Early onset pancreatic cancer-exploring contemporary treatment and outcomes using real-world data.

BACKGROUND: Pancreatic cancer incidence is increasing in younger populations. Differences between early onset pancreatic cancer (EOPC) and later onset pancreatic cancer (LOPC), and how these should inform management warrant exploration in the contemporary setting. METHODS: A prospectively collected multi-site dataset on consecutive pancreatic adenocarcinoma patients was interrogated. Patient, tumour, treatment, and outcome data were extracted for EOPC (≤50 years old) vs LOPC (>50 years old). RESULTS: Of 1683 patients diagnosed between 2016 and 2022, 112 (6.7%) were EOPC. EOPC more frequently had the tail of pancreas tumours, earlier stage disease, surgical resection, and trended towards increased receipt of chemotherapy in the curative setting compared to LOPC. EOPC more frequently received 1st line chemotherapy, 2nd line chemotherapy, and chemoradiotherapy than LOPC in the palliative setting. Recurrence-free survival was improved for the tail of pancreas EOPC vs LOPC in the resected setting; overall survival was superior for EOPC compared to LOPC across the resected, locally advanced unresectable and metastatic settings. CONCLUSIONS: EOPC remains a small proportion of pancreatic cancer diagnoses. The more favourable outcomes in EOPC suggest these younger patients are overall deriving benefits from increased treatment in the curative setting and increased therapy in the palliative setting.

Biology and Clinical Implications of Fecal Occult Blood Test Screen-Detected Colorectal Cancer.

BACKGROUND: Fecal occult blood test (FOBT)-based screening for colorectal cancer (CRC) reduces mortality, with earlier stage at diagnosis a prominent feature. Other characteristics of FOBT screen-detected cancers and any implications for clinical management have not been well explored. METHODS: We examined a multisite clinical registry to compare the characteristics and outcomes of FOBT screen-detected CRC via the Australian National Bowel Cancer Screening Program (NBCSP), which is offered biennially to individuals aged 50-74 years, and age-matched non-screen-detected CRC in the same registry. All statistical tests were 2-sided. Odds ratios (ORs) were calculated using the Baptista-Pike method, and hazard ratios via the log-rank method. RESULTS: Of 7153 registry patients diagnosed June 1, 2006, to June 30, 2020, 4142 (57.9%) were aged between 50 and 74 years. Excluding 406 patients with non-NBCSP screen-detected cancers and 35 patients with unknown method of detection, 473 (12.8%) were screen detected via the NBCSP, and 3228 (87.2%) were non-screen detected. Screen-detected patients were younger (mean age = 62.4 vs 64.2 years; P < .001) and more medically fit (OR for ASA score 1-2 = 1.91, 95% confidence interval [CI] = 1.51 to 2.41; P < .001). Pathologic characteristics within each stage favored the screen-detected patients. Stage III screen-detected colon cancers were more likely to receive adjuvant therapy (OR = 3.58, 95% CI = 1.52 to 8.36; P = .002). Screen-detected patients had superior relapse-free (hazard ratio = 0.41, 95% CI = 0.29 to 0.60; P < .001) and overall survival (hazard ratio = 0.22, 95% CI = 0.15 to 0.35; P < .001), which was maintained in matched stage comparisons and multivariable analysis. CONCLUSIONS: Beyond stage at diagnosis, multiple other factors associated with a favorable outcome are observed in FOBT screen-detected CRC. Given the substantial stage-by-stage differences in survival outcomes, if independently confirmed, individualized adjuvant therapy and surveillance strategies could be warranted for FOBT screen-detected cancers.

Surgical Techniques for Abdominoperineal Resection for Rectal Cancer: One Size Does Not Fit All.

