperability. The system supports (a) teleconsultation between a local primary health care provider and an imaging subspecialist regardless of geographic location and (b) patient education and online scheduling. The developed system can potentially form a foundation for an enterprise-wide health care delivery system. In such a system, the role of radiologist specialists is enhanced from that of a diagnostician to the management of a patient's process of care.

A medical digital library to support scenario and user-tailored information retrieval

Current large-scale information sources are designed to support general queries and lack the ability to support scenario-specific information navigation, gathering, and presentation. As a result, users are often unable to obtain desired specific information within a well-defined subject area. Today's information systems do not provide efficient content navigation, incremental appropriate matching, or content correlation. We are developing the following innovative technologies to remedy these problems: 1) scenario-based proxies, enabling the gathering and filtering of information customized for users within a pre-defined domain; 2) context-sensitive navigation and matching, providing approximate matching and similarity links when an exact match to a user's request is unavailable; 3) content correlation of documents, creating semantic links between documents and information sources; and 4) user models for customizing retrieved information and result presentation. A digital medical library is currently being constructed using these technologies to provide customized information for the user. The technologies are general in nature and can provide custom and scenario-specific information in many other domains (e.g., crisis management).

The urinary tract response to entry of pathogens

The urinary tract response to the entry of pathogens is complex and involves multiple aspects of the immune system. Herein we have divided them into cytokine, immunoglobulin, and cellular responses. Our current understanding suggests that interleukin 6 (IL-6) and IL-8 are the major contributors to the cytokine response. Both IL-6 and IL-8 are produced locally and systemically as part of the initiation of an inflammatory reaction. The cellular response becomes clinically apparent by the appearance of polymorphonuclear neutrophils (PMNs) in the urine. The contribution of gamma delta T-lymphocytes is beginning to be appreciated due to the use of gene-knockout mice in studies of urinary tract infection (UTI). B-lymphocytes are important because antibody response to UTI is important. In addition to the classic systemic antibody response, a local antibody response dominated by secretory immunoglobulin A (sIgA) has been shown to play a major role in the host response to UTI. Efforts to create a vaccine against UTI have focused on stimulation and intensification of this local sIgA production. Investigation continues to define the role of these responses, explain how they interact, and elucidate other aspects of the immune response to UTI that are yet unknown. Ultimately, this work aims to provide more effective treatment and prevention of UTI in those susceptible to invasions of the urinary tract by pathogens. Comprehension of how these responses interact may lead to a better understanding of UTI susceptibility and promote new and innovative types of treatment.

Müllerian-type epithelial tumor arising within a torsed appendix testis

Because it is a remnant of the müllerian duct system, the appendix testis contains müllerian epithelium that theoretically may produce epithelial tumors similar to those that occur in the female genital tract. Few reports of tumors of müllerian origin arising in the testis exist, and rarely are neoplasms arising from the appendix testis identified. We present a case of a serous cystic neoplasm of low malignant potential derived from müllerian-type epithelium that was located in the torsed appendix testis of a young, otherwise healthy, boy.

High-dose melphalan with autotransplantation for refractory multiple myeloma: results of a Southwest Oncology Group phase II trial

PURPOSE

To evaluate high-dose melphalan followed by autologous stem-cell transplantation in patients with refractory multiple myeloma.

PATIENTS AND METHODS

Multiple myeloma patients with alkylating agent or vincristine/doxorubicin/dexamethasone-refractory disease were eligible for the phase II multi-institutional Southwest Oncology Group trial S8993. Patients up to age 70 years were enrolled between April 15, 1991, and May 1, 1996. Patients without prior stem-cell collection were primed with high-dose cyclophosphamide (HD-CTX; 6 g/m(2)) and granulocyte-macrophage colony-stimulating factor. After stem-cell procurement, patients received melphalan 200 mg/m(2) with autologous transplantation. Upon recovery from melphalan, patients were to receive interferon alfa-2b until relapse.

