Germline DNA Repair Genes Pathogenic Variants Among Mexican Patients With Prostate Cancer

BACKGROUND

Early identification of germline mutation carriers may be relevant for the optimal management of prostate cancer and to inform cancer risk in relatives. However, population minorities have limited access to genetic testing. The aim of this study was to describe the frequency of DNA repair gene pathogenic variants (PVs) among Mexican men with prostate cancer referred for Genomic Cancer Risk Assessment and testing.

METHODS

Patients diagnosed with prostate cancer who meet criteria for genetic testing and enrolled in the Clinical Cancer Genomics Community Research Network at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán in Mexico City were included. Descriptive statistics were performed using frequency and proportions for categorical variables and median and range for quantitative variables. X2 and t test were used for group comparisons.

RESULTS

A total of 199 men were enrolled, median age at diagnosis was 66 (range 44-88) years; 45% were de novo metastatic and 44% were high- very high and 10% were intermediate risk group. Four (2%) had a pathogenic germline variant; one each of the following genes: ATM, CHEK2, BRIP1, and MUTYH (all monoallelic). Younger men at diagnosis were more likely to carry a PV than older age at diagnosis (56.7 vs. 66.4 years, P = .01).

CONCLUSION

Our results showed a low prevalence of known prostate cancer associated PVs and no BRCA PVs in Mexican men with prostate cancer. This suggests that the genetic and/or epidemiologic risk factors for prostate cancer are not well characterized in this specific population.

The dynamics of arsenic and copper in solid and aqueous phases in reactive confluences receiving acid drainage: The role of turbidity and particle size

The fate of suspended solids in aqueous systems enriched with copper (Cu) and arsenic (As) is still poorly understood, especially in mildly acidic streams with natural turbidity. This study integrated field, laboratory, and modeling to determine how turbidity, particle size distribution, and the partition of Cu and As interact in two model river confluences in an Andean watershed (upper Elqui, North-Central Chile). The mildly acidic Toro River (4<pH<5; As_TOTAL>0.4 mgL^-1; Cu_TOTAL>8 mgL^-1) was diluted and neutralized at two consecutive confluences, resulting in dissolved As and Cu lower than 0.04 and 0.1 mgL^-1, respectively. On-site laser scattering measurements showed that the size of suspended sediments was dominated by ultrafine (d<6 μm) and fine (6<d<63 μm) size modes, while larger modes (d>200 μm) were not observed, contrasting with other reactive Andean confluences that work as natural coagulation-flocculation reactors. Laboratory mixing experiments with filtered endmembers followed closely the trends observed in the field measurements. SEM observations and thermodynamic calculations, suggested that As-rich amorphous Fe minerals dominated the fine suspended solid inflow (d<15 μm) from the Toro River, while XRD did not reveal significant amounts of crystalline forms of Fe, As, or Cu minerals. Despite fresh precipitates that further associated dissolved As and Cu, the particles from the Toro River grew only slightly after the confluences, thus limiting particle settling potential and a significant metal-(loid)s removal. Consequently, the seasonal variation in the size and chemical nature of suspended solids in acid drainage inflows control the distinct physical and chemical fates of As and Cu after neutralization, as well as hydrodynamic or hydraulic conditions likely also constrain sediment deposition. The combined monitoring of chemical parameters and particle size distributions is a simple and cost-effective method to obtain information about the behavior of metal(loid)s and sediments.

Patient-reported outcomes in RA patients treated with tofacitinib or bDMARDs in real-life conditions in two Latin American countries

OBJECTIVE

To describe efficacy, safety, and patient-reported outcomes (PROs) in patients with rheumatoid arthritis (RA) with an inadequate response to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) treated with tofacitinib or biological DMARDs (bDMARDs) in real-life conditions.

METHODS

A noninterventional study was performed between March 2017 and September 2019 at 13 sites in Colombia and Peru. Outcomes measured at baseline and at the 6-month follow-up were disease activity (RAPID3 [Routine Assessment of Patients Index Data] score), functional status (HAQ-DI [Health Assessment Questionnaire] score), and quality of life (EQ-5D-3L [EuroQol Questionnaire]). The Disease Activity Score-28 (DAS28-ESR) and frequency of adverse events (AEs) were also reported. Unadjusted and adjusted differences from baseline were estimated and expressed as the least squares mean difference (LSMD).

RESULTS

Data from 100 patients treated with tofacitinib and 70 patients with bDMARDs were collected. At baseline, the patients' mean age was 53.53 years (SD 13.77), the mean disease duration was 6.31 years (SD 7.01). The change from baseline at month 6 was not statistically significant different in the adjusted LSMD [SD] for tofacitinib vs. bDMARDs for RAPID3 score (-2.55[.30] vs. -2.52[.26]), HAQ-DI score (-.56[.07] vs. -.50[.08]), EQ-5D-3L score (.39[.04] vs. .37[.04]) and DAS28-ESR (-2.37[.22] vs. -2.77[.20]). Patients from both groups presented similar proportions of nonserious and serious AEs. No deaths were reported.

CONCLUSION

Changes from baseline were not statistically significantly different between tofacitinib and bDMARDs in terms of RAPID3 scores and secondary outcomes. Patients from both groups presented similar proportions of nonserious and serious AEs.

CLINICAL TRIAL NUMBER

NCT03073109.

Abstract P039: Framework for genomic cancer risk assessment dissemination and implementation in Latin America: The GRACIAS (genetic risk assessment for cancer implementation and sustainment) study

Introduction: Lack of public insurance coverage for genetic testing and a limited trained genomic cancer risk assessment (GCRA) workforce are barriers to cancer screening and prevention and to understanding the genetic epidemiology of cancer in low/middle income countries (LMIC) in Latin America. Methods: We implemented an intervention that included professional education for clinicians in Mexico, Peru and Colombia, support from a community of practice and a federated consortium of collaborators, a versatile research registry with a dual purpose (research and clinical care) centralized relational database and pedigree drawing program (web-accessible), and economical NGS multigene panel tests (MGPT). We report here the outcomes of GCRA for 4181 probands (3170 breast, 301 ovarian, 965 other cancer, and 262 unaffected). Results: With a mean age of 45.2 y.o. (39.9 y.o. at breast cancer dx for carriers), a pathogenic variant (PV) was detected in 605 (14.5%) of 2,710 probands (BRCA testing only for 1387, MGPT for 1323): BRCA1 (n=250); BRCA2 (129); CHEK2 (24); PALB2 (20); ATM (14); TP53 (14); PTEN (6); CDH1 (5); MMR genes (62); RAD51C (6); and BRIP1 (3). We have documented growing reach (proportion of those eligible that access GCRA), increasing cascade testing (family member(s) tested (n=541) for 192/470 [40%] probands with a PV), and with median 2.2 years follow up, 209 risk reduction surgeries were performed. Summary: Remarkably, despite systemic limitations, integration of a skilled multidisciplinary team with access to genetic assays and practice support tools, community, and hospital outreach increased GCRA reach, and the expansion of cascade testing and performance of risk-appropriate surgeries reflect maturing prevention programs. Sustainment of progress requires increased multilevel efforts and establishment of GCRA as a supported standard of care, so the opportunity for prevention is not missed for vulnerable and underserved high-risk patients and families.

Citation Format: Jeffrey N. Weitzel, Julio Abugattas, Cynthia Villarreal-Garza, Adrian Daneri Navarro, Alicia Cock-Rada, Yenni Rodriguez, Pamela Mora-Alferez, Dione Aguilar, Azucena del Toro-Valero, Francisco Gutierrez-Delgado, Ana Ferrigno, Josef Herzog, Danielle Castillo, Gubidxa Gutierrez Seymour, Bita Nehoray, Kathleen R. Blazer, Maria E. Fernandez, Yanin Chavarri Guerra. Framework for genomic cancer risk assessment dissemination and implementation in Latin America: The GRACIAS (genetic risk assessment for cancer implementation and sustainment) study. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P039.

UV/solar photo-degradation of furaltadone in homogeneous and heterogeneous phases: Intensification with persulfate

Previous studies on removal of the pharmaceutical drug Furaltadone (FTD) in water have not shown to be totally efficient or are very expensive. In this study, sulfate radicals derived from persulfate anions activated with different irradiation sources (UVA, UVC and solar light) and combined with H₂O₂ and/or TiO₂ have been tested in homogeneous and heterogeneous phases under different operation modes and reaction systems. In homogeneous phase, UV produces a slow mineralization (k = 0.0013 min^-1). The combined processes are faster (k_UV/H2O2 = 0.0185 min^-1, k_UV/PS = 0.0206 min^-1) with the best performance for the UV/PS system yielding nearly 80% of mineralization in half an hour. The overall process (UV/H₂O₂/PS) does not show synergy and mineralization is even slower (k_UV/H2O2/PS = 0.015 min^-1) due to the production of a high amount of radicals favouring unproductive reactions (scavenger effect). A mineralization mechanism is proposed involving formation of 5hydroxymethylene-2(5H)-furanone and NO as the main intermediates. In heterogeneous phase (UVA/TiO₂/PS), the holes play an important role changing the mineralization mechanism. The main intermediates formed were C₁₂H₁₇N₄O₄ and C₁₁H₁₄N₃O₄, which rapidly were degraded to form C₈H₁₅O₃N₃, C₄H₁₀NO and C₅H₁₀NO. An economic study of operation costs has been made for selected processes: UVC/PS, UVA/TiO₂/PS and Solar/TiO₂/PS. The Solar/TiO₂/PS process has the lowest operation costs due to the use of solar energy. However, it would need an additional stage to recover the catalyst. Finally, a loss of 27% in efficiency during mineralization was found after 5 cycles, but the catalyst recovers its initial performance after regeneration at 500 °C.

Clonal Hematopoiesis and Mosaicism Revealed by a Multi-Tissue Analysis of Constitutional TP53 Status

BACKGROUND

Though germline TP53 pathogenic/likely pathogenic variants (PV) are associated with Li-Fraumeni syndrome, many detected by multigene panels represent aberrant clonal expansion (ACE), most due to clonal hematopoiesis (CH). Discerning ACE/CH from germline variants and postzygotic mosaicism (PZM) is critically needed for risk assessment and management.