Abdominoperineal resection (APR) of rectal cancer is associated with poorer oncological outcomes than anterior resection. This may be due to higher rates of intra-operative perforation (IOP) and circumferential resection margin (CRM) involvement causing higher recurrence rates and surgical complications. To address these concerns, several centers advocated a change in technique from a standard APR to a more radical extra-levator abdominoperineal excision (ELAPE). Initial reports showed that ELAPE reduced IOP rates and CRM involvement but increased wound complications and longer surgical duration. However, many of these studies had unacceptable rates of IOP and CRM before retraining in ELAPE. This may indicate that it was a sub-optimal surgical technique, which improved upon training, that had influenced the high CRM and IOP rates rather than the technique itself. Subsequent studies demonstrated that the CRM involvement rate for ELAPE was not always lower than for standard APR and, in some cases, significantly higher. The morbidity of ELAPE can be high, with studies reporting higher adverse events than APR, especially in terms of wound complications from the larger perineal incision required in ELAPE. Whether ELAPE improves short- or long-term oncological outcomes for patients has not been clearly demonstrated. The authors propose that all centers performing rectal cancer surgery audit surgical outcomes of patients undergoing APR or ELAPE and examine CRM involvement, IOP rates, and local recurrence rates, preferably through a national body. If rates of adverse technical or oncological outcomes exceed acceptable levels, then retraining in the appropriate surgical techniques may be indicated.

Biomarkers in Locally Advanced Rectal Cancer: A Review.

Locally advanced rectal cancers (LARC) are the subject of a rapidly evolving treatment paradigm. The critical timepoints where management decisions are required during the care of the LARC patient are: prior to the institution of any treatment, post neoadjuvant therapy and post-surgery. This article reviews the clinical, imaging, blood-based, tissue-based, and molecular biomarkers that can assist clinicians at these timepoints in the patient's management, in prognosticating for their LARC patients or in predicting responses to therapy in the multi-modality neoadjuvant treatment era.

Accuracy of a Rapid Multiplex Polymerase Chain Reaction Plus a Chromogenic Phenotypic Test Algorithm for Detection of Extended-Spectrum ß-Lactamase and Carbapenemase-Producing Gram-Negative Bacilli in Positive Blood Culture Bottles.

We studied the performance of an algorithm combining multiplex polymerase chain reaction with phenotypic detection of extended-spectrum ß-lactamases and carbapenemases directly from positive blood culture bottles in patients with gram-negative bacteremia and found good concordance with routine cultures. Such an algorithm may be a tool to improve time to optimal therapy in patients with gram-negative bacteremia.

Treatment and outcomes of unresectable and metastatic pancreatic cancer treated in public and private Australian hospitals.

BACKGROUND: Prior studies have reported for several cancer types that treatment in the private sector is associated with improved survival outcomes. Data for patients with locally advanced unresectable and metastatic pancreatic ductal adenocarcinoma (PDAC) have not previously been reported. METHODS: Analysis of patients from January 2016 to June 2020 registered to a multicentre prospective cancer database. Baseline demographic and clinicopathologic characteristics were compared. The Kaplan-Meier method was used to compare overall survival (OS). Multivariate Cox and logistic regression analyses were used to determine predictors of mortality and first-line chemotherapy treatment, respectively. RESULTS: Of 822 patients, 22.5% received private care. Private patients were older (median 71.5 vs. 68.9 years, p ≤ .05), had better performance status (ECOG 0 to 1: 82.2 vs. 73.5%, p = .05) and more likely to reside in an area with high socioeconomic advantage (67.0 vs. 19.6%, p ≤ .01). Private patients were more likely to receive first-line chemotherapy (69.7 vs. 54.2%, p ≤ .01) with logistic regression demonstrating private care (OR: 1.87, 95% CI: 1.20 to 2.97) as an independent predictor of receiving chemotherapy. Private patients had prolonged survival (median OS: 9.2 vs. 6.9 months, HR 1.2, p = .05). Receiving first-line chemotherapy was an independent predictor of mortality, but private care was not. CONCLUSIONS: Care in the private system is associated with improved OS, with higher uptake of first-line chemotherapy appearing to be the main contributor. Given the discrepancy, further studies are needed to determine what factors are driving this difference.

Sex Representation in Clinical Trials Associated with FDA Cancer Drug Approvals Differs Between Solid and Hematologic Malignancies.

