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Hubbard AK, Richardson M, Rosesler MA, Cioc A, Nguyen PL, Warlick E, Poynter JN. The association between non-steroidal anti-inflammatory drugs (NSAIDs) and myelodysplastic syndromes in the Adults in Minnesota with Myelodysplastic Syndromes (AIMMS) Study. Leuk Lymphoma 2021; 62:1474-1481. [PMID: 33416407 DOI: 10.1080/10428194.2020.1869962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Myelodysplastic syndromes (MDS) are a heterogeneous group of blood disorders. Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with a chemopreventive effect in some cancers. We evaluated associations between NSAID use and MDS in a population-based case-control study. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Secondary analyses stratified by sex and MDS subtype were also conducted.The analysis included 399 MDS cases and 698 controls. No significant associations between MDS and use of aspirin (OR = 0.87, 95% CI 0.67-1.14), ibuprofen (OR = 0.91, 95% CI 0.64-1.30), acetaminophen (OR = 1.29, 95% CI 0.90-1.84) or NSAIDs overall (OR = 0.92, 95% CI 0.68-1.23) were observed. No significant associations were observed in models stratified by sex or MDS subtype; however, the direction of the effect between NSAID use and MDS varied by MDS subtype. Our results do not support an association between NSAID use and MDS overall.
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Alexander Cole C, Wilson E, Nguyen PL, Hazeltine AM, Greer JA, Jacobsen J. Scaling Implementation of the Serious Illness Care Program Through Coaching. J Pain Symptom Manage 2020; 60:101-105. [PMID: 32201309 DOI: 10.1016/j.jpainsymman.2020.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND We designed group coaching calls to reinforce communication skill acquisition and Serious Illness Care Program uptake in adult primary care. MEASURES Percentage of primary care physicians (PCPs) who have documented a serious illness conversation in the electronic health record (EHR) approximately three and six months after the coaching intervention. Participant feedback surveys to better understand provider attitudes toward the coaching intervention. INTERVENTION We offered 60-minute group coaching calls to internal medicine PCPs, previously trained in serious illness conversation skills, as part of an institutional quality incentive program. The calls addressed communication challenges common to serious illness care and instructed participants about how to document and bill for conversations. OUTCOMES We completed 31 coaching calls during three months, in which 170 of 228 PCPs attended in groups of two to nine participants per call (74.6% penetration rate). The percentage of PCPs who documented at least one serious illness conversation in the EHR increased from 18.4% to 41.2% six months after the intervention. Primary care internal medicine physicians found the one-hour coaching calls to be highly valuable, with 86.9% of respondents attesting they would recommend the calls to their colleagues. Content analysis of participant feedback identified the most useful coaching content elements to be self-reflection around the impact of prior conversation skills training, instruction around using the EHR to find and document advance care planning discussions, the opportunity to share individual challenges and successes with peers, and feedback/advice from communication experts in palliative care. CONCLUSIONS/LESSONS LEARNED Group coaching of PCPs resulted in more than a twofold increase in documented serious illness conversations.
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Kensler KH, Pernar CH, Mahal BA, Nguyen PL, Trinh QD, Kibel AS, Rebbeck TR. PSA Testing and Prostate Cancer Incidence Following the 2012 Update to the U.S. Preventive Services Task Force Prostate Cancer Screening Recommendation: Implications for Racial/Ethnic Disparities. Cancer Epidemiol Biomarkers Prev 2020. [DOI: 10.1158/1055-9965.epi-20-0066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
The 2012 U.S. Preventive Services Task Force (USPSTF) recommendation against prostate specific antigen (PSA) testing led to a decrease in prostate cancer screening, but its impact on prostate cancer racial/ethnic disparities remains unclear. Methods: The proportion of men ages 40–74 years who received a routine PSA test in the past year was estimated over time in the Behavioral Risk Factor Surveillance System (BRFSS; 2012–2018) and the National Health Interview Survey (NHIS; 2005–2018). Screening trends by race/ethnicity were evaluated using logistic regression models to estimate odds ratios (ORs) of screening adjusting for socioeconomic and healthcare-related factors. Prostate cancer incidence rates and rate ratios (IRRs) by race/ethnicity were estimated in the Surveillance, Epidemiology and End Results (SEER) registry data over time (2004–2016). Results: In the 2012 BRFSS, PSA testing rates were highest among non-Hispanic white (NHW) men (32.3%), followed by non-Hispanic black (NHB; 30.3%), Hispanic (21.8%), and Asian/Pacific Islander men (17.7%). The absolute screening frequency declined by 9.5% overall from 2012 to 2018, with a greater decline among NHB (11.6%) than NHW men (9.3%). Adjusting for socioeconomic and healthcare-related factors, the relative decline was greater among NHB (OR per year = 0.86, 95% CI 0.84–0.88) than NHW men (OR = 0.89, 95% CI 0.89–0.90; p-het. = 0.005), driven by a steeper drop among NHB men ages 40–54. In the NHIS, the 2012 update was associated with a 35% decrease in the odds of screening (OR = 0.65, 95% CI 0.51–0.82), though there was no annual change since 2012 (OR = 1.00, 95% CI 0.98–1.03). Trends in the NHIS did not differ by race/ethnicity. The NHB:NHW IRR for total prostate cancer increased from 1.73 in 2011 to 1.87 in 2012 and has remained elevated, driven by differences in the incidence of localized tumors. Disparity IRRs have been consistent since 2012 for other racial/ethnic populations. Conclusions: Although the frequency of prostate cancer screening varies by race/ethnicity, the impact of the 2012 USPSTF recommendation against PSA testing on screening trends did not robustly differ by race/ethnicity. Following 2012, there was a modest increase in the disparity for localized prostate cancer incidence between NHB and NHW men.