METHODS

Participants in the Li-Fraumeni &amp; TP53 Understanding &amp; Progress (LiFT UP) study with a TP53 PV were eligible. Demographics, personal/family cancer history, and clinical laboratory test reports were obtained. DNA from multiple tissues was analyzed using a custom QIAseq assay (ACE panel) that included TP53 and other CH-associated genes; the ACE panel and eyebrow follicles were assessed in a workflow to discern TP53 PV clinical categories.

RESULTS

Among 134 participants there was a significant difference for the age at diagnosis (P &lt; 0.001), component cancers (P = 0.007), and clinical testing criteria (P &lt; 0.001), comparing germline with PZM or ACE. ACE panel analysis of DNA from 55 sets of eyebrow follicles (mean 1.4 ug) and 36 formalin-fixed, paraffin imbedded tissues demonstrated low variance (SE, 3%; P = 0.993) for TP53 variant allele fraction, with no significant difference (P = 0.965) between tissue types, and detected CH gene PVs. Of 55 multi-tissue cases, germline status was confirmed for 20, PZM in seven, ACE for 25, and three were indeterminate. Additional CH variants were detected in six ACE and two germline cases.

CONCLUSIONS

We demonstrated an effective approach and tools for discerning germline TP53 status.

IMPACT

Discernment of PZM and TP53-driven CH increases diagnostic accuracy and enables risk-appropriate care.

Components of interprofessional education programs in neonatal medicine: A focused BEME review: BEME Guide No. 73

BACKGROUND

Care delivery in neonatology is dependent on an interprofessional team. Collaborative learning and education amongst professionals can lead to successful management of critically ill patients. This focused BEME review synthesized the components, outcomes, and impact of such interprofessional education (IPE) programs in neonatal medicine.

METHODS

The authors systematically searched four online databases and hand-searched MedEdPublish up to 10 September 2020. Two authors independently screened titles, abstracts, full-texts, performed data extraction and risk of bias assessment related to study methodology and reporting. Discrepancies were resolved by a third author. We reported our findings based on BEME guidance and the STORIES (STructured apprOach to the Reporting in health education of Evidence Synthesis) statement.

RESULTS

We included 17 studies on IPE in neonatal medicine. Most studies were from North America with varying learners, objectives, instruction, and observed outcomes. Learners represented nurses, respiratory therapists, neonatal nurse practitioners, patient care technicians, parents, early interventionists, physicians, and medical trainees amongst others. Risk of bias assessment in reporting revealed poor reporting of resources and instructor training. Bias assessment for study methodology noted moderate quality evidence with validity evidence as the weakest domain. IPE instruction strategies included simulation with debriefing, didactics, and online instruction. Most studies reported level 1 Kirkpatrick outcomes (76%) and few reported level 3 or 4 outcomes (23%). Challenges include buy-in from leadership and the negative influence of hierarchy amongst learners.

CONCLUSIONS

This review highlights IPE program components within neonatal medicine and exemplary practices including a multimodal instructional approach, asynchronous instruction, an emphasis on teamwork, and elimination of hierarchy amongst learners. We identified a lack of reporting on program development and instructor training. Future work should address long term knowledge and skill retention and impact on patient outcomes and organizations.

Evaluation of Lynch syndrome risk models in a multicenter diverse population

10597

Background: Lynch syndrome (LS) is the most common cause of hereditary colorectal cancer (CRC) with an increased CRC lifetime risk of 70-80%. LS affects 1:250 individuals and is caused by pathogenic variants in the mismatch repair (MMR) genes. Statistical prediction models such as MMRpro and PREMM5 are widely used to identify LS carriers. However, these models are trained and validated in mostly white populations, and there remains a gap in understanding their performance in Hispanic populations. The purpose of this study was to evaluate the performance of MMRpro and PREMM5 on a large Hispanic cohort from the Clinical Cancer Genomics Community Research Network (CCGCRN). Methods: We validated MMRpro and PREMM5 on 3,490 CCGCRN families, of which 1,122 are Hispanic and 2,062 Non-Hispanic. The two models were evaluated for discrimination using the C-statistic, calibration using the observed to expected ratio (O/E), and overall performance using the root Brier score and negative and positive predictive value (NPV/PPV) at the 5% carrier probability threshold. Evaluations were stratified by ethnicity, and 95% confidence intervals were obtained via bootstrapping for all measures. Results: The C-statistic is 0.90 for both MMRpro (95% CI: 0.88, 0.92) and PREMM5 (95% CI: 0.87, 0.92). When stratified by ethnicity, the C-statistics are 0.96 (95% CI: 0.94, 0.97) and 0.86 (95% CI: 0.83, 0.89) for Hispanics and Non-Hispanics, respectively, in MMRpro, and 0.96 (95% CI: 0.94, 0.97) and 0.84 (95% CI: 0.79, 0.88) in PREMM5. Both models underpredict mutation probabilities, with O/E ratios ranging from 1.79 to 1.96. At a 5% threshold, variations in PPV between Hispanics and Non-Hispanics are observed in both models: 0.72 (95% CI: 0.63, 0.80) and 0.43 (95% CI: 0.37, 0.50) in Hispanic and Non-Hispanic groups in MMRpro; 0.50 (95% CI: 0.43, 0.57) and 0.25 (95% CI: 0.20, 0.30) in PREMM5. We observe less variation and higher values in NPVs in both models. Conclusions: Overall, MMRpro and PREMM5 perform well in this cohort in predicting the probability of having a pathogenic variant in an MMR gene, with modest underprediction. While these results offer reassurance for the clinical use of MMRpro and PREMM5 in Hispanic populations, further validation studies in underrepresented racial and ethnic populations are crucial.

POS0823 KL-6 IN ANCA-ASSOCIATED VASCULITIS PATIENTS WITH AND WITHOUT ILD: A MACHINE LEARNING APPROACH

Background

ANCA-associated vasculitis (AAV) are small vessel vasculitis which may variously affect upper and lower respiratory tract. Patients with microscopic polyangiitis (MPA) and, less commonly, granulomatosis with polyangiitis (GPA), especially those who are ANCA-MPO-positive, may suffer from interstitial lung disease (ILD), which is associated with high morbidity and mortality as it is often underdiagnosed and responds poorly to conventional treatments

Objectives

In this study, we aimed to assess whether Krebs von den Lungen-6 (KL-6), a marker of fibrotic ILD, may be useful for distinguishing AAV patients with ILD from those without ILD, and whether its changes over time are correlated with disease activity.

Methods

We enrolled all consecutive patients evaluated in the period December 2020 - November 2021. Inclusion criteria were a diagnosis of GPA or MPA, active disease, and eligibility for Rituximab treatment according to EULAR recommendations. All patients underwent concomitant rheumatological and pneumological evaluation, lung function tests, routine blood tests, autoimmunity evaluation and KL-6 assay. Current and previous treatments, Birmingham vasculitis score (BVAS) and vasculitis damage index were also recorded.

Results

A total of 13 patients (Table 1) were enrolled. One was excluded due to a concomitant diagnosis of lung cancer. Higher serum KL-6 were in AAV-ILD compared with those without ILD (972.8±398.5 vs 305.4±93.9, p=0.0040). Area under the Receiver Operating Characteristics curve showed 100% of the diagnostic performance of KL-6 for identifying the ILD involvement (accuracy 91.7%) and the best cutoff value of 368 U/mL (Sensitivity 100% and specificity 87.5%). The decision-tree model showed a 33% improvement in class purity using a cut-off value of 513 U/mL to distinguish AAV patients with and without ILD (Figure 1). Stratifying AAV patients as MPA and GPA with and without ILD considering T0 and T1 KL-6, the model obtained an improvement of 40% for classifying GPA non-ILD with a T0 serum KL-6 cut-off value of 513 U/mL and a T1 KL-6 cut-off of 301 U/mL. A direct correlation was found between serum T0 KL-6 and T0 BVAS (r=0.578, p=0.044).

Table 1.

Patients’ features

Sex/ageDiagnosisLength of disease * (months)Organs involvedType of lung involvementT0 KL6 levelsT0 BVAST0 VDIT1 KL6 levelsT1 BVAST1 VDIF/83MPA28Lung, kidney, PNSILD, alveolar hemorrhage6258732507M/48GPA1Lung, kidney, nose, eyeNodules35218027920F/55GPA252Lung, skinNodules40115360233F/38MPA1Skin-34760---F/74MPA180Kidney, PNS-36811541405M/77MPA8Lung, kidney, PNS, skinILD, alveolar hemorrhage982241---F/49GPA60Nose, eye-1226211602M/60MPA40Skin, PNS-20591---F/39GPA4Nose-31063---M/71GPA24Lung, eye, jointsNodules, ILD152893---F/64MPA24LungILD7564-10030-F/59GPA72LungNodules3384--0-Figure 1.

ROC curve and decision tree model

Conclusion

Our multicentre study demonstrated KL-6 as a reliable, non-invasive and easy-to-perform marker of ILD in AAV patients and its helpfulness for disease activity assessment. Changes in serum concentrations of KL-6 over time could be useful for monitoring AAV patients. Further study of KL-6 as a marker of response to therapy during long-term follow-up would also be worthwhile.

Disclosure of Interests

None declared

Work productivity in rheumatoid arthritis patients from two Latin American countries treated with tofacitinib or biological DMARDs

OBJECTIVE

To evaluate work productivity of adult Latin American patients with rheumatoid arthritis (RA) treated with tofacitinib and biological disease-modifying anti-rheumatic drugs (bDMARDs) measured by the Work Productivity and Activity Impairment (WPAI) in RA questionnaire at 0- and 6-month follow-up.

METHODS

This non-interventional study was performed in Colombia and Peru. Evaluated the effects of tofacitinib and bDMARDs in patients with RA after failure of conventional DMARDs. The WPAI-RA questionnaire was administered at baseline and at the 6-month (±1 month) follow-up. The results are expressed as least squares means (LSMs), and standard errors (SEs).

RESULTS

One hundred patients treated with tofacitinib and 70 patients treated with bDMARDs were recruited. Twenty-eight percent of patients from the tofacitinib group and 40.0% from the bDMARDs group were working for pay at baseline. At month 6, the changes in absenteeism, presenteeism, and work impairment due to health were -18.3% (SE 7.7), -34.8% (SE 5.9), and -11.0% (SE 16.5), respectively, in the tofacitinib group and -19.4% (SE 8.0), -34.8% (SE 6.2), and -15.9% (SE 15.0), for the bDMARD group.