BACKGROUND: Proportionate female representation in health research is necessary for scientific rigor and health equity. We aimed to assess the representation of women in clinical trials leading to U.S. Food and Drug Administration (FDA) cancer drug approvals. MATERIALS AND METHODS: Trials supporting FDA cancer drug approvals between July 2008 and June 2018 were sourced from PubMed and ClinicalTrials.gov. The ratio of female to male trial enrollment was compared with cancer incidence and mortality in the U.S. using International Agency for Research on Cancer data. Reproductive tract and breast cancers were excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) comparing trial enrollment with population incidence and mortality were calculated. RESULTS: A total of 186 trials leading to 170 FDA cancer drug approvals showed slight female underrepresentation compared with overall cancer incidence in the U.S. (OR, 0.97; 95% CI, 0.95-0.98, p < .0001). Female enrollment for drugs approved between 2008-2013 and 2014-2018 was unchanged (OR, 1.02; 95% CI, 0.99-1.05, p = .25). There was slight female underrepresentation in hematological trials (OR, 0.95; 95% CI, 0.91-0.998; p = .040 for leukemia; OR, 0.95; 95% CI, 0.90-0.997; p = .040 for lymphoma) and significant female underrepresentation in colorectal (OR, 0.72; 95% CI, 0.69-0.76; p < .0001), pancreas (OR, 0.85; 95% CI, 0.78-0.93; p = .0004), lung (OR, 0.77; 95% CI, 0.75-0.80; p < .0001), kidney (OR, 0.63; 95% CI, 0.60-0.67; p < .0001), and thyroid cancer trials (OR, 0.26; 95% CI, 0.23-0.28; p < .0001) compared with U.S. incidence. CONCLUSION: Female underrepresentation has persisted within solid organ tumor trials but is less notable in hematologic trials. Additional work is required to identify drivers of such disparity. IMPLICATIONS FOR PRACTICE: Adequate gender representation in clinical trials is a matter of health equity. This study demonstrates that women remain underrepresented in trials across hematological and solid organ trials compared with cancer incidence and mortality in women, with the disparity worse in a number of solid organ tumor types. There are thus still significant improvements to be made regarding adequate representation of women in trials. Studies exploring the reasons for ongoing disparity in gender representation are warranted to help clinicians to rectify this.

Delving into Early-onset Pancreatic Ductal Adenocarcinoma: How Does Age Fit In?

PURPOSE: With the rising incidence of early-onset pancreatic cancer (EOPC), molecular characteristics that distinguish early-onset pancreatic ductal adenocarcinoma (PDAC) tumors from those arising at a later age are not well understood. EXPERIMENTAL DESIGN: We performed bioinformatic analysis of genomic and transcriptomic data generated from 269 advanced (metastatic or locally advanced) and 277 resectable PDAC tumor samples. Patient samples were stratified into EOPC (age of onset ≤55 years; n = 117), intermediate (age of onset 55-70 years; n = 264), and average (age of onset ≥70 years; n = 165) groups. Frequency of somatic mutations affecting genes commonly implicated in PDAC, as well as gene expression patterns, were compared between EOPC and all other groups. RESULTS: EOPC tumors showed significantly lower frequency of somatic single-nucleotide variant (SNV)/insertions/deletions (indel) in CDKN2A (P = 0.0017), and were more likely to achieve biallelic mutation of CDKN2A through homozygous copy loss as opposed to heterozygous copy loss coupled with a loss-of-function SNV/indel mutation, the latter of which was more common for tumors with later ages of onset (P = 1.5e-4). Transcription factor forkhead box protein C2 (FOXC2) was significantly upregulated in EOPC tumors (P = 0.032). Genes significantly correlated with FOXC2 in PDAC samples were enriched for gene sets related to epithelial-to-mesenchymal transition (EMT) and included VIM (P = 1.8e-8), CDH11 (P = 6.5e-5), and CDH2 (P = 2.4e-2). CONCLUSIONS: Our comprehensive analysis of sequencing data generated from a large cohort of PDAC patient samples highlights a distinctive pattern of biallelic CDKN2A mutation in EOPC tumors. Increased expression of FOXC2 in EOPC, with the correlation between FOXC2 and EMT pathways, represents novel molecular characteristics of EOPC.See related commentary by Lou, p. 8.