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He R, Devine DJ, Tu ZJ, Mai M, Chen D, Nguyen PL, Oliveira JL, Hoyer JD, Reichard KK, Ollila PL, Al-Kali A, Tefferi A, Begna KH, Patnaik MM, Alkhateeb H, Viswanatha DS. Hybridization capture-based next generation sequencing reliably detects FLT3 mutations and classifies FLT3-internal tandem duplication allelic ratio in acute myeloid leukemia: a comparative study to standard fragment analysis. Mod Pathol 2020; 33:334-343. [PMID: 31471587 PMCID: PMC7051912 DOI: 10.1038/s41379-019-0359-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 01/12/2023]
Abstract
FLT3-internal tandem duplication occurs in 20-30% of acute myeloid leukemia and confers an adverse prognosis with its allelic ratio being a key risk stratifier. The US Food and Drug Administration recently approved FLT3 inhibitors midostaurin and gilteritinib in FLT3 mutation-positive acute myeloid leukemia. Historically, FLT3 was tested by fragment analysis, which has become the standard method endorsed by international guidelines. However, next generation sequencing is increasingly used at acute myeloid leukemia diagnosis given its ability to simultaneously evaluate multiple clinically informative markers. As FLT3-internal tandem duplication detection was known to be challenging by next generation sequencing and the results carry profound prognostic and therapeutic implications, it is important to thoroughly examine its performance in FLT3-internal tandem duplication detection and allelic ratio classification. In a comparative study with fragment analysis, we retrospectively reviewed our experience using a custom-designed, hybridization capture-based, targeted next generation sequencing panel. Among 7902 cases, FLT3-internal tandem duplication was detected in 335 with variable sizes (3-231 bp) and insertion sites. Fragment analysis was also performed in 402 cases, demonstrating 100% concordance in FLT3-internal tandem duplication detection. In 136 dual-tested, positive cases, 128/136 (94%) exhibited concordant high/low allelic ratio classifications. The remaining 6% showed borderline low allelic ratio by next generation sequencing. The two methods were concordant in FLT3-tyrosine kinase domain mutation detection at the hotspot D835/I836 targeted by fragment analysis. Furthermore, seven mutations which may benefit from FLT3 inhibitor therapy were detected by next generation sequencing, in regions not covered by fragment analysis. Our study demonstrates that using a hybridization capture-based chemistry and optimized bioinformatics pipeline, next generation sequencing can reliably detect FLT3-internal tandem duplication and classify its allelic ratio for acute myeloid leukemia risk stratification. Next generation sequencing also exhibits superior comprehensiveness in FLT3 mutation detection and may further improve personalized, targeted therapy in acute myeloid leukemia.
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Semkiu KM, Oliveira JL, Nguyen PL, Porter TR, Wilson DB. Hb F-Wentzville [ Gγ24(B6)Gly→Glu; HBG2: c.74G>A, p.Gly25Glu]: An Unstable Gγ-Globin Variant Associated with Neonatal Hemolytic Anemia. Hemoglobin 2020; 44:67-69. [PMID: 31985299 DOI: 10.1080/03630269.2020.1716002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A novel unstable Gγ-globin variant, Hb F-Wentzville [Gγ24(B6)Gly→Glu; HBG2: c.74G>A, (p.Gly25Glu)], was identified in a young infant who required a single transfusion of erythrocytes for hemolytic anemia. This is the first reported γ-globin variant affecting the highly conserved glycine residue at helical position B6. In the tertiary structure of hemoglobin (Hb), glycine at B6 is in close proximity to another invariant glycine residue at E8. Prior studies have shown that replacement of the B6 or E8 glycine residues with bulkier amino acids disrupts packing between the B and E helices, resulting in Hb instability. Thus, Hb F-Wentzville is analogous to the following unstable β-globin B6 variants: Hb Savannah (HBB: c.74G>T, p.Gly24Val), Hb Riverdale-Bronx (HBB: c.73G>C, p.Gly24Arg), and Hb Moscva (HBB: c.74G>A, p.Gly24Asp).
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Alkharabsheh O, Patnaik MM, Gangat N, Begna KH, Alkhateeb HB, Shah MV, Hogan WJ, He R, Greipp P, Nguyen PL, Litzow MR, Al-Kali A. Impact of marrow blasts percentage on high-grade myelodysplastic syndrome assessed using revised international prognostic scoring system. Ann Hematol 2020; 99:513-518. [PMID: 31974678 DOI: 10.1007/s00277-020-03917-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 01/13/2020] [Indexed: 10/25/2022]
Abstract
Clinical trials and treatment guidelines for myelodysplastic syndrome depend on several prognostic scoring systems to stratify patients by risk. These include different variables: the degree of cytopenia, percentage of bone marrow blasts, and cytogenetics. Little is known about the impact of bone marrow blasts in patients with adverse cytogenetics. In this retrospective study, we analyzed 536 patients with high-grade myelodysplastic syndrome to examine the differences in survival for patients with different percentages of bone marrow blasts. The median overall survival in patients with ≥ 5% marrow blasts was not statistically different from that for patients with < 5% marrow blasts; however, the former group had a higher risk of progression to acute myeloid leukemia (p < 0.001). Therefore, cytogenetics is the most important factor in our prognostic tools to determine survival outcomes for patients with myelodysplastic syndrome, and patients with high-risk disease have poor prognosis irrespective of their marrow blasts percentage.