CONCLUSION

For patients who reported working, there were improvements in presenteeism, absenteeism, and work impairment due to health in both groups.

TRIAL REGISTRATION

NCT03073109.

Germline pathogenic variants in Mexican patients with hereditary triple-negative breast cancer

Objective. Describe the prevalence of breast cancer (BC)- associated germline pathogenic variants (PVs) among Mexican patients with triple-negative BC (TNBC). Materials and methods. The spectrum of PVs identified among patients with TNBC who were enrolled in a prospective registry and underwent genetic testing was analyzed. Results. Of 387 patients with invasive TNBC and a median age at diagnosis of 39 years (range 21-72), 113 (29%) were carriers of PVs in BC-susceptibility genes: BRCA1 (79%), BRCA2 (15%), and other (6%: ATM, BRIP1, PALB2, PTEN, RAD51C, and TP53). PV carriers were younger at BC diagnosis (37 vs. 40 years, p=0.004) than non-carriers. Conclusion. A large proportion of TNBC in Mexican patients is associated with germline PVs, the vast majority in BRCA. The incremental yield of PVs in other BC-susceptibility genes was modest, and a stepwise approach starting with BRCA testing may be justified if it is more cost-effective than multigene panel testing.

Abstract P3-13-07: A comprehensive germline genetic landscape in young Jewish & Arab women with breast cancer

Background: After decades of research on Ashkenazi Jewish (AJ) founder mutations in BRCA1 and BRCA2 (BRCA), there is still little known about genetics in non-AJ and Arab breast cancer populations in Israel and non-BRCA pathogenic variants (PV) in the total population. We used multigene panel testing (MGPT) to characterize the spectrum and prevalence of PV in cancer susceptibility genes in various Jewish and Arab demographic subgroups. Methods: A population-based cohort of women diagnosed with breast cancer before the age of 46 in a defined geographical area in Northern Israel was recruited as part of the BCINIS study and underwent MGPT. Probability matrices of proportion of PV by gene, and by ethnic sub-group (AJs, Sephardi Jews of North African origin, Sephardi Jews of other Eastern origins, Arabs), age-sub-group (35 and under, 36-45) and first-degree family history of breast, ovary or pancreatic cancer were calculated. Results: Overall, 1650 women were tested, including 1012 Jewish, 530 Arab and 108 non-Jewish/non-Arab women. We detected 375 PV among 363 women (22.7%): 212 in AJ (33.4% of AJs), 61 in Sephardi Jews (14.2% of Sephardi), and 69 in Arabs (13.0% of Arab). Only 162 of the PV (43.2%) were the BRCA AJ founders, another 39 BRCA PV (10.4%) were reported previously, while 15 BRCA PV (4.0%) are likely private. The remaining non-BRCA PV (42.4%) were distributed across 18 genes, with findings predominantly in CHEK2, MUTYH, ATM, BLM, ERCC3, PALB2, and FANCA. The prevalence of PV varied significantly across the ancestral subsets, from 95.5% probability in AJ women diagnosed before age 36 and with first degree family history to only 9.3% in Arab women diagnosed at age 36-45 and without family history. Conclusions: In this comprehensive, population-based, cohort of women with young onset breast cancer, the presence of PV in more than 15 genes is compelling and informs a necessarily broader approach to genetic testing and counseling.

Citation Format: Gad Rennert, Bita Nehoray, Flavio Lejbkowicz, Sara Dishon, Shiri Kalet, Joseph Herzog, Thomas Slavin, Danielle Castillo, Kevin Tsang, Sharon Sand, Hedy S Rennert, Jeffrey Weitzel. A comprehensive germline genetic landscape in young Jewish & Arab women with breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-13-07.

Pathogenic variants among Mexican patients with colorectal cancer referred for genetic cancer risk assessment

69

Background: Lynch syndrome (LS) is the most frequent hereditary cancer syndrome among patients with colorectal cancer. Screening tests such as immunohistochemistry (IHC) for mismatch repair (MMR) proteins and PREMM5 model help to identify patients at risk of germline pathogenic variants (PVs). However, there has been a disparity in that evaluation of these screening tools and their correlation with pathogenic variants (PVs) has been limited in Hispanic populations. Methods: Patients with colorectal cancer referred for genetic cancer risk assessment were enrolled in the Clinical Cancer Genomics Community Research Network (CCGCRN) registry from October 2017 to February 2021 at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Genetic testing was performed by full sequencing of the MMR genes ( MLH1, PMS2, MSH2, MSH6 and EPCAM) and other cancer-associated genes ( APC, BRCA1, BRCA2, TP53, NF1, ATM, CHEK2, PALB2, BRIP1) and multiplex ligation dependent probe amplification to detect copy number variants (CNV) was performed for selected genes. Demographic, clinical characteristics and IHC results were obtained from clinical records. MMR PV probability was calculated using PREMM5. Results: Sixty-nine patients with colorectal cancer were included; mean age at diagnosis was 50 (26-82) years and 39/69 (56%) were women. A MMR gene PV was identified in 23/69 patients (33%); most frequently in MLH1 n = 14, followed by MSH2 n = 2, MSH6 n = 2 and PMS2 n = 1. Four recurrent PVs in MLH1 and MSH2 represented 22% of PVs. CNVs were identified in 4/23 (17.4%) patients with LS. PVs in other genes were identified in 8.6% of the cases: 2 ATM, 1 APC, 1 PALB2, 1 BRIP1 and 1 BRCA1. IHC results were available in 52/69 cases (75.4%) and MMR protein deficiency was found in 16/17 (94%) carriers and in 14/31 (45%) non-carriers (sensitivity 94.1% and specificity 54.8%). The area under the ROC curve for PREMM5 score was 0.94 (95% CI 0.88-0.99) with a mean score 31.6 (2.4-50) in patients with LS and 4.1 (0.9-50) in non-carriers. The diagnosis of a second primary colon cancer was more frequent among LS (30% vs 2.5%; p < 0.01). Conclusions: We found a high frequency of MMR gene PVs among patients referred for GCRA with personal history of colon cancer, and only a small proportion with PVs in other genes. Our results showed a good performance of PREMM5 model and a high sensitivity of MMR IHQ in a Mexican population, indicating that these are tools that can be used to prioritize patient selection for germline testing.

Germline pathogenic variants among Mexican patients with adenocarcinoma of the pancreas

540

Background: The reported frequency of germline pathogenic variants (PVs) in patients with pancreatic cancer is 8-10%. Depending on the setting, pancreatic cancer-associated germline PVs in the BRCA and CDKN2A genes are the most commonly detected. The mismatch repair genes (MMR; Lynch syndrome) , TP53, STK11, ATM and PALB2 are also associated with an increased risk of pancreatic cancer . The identification of PVs in patients with pancreatic cancer is important as there may be a benefit of targeted therapies, such as PARP inhibitors for cases with defective double strand break repair or response to immunotherapy with defective MMR and high tumor mutational burden. Additionally, identification of predisposing PVs can enable screening and prevention for other family members through cascade testing. According to international guidelines, all patients diagnosed with exocrine pancreatic cancer are candidates for genetic testing. However, there is an underrepresentation of ethnic/ racial minorities, including Hispanic patients, in genetic studies. Methods: Between April 2017 and May 2020, patients with diagnosis of pancreatic adenocarcinoma who were treated at the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán and enrolled in the international Clinical Cancer Genomics Community Research Network registry were included in this analysis. Genetic testing was performed by full sequencing of the following genes: BRCA1, BRCA2, TP53, NF1, ATM, CHEK2, PALB2, CDKN2A, BRIP1, RAD50, RAD51C, RAD51D, MLH1, MSH2, MSH6, PMS2 and EPCAM, as well as multiplex ligation-dependent probe amplification for selected genes and BRCA1 ex9-12del (Mexican founder mutation) screening with a three-primer polymerase chain reaction. Pedigrees, clinical and demographic data were obtained from the clinical records. Results: Forty-two patients with a diagnosis of pancreatic adenocarcinoma were included, with a median age at diagnosis of 57 years (range, 43-79), and 23/42 (55%) were women. The proportion of cases with operable, unresectable and metastatic disease at diagnosis was similar (33.3% for each group). The frequency of PVs was 11.9% ( ATM n =2, TP53 n =1, PALB2 n =1 and CHEK2 n =1). With a median follow-up 20 months 29/42 patients had died at the time of analysis (69%), the median overall survival was 16 months (range 3-84 months). No PVs were detected in the 4/42 patients who met the definition of familial pancreatic cancer (9.5%). Conclusions: Our results confirm the presence of PVs in cancer susceptibility genes in Mexican patients with pancreatic cancer, which is similar to that reported in other populations. However, it is notable that no BRCA PVs were identified in this small sample, as they are the most common PV found in other populations. Given to the heterogeneity of the PVs identified, our study supports the use of multi- gene panel testing in Hispanic patients with pancreatic cancer.

Influence of germline BRCA genotype on the survival of patients with triple-negative breast cancer

The presence of BRCA pathogenic variants (PVs) in triple-negative breast cancer (TNBC) is associated with a distinctive genomic profile that makes the tumor particularly susceptible to DNA-damaging treatments. However, patients with BRCA PVs can develop treatment resistance through the appearance of reversion mutations and restored BRCA expression. As copy-number variants (CNV) could be less susceptible to reversion mutations than point mutations, we hypothesize that carriers of BRCA CNVs may have improved survival after treatment compared to carriers of other BRCA PVs or BRCA wild-type. Women diagnosed with stage I-III TNBC at ≤50 years at a cancer center in Mexico City were screened for BRCA PVs using a recurrent PV assay (HISPANEL; 77% sensitivity). The recurrence-free (RFS) and overall survival (OS) were compared according to mutational status. Among 180 women, 17 (9%) were carriers of BRCA1 ex9-12del CNV and 26 (14%) of other BRCA PVs. RFS at ten years for the whole cohort was 79.2% (95% CI 72.3-84.6%), with no significant differences according to mutational status. 10-year OS for the entire cohort was 85.3% (95%CI: 78.7-90.0%), with BRCA CNV carriers demonstrating numerically superior OS rates other PV carriers and non-carriers (100% vs. 78.6% and 84.7%; log-rank p=0.037 and p=0.051, respectively). This study suggests that BRCA1 ex9-12del CNV carriers with TNBC may have a better OS, and supports the hypothesis that the genotype of BRCA PVs may influence survival by limiting treatment resistance mediated by reversion mutations among CNV carriers.