RESULTS

Seventy-two patients were enrolled onto S8993; five were ineligible and one received no therapy. Of the 66 assessable patients, 56 patients underwent the transplant procedure; 54 were assessable for response and 56 for toxicity. The response to HD-CTX (n = 37) included three complete remissions (CRs; 8%) and five partial remissions (PR; 14%); response to melphalan (n = 54) included 16 CRs (30%) and 19 PRs (35%), for an overall CR and >/= PR (n = 66; intent-to-treat) of 27% and 58%, respectively. Toxicities included six treatment-related deaths: two during HD-CTX and four during transplantation. The median progression-free survival (PFS) and overall survival (OS) durations on an intent-to-treat basis from transplant registration was 11 months and 19 months (95% confidence interval, 14 to 29 months), respectively. The 3-year actuarial PFS and OS rates were 25% and 31%, respectively.

CONCLUSION

High-dose therapy with melphalan 200 mg/m(2) is feasible with high response rates (58% overall) and an OS of 19 months in patients with refractory multiple myeloma.

Leaching of pyrite by acidophilic heterotrophic iron-oxidizing bacteria in pure and mixed cultures

Seven strains of heterotrophic iron-oxidizing acidophilic bacteria were examined to determine their abilities to promote oxidative dissolution of pyrite (FeS2) when they were grown in pure cultures and in mixed cultures with sulfur-oxidizing Thiobacillus spp. Only one of the isolates (strain T-24) oxidized pyrite when it was grown in pyrite-basal salts medium. However, when pyrite-containing cultures were supplemented with 0.02% (wt/vol) yeast extract, most of the isolates oxidized pyrite, and one (strain T-24) promoted rates of mineral dissolution similar to the rates observed with the iron-oxidizing autotroph Thiobacillus ferrooxidans. Pyrite oxidation by another isolate (strain T-21) occurred in cultures containing between 0.005 and 0.05% (wt/vol) yeast extract but was completely inhibited in cultures containing 0.5% yeast extract. Ferrous iron was also needed for mineral dissolution by the iron-oxidizing heterotrophs, indicating that these organisms oxidize pyrite via the "indirect" mechanism. Mixed cultures of three isolates (strains T-21, T-23, and T-24) and the sulfur-oxidizing autotroph Thiobacillus thiooxidans promoted pyrite dissolution; since neither strains T-21 and T-23 nor T. thiooxidans could oxidize this mineral in yeast extract-free media, this was a novel example of bacterial synergism. Mixed cultures of strains T-21 and T-23 and the sulfur-oxidizing mixotroph Thiobacillus acidophilus also oxidized pyrite but to a lesser extent than did mixed cultures containing T. thiooxidans. Pyrite leaching by strain T-23 grown in an organic compound-rich medium and incubated either shaken or unshaken was also assessed. The potential environmental significance of iron-oxidizing heterotrophs in accelerating pyrite oxidation is discussed.

Initial experiences with building a health care infrastructure based on Java and object-oriented database technology

A multi-tiered telemedicine system based on Java and object-oriented database technology has yielded a number of practical insights and experiences on their effectiveness and suitability as implementation bases for a health care infrastructure. The advantages and drawbacks to their use, as seen within the context of the telemedicine system's development, are discussed. Overall, these technologies deliver on their early promise, with a few remaining issues that are due primarily to their relative newness.

Creating and indexing teaching files from free-text patient reports

Teaching files based on real patient data can enhance the education of students, staff and other colleagues. Although information retrieval system can index free-text documents using keywords, these systems do not work well where content bearing terms (e.g., anatomy descriptions) frequently appears. This paper describes a system that uses multi-word indexing terms to provide access to free-text patient reports. The utilization of multi-word indexing allows better modeling of the content of medical reports, thus improving retrieval performance. The method used to select indexing terms as well as early evaluation of retrieval performance is discussed.

Changes in left ventricular mass and volumes in patients receiving angiotensin-converting enzyme inhibitor therapy for left ventricular dysfunction after Q-wave myocardial infarction

OBJECTIVES

We evaluated global and segmental left ventricular (LV) mass and LV mass/volume ratio in patients with LV dysfunction receiving angiotensin-converting enzyme (ACE) inhibitor therapy after acute myocardial infarction (MI).