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Ravindran A, He R, Ketterling RP, Jawad MD, Chen D, Oliveira JL, Nguyen PL, Viswanatha DS, Reichard KK, Hoyer JD, Go RS, Shi M. The significance of genetic mutations and their prognostic impact on patients with incidental finding of isolated del(20q) in bone marrow without morphologic evidence of a myeloid neoplasm. Blood Cancer J 2020; 10:7. [PMID: 31974359 PMCID: PMC6978416 DOI: 10.1038/s41408-020-0275-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 12/25/2019] [Accepted: 01/03/2020] [Indexed: 12/22/2022] Open
Abstract
Patients with a sole del(20q) chromosomal abnormality and without morphologic features of a myeloid neoplasm (MN) have shown variable clinical outcomes. To explore the potential risk stratification markers in this group of patients, we evaluated their genetic mutational landscape by a 35-gene MN-focused next-generation sequencing (NGS) panel and examined the association of mutations to progression of MNs. Our study included 56 patients over a 10-year period with isolated del(20q), of whom 23 (41.1%) harbored at least one mutation. With a median follow-up of 32.6 months (range: 0.1−159.1), 9 of 23 patients with mutation(s) progressed to MNs, while all 33 patients without mutations did not progress to MN. Kaplan−Meier survival analysis demonstrated the presence of mutation(s) as a significant risk factor for progression to MN (P < 0.0001). MN progression was strongly associated with the presence of non-DNMT3A/TET2/ASXL1 epigenetic modifiers and nonspliceosome mutations (P = 0.003). There was no significant difference among patients with and without MN progression with respect to the number of mutations, variant allele frequency, percentage of del(20q), and other clinical/laboratory variables. This study illustrates the underlying genetic heterogeneity and complexity of isolated del(20q), and underscores the prognostic value of NGS mutational analysis in these cases.
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He R, Devine DJ, Tu ZJ, Mai M, Chen D, Nguyen PL, Oliveira JL, Hoyer JD, Reichard KK, Ollila PL, Al-Kali A, Tefferi A, Begna KH, Patnaik MM, Alkhateeb H, Viswanatha DS. Correction to: Hybridization capture-based next-generation sequencing reliably detects FLT3 mutations and classifies FLT3-internal tandem duplication allelic ratio in acute myeloid leukemia: a comparative study to standard fragment analysis. Mod Pathol 2020; 33:514. [PMID: 31591496 PMCID: PMC7608401 DOI: 10.1038/s41379-019-0378-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Jacobsen AM, Poynter JN, Richardson MR, Nguyen PL, Hirsch B, Cioc A, Roesler MA, Warlick ED. Factors predicting early mortality after new diagnosis of myelodysplastic syndrome: A population-based study. Eur J Haematol 2019; 103:56-63. [PMID: 31058390 PMCID: PMC6831083 DOI: 10.1111/ejh.13243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 04/26/2019] [Accepted: 04/30/2019] [Indexed: 12/14/2022]
Abstract
OBJECTIVE Little prospective data regarding factors determining patient outcomes in myelodysplastic syndromes (MDS) are available. To establish features of early mortality in MDS, we compare characteristics of patients dying within 1 year of diagnosis with those surviving longer. METHODS We prospectively enrolled adults with a new MDS diagnosis in a population-based case-control study. Logistic regression was used to calculate odds ratios and 95% confidence intervals for potential predictors of early mortality. Subgroup analyses were conducted within the following groups: high-/very-high-risk IPSS-R; very-low-/low-/intermediate-risk IPSS-R; treated patients; and supportive care only patients. RESULTS We observed early mortality in those with abnormal cytogenetics (OR: 3.36, 95% CI: 1.52-7.46), three or greater cytogenetic abnormalities (OR: 3.48, 95% CI: 1.51-7.99), treatment at a community medical center (versus academic) (OR: 2.55, 95% CI: 1.18-5.47), and with 2-3 concurrent medical comorbidities (OR: 2.14, 95% CI: 1.08-4.22). Similarly, in subgroup analyses, abnormal cytogenetics remained the main predictor of early mortality. CONCLUSION Complex cytogenetics and prognostic risk category have been associated with early mortality without intervention. Our data confirm these associations in a large, prospectively followed cohort and highlight the significance of cytogenetic abnormalities and complexity regardless of IPSS-R risk categorization or treatment.
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Yogarajah M, Nguyen PL, He R, Alkhateeb H, Shah MV, Patnaik MM, Gangat N, Hogan WJ, Tefferi A, Litzow MR, Al-Kali A. Discrepancy of blast percentage between the bone marrow aspirate and biopsy and its impact on survival outcomes in patients with myelodysplastic syndromes excess blast (MDS-EB). J Clin Oncol 2019. [DOI: 10.1200/jco.2019.37.15_suppl.7053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
7053 Background: The revised International Prognostic Scoring System (IPSS-R) aids in prognosticating MDS. The percentage (%) of blasts in the bone marrow is one of the major determinants of the scoring system. The aspirate blast % is utilized as the standard of care, but there could be discrepancies in the blast % reported by the aspirate and the biopsy. We aim to study the possible use of bone marrow biopsy blasts in MDS-EB in calculating IPSS-R. Methods: The MDS database was reviewed for cases of MDS-EB after due IRB approval. We calculated IPSS-R scores based on the aspirate blast % (IPSS-RAsp) and biopsy blast % (IPSS-RBx). The biopsy blast % was reported morphologically or by the CD34 stain. Whenever a range was reported the highest value was utilized as the blast %. Suboptimal aspirates were excluded from the study. The overall survival (OS) was determined by IPSS-RAsp, IPSS-RBx and IPSS-R highest blast (IPSS-RHi). OS estimates were calculated by Kaplan-Meier curves and log-rank testing using