Evaluation of TP53 Variants Detected on Peripheral Blood or Saliva Testing: Discerning Germline From Somatic TP53 Variants

PURPOSE

Multigene panel testing (MGPT) identifies TP53 pathogenic or likely pathogenic (P/LP) variants in patients with diverse phenotypes, of which only one is classic Li-Fraumeni syndrome. Low variant allelic fraction (VAF) in TP53 found on germline testing may suggest aberrant clonal expansion or constitutional mosaicism. We evaluated TP53-positive probands seen in a cancer genetics program to determine germline versus somatic status.

METHODS

We reviewed TP53-positive probands from 2012 to 2019 identified by MGPT on blood or saliva (N = 84). Available VAFs were collected. Probands with a familial variant, who met Li-Fraumeni syndrome testing criteria or who carried a founder variant, were considered germline. For those with uncertain germline status, TP53 variants were further examined using ancillary data of family members and somatic tissue.

RESULTS

Of the 84 probands, 54.7% had germline variants with 33.3% meeting criteria for germline status and 21.4% confirmed through ancillary testing. Aberrant clonal expansion comprised 13.1% with clonal hematopoiesis of indeterminate potential and 2.4% with a hematologic malignancy. Constitutional mosaicism was confirmed in 8.3% probands. Definitive status could not be determined in 3.6% despite ancillary assessment, and 17.9% did not have ancillary testing.

CONCLUSION

A TP53 P/LP variant found on peripheral blood or saliva MGPT does not always originate in the germline. In a clinical cancer genetics cohort, approximately half of the patients had TP53 P/LP germline variants; these patients plus those with constitutional mosaicism require intensified surveillance. A framework of multiple strategies enables discernment of germline from constitutional mosaic and acquired variants, which is essential for appropriate management.

Maintaining access to genomic cancer risk assessment (GCRA) during the COVID-19 pandemic using telemedicine in a resource-limited setting

286

Background: COVID-19 has disrupted cancer care services globally, and particularly in low- and middle-income countries. The cancer genetics clinic at Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán has provided GCRA for over 1000 underserved Mexican patients with cancer since 2017 through a collaboration with the Clinical Cancer Genomics Community Research Network (CCGCRN). During the COVID-19 pandemic, in-person clinic visits were suspended, and telemedicine emerged as a potential way to provide GCRA while reducing the risk of COVID-19. Here, we report our experience using telemedicine to provide GCRA in a resource-limited setting. Methods: During the COVID-19 pandemic, new patients meeting criteria for GCRA were invited to join the CCGCRN via phone call. Candidates received detailed information regarding the protocol procedures and multigene genetic testing. Those who accepted were sent an electronic consent form, family medical history forms, and risk reduction questionnaires to be completed before their appointment. Blood testing was performed during a short visit to the hospital, or mailed by the patient. Patients who had already received GCRA and genetic testing prior to the start of the pandemic were contacted to cancel their in-person appointment and to schedule a telemedicine visit. According to patient preferences and availability, results were disclosed via phone call, video call, or teleconferencing software employing end-to-end encryption communication apps. Results: Between July 2020 and May 2021, 273 new patients fulfilling GCRA criteria were invited to the CCGCRN protocol. Median age at the time of enrollment was 44 years (range 27-66), 87% (n = 237) were women, and 68% (n = 187) had a personal history of cancer (90% breast). Eighty-three percent of new patients (n = 227) completed all the protocol procedures. Median length of the enrollment phone call was 10 minutes (range 4-71 min). During the same period, 439 genetic testing results (including those of patients who received GCRA before the pandemic and of new patients) were disclosed: 356 were negative and 83 had a pathogenic variant (PV). Ninety-nine percent of patients with negative testing received their results via phone call, and 96% were sent a digital written report. For patients with a PV, 80% of results were disclosed via videoconferencing platforms (WhatsApp or Zoom). All patients with PV were sent a digital written report, risk reduction and early detection recommendations, a family letter, and specific PV information. Conclusions: Providing access to GCRA and testing using readily-available telemedicine platforms proved feasible in a resource-limited setting during the COVID-19 pandemic. Our results show that telemedicine represents an excellent method to identify, recruit, and test patients meeting criteria for GCRA, and to provide genetic testing results.

Genetic epidemiology of BRCA1- and BRCA2-associated cancer across Latin America

The prevalence and contribution of BRCA1/2 (BRCA) pathogenic variants (PVs) to the cancer burden in Latin America are not well understood. This study aims to address this disparity. BRCA analyses were performed on prospectively enrolled Latin American Clinical Cancer Genomics Community Research Network participants via a combination of methods: a Hispanic Mutation Panel (HISPANEL) on MassARRAY; semiconductor sequencing; and copy number variant (CNV) detection. BRCA PV probability was calculated using BRCAPRO. Among 1,627 participants (95.2% with cancer), we detected 236 (14.5%) BRCA PVs; 160 BRCA1 (31% CNVs); 76 BRCA2 PV frequency varied by country: 26% Brazil, 9% Colombia, 13% Peru, and 17% Mexico. Recurrent PVs (seen ≥3 times), some region-specific, represented 42.8% (101/236) of PVs. There was no ClinVar entry for 14% (17/125) of unique PVs, and 57% (111/196) of unique VUS. The area under the ROC curve for BRCAPRO was 0.76. In summary, we implemented a low-cost BRCA testing strategy and documented a significant burden of non-ClinVar reported BRCA PVs among Latin Americans. There are recurrent, population-specific PVs and CNVs, and we note that the BRCAPRO mutation probability model performs adequately. This study helps address the gap in our understanding of BRCA-associated cancer in Latin America.

A Novel, Likely Pathogenic MAX Germline Variant in a Patient With Unilateral Pheochromocytoma

Context

Inherited MYC-associated factor X (MAX) gene pathogenic variants (PVs) increase risk for pheochromocytomas (PCCs) and/or paragangliomas (PGLs) in adults and children. There is little clinical experience with such mutations.

Objective

This report highlights an important approach.

Methods

Clinical assessment, including blood chemistry, imaging studies, and genetic testing were performed.

Results

A 38-year-old Hispanic woman was diagnosed with PCC in 2015, treated with adrenalectomy, and referred to endocrinology clinic. Notably, she presented to her primary care physician 3 years earlier complaining of left flank pain, intermittent diaphoresis, and holocranial severe headache. We confirmed severe hypertension (180/100 mm Hg) over multiple antihypertensive regimens. Biochemical and radiological studies workup revealed high plasma metanephrine of 255 pg/mL (normal range, < 65 pg/mL) and plasma normetanephrine of 240 pg/mL (normal range, < 196 pg/mL). A noncontrast computed tomography scan of the abdomen revealed a 4.2 × 4.3 × 4.9-cm, round-shaped and heterogenous contrast enhancement of the left adrenal gland, and a 2-mm nonobstructive left kidney stone. A presumptive diagnosis of secondary hypertension was made. After pharmacological therapy, laparoscopic left adrenalectomy was performed and confirmed the diagnosis of pheochromocytoma. Based on her age, family history, and a high suspicion for genetic etiology, genetic testing was performed that revealed the presence of a novel likely pathogenic variant involving a splice consensus sequence in the MAX gene, designated c0.64-2A > G.

Conclusion

The phenotype of MAX PV-related disease and paraganglioma are highlighted. The novel c0.64-2A > G mutation is reported here and should be considered in the diagnostic workup of similar cases.

Development and Pilot Implementation of the Genomic Risk Assessment for Cancer Implementation and Sustainment (GRACIAS) Intervention in Mexico

PURPOSE

Genomic cancer risk assessment (GCRA) is standard-of-care practice that uses genomic tools to identify individuals with increased cancer risk, enabling screening for early detection and cancer prevention interventions. GCRA is not available in most of Mexico, where breast cancer (BC) is the leading cause of cancer death and ovarian cancer has a high mortality rate.

METHODS

Guided by an implementation science framework, we piloted the Genomic Risk Assessment for Cancer Implementation and Sustainment (GRACIAS) intervention, combining GCRA training, practice support, and low-cost BRCA1/2 (BRCA) gene testing at four centers in Mexico. The RE-AIM model was adapted to evaluate GRACIAS intervention outcomes, including reach, the proportion of new patients meeting adapted National Comprehensive Cancer Network criteria who participated in GCRA. Barriers to GCRA were identified through roundtable sessions and semistructured interviews.

RESULTS

Eleven clinicians were trained across four sites. Mean pre-post knowledge score increased from 60% to 67.2% (range 53%-86%). GCRA self-efficacy scores increased by 31% (95% CI, 6.47 to 55.54; P = .02). Participant feedback recommended Spanish content to improve learning. GRACIAS promoted reach at all sites: 77% in Universidad de Guadalajara, 86% in Instituto Nacional de Cancerología, 90% in Tecnológico de Monterrey, and 77% in Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Overall, a pathogenic BRCA variant was identified in 15.6% (195 of 1,253) of patients. All trainees continue to provide GCRA and address barriers to care.

CONCLUSION

We describe the first project to use implementation science methods to develop and deliver an innovative multicomponent implementation intervention, combining low-cost BRCA testing, comprehensive GCRA training, and practice support in Mexico. Scale-up of the GRACIAS intervention will promote risk-appropriate care, cancer prevention, and reduction in related mortality.