BACKGROUND

ACE inhibitors attenuate LV dilatation and compensatory hypertrophy after acute MI in animal models. However, LV remodeling in patients after acute MI has been largely defined on the basis of changes in chamber volume alone.

METHODS AND RESULTS

Twenty-nine patients with LV ejection fraction <40% received the ACE inhibitor ramipril (range 2.5 to 20 mg/day) within 5 days of their first Q-wave MI. Magnetic resonance imaging was performed at baseline and at 3 months, providing global and regional LV volumes and mass from summated serial short-axis slices. Mean arterial blood pressure was unchanged from baseline to 3-month follow-up (89 +/- 10 to 92 +/- 17 mm Hg). LV mass decreased (90 +/- 25 to 77 +/- 21 gm/m2, p < 0.0005) as LV end-diastolic volumes increased (65 +/- 13 to 73 +/- 22 ml/m2, p < 0.01). Global LV mass to volume ratio decreased from 1.40 +/- 0.28 to 1.08 +/- 0.18 gm/ml (p < 0.0001), as did circumferential wall thickness to volume ratio of noninfarcted myocardium at the base of the LV (0.06 +/- 0.02 to 0.05 +/- 0.02 mm/ml, p < 0.001). LV ejection fraction increased from 35 +/- 6 to 40 +/- 9% (p < 0.001) in the presence of an increase in calculated end-systolic wall stress (185 +/- 57 to 227 +/- 54 gm/cm2, p < 0.01).

CONCLUSIONS

ACE inhibitor therapy was associated with improved LV function in the face of a decrease in mass to volume ratio of the LV as well as a decrease in wall thickness to volume ratio of noninfarcted myocardium. Whether ACE inhibitor therapy had direct or indirect effects on these changes in LV mass and function are open questions that require further investigation.

Nutrition and feeding in infants with bronchopulmonary dysplasia after initial hospital discharge: risk factors for growth failure

OBJECTIVE

To identify nutritional risk factors for growth failure in infants with bronchopulmonary dysplasia (BPD) after initial hospital discharge, and to describe growth in and feeding concerns about these infants after discharge to the community.

DESIGN

A cohort of 40 infants with BPD was followed up for 7 monthly visits after initial hospital discharge. Data on potential risk factors were gathered prospectively.

SUBJECTS/SETTING

Forty infants with BPD were recruited from all 4 tertiary-level neonatal intensive care units in the Puget Sound area of Washington. Exclusionary criteria included congenital or chromosomal anomalies, grade IV intraventricular hemorrhage, and drug or alcohol exposure in utero.

MAIN OUTCOME MEASURES

Growth failure defined as weight less than the 5th percentile on National Center for Health Statistics growth curves at 2 or more points in time and a decrease in weight-for-age z score during the study period.

STATISTICAL ANALYSES PERFORMED

Relative risk of growth failure with exposure to each risk factor was determined. The chi 2 test was used to measure association between growth and development, and change in z scores was used to examine growth patterns.

RESULTS

Growth failure occurred in 8 of 40 infants. Twenty-nine of the infants experienced a drop in weight-for-age z score from the initial to the final study visit. Growth failure was associated with low socioeconomic status (relative risk = 4.0, 95% confidence interval = 1.3, 12.6), postdischarge days of illness (relative risk = 10.5, 95% confidence interval = 1.4, 77.4) and "suspect" development (chi 2 = 7.12, P = .014).

APPLICATIONS

Infants with BPD may benefit from comprehensive postdischarge nutrition and feeding therapy that includes ensuring adequate energy intake, parental support and education, and feeding evaluation and therapy.

Hyperad: augmenting and visualizing free text radiology reports

Hyperad is an automated computer system designed to extract key concepts from thoracic radiology reports and give physicians access to a large database containing the reports and key concepts. The concepts are extracted from textual documents with natural language processing techniques, then stored with the original documents in the database, which can be queried in terms of findings or associated attributes from an intuitive and easily accessible interface. The extracted concepts are represented both textually in a coded hypertext format and graphically on a coronal cross-sectional anatomy atlas, an idealized graphical model of human anatomy. To facilitate implementation, the communication protocols and standards of the World Wide Web (Web) were adopted. The reports and associated forms are encoded in standard hypertext markup language, which makes it possible to use hypermedia links to navigate the Hyperad database with any graphical Web browser. In the future, Hyperad may prove useful for other applications.

