Availability of Primary Care Physicians and Racial Disparities in Colorectal Cancer-Related Mortality in the United States.

INTRODUCTION: Colorectal cancer (CRC) is the second leading cause of cancer-related deaths in the United States (US), however racial disparities in outcomes persist. We sought to assess the correlation of availability of primary care physicians (PCPs) and racial disparities in CRC-related mortality. METHODS: We studied the correlation between age-adjusted incidence and mortality rates of CRC among all 50 states and the District of Columbia (D.C.) from the Center for Disease Control (CDC) Wide-Ranging Online Data for Epidemiologic Research (WONDER) with the number of actively practicing PCPs in all 50 states and D.C. from the Association of American Medical Colleges (AAMC) State Physician Workforce Data Report. Pearson's coefficient was used to study correlations and the two-sample t test was used for comparing state-level PCP/CRC ratios between the two groups. Statistical analysis was performed using VassarStats. RESULTS: The mean AAMR per 100,000 population for CRC was significantly higher among AA versus White populations (t = 5.79, p < 0.001). Higher state-wide PCP per CRC case ratio correlated with lower state-wide CRCrelated mortality (r = -0.36, p = 0.011). The mean PCP per CRC case ratio was significantly lower among AA compared to White populations (t = -15.95, p < 0.0001). Higher PCP per CRC case ratio correlated with lower CRC-related mortality among both White (r = -0.64, p < 0.0001) and AA (r = -0.57, p = 0.0002) populations. CONCLUSIONS: These findings suggest that racial disparities in CRC-related mortality may at least in part be related to lower availability of PCPs. Efforts focused on the development of strategies focused on improving access to primary care may help bridge racial disparities in CRC-related outcomes.

Detection of microsatellite instability-high (MSI-H) by liquid biopsy predicts robust and durable response to immunotherapy in patients with pancreatic cancer.

Clinical trials reporting the robust antitumor activity of immune checkpoint inhibitors (ICIs) in microsatellite instability-high (MSI-H) solid tumors have used tissue-based testing to determine the MSI-H status. This study assessed if MSI-H detected by a plasma-based circulating tumor DNA liquid biopsy test predicts robust response to ICI in patients with pancreatic ductal adenocarcinoma (PDAC). Retrospective analysis of patients with PDAC and MSI-H identified on Guardant360 from October 2018 to April 2021 was performed; clinical outcomes were submitted by treating providers. From 52 patients with PDAC +MSI-H, outcomes were available for 10 (19%) with a median age of 68 years (range: 56-82 years); the majority were male (80%) and had metastatic disease (80%). Nine of 10 patients were treated with ICI. Eight out of nine patients received single-agent pembrolizumab (8/9), while one received ipilimumab plus nivolumab. The overall response rate by Response Evaluation Criteria in Solid Tumors was 77% (7/9). The median progression-free survival and overall survival were not reached in this cohort. The median duration of treatment with ICI was 8 months (range: 1-24), and six out of seven responders continued to show response at the time of data cut-off after a median follow-up of 21 months (range: 11-33). Tissue-based MSI results were concordant with plasma-based G360 results in five of six patients (83%) who had tissue-based test results available, with G360 identifying one more patient with MSI-H than tissue testing. These results suggest that detecting MSI-H by a well-validated liquid biopsy test could predict a robust response to ICI in patients with PDAC. The use of liquid biopsy may expand the identification of PDAC patients with MSI-H tumors and enable treatment with ICI resulting in improved outcomes.

SMAD4 loss is associated with response to neoadjuvant chemotherapy plus hydroxychloroquine in patients with pancreatic adenocarcinoma.

SMAD4, a tumor suppressor gene, is lost in up to 60%-90% of pancreatic adenocarcinomas (PDAs). Loss of SMAD4 allows tumor progression by upregulating autophagy, a cell survival mechanism that counteracts apoptosis and allows intracellular recycling of macromolecules. Hydroxychloroquine (HCQ) is an autophagy inhibitor. We studied whether HCQ treatment in SMAD4 deficient PDA may prevent therapeutic resistance induced by autophagy upregulation. We retrospectively analyzed the SMAD4 status of patients with PDA enrolled in two prospective clinical trials evaluating pre-operative HCQ. The first dose escalation trial demonstrated the safety of preoperative gemcitabine with HCQ (NCT01128296). More recently, a randomized trial of gemcitabine/nab-paclitaxel +/- HCQ evaluated Evans Grade histopathologic response (NCT01978184). The effect of SMAD4 loss on response to HCQ and chemotherapy was studied for association with clinical outcome. Fisher's exact test and log-rank test were used to assess response and survival. Fifty-two patients receiving HCQ with neoadjuvant chemotherapy were studied. Twenty-five patients had SMAD4 loss (48%). 76% of HCQ-treated patients with SMAD4 loss obtained a histopathologic response greater than or equal to 2A, compared with only 37% with SMAD4 intact (p = 0.006). Although loss of SMAD4 has been associated with worse outcomes, in the current study, loss of SMAD4 was not associated with a detriment in median overall survival in HCQ-treated patients (34.43 months in SMAD4 loss vs. 27.27 months in SMAD4 intact, p = 0.18). The addition of HCQ to neoadjuvant chemotherapy in patients with PDA may improve treatment response in those with SMAD4 loss. Further study of the relationship among SMAD4, autophagy, and treatment outcomes in PDA is warranted.