Nearly half of TP53 variants are misattributed to Li-Fraumeni syndrome: A clinical evaluation of individuals with TP53 variants detected by hereditary cancer panel assays on blood or saliva

10501

Background: Multigene panel testing (MGPT) has identified TP53 pathogenic or likely pathogenic (P/LP) variants in patients with diverse phenotypes from no cancer to classic Li-Fraumeni syndrome (LFS). There is increasing recognition of variants at low allelic fraction (VAF) for TP53 in particular, which can be suggestive of post-zygotic mosaicism or aberrant clonal expansion (ACE), comprising clonal hematopoiesis of indeterminate potential (CHIP) or occult hematologic neoplasia. Distinguishing among these categories is essential because of widely different cancer risk and management implications for patients and their relatives. We report an evaluation of TP53 positive probands to determine germline versus somatic status from a cancer genetics clinic. Methods: We reviewed probands with TP53 P/LP variants by MGPT on blood (N = 83) or saliva (N = 1) samples from 2012-2019. Available VAFs were collected from commercial testing laboratories. Probands positive for a known familial variant, who met LFS testing criteria without indication of low VAF, or who carried the Brazil founder p.R337H variant were considered germline. For those with uncertain germline status, data was obtained from ancillary testing of family members, cultured skin fibroblasts, and other somatic benign or tumor tissues. TP53 variants were further categorized based on all available data. Results: Of the 84 probands, 28 (33%) had germline TP53 P/LP variants determined by above initial criteria; 18 (21%) were confirmed germline through ancillary testing. Seven (8%) individuals were classified as having constitutional mosaicism. In eleven (13%) individuals, the TP53 variants were consistent with ACE, in 9 (11%) with CHIP and in 2 (2%) with a hematologic malignancy (1 CLL, 1 NHL). Five (6%) cases could not be categorized despite ancillary testing. Fifteen (18%) probands declined any further workup. Conclusions: A TP53 P/LP variant found on peripheral blood or saliva MGPT does not always originate in the germline. In a clinical cancer genetics cohort, only 54% of patients had TP53 P/LP germline variants; these patients plus those with constitutional mosaicism (8%) require intensified surveillance. Assessment of VAF, family member testing, and analysis of TP53 in cultured fibroblasts or other tissue samples may distinguish germline and constitutional mosaic variants from the ACE spectrum. Expanding use of MGPT will increase this clinical challenge, which may motivate the modification of lab reports to include VAF and possible non-germline explanations. The findings of this study support a framework of multiple strategies to discern true constitutional status of a TP53 P/LP variant.

AB0666 PROGNOSTIC VALUE OF SERUM KREBS VON DEN LUNGEN-6 GLYCOPROTEIN CIRCULATING LEVELS IN COVID-19 PNEUMONIA: A PROSPECTIVE COHORT STUDY

Background:

Currently, there are no biomarkers to predict respiratory worsening in patients with Coronavirus infectious disease, 2019 (COVID- 19) pneumonia.

Objectives:

We aimed to determine the prognostic value of Krebs von de Lungen-6 circulating serum levels (sKL-6) predicting COVID- 19 evolving trends.

Methods:

We prospectively analyzed the clinical and laboratory characteristics of 375 COVID- 19 patients with mild lung disease on admission. sKL-6 was obtained in all patients at baseline and compared among patients with respiratory worsening.

Results:

45.1% of patients developed respiratory worsening during hospitalization. Baseline sKL-6 levels were higher in patients who had respiratory worsening (median [IQR] 303 [209-449] vs. 285.5 [15.8-5724], P=0.068). The best sKL-6 cut-off point was 408 U/mL (area under the curve 0.55; 33% sensitivity, 79% specificity). Independent predictors of respiratory worsening were sKL-6 serum levels, age >51 years, time hospitalized, and dyspnea on admission. Patients with baseline sKL-6 ≥ 408 U/mL had a 39% higher risk of developing respiratory aggravation seven days after admission. In patients with serial determinations, sKL-6 was also higher in those who subsequently worsened (median [IQR] 330 [219-460] vs 290.5 [193-396]; p<0.02).

Conclusion:

sKL-6 has a low sensibility to predict respiratory worsening in patients with mild COVID-19 pneumonia. Baseline sKL-6 ≥ 408 U/mL is associated to a higher risk of respiratory worsening. sKL-6 levels are not useful as a screening tool to stratify patients on admission but further research is needed to investigate if serial determinations of sKL-6 may be of prognostic use.

References:

[1]Zhou F, Yu T, Du R, Fan G, Liu Y, Liu Z, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet. 2020;395(10229):1054-62. 5.

[2]Tian W, Jiang W, Yao J, Nicholson CJ, Li RH, Sigurslid HH, et al. Predictors of mortality in hospitalized COVID-19 patients: A systematic review and meta-analysis. J Med Virol. 2020.

[3]Wang D, Li R, Wang J, Jiang Q, Gao C, Yang J, et al. Correlation analysis between disease severity and clinical and biochemical characteristics of 143 cases of COVID-19 in Wuhan, China: a descriptive study. BMC Infect Dis. 2020;20(1):519.

Disclosure of Interests:

None declared.

Abstract PS8-25: Genetic cancer risk assessment and its impact on the uptake of cancer risk reduction strategies: The experience of a Mexican center

Background: The implementation of genetic cancer risk assessment (GCRA) in resource-constrained settings is limited due to multiple factors, including insufficient access to preventive strategies. In our center, GCRA was formally established in 2014, and access to genetic testing is provided to underserved patients through a research collaboration with City of Hope's CCGCRN. The aim of this study is to determine the proportion of patients with germline mutations that underwent risk-reducing surgeries (RRS) and followed recommended breast cancer (BC) screening strategies.

Methods: Patients that received GCRA in a center located in Monterrey, Mexico who met NCCN criteria for testing for BC predisposition genes were eligible. Information on mutation status, performance of RRS and BC screening strategies was prospectively collected. The patients were grouped by type of healthcare (i.e. private vs public), with differences explored using Fisher's exact or Mann Whitney U tests, as appropriate.

Results: Between 2014 and 2019, a total of 437 probands and 139 of their relatives underwent GCRA. Of these, 23% and 37% were identified as mutation carriers, respectively: BRCA1/2 (72.5%), PALB2 (6.4%), CHEK2 (6.4%) and others (14.7%). The median time elapsed from disclosure of genetic test results to collection of data was 16 months. The median age was 41 years, with no statistical difference according to type of healthcare. Based on NCCN guidelines, 151 RRS were recommended according to mutational status and age, of which 52 (34%) were performed: 28 risk-reducing mastectomies (RRM) and 24 risk-reducing salpingo-oophorectomies (RRSO). A substantial proportion of these were funded by non-governmental organizations, while the rest were covered by public health insurance (as adjuvant treatment), private health insurance or the patient herself. Regarding BC screening, after excluding 78 patients because of active BC treatment, bilateral mastectomy or male sex, 92% of eligible patients followed NCCN recommendations. No differences in the performance of RRS or BC screening strategies were found according to type of healthcare delivery.

Conclusion: In this cohort, an adequate adherence to recommended screening strategies was observed but only one-third of recommended RRS were performed. Notably, type of healthcare was not a determining factor for the adherence to NCCN's recommended prevention strategies, suggesting that economical barriers might not be the main limiting factor. Efforts to elucidate if sociocultural barriers limit adherence to RRS are being conducted in order to enhance standard of care at Mexican centers with GCRA programs.

Characteristics according to healthcare coverage.Private insurancePublic insurancep valueMutational status- Probands: carriers/tested32/117 (27%)67/320 (21%)NS- Relatives: carriers/tested10/42 (24%)42/97 (43%)0.036RRS- RRM performed/recommended9/24 (38%)19/65 (29%)NS- RRSO performed/recommended6/18 (33%)18/44 (41%)NS- RRS covered by NGOs0 (0%)11/37 (30%)0.022Current BC screening modality- Mammogram (MMG) ± US9 (41%)33 (65%)0.033- MRI ± MMG ± US9 (41%)6 (12%)- None3 (14%)1 (2%)- Unknown1 (5%)11 (22%)Follow BC screening recommendations- Yes19 (90%)37 (93%)NS- No2 (10%)3 (8%)

Citation Format: Dione Aguilar, Alejandro Aranda-Gutierrez, Ana S Ferrigno, Jeffrey N Weitzel, Kathleen N Blazer, Danielle Castillo, Josef Herzog, Rosa Mejia, Nancy L Sada-Villarreal, Servando Cardona, Mauricio Canavati-Marcos, Margarita Garza-Montemayor, Cynthia Villarreal-Garza. Genetic cancer risk assessment and its impact on the uptake of cancer risk reduction strategies: The experience of a Mexican center [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS8-25.

Abstract PS8-15: The spectrum of germline susceptibility gene variants in Mexican patients with breast cancer (BC): A Prospective Multicenter study

Background: BRCA mutations are responsible for a significant proportion of hereditary breast and ovarian cancers. However, other cancer susceptibility genes are also associated with an increased risk of developing breast cancer (BC). In Mexico, approximately 15% of patients with BC have been identified with BRCA mutations. Despite our growing understanding of BRCA mutations, the contribution and characterization of non-BRCA mutations in Mexican patients with a BC diagnosis remains unknown. We aimed to investigate the spectrum of BC-associated mutations among Mexican patients with BC referred for genetic cancer risk assessment (GCRA) in the multinational Clinical Cancer Genomics Community Research Network (CCGCRN). Methods: Mexican patients with a primary BC who were enrolled in the IRB-approved CCGCRN registry protocol and underwent genetic counseling and multigene panel testing (MGPT) were included. Pathogenic and likely pathogenic variants (PV) in genes associated with increased BC risk were used for analyses. Clinical and demographic characteristics of BRCA and non-BRCA carriers were compared. Results: From December 2012 to February 2020, 725 Mexican patients with BC who had MGPT results with a median age (years) of 41 (range 25-76) were included. 142 (19.6%) patients carried a BC-associated PV. Of these, 98 (69.0%) carried BRCA PVs: 58 in BRCA1 (41.5%) and 40 in BRCA2 (26.7%). PVs in other BC-associated genes (n = 42) accounted for 29.5% of all observed PVs and were distributed as follows: PALB2 (n = 13), CHEK2 (n = 11), RAD51C (n = 6), ATM (n = 3), PTEN (n = 3), TP53 (n = 3), BRIP1 (n = 2), and CDH1(n = 1). Other actionable genes represented 3.5% of all PVs (PMS2 [n = 3]; MSH6 [n = 1]; MSH2 [n = 1]). Suspected founder mutations in Latinas, PALB2 c.2167_2168delAT (n = 5) and CHEK2 c.707T&gt;C (n = 9), represented 33.3% (n = 14/42) of the detected non-BRCA PVs. Mean age at first cancer diagnosis (years) for BRCA and non-BRCA carriers was: 37 (range 26-58) and 42 (range 25-76) (p&lt;0.05), respectively. Among carriers, those with BRCA PVs had a significantly greater proportion of triple-negative (TN) tumors compared to non-BRCA PVs (45.2% vs 9.5%; p&lt;0.05). Conclusion: A significant proportion of Mexican women carried a BC-associated mutation and a third were non-BRCA PVs. Among non-BRCA PVs, recurrent PALB2 and CHEK2, which had previously been characterized in BRCA-negative US Latinas with BC, were the most common and confirms their presence and clinical impact in Mexico. BRCA carriers were younger and more commonly had the TN molecular subtype.