The Effect of Sample Site, Illness Duration, and the Presence of Pneumonia on the Detection of SARS-CoV-2 by Real-time Reverse Transcription PCR.

BACKGROUND: The performance of real-time reverse transcription polymerase chain reaction (rRT-PCR) for SARS-CoV-2 varies with sampling site(s), illness stage, and infection site. METHODS: Unilateral nasopharyngeal, nasal midturbinate, throat swabs, and saliva were simultaneously sampled for SARS-CoV-2 rRT-PCR from suspected or confirmed cases of COVID-19. True positives were defined as patients with at least 1 SARS-CoV-2 detected by rRT-PCR from any site on the evaluation day or at any time point thereafter, until discharge. Diagnostic performance was assessed and extrapolated for site combinations. RESULTS: We evaluated 105 patients; 73 had active SARS-CoV-2 infection. Overall, nasopharyngeal specimens had the highest clinical sensitivity at 85%, followed by throat, 80%, midturbinate, 62%, and saliva, 38%-52%. Clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 95%, 88%, 72%, and 44%-56%, respectively, if taken ≤7 days from onset of illness, and 70%, 67%, 47%, 28%-44% if >7 days of illness. Comparing patients with upper respiratory tract infection (URTI) vs pneumonia, clinical sensitivity for nasopharyngeal, throat, midturbinate, and saliva was 92% vs 70%, 88% vs 61%, 70% vs 44%, 43%-54% vs 26%-45%, respectively. A combination of nasopharyngeal plus throat or midturbinate plus throat specimen afforded overall clinical sensitivities of 89%-92%; this rose to 96% for persons with URTI and 98% for persons ≤7 days from illness onset. CONCLUSIONS: Nasopharyngeal specimens, followed by throat specimens, offer the highest clinical sensitivity for COVID-19 diagnosis in early illness. Clinical sensitivity improves and is similar when either midturbinate or nasopharyngeal specimens are combined with throat specimens. Upper respiratory specimens perform poorly if taken after the first week of illness or if there is pneumonia.

Endogenous Retrovirus Transcript Levels Are Associated with Immunogenic Signatures in Multiple Metastatic Cancer Types.

Next-generation sequencing of solid tumors has revealed variable signatures of immunogenicity across tumors, but underlying molecular characteristics driving such variation are not fully understood. Although expression of endogenous retrovirus (ERV)-containing transcripts can provide a source of tumor-specific neoantigen in some cancer models, associations between ERV levels and immunogenicity across different types of metastatic cancer are not well established. We performed bioinformatics analysis of genomic, transcriptomic, and clinical data across an integrated cohort of 199 patients with metastatic breast, colorectal, and pancreatic ductal adenocarcinoma tumors. Within each cancer type, we identified a subgroup of viral mimicry tumors in which increased ERV levels were coupled with transcriptional signatures of autonomous antiviral response and immunogenicity. In addition, viral mimicry colorectal and pancreatic tumors showed increased expression of DNA demethylation gene TET2 Taken together, these data demonstrate the existence of an ERV-associated viral mimicry phenotype across three distinct metastatic cancer types, while indicating links between ERV abundance, epigenetic dysregulation, and immunogenicity.

Right versus left sided metastatic colorectal cancer: Teasing out clinicopathologic drivers of disparity in survival.