Extraskeletal mesenchymal chondrosarcoma of the rectus sheath

Mesenchymal chondrosarcomas (MSCs) are a rare form of chondrosarcoma which usually arise in bone. Extraskeletal chondrosarcomas constitute a minority (14-25%) of MSCs. We describe the imaging features of an extraskeletal mesenchymal chondrosarcoma that arose from the rectus abdominus muscle.

Gadolinium-enhanced magnetic resonance angiography of renal transplants

Our purpose was to investigate three-dimensional (3D) gadolinium-enhanced magnetic resonance angiography (Gd-MRA) in the evaluation of renal transplant arteries. Eleven MR angiography examinations were performed in nine renal transplant patients. Gd-MRA, three-dimensional phase contrast (3D-PC) post-gadolinium, and two-dimensional time-of-flight (2D-TOF) MR angiography were performed and independently reviewed by three vascular radiologists who, for each MR angiography sequence, separately graded occlusive disease in the ipsilateral iliac artery, the transplant artery anastomosis, and the transplant artery itself. The Gd-MRA and 3D-PC data were reviewed as maximum intensity projections (MIP) reconstructed in standard planes, and the 2D-TOF data were interpreted from source images. In addition, a single vascular radiologist prospectively interpreted the Gd-MRA and 3D-PC data together, hereinafter Gd/PC, from MIP reconstructions for each case. In all of these patients either surgical (n = 3) or angiographic studies (n = 8) were performed within 21 days following the MR examination, which served as a reference standard to determine sensitivity and specificity. The sensitivity/specificity for the detection of significant stenosis were as follows: Gd-MRA, 67/88; 3D-PC, 60.3/76.6; 2D-TOF, 47/81; and Gd/PC, 100/100. The kappa statistic (kappa) for interobserver agreement for the grading of stenoses by 2D-TOF, Gd-PC, and Gd-MRA was 0.48, 0.60, and 0.74, respectively. The percentage of all vascular segments seen well enough to grade (cumulative for all three observers) was 94%, 85%, and 79% for Gd-MRA, 3D-PC, and 2D-TOF, respectively. The combination of Gd-MRA and 3D-PC is a promising approach to the evaluation of transplant renal arteries.

Uniparental disomy of the entire X chromosome in a female with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a severe, progressive, X-linked muscle-wasting disorder with an incidence of approximately 1/3,500 male births. Females are also affected, in rare instances. The manifestation of mild to severe symptoms in female carriers of dystrophin mutations is often the result of the preferential inactivation of the X chromosome carrying the normal dystrophin gene. The severity of the symptoms is dependent on the proportion of cells that have inactivated the normal X chromosome. A skewed pattern of X inactivation is also responsible for the clinical manifestation of DMD in females carrying X;autosome translocations, which disrupt the dystrophin gene. DMD may also be observed in females with Turner syndrome (45,X), if the remaining X chromosome carries a DMD mutation. We report here the case of a karyotypically normal female affected with DMD as a result of homozygosity for a deletion of exon 50 of the dystrophin gene. PCR analysis of microsatellite markers spanning the length of the X chromosome demonstrated that homozygosity for the dystrophin gene mutation was caused by maternal isodisomy for the entire X chromosome. This finding demonstrates that uniparental isodisomy of the X chromosome is an additional mechanism for the expression of X-linked recessive disorders. The proband's clinical presentation is consistent with the absence of imprinted genes (i.e., genes that are selectively expressed based on the parent of origin) on the X chromosome.

Angiotensin-converting enzyme inhibitor therapy affects left ventricular mass in patients with ejection fraction > 40% after acute myocardial infarction

OBJECTIVES

We tested the hypothesis that angiotensin-converting enzyme (ACE) inhibitor therapy decreases left ventricular (LV) mass in patients with a left ventricular ejection fraction (LVEF) > 40% and no evidence of heart failure after their first acute Q wave myocardial infarction (MI).