Patterns of disease progression to checkpoint inhibitor immunotherapy in patients with stage IV non-small cell lung cancer.

INTRODUCTION: The purpose of this study was to assess patterns of disease progression for patients with metastatic non-small cell lung cancer (NSCLC) on checkpoint inhibitor immunotherapy. METHODS: This single centre, retrospective study included all patients diagnosed with Stage IV NSCLC from 2015 to 2019 who received at least 2 cycles of immunotherapy, with or without concurrent chemotherapy. Immune RECIST criteria were used to assess patterns of disease progression, and progression-free survival (PFS), excluding irradiated tumours. The chi-square and log-rank tests assessed for associations between baseline clinical characteristics and progressive disease in initial sites only (vs. new or combined sites), and PFS, respectively. RESULTS: Among 143 eligible patients with a median follow-up of 11 months, 97 (68%) developed disease progression. Of these, 67 patients (69.1%) progressed only at initial disease site(s), 10 patients (10.3%) progressed only at new disease site(s), and 20 patients (20.6%) progressed in both initial and new sites. Rates of disease progression based on tumour location were higher for liver (64%) and lung metastases (61%) than for other metastatic sites (33-36%) or the primary tumour (24%). Only higher PD-L1 expression (P = 0.002) and absence of lung metastasis (P = 0.048) at baseline were associated with improved PFS. No baseline characteristics significantly impacted the probability of initial disease site-only progression, though a trend was observed for untreated primary tumour (72% vs. 56%, P = 0.169). CONCLUSIONS: The dominant pattern of disease progression is in the initial sites of disease alone, suggesting a potential role for local radiation therapy as a complementary treatment modality to immunotherapy.

Single versus double-unit transfusion: Safety and efficacy for patients with hematologic malignancies.

OBJECTIVES: Although hemoglobin thresholds for red blood cell (RBC) transfusion have decreased, double-unit RBC transfusion practices persist. We studied the effects switching from predominantly double-unit to single-unit RBC transfusions had on utilization and clinical outcomes for malignant hematology patients. METHODS: Retrospective chart review compared malignant hematology patients before and after implementing single-unit RBC transfusion policy. Hemoglobin threshold was 8.0 g/dL for both groups. RBC utilization metrics included number of RBC units transfused, RBC units transfused per admission, and number of transfusion episodes. Clinical outcomes included length of stay, 30-day mortality, and outpatient RBC transfusion 30-days post-discharge. RESULTS: Baseline hemoglobin was similar in both groups. The single-unit group was transfused with fewer RBC units per admission (5.1 vs 4.5, P = 0.01) than the double-unit group, but had more transfusion episodes per admission (4.1 vs 2.7, P < 0.001). After implementing single-unit policy, a 29% reduction in RBC utilization was observed. Mean hemoglobin at discharge was lower in the single-unit group (8.9 vs 9.5 g/dL, P = 0.005). No significant differences in length of stay or 30-day mortality were observed. CONCLUSION: Transfusing malignant hematology patients with single RBC units is safe and efficacious. Electronic provider order systems facilitating RBC transfusion requests provide excellent adherence to transfusion policy.

Low-Dose Acyclovir Prophylaxis for Varicella zoster Reactivation in Autologous Hematopoietic Cell Transplantation Recipients.

Varicella zoster virus (VZV) reactivation after autologous hematopoietic cell transplantation (auto-HCT) may be observed in a quarter of patients. Currently, prophylactic use of acyclovir 800 mg twice daily or valacyclovir 500 mg twice daily is recommended for prophylaxis against VZV reactivation for at least one-year post-HCT, with continued use recommended in immunosuppressed recipients. Acyclovir dosing regimens vary between institutions despite the noted recommendations. In this single-center, retrospective study, recipients of auto-HCT who received at least one year of low-dose antiviral prophylaxis defined as the equivalent of acyclovir 400 mg orally twice daily or valacyclovir 500 mg daily were included. The primary objective of this study was to assess the incidence of VZV reactivation with low-dose acyclovir/valacyclovir prophylaxis in autograft recipients. One hundred and eighty patients undergoing auto-HCT between April 2008 and March 2015 were included. Patients received low-dose acyclovir, for a median duration of 55.5 months (range 12-100). There were no occurrences of VZV reactivation while patients were on these drugs. However, 2 patients (1.1%) had VZV reactivation after discontinuation of therapy, occurring 18.8 and 14 months from transplant and 6.7 and 2 months after stopping prophylaxis, respectively. Our retrospective analysis found low-dose antiviral prophylaxis with oral acyclovir 400 mg twice daily or valacyclovir 500 mg daily to be effective in preventing VZV reactivation in auto-HCT recipients.