BACKGROUND: Metastatic colorectal cancer (mCRC) patients with a right-sided primary (RC) have an inferior survival to mCRC arising from a left-sided primary (LC). Previous analyses have suggested multiple factors contribute. METHODS: The Treatment of Recurrent and Advanced Colorectal Cancer (TRACC) Registry prospectively captured data on consecutive mCRC patients. RC were defined as tumors proximal to the splenic flexure; LC were those at and distal to the splenic flexure and included rectal cancers. Patient, tumor, treatment, and survival data were analyzed stratified by side. RESULTS: Of 2306 patients enrolled from July 2009-March 2018, 747 (32%) had an RC. Patients with RC were older, more likely to be female and have a Charlson score ≥3. RC were more frequently BRAF mutated, deficient in mismatch repair, associated with peritoneal metastases, and less likely to receive chemotherapy. Progression-free survival on first-line systemic therapy was inferior for RC patients (8.1 vs. 10.8 months, hazard ratio [HR] for progression in RC 1.38, P < 0.001). Median overall survival for all RC patients was inferior (19.6 vs. 27.5 months, HR for death in RC 1.44, P < 0.001), and inferior within the treated (21 vs. 29.5 months, HR 1.52, P < 0.001) and untreated subgroups (5.9 vs. 10.3 months, HR 1.38, P = 0.009). Primary side remained a significant factor for overall survival in multivariate analysis. CONCLUSION: Our data from a real-world population confirms the poorer prognosis associated with RC. Primary tumor location remains significantly associated with overall survival even when adjusting for multiple factors, indicating the existence of further side-based differences that are as yet undefined.

Atypical, Non-V600 BRAF Mutations as a Potential Mechanism of Resistance to EGFR Inhibition in Metastatic Colorectal Cancer.

PURPOSE: Atypical, non-V600 BRAF (aBRAF) mutations represent a rare molecular subtype of metastatic colorectal cancer (mCRC). Preclinical data are used to categorize aBRAF mutations into class II (intermediate to high levels of kinase activity, RAS independent) and III (low kinase activity level, RAS dependent). The clinical impact of these mutations on anti-EGFR treatment efficacy is unknown. PATIENTS AND METHODS: Data from 2,084 patients with mCRC at a single institution and from an external cohort of 5,257 circulating tumor DNA (ctDNA) samples were retrospectively analyzed. Overall survival (OS) was calculated using Kaplan-Meier and log-rank tests. Statistical tests were two-sided. RESULTS: BRAF mutations were harbored by 257 patients, including 36 with aBRAF mutations: 22 class III, 10 class II, four unclassified. For patients with aBRAF mCRC, median OS was 36.1 months, without a difference between classes, and median OS was 21.0 months for patients with BRAFV600E mCRC. In contrast to right-sided predominance of tumors with BRAFV600E mutation, 53% of patients with aBRAF mCRC had left-sided primary tumors. Concurrent RAS mutations were noted in 33% of patients with aBRAF mCRC, and 67% of patients had microsatellite stable disease. Among patients with aBRAF RAS wild-type mCRC who received anti-EGFR antibodies (monotherapy, n = 1; combination therapy, n = 10), no responses to anti-EGFR therapy were reported, and six patients (four with class III aBRAF mutations, one with class II, and one unclassified) achieved stable disease as best response. Median time receiving therapy was 4 months (range, 1 to 16). In the ctDNA cohort, there was an increased prevalence of aBRAF mutations and subclonal aBRAF mutations (P < .001 for both) among predicted anti-EGFR exposed compared with nonexposed patients. CONCLUSION: Efficacy of anti-EGFR therapy is limited in class II and III aBRAF mCRC. Detection of aBRAF mutations in ctDNA after EGFR inhibition may represent a novel mechanism of resistance.

Clinical and Molecular Correlates of Escherichia coli Bloodstream Infection from Two Geographically Diverse Centers in Rochester, Minnesota, and Singapore.