Citation Format: Yanin Chavarri-Guerra, Cynthia Villarreal-Garza, Gubidxa Gutierrez Seymour, Dione Aguilar y Mendez, Jazmin Arteaga-Vazquez, Servando Cardona-Huerta, Adrian Daneri-Navarro, Azucena del Toro Valero, Alejandro Mohar-Betancourt, Andrés Rodríguez-Faure, Jose Luis Rodriguez-Olivares, Gregorio Quintero Beulo, Danielle Castillo, Kai Yang, Joseph Herzog, Rosa Mejia, Sharon Sand, Jeffrey N Weitzel. The spectrum of germline susceptibility gene variants in Mexican patients with breast cancer (BC): A Prospective Multicenter study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS8-15.

Tissue-Biased Expansion of DNMT3A-Mutant Clones in a Mosaic Individual Is Associated with Conserved Epigenetic Erosion

DNA methyltransferase 3A (DNMT3A) is the most commonly mutated gene in clonal hematopoiesis (CH). Somatic DNMT3A mutations arise in hematopoietic stem cells (HSCs) many years before malignancies develop, but difficulties in comparing their impact before malignancy with wild-type cells have limited the understanding of their contributions to transformation. To circumvent this limitation, we derived normal and DNMT3A mutant lymphoblastoid cell lines from a germline mosaic individual in whom these cells co-existed for nearly 6 decades. Mutant cells dominated the blood system, but not other tissues. Deep sequencing revealed similar mutational burdens and signatures in normal and mutant clones, while epigenetic profiling uncovered the focal erosion of DNA methylation at oncogenic regulatory regions in mutant clones. These regions overlapped with those sensitive to DNMT3A loss after DNMT3A ablation in HSCs and in leukemia samples. These results suggest that DNMT3A maintains a conserved DNA methylation pattern, the erosion of which provides a distinct competitive advantage to hematopoietic cells.

Clinical conundrums: Developing a strategy for discerning TP53-associated chip and coherent clinical care

1514

Background: Germline TP53 mutations are associated with Li-Fraumeni syndrome (LFS). However, approximately 20% of commercial laboratory multigene panel test (MGPT)-detected pathogenic TP53 variants represent aberrant clonal expansion (ACE), rather than a germline finding, and are often detected in individuals that lack classic features of LFS. Clonal hematopoiesis (CH) is a form of ACE, and in the absence of an abnormal hemogram is termed Clonal hematopoiesis of indeterminate potential (CHIP). CHIP is often associated with a pathogenic variant (PV) in hematopoietic pathway gene(s) at a variant allele frequency (VAF) less than expected for a heterozygous germline finding. The prevalence increases with age and exposure to chemotherapy. The presence of a skewed VAF is usually noted in a comment on a genetic test result, however, clinicians without genetic training often lack understanding of the comment and need strategies to discern the difference between germline findings, CHIP, and post-zygotic mosaicism. Our studies illuminate possible strategies for discernment for clinicians. Methods: Among 113 cases with MGPT-detected TP53 PVs, enrolled in the Clinical Cancer Genomics Community Research Network registry, we obtained additional tissues, family history and complete blood count (CBC) reports on 42 cases. DNA extracted from formalin fixed paraffin embedded (FFPE) tumor/normal tissues, blood, saliva, eyebrow plucks, was analyzed using a previously validated custom myeloid and CH gene (n = 79) amplicon-based QIAseq panel. PVs with VAF > 2% were included in analyses. Results: Germline status was confirmed for 6 cases (one with a CH PV), post-zygotic mosaicism was supported for 5 cases and 2 were indeterminant. 12 had results supporting ACE/CH, with additional CH-associated PV(s) identified in 5/12 (41%); n = 2 of each TET2, ATM, TP53; and increasing VAF over time for the driver TP53 PV was noted in 2. Of these 2 one was identified to have a hematopoietic malignancy identified through analysis of the CBCs and bone marrow biopsy in parallel with the increasing VAF. Additional results are pending for 7 cases. Conclusions: With the use of our multi-tissue NGS strategy, serial sampling of suspected ACE/CH cases, family history and CBC analyses we were able to discern the status of most TP53 genetic findings. This work has direct translational impact, refining risk estimation and improving the clinical care of patients with TP53 PVs, while avoiding unnecessary LFS-related care and enabling appropriate care for those with ACE.

Communication of genetic testing results and cascade testing among Mexican carriers of cancer-associated variants and their families

e13541

Background: Most hereditary cancer syndromes exhibit autosomal dominant inheritance. Therefore, communicating results to family members and performing cascade testing is crucial in order to identify individuals at risk and offer them appropriate risk-reducing strategies. The process of communicating medical information within families is highly variable and might be affected by several factors (including culture, education, understanding of results, and family conflicts) which remain understudied among individuals living in developing countries. We sought to investigate communication of results and cascade testing reach within the families of Mexican individuals carrying cancer-associated pathogenic variants (PVs). Methods: Individuals seen at a single center in Mexico City carrying a cancer-associated PV and enrolled in the Clinical Cancer Genomics Community Research Network (CCGCRN) were included. Carriers received genetic counseling at the time of results disclosure, a family letter was provided to facilitate the communication of results, and cascade testing was offered. After >3 months from results disclosure, participants were surveyed regarding genetic testing results communication patterns, performance of cascade testing, and surveillance behaviors. Data was analyzed using descriptive statistics. Results: Among 354 probands, 53 (15%) were identified as carriers of a cancer-associated PV. Mean age was 48.3 (range 21-82) years. Cascade testing (≥1 family member) was initiated in 74% of families (n = 39), with a median of 3 (range 0-16) family members tested per proband. 53 carriers responded the survey (29 probands and 24 relatives). 98% (n = 43) had shared results with their family, and 53% (24/45) had shared them with their treating physicians. Most respondents were receiving active surveillance (n = 36, 80%); with 43% (n = 15) reporting having at least one barrier for complying with surveillance (financial: n = 8; distance to the hospital: n = 3). Around half of the carriers perceived their cancer risk to be of ≥50%. Conclusions: Our results show that both the communication of genetic testing results and the proportion of cascade testing within Mexican families are high. Family involvement in health care decision-making is common in Mexico, as in other Latin American countries, which might lead to improved family communication. However, strategies to improve communication with providers are needed in order to tackle barriers and improve surveillance of individuals carrying cancer associated PVs.

Older breast cancer survivors may harbor hereditary cancer predisposition pathogenic variants and are at risk for clonal hematopoiesis

OBJECTIVE

Our goal was to identify pathogenic variants (PV) associated with germline cancer predisposition in an unselected cohort of older breast cancer survivors. Older patients with cancer may also be at higher risk for clonal hematopoiesis (CH) due to their age and chemotherapy exposure. Therefore, we also explored the prevalence of PVs suggestive of CH.

METHODS

We evaluated 44 older adults (65 years or older) diagnosed with breast cancer who survived at least two years after diagnosis from a prospective study, compared to healthy controls over the age of 65 (n = 36). DNA extracted from blood samples and a multi-gene panel test was used to evaluate for common hereditary cancer predisposition and CH PVs. Fisher's exact test was used to compare PV rates between groups.

RESULTS

Eight PVs in ATM, BRCA2 (x2), PALB2, RAD51D, BRIP1, and MUTYH (x2) were identified in 7 of 44 individuals with breast cancer (15.9%, 95% CI: 7-30%), whereas none were identified in healthy controls (p = .01). Results remained statistically significant after removal of MUTYH carriers (p = .045). PVs indicative of CH (ATM, NBN, and PPM1D [x2]) were identified in three of 27 individuals with breast cancer who received chemotherapy and in one healthy control.

CONCLUSION

Moderate-risk and later disease onset high-risk hereditary cancer predisposition PVs were statistically significantly enriched in our survivorship cohort compared to controls. Because age- and chemotherapy-related CH are more frequent in this population, care must be taken to differentiate potential CH PVs from germline cancer predisposition PVs.

Fatiga ocasionada por diferentes formatos de juegos reducidos en futbolistas jóvenes

El principal objetivo de este estudio fue analizar la influencia de diferentes formatos de juego reducido (JR) en la carga interna medida mediante el esfuerzo percibido (CI EP) declarado por los futbolistas, y en el rendimiento del salto horizontal (SH) y la capacidad de acelerar y esprintar. Diez futbolistas cadetes (sub-16) participaron en el estudio. Los jugadores disputaron 4 formatos de JR con modificaciones en el espacio de juego y en la duración de las repeticiones. Los participantes realizaron un esprint de 30 m y un SH antes y después de cada repetición y también declararon el EP. Los resultados mostraron una mayor CI EP. Además, se observó un empeoramiento del esprint en 10 y 30 m después de la última repetición. Este conocimiento podría ayudar a los cuerpos técnicos a establecer de manera más apropiada la duración total y de cada repetición de los JRs.

Pathogenic and likely pathogenic variants in PALB2, CHEK2, and other known breast cancer susceptibility genes among 1054 BRCA-negative Hispanics with breast cancer

BACKGROUND

Breast cancer (BC) is the most common cancer and related cause of mortality among Hispanics, yet susceptibility has been understudied. BRCA1 and BRCA2 (BRCA) mutations explain less than one-half of hereditary BC, and the proportion associated with other BC susceptibility genes is unknown.