BACKGROUND

Recently, ACE inhibitor therapy has been shown to have an early mortality benefit in unselected patients with acute MI, including patients without heart failure and a LVEF > 35%. However, the effects on LV mass and volume in this patient population have not been studied.

METHODS

Thirty-five patients with a LVEF > 40% after their first acute Q wave MI were randomized to titrated oral ramipril (n = 20) or conventional therapy (control, n = 15). Magnetic resonance imaging (MRI) performed an average of 7 days and 3 months after MI provided LV volumes and mass from summated serial short-axis slices.

RESULTS

Left ventricular end-diastolic volume index did not change in ramipril-treated patients (62 +/- 16 [SD] to 66 +/- 17 ml/m2) or in control patients (62 +/- 16 to 68 +/- 17 ml/m2), and stroke volume index increased significantly in both groups. However, LV mass index decreased in ramipril-treated patients (82 +/- 18 to 73 +/- 19 g/m2, p = 0.0002) but not in the control patients (77 +/- 15 to 79 +/- 23 g/m2). Systolic arterial pressure did not change in either group at 3-month follow-up.

CONCLUSIONS

In patients with a LVEF > 40% after acute MI, ramipril decreased LV mass, and blood pressure and LV function were unchanged after 3 months of therapy. Whether the decrease in mass represents a sustained effect that is associated with a decrease in morbid events requires further investigation.

Magnetic resonance imaging in the evaluation of cerebrospinal fluid fistulae

Twenty-four patients with a clinical diagnosis of cerebrospinal fluid (CSF) fistulae who were assessed by MR are reported and the literature reviewed on the use of MR in the evaluation of CSF fistulae. Thirteen patients presented with rhinorrhoea, three had otorhinorrhoea and two had recurrent meningitis. Six patients had a combination of symptoms. Nine patients did not have active leakage of CSF at the time of MR scanning. The site of the CSF leak was identified in all 24 patients (100%) and was verified at operation in all patients. This study suggests that MR is a sensitive and accurate technique for detection of CSF leaks even in patients who are not actively leaking at the time of evaluation. MR imaging is a useful technique in the assessment of patients with CSF fistulae; it is non-invasive, offers excellent anatomical detail and has no radiation risk.

Cardiac hypertrophy and failure in hypertension

Left ventricular hypertrophy is both a major adaptive response to chronic pressure overload and an important risk factor in patients with hypertension. It is now well appreciated that structural changes in the myocardium are mediated not only by the mechanical stress of pressure overload but also by various neurohormonal substances that exert trophic effects on myocytes and non-myocytes in the heart. Both earlier recognition and improved understanding of cardiac hypertrophy may lead to more effective therapeutic strategies for hypertension. This review focuses on the underlying mechanisms in hypertensive heart disease that lead to heart failure.

A concept-based retrieval system for thoracic radiology

Current digital information systems in radiology are insufficient to accommodate the retrieval needs of academicians. Significant efforts are required in retrieving clinical cases for teaching and research. We describe a prototype system that supports intelligent case retrieval based on a combined specification of patient demographics, radiologic findings, and pathologic diagnoses. The documents for these cases can be distributed among multiple heterogeneous data bases. The system features automatic indexing of radiology and pathology reports, a comprehensive lexicon for thoracic radiology, an interface to a hospital information system, radiology information system, and picture archiving and communication systems, and a graphical user interface for query formulation and results visualization. The prototype system was developed within the domain of thoracic radiology involving patients with lung cancer.