Escherichia coli bacteremia is caused mainly by sequence type complex 131 (STc131) and two clades within its fluoroquinolone-resistance-associated H30 subclone, H30R1 and H30Rx. We examined clinical and molecular correlates of E. coli bacteremia in two geographically distinct centers. We retrospectively studied 251 unique E. coli bloodstream isolates from 246 patients (48 from the Mayo Clinic, Rochester, MN [MN], and 198 from Tan Tock Seng Hospital, Singapore [SG]), from October 2013 through March 2014. Isolates underwent PCR for phylogroup, STc, blaCTX-M type, and virulence gene profiles, and medical records were reviewed. Although STc131 accounted for 25 to 27% of all E. coli bacteremia isolates at each site, its extended-spectrum-ß-lactamase (ESBL)-associated H30Rx clade was more prominent in SG than in MN (15% versus 4%; P = 0.04). In SG only, patients with STc131 (versus other E. coli STc isolates) were more likely to receive inactive initial antibiotics (odds ratio, 2.8; P = 0.005); this was true specifically for patients with H30Rx (odds ratio, 7.0; P = 0.005). H30Rx comprised 16% of community-onset bacteremia episodes in SG but none in MN. In SG, virulence scores were higher for H30Rx than for H30R1, non-H30 STc131, and non-STc131 isolates (P < 0.02 for all comparisons). At neither site did mortality differ by clonal status. The ESBL-associated H30Rx clade was more prevalent and more often of community onset in SG, where it predicted inactive empirical treatment. The clonal distribution varies geographically and has potentially important clinical implications. Rapid susceptibility testing and clonal diagnostics for H30/H30Rx might facilitate earlier prescribing of active therapy.

Efficacy of anti-PD-1 therapy in patients with melanoma brain metastases.

BACKGROUND: There is limited data on the efficacy of anti-programmed death 1 (PD-1) antibodies in patients (pts) with melanoma brain metastasis (BM), particularly those which are symptomatic. METHOD: We retrospectively assessed pts with melanoma BM treated with PD-1 antibodies, nivolumab and pembrolizumab. Clinicopathologic and treatment parameters were collected and outcomes determined for intracranial (IC) response rate (RR) using a modified RECIST criteria, with up to five IC target lesions used to determine IC response, disease control rate (DCR) and progression-free survival (PFS). RESULTS: A total of 66 pts were identified with a median follow up of 7.0 months (range 0.8-24.5 months). A total of 68% were male and 45% BRAF V600 mutation positive. At PD-1 antibody commencement, 50% had an elevated LDH; 64% had local therapy to BM prior to commencing anti-PD1, of which 5% had surgical resection, 14% stereotactic radiosurgery (SRS), 18% whole-brain radiotherapy (WBRT), 27% had surgery and radiotherapy. Twenty-one per cent started anti-PD-1 as first line systemic therapy. No pt had prior anti-PD-1 treatment. The IC overall RR was 21 and DCR 56%. Responses occurred in 21% of pts with symptomatic BM. The median OS was 9.9 months (95% CI 6.93-17.74). Pts with symptomatic BM had shorter PFS than those without symptoms (2.7 vs 7.4 months, P=0.035) and numerically shorter OS (5.7 vs 13.0 months, P=0.068). Pts requiring corticosteroids also had a numerically shorter PFS (3.2 vs 7.4 months, P=0.081) and OS (4.8 vs 13.1 months, P=0.039). CONCLUSIONS: IC responses to anti-PD-1 antibodies occur in pts with BM, including those with symptomatic BM requiring corticosteroids. Prospective trials evaluating anti-PD-1 therapy in pts with BM are underway.

Postoperative Mycoplasma hominis brain abscess: keep it in mind!

A temporal lobe abscess was diagnosed in a 57-year-old man. A urethral catheter had been inserted 12 days earlier, just prior to clot evacuation of a subacute haematoma secondary to an arterio-venous malformation. Fever persisted despite debridement and treatment with meropenem and vancomycin. Gram stains of operative samples showed no bacteria. Extended cultures grew pinpoint colonies after 5 days. Meanwhile, sequencing of bacterial 16S rDNA from operative specimens had identified Mycoplasma hominis; the bacterial colonies were subsequently similarly identified. The patient responded promptly following addition of oral doxycycline 100 mg two times per day. There is a growing literature of similar cases. Transient bacteraemia, following urinary catheterisation, with seeding of existing sites of inflammation is the proposed explanation. Urethral carriage of M. hominis is 15% and catheterisation is a common procedure. Mycoplasma hominis maybe more common than appreciated, especially as the need for extended cultures makes a correct diagnosis less likely.