METHODS

Germline DNA from 1054 BRCA-mutation-negative Hispanic women with hereditary BC (BC diagnosed at age <51 years, bilateral BC, breast and ovarian cancer, or BC diagnosed at ages 51-70 years with ≥2 first-degree or second-degree relatives who had BC diagnosed at age <70 years), 312 local controls, and 887 multiethnic cohort controls was sequenced and analyzed for 12 known and suspected, high-penetrance and moderate-penetrance cancer susceptibility genes (ataxia telangiectasia mutated [ATM], breast cancer 1 interacting protein C-terminal helicase 1 [BRIP1], cadherin 1 [CDH1], checkpoint kinase 2 [CHEK2], nibrin [NBN], neurofibromatosis type 1 [NF1], partner and localizer of BRCA2 [PALB2], phosphatase and tensin homolog [PTEN], RAD51 paralog 3 [RAD51C], RAD51D, serine/threonine kinase 11 [STK11], and TP53).

RESULTS

Forty-nine (4.6%) pathogenic or likely pathogenic variants (PVs) in 47 of 1054 participants (4.5%), including 21 truncating frameshift, 20 missense, 5 nonsense, and 4 splice variants, were identified in CHEK2 (n = 20), PALB2 (n = 18), ATM (n = 5), TP53 (n = 3), BRIP1 (n = 2), and CDH1 and NF1 (both n = 1) and none were identified in NBN, PTEN, STK11, RAD51C, or RAD51D. Nine participants carried the PALB2 c.2167_2168del PV (0.85%), and 14 carried the CHEK2 c.707T>C PV (1.32%).

CONCLUSIONS

Of 1054 BRCA-negative, high-risk Hispanic women, 4.5% carried a PV in a cancer susceptibility gene, increasing understanding of hereditary BC in this population. Recurrent PVs in PALB2 and CHEK2 represented 47% (23 of 49) of the total, suggesting a founder effect. Accurate classification of variants was enabled by carefully controlling for ancestry and the increased identification of at-risk Hispanics for screening and prevention.

Effect of germline ATM mutations on clonal hematopoiesis

1509

Background: Clonal hematopoiesis (CH) in myeloid related-genes is associated with development of primary and secondary leukemia and atherosclerotic disease, as well as, decreased overall survival. Identification of factors beyond age and cytotoxic exposures that predispose to CH may be useful to both recognize individuals at increased risk for CH and to better understand how CH develops. We have previously shown that germline mutations in the DNA repair gene ATM may predispose to CH. We hypothesized here that heterozygous ATM germline mutation carriers would have higher rates of CH in myeloid genes compared to controls. Methods: Germline DNA samples from 34 heterozygous ATM germline mutation carriers (cases) and 22 controls without ATM germline mutations were sequenced on an Illumina 2500 using a custom 79-gene-myeloid-CH-coding-exon-amplicon-based Qiaseq panel. Read depth averaged 130x. Pathogenic and likely pathogenic CH variants (PV) above an allele fraction of 2% were used for analyses. Cases and controls were compared using a rank-sum test. Results: Cases had a higher median age (56 years, range 30-82) than controls (48 years, range 5-72). Cases and controls were similar in solid tumor cancer history and known exposure to cancer cytotoxic therapy; 73.5% vs 86.4%, and 18.1 vs 20.6%, respectively. The number of CH PV was similarly associated with age in both cases and controls (cor = 0.31, p = 0.01). Cases displayed more CH PVs than controls (total 62 vs 3 PVs, median 2 PVs vs 0, p = 10-6). Of note, cases frequently had a concomitant second (n = 10; 29% of cases) or third (n = 4; 11.8% of cases) unique ATM CH PV, whereas no ATM CH PVs were seen in controls. Even after excluding ATM CH PVs, CH PVs were more frequent in cases (p = 0.00003). After ATM CH PVs, the most frequent CH PVs in cases were in NF1 (5 PVs), BCORL1 (4 PVs), and DMNT3A (4 PVs). Conclusions: Our study supports ATM as a strong predisposition locus for myeloid gene CH. CH in ATM germline mutation carriers frequently involved unique low allele fraction PVs in ATM, suggesting ATM germline PVs are driving production of likely bi-allelic ATM inactivation in white blood cells, or complete ATM loss. Complete ATM loss may be a nidus particularly for lymphocytic leukemia, as bi-allelic ATM inactivation is a frequent somatic finding.

Enhancing access to genetic cancer risk assessment (GCRA) in Monterrey, Mexico: The beginning of a prevention program

e13150

Background: In limited-resource countries like Mexico, GCRA is not routinely provided due to elevated costs, lack of public coverage for testing and prophylactic surgeries, and limited GCRA expertise or awareness among providers and patients. Thus, GCRA services in Mexico are 20 years behind higher income countries, resulting in suboptimal care and limited opportunity for prevention. The Breast Cancer Center TecSalud established formal GCRA services for underserved patients by recruiting a cancer geneticist who provides care at no added expense to patients, building academic collaborations for training and research with City of Hope, and enabling free genetic testing through the Clinical Cancer Genomics Community Research Network, supported in part by the Breast Cancer Research Foundation. Aim: To report the uptake of the GCRA program by patients and relatives at TecSalud from January 2016 - December 2018. Methods: Eligibility includes Mexican women who meet hereditary breast cancer testing criteria and family members of mutation carriers. Risk reduction procedures are covered by Seguro Popular and/or the NGO Fundación Santos y de la Garza Evia. Results: GCRA was offered to 255 patients and 74 at risk relatives, with an increasing reach (proportion of those eligible who access the program). A significant growth of cascade testing and access to risk reduction surgery over time are noted. Conclusions: A growing number of referrals and GCRA visits shows improving reach, possibly due to engagement of the multidisciplinary team and increased patient awareness. The expansion of cascade testing and performance of risk-appropriate surgeries reflects a maturing prevention program. Key determinants of our progress are collaborations that provided us with crucial mentorship, access to genetic assays, as well as the increasing involvement of local leaders, administrators and benefactors for the establishment of vital clinical and research capacity. Multilevel efforts should continue to enhance the delivery of standard of medical care for the most vulnerable and underserved high-risk patients and families. [Table: see text]

Germline mutations and onset of lung adenocarcinoma in smokers and nonsmokers

1518

Background: Eligibility for lung cancer screening is based largely on pack-years of smoking, missing many cases. To propose additional groups for screening, this observational study evaluated whether germline mutations associated with cancer risk accelerate onset of lung adenocarcinoma (LA) in ever- and never-smokers. Methods: Patients with LA and family history of cancer were recruited from our oncology clinic and the Clinical Cancer Genomics Community Research Network. With consent, blood samples were screened by large multi-gene panel for 4 categories of germline mutation [lung cancer-associated genes ( TP53, EGFR); BRCA2; other genes in Fanconi anemia (FA) pathway; other DNA repair genes]. Accelerated failure-time models of age at LA diagnosis, adjusted for sex, ethnicity, and packs per day, were constructed for never-smokers and ever-smokers. Statistical significance, at p<0.05 limited the False Discovery Rate to 5% across 8 hypotheses. Results: In never-smokers with LA (n=104), mutated BRCA2, TP53 or EGFR were associated with younger age at diagnosis, while mutation in other FA or DNA repair gene was not. In ever-smokers with LA (n=65), mutated BRCA2 and other FA gene were associated with younger age at diagnosis, while other mutation categories were not (Table). Conclusions: Regardless of smoking history, BRCA2 mutation carriers experience accelerated onset of LA, as do never-smokers carrying TP53 or EGFR mutation and ever-smokers with mutation in FA gene other than BRCA2. With the exception of TP53 carriers (who merit whole body MRI), lung cancer screening with low-dose computed tomography, starting earlier in adulthood than usual, may be warranted for individuals with germline mutations in these genes. Age at Diagnosis of Lung Adenocarcinoma, by Germline Mutation and Smoking History, Adjusted for Sex, Ethnicity, and Packs per Day. [Table: see text]

Germline mutation profile among Hispanic women with epithelial ovarian cancer (EOC)

1584

Background: Hospital-based studies have reported a 15% prevalence of BRCA1/ BRCA2( BRCA) mutations, with a slightly higher yield of other predisposition genes on multigene panel testing (MGPT) among women with EOC, and National Comprehensive Cancer Network guidelines recommend genetic cancer risk assessment for women with EOC. However, there is limited data about the genetic epidemiology of EOC among underrepresented populations, such as Hispanics. Consequently, we determined the germline mutation profile of Hispanics with EOC, and compared them with non-Hispanics. Methods: We included all women with a personal history of EOC from the U.S. and Latin America (LatAm; Mexico, Colombia, and Peru), enrolled in the Clinical Cancer Genomics Community Research Network registry. We assessed the prevalence of pathogenic variants (PV) in BRCA1/ BRCA2( BRCA) and other genes, contrasting the germline mutation profile between Hispanics living in LatAm, U.S. Hispanics, women of Ashkenazi Jewish (AJ) ancestry in the US, and other U.S. non-Hispanics. Results: Among 1186 women with EOC (209 from LatAm, 254 U.S. Hispanics l, 78 AJ, and 645 other non-Hispanic), 262 (22%) had a PV in BRCAgenes. Hispanics from LatAm and the U.S. had a similar frequency of BRCAmutations to AJ (30.6%, 29.9%, and 38.4%, respectively; p = 0.14); while non-Hispanics showed a significantly lower frequency of BRCAmutations (14.2%, p = 0.03). The most frequently mutated gene was BRCA1(n = 197, 74.6%), followed by BRCA2(n = 67, 25.3%). Among BRCA-negative cases (n = 924), 59% (n = 545) were evaluated by MGPT and PVs were identified in 2.9% [6 Hispanics (1.2%), 3 AJ (3.8%) and 26 Non-Hispanics (4%)]), of which 66% (n = 23) were in mismatch repair genes ( MSH2, MLH1, MSH6, PMS2), and 34% (n = 12) in other EOC-associated genes ( BRIP1, NBN, PALB2, RAD51C, and RAD51D). Clinically actionable PVs in ATM (n = 4; 0.3% ) and CHEK2 (n = 6; 0.5% ) were also observed. Conclusions: Hispanics with EOC have an elevated frequency of PV, similar to that of classic founder populations such as AJ, and significantly higher than other non-Hispanics. This is partially explained by a high prevalence of recurrent LatAm-specific PV, highlighting the importance of conducting genetic studies in underrepresented populations. There was modest incremental benefit of MGPT.