JMP v.13. Uno’s concordance statistic was used to compare all 3 risk scoring systems. Results: Of 1322 patients, 431 (33%) cases were identified with MDS-EB; out of which 173 cases had both blasts reported in the biopsy and the aspirate. Out of 173 cases, 35 (20%) had MDS-EB1, and 61 (35%) had MDS EB-2 based on both biopsy and aspirate (concordant cases). Seventy seven (45%) patients changed from EB-1 to EB2 or vice versa based on the biopsy blast (44/77 (57%) cases were upstaged). The OS outcomes based on the IPSS-RBx biopsy showed a clear and meaningful separation with median OS decreasing with increased risk but IPSS-RAsp and IPSS-RHi did not (Table). We compared the 3 models for observed OS differences using the Uno model and there was no statistically significant difference. Conclusions: IPSS-RBx (but not IPSS-RAsp and IPSS-RHi) identified prognostic groups for OS with median OS decreasing with increased risk. The small sample size may have led to an insignificant effect on model power by Uno model. This finding needs to be validated by other centers. [Table: see text]
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Zblewski D, Nguyen PL, He R, Greipp PT, Begna K, Patnaik MM, Gangat N, Shah MV, Alkhateeb H, Litzow MR, Al-Kali A. Pyridoxine impact on patients with myelodysplastic syndromes with ring sideroblasts: Single institution retrospective study. J Clin Oncol 2019. [DOI: 10.1200/jco.2019.37.15_suppl.e18549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e18549 Background: Many vitamin deficiencies can cause anemia. It is prudent prior to diagnosing a myeloid neoplasm, to check for vitamin deficiencies and correct them. Myelodysplastic syndromes with ring sideroblasts (MDS-RS) are associated with anemia. Pyridoxine (Vit B6) replacement may improve anemia found in sideroblastic anemia. The study was to determine how frequently Vit B6 was assessed, replaced and impact replacement had on outcomes in MDS-RS. Methods: Study subjects were from the Mayo Clinic Myelodysplastic syndrome (MDS) database which contains 1315 patients (pts). Appropriate IRB approval was obtained. Diagnosis of MDS and its sub-classification was done according to World Health Organization 2016 criteria. A response was any improvement in hemoglobin. Overall survival (OS) estimates were calculated using Kaplan-Meier curves and univariate and multivariate analysis was done using JMP software version 13. Results: Among 1315 pts with MDS, 161 pts had a diagnosis of MDS-RS. Median age was 73, and 55 (34%) pts were females. Thirty-nine (36%) pts had very low, 53 (50%) low, 9 (8%) intermediate, 3 (3%) high, and 2 (1%) had very high revised international prognostic score. The median white blood cell count was 5.4 x109, platelet count was 255 x109, and hemoglobin was 9.9 gm/dL. Five pts (3%) had a Vit B6 levels done; out of whom, 4 (80%) were not Vit B6 deficient. Among 42 (26%) pts who had Vit B6 replacement, 21 (50%) had no response, 4 (10%) had a response and 17 (40%) had unknown response. 103 (64%) of the pts were transfusion independent (TI). Overall survival in pts who are transfusion dependent was 68 months compared to 85 in pts who are TI (Wilcoxon P =.03). There was an improvement in OS in the group that had Vit B6 replacement compared to the group with no Vit B6 replacement (92 months vs 68 months, Wilcoxon P =.07). Response to Vit B6 replacement did not show OS benefit. Acute Leukemia transformation in Vit B6 replacement was 2% and 6% in pts. who did not have Vit B6 replacement (P= .4). Conclusions: Vit B6 was not checked often in MDS-RS pts. There was a borderline improvement in OS in Vit B6 replacement group (p= .07). Response did not affect OS. A larger prospective study is needed to study Vit B6 role in MDS-RS.
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Le-Rademacher JG, Rowland K, Atherton PJ, Dakhil C, Sun Z, Tan A, Schmidt L, Nguyen PL, Radecki Breitkopf C, Pittelkow M, Tindall D, Menon S, Jatoi A. Androgen Mediation-and Antiandrogens Mitigation-of the Epidermal Growth Factor Receptor (EGFR) Inhibitor-Induced Rash: Results From a Pilot Randomized Trial and Small Translational Case Series. Am J Hosp Palliat Care 2019; 36:519-525. [PMID: 30602311 DOI: 10.1177/1049909118819820] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Although 50% to 90% of patients who receive epidermal growth factor receptor (EGFR) inhibitors develop a rash, options for rash prevention or palliation remain limited. This issue is particularly important from a palliative care standpoint because these agents are prescribed only to patients with incurable cancer. Here, we report (1) gene expression profiling of skin biopsies from patients with an EGFR inhibitor-induced rash and (2) a randomized, placebo-controlled feasibility trial with the antiandrogen, spironolactone. Both investigations were undertaken to begin to explore the hypothesis that androgens mediate EGFR inhibitor-induced rash and that antiandrogens palliate it. METHODS/RESULTS First, 4 skin biopsies from patients with EGFR inhibitor-induced rash (3 men and 1 woman) were subject to gene expression microarray profiling. A public data set of normal skin gene expression (Gene Expression Omnibus, GSE22998) served as a reference. Sixty percent of commonly interrogated androgen receptor genes (207 of 308 between the 2 data sets) were differentially expressed ( P < .05) in the rash samples. Second, in a 17-patient double-blinded, placebo-controlled trial with topical spironolactone applied to the face, although the primary feasibility end point was not achieved, patients in the spironolactone arm received more doses of EGFR inhibitor, and anecdotal photographic evidence suggested salutatory effects of spironolactone on rash. CONCLUSIONS Epidermal growth factor receptor inhibitor-induced rash appears to be androgen-mediated; antiandrogen therapy merits further study for rash prevention/palliation.