Adult Sporadic Burkitt's Lymphoma Presenting with Rapid Development of Peritoneal Lymphomatosis.

Sporadic Burkitt's Lymphoma (BL) is a highly aggressive form of non-Hodgkin's lymphoma which requires prompt diagnosis and treatment. Though usual presentation involves abdominal lymphadenopathy with possible solid organ involvement, sporadic BL can rarely present with peritoneal lymphomatosis. We present a unique case with rapid evolution of BL presenting as peritoneal and omental lymphomatosis with hepatic lesions and pelvic and pericardial adenopathy.

Dermatomyositis Associated with Myelofibrosis following Polycythemia Vera.

Dermatomyositis (DM) is a unique inflammatory myopathy with clinical findings of proximal muscle weakness, characteristic rash, and elevated muscle enzymes. The association of DM and malignancy, most commonly adenocarcinoma, is well known. There have been few case reports of primary myelofibrosis associated with DM. We present the case of a 69-year-old male with a history of polycythemia vera (PV) who developed proximal muscle weakness, dysphagia, and rash. He was found to have elevated creatinine kinase and skin biopsy was consistent with DM. Due to persistent pancytopenia a bone marrow biopsy was performed and showed postpolycythemic myelofibrosis. To our knowledge, this is the first case reported of this unique association.

Get1p and Get2p are required for maintenance of mitochondrial morphology and normal cardiolipin levels.

Cardiolipin (CL) is the signature phospholipid of mitochondrial membranes. CL deficiency leads to defects in mitochondrial function. Using a targeted synthetic lethality screen to identify defects that exacerbate CL deficiency, we determined that deletion of mitochondrial morphology genes in cells lacking CL leads to severe growth defects. We show that ER membrane proteins Get1p and Get2p are required for maintaining normal levels of CL. We propose that these proteins regulate the level of CL by maintaining wild type-like tubular mitochondrial morphology. The genetic interactions observed in this study identify novel physiological modifiers that are required for maintenance of CL levels and mitochondrial morphology.

Head and neck cancer screenings and human papillomavirus knowledge across diverse suburban and urban populations.

BACKGROUND: Minimal research has explored community dwelling adults' knowledge of the human papillomavirus (HPV) in relation to head and neck cancer (HNC). The purpose of this study was to report on community dwelling adults' knowledge of HPV in relation to infection, symptoms, and the development of HNC. METHODS: Cross-sectional assessment of community-dwelling adults on history of behavioral risk factors for HNC, health literacy, and knowledge regarding HPV in relation to HNC. RESULTS: Of those who completed the measure of health literacy, 17.1% read at or below an 8th grade level. Participants reported a range of history of behaviors putting them at increased risk for HPV and HNC. Respondents answered an average of 67.2% of HPV questions correctly, only one person answered all 15 questions correctly. There were no differences in knowledge of HPV in relation to HNC based upon demographics, suburban versus urban location, health literacy, or cancer history. CONCLUSIONS: Adults reported a range of behaviors associated with an increased risk of HPV transmission but also displayed large gaps in knowledge regarding HPV in relation to HNC.

Cardiolipin and mitochondrial phosphatidylethanolamine have overlapping functions in mitochondrial fusion in Saccharomyces cerevisiae.

The two non-bilayer forming mitochondrial phospholipids cardiolipin (CL) and phosphatidylethanolamine (PE) play crucial roles in maintaining mitochondrial morphology. We have shown previously that CL and PE have overlapping functions, and the loss of both is synthetically lethal. Because the lack of CL does not lead to defects in the mitochondrial network in Saccharomyces cerevisiae, we hypothesized that PE may compensate for CL in the maintenance of mitochondrial tubular morphology and fusion. To test this hypothesis, we constructed a conditional mutant crd1Δpsd1Δ containing null alleles of CRD1 (CL synthase) and PSD1 (mitochondrial phosphatidylserine decarboxylase), in which the wild type CRD1 gene is expressed on a plasmid under control of the TET(OFF) promoter. In the presence of tetracycline, the mutant exhibited highly fragmented mitochondria, loss of mitochondrial DNA, and reduced membrane potential, characteristic of fusion mutants. Deletion of DNM1, required for mitochondrial fission, restored the tubular mitochondrial morphology. Loss of CL and mitochondrial PE led to reduced levels of small and large isoforms of the fusion protein Mgm1p, possibly accounting for the fusion defect. Taken together, these data demonstrate for the first time in vivo that CL and mitochondrial PE are required to maintain tubular mitochondrial morphology and have overlapping functions in mitochondrial fusion.