Comparative studies of bacterial biofilms on steel surfaces using atomic force microscopy and environmental scanning electron microscopy

Environmental scanning electron microscopy (ESEM) and atomic force microscopy (AFM) were compared as tools for the observation of bacterial biofilms developed on carbon steel and AISI 316 stainless steel surfaces under stagnant conditions. Biofilms were generated in batch cultures of two different isolates of marine sulphate reducing bacteria (SRB) and in cultures consisting of mixed populations of acidophilic bacteria, known as "acid streamers";. Imaging of single SRB cells on mica was also carried out to reveal the surface topography of individual bacterial cells at nanometre resolution. Following the removal of biofilms, the stainless steel surfaces were profiled using AFM to determine the degree of steel deterioration. ESEM and AFM studies of bacterial biofilms in-situ, gave both qualitative and quantitative information on biofilm structure at high resolution. The use of AFM image analysis software allowed estimation of the width and height of bacterial cells, the thickness and width of exopolymeric (EPS) capsule and bacterial flagella, as well as characterisation of the surface roughness of the steel, including measurements of depth and diameter of individual pits. Exposure of stainless steel specimens to acid streamers resulted in a significant increase in the surface roughness of the steel, compared to specimens placed in sterile medium.

Laryngeal chondroma: an unusual cause of upper airway obstruction

Cartilaginous tumours of the larynx should be considered in the differential diagnosis of upper airway obstruction. We report two cases of chondroma of the thyroid cartilage and discuss the radiological findings in each case.

Prostate-specific antigen concentration: influence of age and ethnicity

This pilot study evaluated the influence of age and ethnicity on serum prostate-specific antigen (PSA) concentration in Asian and white men without a clinical diagnosis of prostate cancer. Between October and December 1993, 1260 patients who underwent serum PSA determination (Hybritech Tandem-R assay, San Diego, California) at Straub Clinic & Hospital were retrospectively analyzed. Of these, 885 (70%) men aged 40 to 79 years were either Asian (Chinese, Filipino, Japanese, and Korean) or white and had a serum PSA less than 10.0 ng/ml. The PSA for the entire group was 2.1 +/- 2.0 ng/ml (mean +/- SD). PSA correlated with age (r = 0.31, p = 0.0001) and age accounted for 10% of the variance in serum PSA. Using the regression formula, serum PSA increased 2.5% (0.06 ng/ml) per year of age. The entire study group was about equally divided between whites (49%) and Asians (51%). Nearly three-fourths of the Asian men were Japanese. The mean PSA was very close in the Asian and white groups. There was no direct correlation between serum PSA and ethnicity (r = 0.03; p = 0.3201). Ethnicity contributed 0.1% of the variance in PSA. In conclusion, this preliminary study suggests serum PSA increases with age in Asian and white men without a clinical diagnosis of prostate cancer. No difference was found in PSA between men of Asian and white ethnicity.

Carmustine, Ara C, cyclophosphamide and etoposide with autologous bone marrow transplantation in relapsed or refractory lymphoma: a dose-finding study

The purpose of this study was to define the dose-limiting non-hematologic toxicity of carmustine, Ara C, cyclophosphamide and etoposide (BACE). Between October 1986 and March 1990, 37 patients with relapsed or refractory lymphoma received escalating doses of combination chemotherapy followed by autologous bone marrow transplant (ABMT). Twenty patients with Hodgkin's disease (HD) and 17 patients with intermediate or high grade non-Hodgkin's lymphoma (NHL) initially received conventional-dose therapy with either a 7 week course of modified MACOP-B or a single dose of cyclophosphamide (CY) at 2 g/m2 depending on prior therapy and response. Regardless of response, patients then received escalating doses of BACE, toxicity permitting. Ten patients obtained complete responses (CR) and 12 patients were partial responders (PR), CR+PR (75%) with modified MACOP-B and 7 (64%) patients obtained PR with CY. The maximum-tolerated dose (MTD) for BACE was determined to be carmustine 700 mg/m2, Ara C 1500 mg/m2, CY 150 mg/kg and etoposide 1500 mg/m2. When Ara C was escalated from 1500 mg/m2 to 3000 mg/m2 holding the other drugs at the prior doses, the next two patients died secondary to diffuse alveolar damage. Overall and event-free survivals are identical with 14 of 37 patients (38%) alive with a median follow-up of 61 months (range 38-79 months). Ten patients were treated at the MTD, none of whom died a toxic death and 3 (30%) are alive with a median follow-up of 42 months (range 38-52 months). We defined the MTD and BACE showing pulmonary toxicity to be the dose-limiting non-hematologic toxicity.(ABSTRACT TRUNCATED AT 250 WORDS)