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Alkharabsheh O, Saadeh SS, Patnaik MS, Alkhateeb H, Gangat N, Begna KH, Hogan WJ, Greipp PT, He R, Nguyen PL, Litzow MR, Al-Kali A. Impact of clone size with a single cytogenetic abnormality on the revised International Prognostic Scoring System in myelodysplastic syndromes. Am J Hematol 2018; 93:E398-E401. [PMID: 30218541 DOI: 10.1002/ajh.25287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 11/09/2022]
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Alkharabsheh O, Al-Kali A, Saadeh S, He R, Viswanatha D, Greipp P, Reichard K, Shah M, Gangat N, Patnaik M, Hogan W, Litzow M, Alkhateeb H, Nguyen PL. The clinical outcomes of reclassified erythroleukemia (erythroid/myeloid) as myelodysplastic syndrome (MDS) per 2017 WHO guideline compared to MDS. Am J Hematol 2018; 93:E355-E357. [PMID: 30074268 DOI: 10.1002/ajh.25239] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 11/06/2022]
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Neff JL, Rangan A, Jevremovic D, Nguyen PL, Chiu A, Go RS, Chen D, Morice WG, Shi M. Mixed-phenotype large granular lymphocytic leukemia: a rare subtype in the large granular lymphocytic leukemia spectrum. Hum Pathol 2018; 81:96-104. [PMID: 29949739 DOI: 10.1016/j.humpath.2018.06.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/01/2018] [Accepted: 06/09/2018] [Indexed: 01/18/2023]
Abstract
Large granular lymphocytic leukemia (LGLL) is a chronic proliferation of cytotoxic lymphocytes in which more than 70% of patients develop cytopenia(s) requiring therapy. LGLL includes T-cell LGLL and chronic lymphoproliferative disorder of natural killer (NK) cells. The neoplastic cells in LGLL usually exhibit a single immunophenotype in a patient, with CD8-positive/αβ T-cell type being the most common, followed by NK-cell, γδ T-cell, and CD4-positive/αβ T-cell types. We investigated a total of 220 LGLL cases and identified 12 mixed-phenotype LGLLs (5%): 7 cases with coexistent αβ T-cell and NK-cell clones and 5 with coexistent αβ and γδ T-cell clones. With a median follow-up of 48 months, the clinicopathological characteristics of these patients seemed similar to those of typical LGLL patients. Treatment was instituted in 9 patients, and 5 patients (55%) attained complete hematologic response or partial response. The therapeutic response rate of this cohort is comparable to the reported overall response rate of 40% to 60% in typical LGLL patients. Three patients who did not receive any treatment had progressive or persistent cytopenias. Interestingly, inverted proportions of 2 clones at disease recurrence were identified in 4 patients (36%) and stable clonal proportions in 7 patients (64%). Mixed-phenotype LGLL is rare, and this study underscores the importance of recognizing this rare type of LGLL in patients who may benefit from LGLL treatment.
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Guthier CV, D'Amico AV, King MT, Nguyen PL, Orio PF, Sridhar S, Makrigiorgos GM, Cormack RA. Determining optimal eluter design by modeling physical dose enhancement in brachytherapy. Med Phys 2018; 45:3916-3925. [PMID: 29905964 DOI: 10.1002/mp.13051] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 05/30/2018] [Accepted: 06/06/2018] [Indexed: 11/05/2022] Open
Abstract
PURPOSE In situ drug release concurrent with radiation therapy has been proposed to enhance the therapeutic ratio of permanent prostate brachytherapy. Both brachytherapy sources and brachytherapy spacers have been proposed as potential eluters to release compounds, such as nanoparticles or chemotherapeutic agents. The relative effectiveness of the approaches has not been compared yet. This work models the physical dose enhancement of implantable eluters in conjunction with brachytherapy to determine which delivery mechanism provides greatest opportunity to enhance the therapeutic ratio. MATERIALS AND METHODS The combined effect of implanted eluters and radioactive sources were modeled in a manner that allowed the comparison of the relative effectiveness of different types of implantable eluters over a range of parameters. Prostate geometry, source, and spacer positions were extracted from treatment plans used for 125 I permanent prostate implants. Compound concentrations were calculated using steady-state solution to the diffusion equation including an elimination term characterized by the diffusion-elimination modulus (ϕb ). Does enhancement was assumed to be dependent on compound concentration up to a saturation concentration (csat ). Equivalent uniform dose (EUD) was used as an objective to determine the optimal configuration of eluters for a range of diffusion-elimination moduli, concentrations, and number of eluters. The compound delivery vehicle that produced the greatest enhanced dose was tallied for points in parameter space mentioned to determine the conditions under whether there are situations where one approach is preferable to the other. RESULTS The enhanced effect of implanted eluters was calculated for prostate volumes from 14 to 45 cm3 , ϕb from 0.01 to 4 mm-1 , csat from 0.05 to 7.5 times the steady-state compound concentration released from the surface of the eluter. The number of used eluters (ne ) was simulated from 10 to 60 eluters. For the region of (csat , Φ)-space that results in a large fraction of the gland being maximally sensitized, compound eluting spacers or sources produce equal increase in EUD. In the majority of the remaining (csat , Φ)-space, eluting spacers result in a greater EUD than sources even where sources often produce greater maximal physical dose enhancement. Placing eluting implants in planned locations throughout the prostate results in even greater enhancement than using only source or spacer locations. CONCLUSIONS Eluting brachytherapy spacers offer an opportunity to increase EUD during the routine brachytherapy process. Incorporating additional needle placements permits compound eluting spacer placement independent of source placement and thereby allowing a further increase in the therapeutic ratio. Additional work is needed to understand the in vivo spatial distribution of compound around eluters, and to incorporate time dependence of both compound release and radiation dose.
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Alkharabsheh O, Saadeh SS, Patnaik MM, Alkhateeb H, Gangat N, Begna K, Hogan WJ, Greipp PT, He R, Nguyen PL, Litzow MR, Al-Kali A. The impact of clonal size on the revised international prognostic scoring system (R-IPSS) in myelodysplastic syndromes (MDS) with a single cytogenetic abnormality. J Clin Oncol 2018. [DOI: 10.1200/jco.2018.36.15_suppl.7068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Alkharabsheh O, Al-Kali A, Saadeh SS, He R, Viswanatha D, Greipp PT, Reichard K, Shah MV, Gangat N, Patnaik MM, Hogan WJ, Litzow MR, Alkhateeb H, Nguyen PL. The clinical outcomes of reclassified erythroleukemia (erythroid/myeloid) as myelodysplastic syndrome per 2017 WHO guideline compared to de novo MDS. J Clin Oncol 2018. [DOI: 10.1200/jco.2018.36.15_suppl.e19026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Mahal BA, Chen YW, Muralidhar V, Mahal AR, Choueiri TK, Hoffman KE, Hu JC, Sweeney CJ, Yu JB, Feng FY, Kim SP, Beard CJ, Martin NE, Trinh QD, Nguyen PL. Racial disparities in prostate cancer outcome among prostate-specific antigen screening eligible populations in the United States. Ann Oncol 2018; 28:1098-1104. [PMID: 28453693 DOI: 10.1093/annonc/mdx041] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Background In 2012, the United States Preventive Services Task Force (USPSTF) recommended against prostate-specific antigen (PSA) screening, despite evidence that Black men are at a higher risk of prostate cancer-specific mortality (PCSM). We evaluated whether Black men of potentially screening-eligible age (55-69 years) are at a disproportionally high risk of poor outcomes. Patients and methods The SEER database was used to study 390 259 men diagnosed with prostate cancer in the United States between 2004 and 2011. Multivariable logistic regression modeled the association between Black race and stage of presentation, while Fine-Gray competing risks regression modeled the association between Black race and PCSM, both as a function of screening eligibility (age 55-69 years versus not). Results Black men were more likely to present with metastatic disease (adjusted odds ratio [AOR] 1.65; 1.58-1.72; P < 0.001) and were at a higher risk of PCSM (adjusted hazard ratio [AHR] 1.36; 1.27-1.46; P < 0.001) compared to non-Black men. There were significant interactions between race and PSA-screening eligibility such that Black patients experienced more disproportionate rates of metastatic disease (AOR 1.76; 1.65-1.87 versus 1.55; 1.47-1.65; Pinteraction < 0.001) and PCSM (AHR 1.53; 1.37-1.70 versus 1.25; 1.14-1.37; Pinteraction = 0.01) in the potentially PSA-screening eligible group than in the group not eligible for screening. Conclusions Racial disparities in prostate cancer outcome among Black men are significantly worse in PSA-screening eligible populations. These results raise the possibility that Black men could be disproportionately impacted by recommendations to end PSA screening in the United States and suggest that Black race should be included in the updated USPSTF PSA screening guidelines.
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Nguyen PL, Martin NE, Choeurng V, Palmer-Aronsten B, Kolisnik T, Beard CJ, Orio PF, Nezolosky MD, Chen YW, Shin H, Davicioni E, Feng FY. Utilization of biopsy-based genomic classifier to predict distant metastasis after definitive radiation and short-course ADT for intermediate and high-risk prostate cancer. Prostate Cancer Prostatic Dis 2017; 20:186-192. [PMID: 28117383 PMCID: PMC5435968 DOI: 10.1038/pcan.2016.58] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 09/14/2016] [Accepted: 10/12/2016] [Indexed: 11/22/2022]
Abstract
BACKGROUND We examined the ability of a biopsy-based 22-marker genomic classifier (GC) to predict for distant metastases after radiation and a median of 6 months of androgen deprivation therapy (ADT). METHODS We studied 100 patients with intermediate-risk (55%) and high-risk (45%) prostate cancer who received definitive radiation plus a median of 6 months of ADT (range 3-39 months) from 2001-2013 at a single center and had available biopsy tissue. Six to ten 4 micron sections of the needle biopsy core with the highest Gleason score and percentage of tumor involvement were macrodissected for RNA extraction. GC scores (range, 0.04-0.92) were determined. The primary end point of the study was time to distant metastasis. Median follow-up was 5.1 years. There were 18 metastases during the study period. RESULTS On univariable analysis (UVA), each 0.1 unit increase in GC score was significantly associated with time to distant metastasis (hazard ratio: 1.40 (1.10-1.84), P=0.006) and remained significant after adjusting for clinical variables on multivariable analysis (MVA) (adjusted hazard ratio: 1.36 (1.04-1.83), P=0.024). The c-index for 5-year distant metastasis was 0.45 (95% confidence interval: 0.27-0.64) for Cancer of the Prostate Risk Assessment score, 0.63 (0.40-0.78) for National Comprehensive Cancer Network (NCCN) risk groups, and 0.76 (0.57-0.89) for the GC score. Using pre-specified GC risk categories, the cumulative incidence of metastasis for GC>0.6 reached 20% at 5 years after radiation (P=0.02). CONCLUSIONS We believe this is the first demonstration of the ability of the biopsy-based GC score to predict for distant metastases after definitive radiation and ADT for intermediate- and high-risk prostate cancer. Patients with the highest GC risk (GC>0.6) had high rates of metastasis despite multi-modal therapy suggesting that they could potentially be candidates for treatment intensification and/or enrollment in clinical trials of novel therapy.
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Nanah R, Zblewski D, He R, Nguyen PL, Gangat N, Begna K, Elliott MA, Hogan WJ, Patnaik M, Litzow MR, Al-Kali A. Interaction between ring sideroblasts and treatment with hypomethylating agents (HMA) in patients with refractory anemia with ring sideroblasts. J Clin Oncol 2017. [DOI: 10.1200/jco.2017.35.15_suppl.e18559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e18559 Background: Myelodysplastic syndromes (MDS) are a group of myeloid neoplasms defined by ineffective hematopoiesis, dysplastic morphologic features, and variable risks of progression to acute myeloid leukemia (AML). Refractory anemia with ring sideroblasts (RARS) is a subtype of MDS defined by < 5% basts and > 15% ring sideroblasts (per 2008 WHO). Because RARS is a lower risk disease which does not frequently require HMA therapy, very little is known about the effects of HMA on RARS. Methods: A total of 1325 MDS patients’ data from 1993-2016 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. Patients were considered for our study if they received HMA for their RARS. Response was identified based on MDS IWG 2006 criteria. Prognostic factors were analyzed by univariate and multivariate analyses. Survival estimates were calculated using Kaplan-Meier curves. Results: 168 of the initial 1325 patient were RARS (14%); only 14 (8%) were treated with HMA. Median age was 72 years (range, 51-85); half were males, with median overall survival of 91.3 months. The median number of ring sideroblasts (RS) at diagnosis was 40% (range 10-85%). Of the 14 patients, 11 (79%) received azacitidine (AZA), 2 (14%) decitabine (DAC) and one received both (7%). The median number of cycles for AZA was 6.5 (range, 2-28) vs 6 cycles for DAC (range, 1-24). Of the 14 patients receiving HMA, only 3 responded (21%) achieving hematologic improvement. All 3 responders received AZA. 6 of the 14 RARS patients (43%) had their bone marrow biopsy repeated after HMA therapy, 3 of whom were among the responders to AZA therapy and 3 were non-responders. In 5 patients, ring sideroblasts decreased after HMA therapy by a median of 15% (range 0-80); they remained the same in 1 patient; one patient who had developed AML had a decrease in RS from 85% to 5%. Conclusions: RARS is a low-risk subtype of MDS that is infrequently treated with HMA (8% in our study). Response rate to HMA (21%) was inferior to known rates in MDS. HMA therapy seems to decrease the number of ring sideroblasts irrespective of response. RARS patients should be treated on clinical trials if available.
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Nanah R, Patnaik M, Gangat N, Zblewski D, He R, Nguyen PL, Elliott MA, Hogan WJ, Litzow MR, Al-Kali A. Clinical significance of HFE gene mutations in patients with refractory anemia with ring sideroblasts (RARS). J Clin Oncol 2017. [DOI: 10.1200/jco.2017.35.15_suppl.e18556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e18556 Background: RARS is a subtype of myelodysplastic syndromes (MDS) defined by < 5% blasts and ≥15% ring sideroblasts (WHO 2008). Hereditary hemochromatosis is a disorder characterized by dysregulations in iron absorption, largely associated with C282Y and H63D mutations of the HFE gene. Iron levels are elevated in both disorders and pathophysiologic correlations were suggested. HFE gene mutations were previously found higher in MDS compared to controls (50% vs 36%) ( Nearman et al, Am J Hematol 2007). Methods: A total of 168 RARS patients’ data from 1994 to 2015 at Mayo Clinic were reviewed after appropriate IRB approval was obtained. All cases had their bone marrow slides reviewed at our center. We searched patients’ records retrospectively to Identify those tested for HFE gene (C282Y, H62D, S65C) mutations, done inside or outside our institution. Survival estimates were calculated using Kaplan-Meier curves. Results: Out of the 168 RARS patients, only 17 (10%) were tested for HFE gene mutations. Out of the 17 tested, 11 (65%) were found to have mutations; 2 of which (18%) had homozygous H63D mutation, 1 patient (9%) had double heterozygous H63D and C282Y mutations, 5 (45%) had only one H36D heterozygous mutation vs 3 patients (27%) with only one C282Y heterozygous mutation. Only one patient was tested for the additional S65C mutation and it was not detected. H63D mutation was present in a total of 8 patients (73%) vs C282Y mutation which was present in 4 patients (36%). Bone marrow iron stores were increased in all 17 tested patients, except one who had decreased stores, this patient had one heterozygous C282Y mutation. Median overall survival (mOS) was 117 months in the HFE mutated patients vs 75 months in the non-mutated (p = 0.6). Conclusions: Our study found the HFE gene, when tested, to be mutated in higher frequencies among patients with RARS compared to that reported in the general population (65% vs 36%), with H63D mutation in almost three quarters of all mutated patients. Although it did not reach statistical significance, the longer survival observed among HFE mutated patients compared to the wild-type raises the question whether testing for HFE gene mutations among patients with MDS-RARS should be further explored.
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Al-Kali A, He R, Patnaik M, Hanna K, Viswanatha D, Greipp PT, Zblewski D, Elliott MA, Litzow MR, Nguyen PL. Outcome of patients younger than 50 years old diagnosed with myelodysplastic syndromes (MDS): Single institution experience. J Clin Oncol 2017. [DOI: 10.1200/jco.2017.35.15_suppl.e18560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
e18560 Background: Myelodysplastic syndromes (MDS) are rare hematological neoplasms typically seen in the elderly. Young MDS (yMDS) patients ( < 50 years old) have been reported to comprise between 3-6% in the Surveillance, Epidemiology and End Results (Ma X et al, Cancer 2007; Rollison R et al, Blood 2008) with a better overall survival (OS). Methods: 1012 MDS patients from 1993 to 2015 were found after IRB approval was obtained. All cases had their bone marrow slides reviewed at our institution. yMDS Patients were included as cohort 1, while the rest as cohort 2. Survival estimates were calculated using Kaplan-Meier curves and univariate and multivariate analyses was based on log-rank testing using JMP software version 10. Results: We found 68 (7%) yMDS patients with a median age of 42 years (range, 18-49). Female gender was more common (43% vs 31%, p = 0.05) while platelets were lower in yMDS (61 vs 102, p < 0.0001). Therapy related MDS (t-MDS) was more frequent (33% vs 17%, p = 0.005), as was transformation to acute myeloid leukemia (AML) in yMDS (28 % vs 11%, p = 0.0004). Allogenic hematopoietic cell transplantation (HCT) was more frequent in yMDS (42% vs 4%, p < 0.0001). Survival outcome: Median OS was longer for cohort 1 vs cohort 2 but did not reach statistical significance (43 vs 21 months, p = 0.1). Median progression free survival (PFS) was shorter for cohort 1 vs cohort 2 but also did not reach statistical significance (8 vs 12 months, p = 0.3). Median OS for cohort 1 based on R-IPSS was 44, 105, 40, 18, and 12 months for very low, low, intermediate, high and very high risk groups, respectively (p = 0.09). Median OS was shorter in t-MDS vs de novo MDS in yMDS (13 vs 47 months, p = 0.04). yMDS patients who transformed to AML had worse median OS (18 vs 93 months, p = 0.001). On multivariate analysis neither t-MDS nor R-IPSS had a statistically significant impact on OS. Conclusions: MDS is rarely diagnosed under the age of 50 with IPSS-R being less powerful in detecting mOS. Among yMDS patients, there was a higher proportion of t-MDS compared to older patients with subsequent higher rates of AML transformation and higher rates of allogeneic HCT. In our study, we did not find an improved OS for yMDS patients compared to older patients.
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Nead KT, Sinha S, Nguyen PL. Androgen deprivation therapy for prostate cancer and dementia risk: a systematic review and meta-analysis. Prostate Cancer Prostatic Dis 2017; 20:259-264. [PMID: 28349979 DOI: 10.1038/pcan.2017.10] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/10/2017] [Accepted: 02/13/2017] [Indexed: 01/11/2023]
Abstract
BACKGROUND Androgen deprivation therapy (ADT) to treat prostate cancer may be associated with an increased risk of dementia, but existing studies have shown conflicting results. Here we synthesize the literature on the association of ADT for the treatment of prostate cancer with dementia risk. METHODS We conducted a systematic review of articles reporting the outcome of dementia among individuals with prostate cancer in those exposed to ADT versus a lesser-exposed comparison group (for example, ADT versus no-ADT; continuous versus intermittent ADT) using PubMed (1966-present), Web of Science (1945-present), Embase (1966-present) and PsycINFO (1806-present). The search was undertaken on 4 December 2016 by two authors. We meta-analyzed studies reporting an effect estimate and controlling for confounding. Random- or fixed-effects meta-analytic models were used in the presence or absence of heterogeneity per the I2 statistic, respectively. Small study effects were evaluated using Egger and Begg's tests. RESULTS Nine studies were included in the systematic review. Seven studies reported an adjusted effect estimate for dementia risk. A random-effects meta-analysis of studies reporting any dementia outcome, which included 50 541 individuals, showed an increased risk of dementia among ADT users (hazard ratio (HR), 1.47; 95% confidence interval (CI), 1.08-2.00; P=0.02). We separately meta-analyzed studies reporting all-cause dementia (HR, 1.46; 95% CI, 1.05-2.02; P<0.001) and Alzheimer's disease (HR, 1.25; 95% CI, 0.99-1.57; P=0.06). There was no evidence of bias from small study effects (Egger, P=0.19; Begg, P=1.00). CONCLUSION The currently available combined evidence suggests that ADT in the treatment of prostate cancer may be associated with an increased dementia risk. The potential for neurocognitive deficits secondary to ADT should be discussed with patients and evaluated prospectively.
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Brivio D, Nguyen PL, Sajo E, Ngwa W, Zygmanski P. A Monte Carlo study of I-125 prostate brachytherapy with gold nanoparticles: dose enhancement with simultaneous rectal dose sparing via radiation shielding. Phys Med Biol 2017; 62:1935-1948. [PMID: 28140338 DOI: 10.1088/1361-6560/aa5bc7] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We investigate via Monte Carlo simulations a new 125I brachytherapy treatment technique for high-risk prostate cancer patients via injection of Au nanoparticle (AuNP) directly into the prostate. The purpose of using the nanoparticles is to increase the therapeutic index via two synergistic effects: enhanced energy deposition within the prostate and simultaneous shielding of organs at risk from radiation escaping from the prostate. Both uniform and non-uniform concentrations of AuNP are studied. The latter are modeled considering the possibility of AuNP diffusion after the injection using brachy needles. We study two extreme cases of coaxial AuNP concentrations: centered on brachy needles and centered half-way between them. Assuming uniform distribution of 30 mg g-1 of AuNP within the prostate, we obtain a dose enhancement larger than a factor of 2 to the prostate. Non-uniform concentration of AuNP ranging from 10 mg g-1 and 66 mg g-1 were studied. The higher the concentration in a given region of the prostate the greater is the enhancement therein. We obtain the highest dose enhancement when the brachytherapy needles are coincident with AuNP injection needles but, at the same time, the regions in the tail are colder (average dose ratio of 0.7). The best enhancement uniformity is obtained with the seeds in the tail of the AuNP distribution. In both uniform and non-uniform cases the urethra and rectum receive less than 1/3 dose compared to an analog treatment without AuNP. Remarkably, employing AuNP not only significantly increases dose to the target but also decreases dose to the neighboring rectum and even urethra, which is embedded within the prostate. These are mutually interdependent effects as more enhancement leads to more shielding and vice-versa. Caution must be paid since cold spot or hot spots may be created if the AuNP concentration versus seed position is not properly distributed respect to the seed locations.
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