Prospective Study of Cancer Genetic Variants: Variation in Rate of Reclassification by Ancestry

BACKGROUND

In germline genetic testing, variants from understudied ancestries have been disproportionately classified as being of uncertain significance. We hypothesized that the rate of variant reclassification likewise differs by ancestry.

METHODS

Nonbenign variants in actionable genes were collected from consenting subjects undergoing genetic testing at two Southern California sites from September 1996 through December 2016. Variant reclassifications were recorded as they were received, until February 2017 or reclassification to benign. Excluding duplicate variants (same ancestry, laboratory, classification), generalized linear models for the hereditary breast cancer genes (BRCA1/2) and other variants investigated whether rate of reclassification differed for seven categories of ancestry compared with non-Hispanic European. Models took into account laboratory, year, gene, sex, and current classification (handled as a time-dependent covariate) and were adjusted for multiple hypothesis testing.

RESULTS

Among 1483 nonbenign variants, 693 (46.7%) involved BRCA1/2. Overall, 268 (18.1%) variants were reclassified at least once. Few (9.7%) reclassified variants underwent a net upgrade in pathogenicity. For BRCA1/2 variants, reclassification rates varied by ancestry and increased over time, more steeply for ancestries with lower initial rates (African, Ashkenazi, Chinese) than for ancestries whose initial rates were high (Middle Eastern) or similar to non-Hispanic European (non-Chinese Asian, Native American, Hispanic). In contrast, reclassification rates of non-BRCA1/2 variants did not vary over time but were elevated for most minority ancestries except non-Chinese Asian and Native American.

CONCLUSIONS

For nonbenign variants in cancer-related genes, the rates at which reclassifications are issued vary by ancestry in ways that differ between BRCA1/2 and other genes.

Prospective Study of Cancer Genetic Variants: Variation in Rate of Reclassification by Ancestry

Background

In germline genetic testing, variants from understudied ancestries have been disproportionately classified as being of uncertain significance. We hypothesized that the rate of variant reclassification likewise differs by ancestry.

Methods

Nonbenign variants in actionable genes were collected from consenting subjects undergoing genetic testing at two Southern California sites from September 1996 through December 2016. Variant reclassifications were recorded as they were received, until February 2017 or reclassification to benign. Excluding duplicate variants (same ancestry, laboratory, classification), generalized linear models for the hereditary breast cancer genes (BRCA1/2) and other variants investigated whether rate of reclassification differed for seven categories of ancestry compared with non-Hispanic European. Models took into account laboratory, year, gene, sex, and current classification (handled as a time-dependent covariate) and were adjusted for multiple hypothesis testing.

Results

Among 1483 nonbenign variants, 693 (46.7%) involved BRCA1/2. Overall, 268 (18.1%) variants were reclassified at least once. Few (9.7%) reclassified variants underwent a net upgrade in pathogenicity. For BRCA1/2 variants, reclassification rates varied by ancestry and increased over time, more steeply for ancestries with lower initial rates (African, Ashkenazi, Chinese) than for ancestries whose initial rates were high (Middle Eastern) or similar to non-Hispanic European (non-Chinese Asian, Native American, Hispanic). In contrast, reclassification rates of non-BRCA1/2 variants did not vary over time but were elevated for most minority ancestries except non-Chinese Asian and Native American.

Conclusions

For nonbenign variants in cancer-related genes, the rates at which reclassifications are issued vary by ancestry in ways that differ between BRCA1/2 and other genes.

Factors Affecting β2-Microglobulin Plasma Concentration during Hemodialysis

We studied ten patients on hemodialysis (HD) treated in sequence with cuprophan (CU), ethylenevinylalcohol (EVAL), polyacrylonitrile (A-69) and polysulphone (PSP) membrane dialyzers. ß2-microglobulin (ß2m) was measured by radioimmunoassay in plasma and dialysate samples. Plasma concentrations were corrected for changes in extracellular volume (ECV). We also studied adsorption in vitro by incubating the above membranes with I-125-labelled ß2m. There were no changes in ß2m plasma concentration after HD with CU dialyzers, but a significant decrease was observed with the other membranes tested. Filtration of ß2m across the dialyzer was absent with CU and minimal with EVAL. However, large amounts were recovered from dialysate with the high-permeability dialyzers, AN-69 and PSP. In vitro studies showed that maximal adsorption capacity was obtained with AN-69 (73%) compared to 9% with CU, 4% with EVAL and 7% with PSP. In summary, ß2m clearance with PSP is achieved through greater removal of this protein by mass transport across the membrane. The mechanism by which ß2m is removed from blood during AN-69 dialysis seems to include both adsorption to and filtration by the membrane itself.

Short-term and long-term measures of cortisol in saliva and hair in atypical and non-atypical depression

BACKGROUND

Atypical depression may show lowered rather than raised short-term cortisol levels. Atypical major depressive episodes (A-MDE) may also be more closely linked to environmental factors and show overlap with somatic symptom disorders. Hair specimens allow measuring long-term cortisol levels.

METHODS

Twenty-seven A-MDE and 44 NA-MDE patients and 40 matched controls were tested. Measures of hair cortisol concentration [HCC] covering the previous 3 months and short-term cortisol parameters (six saliva specimens to assess the cortisol awakening response [CAR] and total daily cortisol output calculated as the area under the curve [AUCg]) were taken alongside measures of environmental factors and clinical variables.

RESULTS

There were no differences in HCC between the three groups (P = 0.8), and no difference in the CAR (P = 0.95). However, A-MDE showed lowered short-term cortisol output (AUCg) compared to controls (P = 0.04). A-MDE patients also reported a higher number of daily hassles, and higher levels of fatigue and impaired concentration than NA-MDE.

CONCLUSIONS

Normal long-term (HCC) and reduced short-term (AUCg) cortisol levels in A-MDE could suggest a disrupted long-term cortisol rhythm, perhaps affected by environmental factors or by certain symptoms, such as mid-nocturnal insomnia. However, other underlying explanations for these findings should also be investigated in the future.

Comparative assessment of Vibrio virulence in marine fish larvae

Vibrionaceae infections are a major obstacle for marine larviculture; however, little is known about virulence differences of Vibrio strains. The virulence of Vibrio strains, mostly isolated from vibriosis outbreaks in farmed fish, was tested in larval challenge trials with cod (Gadus morhua), turbot (Scophthalmus maximus) and halibut (Hippoglossus hippoglossus) using a multiwell dish assays with single-egg/larvae cultures. The strains differed significantly in virulence as some caused a high mortality of larva reaching 100% mortality after a few days, while others had no or only marginal effects on survival. Some Vibrio strains were pathogenic in all of the larva species, while some caused disease only in one of the species. Twenty-nine of the Vibrio anguillarum strains increased the mortality of larvae from at least one fish species; however, pathogenicity of the strains differed markedly. Other Vibrio species had no or less pronounced effects on larval mortalities. Iron uptake has been related to V. anguillarum virulence; however, the presence or absence of the plasmid pJM1 encoding anguibactin did not correlate with virulence. The genomes of V. anguillarum were compared (D. Castillo, P.W. D'Alvise, M. Middelboe & L. Gram, unpublished data) and most of the high-virulent strains had acquired virulence genes from other pathogenic Vibrio.

Genetic Gastric Cancer Susceptibility in the International Clinical Cancer Genomics Community Research Network

Few susceptibility genes for gastric cancer have been identified. We sought to identify germline susceptibility genes from participants with gastric cancer from an international hereditary cancer research network. Adults with gastric cancer of any histology, and with a germline DNA sample (n = 51), were retrospectively selected. For those without previously identified germline mutations (n = 43), sequencing was performed for 706 candidate genes. Twenty pathogenic or likely pathogenic variants were identified among 18 participants. Eight of the 18 participants had previous positive clinical testing, including six with CDH1 pathogenic or likely pathogenic variants, and two with pathogenic MSH2 and TP53 variants. Of the remaining 10, six were in BRCA1 DNA damage response pathway genes (ATM, ATR, BRCA2, BRIP1, FANCC, TP53), other variants were identified in CTNNA1, FLCN, SBDS, and GNAS. Participants identified with pathogenic or likely pathogenic variants were younger at gastric cancer diagnosis than those without, 39.1 versus 48.0 years, and over 50% had a close family member with gastric cancer (p-values < 0.0001). In conclusion, many participants were identified with mutations in clinically-actionable genes. Age of onset and family history of gastric cancer were mutation status predictors. Our findings support multigene panels in identifying gastric cancer predisposition.

A systematic review and meta-analysis of the treatment of anal fissure

BACKGROUND

Anal fissure has a very large number of treatment options. The choice is difficult. In an effort to assist in that, choice presented here is a systematic review and meta-analysis of all published treatments for anal fissure that have been studied in randomized controlled trials.

METHODS

Randomized trials were sought in the Cochrane Controlled Trials Register, Medline, EMBASE and the trials registry sites clinicaltrials.gov and who/int/ictrp/search/en. Abstracts were screened, full-text studies chosen, and finally eligible studies selected and abstracted. The review was then divided into those studies that compared two or more surgical procedures and those that had at least one arm that was non-surgical. Studies were further categorized by the specific interventions and comparisons. The outcome assessed was treatment failure. Negative effects of treatment assessed were headache and anal incontinence. Risk of bias was assessed for each study, and the strength of the evidence of each comparison was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach.

RESULTS

One hundred and forty-eight eligible trials were found and assessed, 31 in the surgical group and 117 in the non-surgical group. There were 14 different operations described in the surgical group and 29 different non-surgical treatments in the non-surgical group along with partial lateral internal sphincterotomy (LIS). There were 61 different comparisons. Of these, 47 were reported in 2 or fewer studies, usually with quite small patient samples. The largest single comparison was glyceryl trinitrate (GTN) versus control with 19 studies. GTN was more effective than control in sustained cure (OR 0.68; 95% CI 0.63-0.77), but the quality of evidence was very poor because of severe heterogeneity, and risk of bias due to inadequate clinical follow-up. The only comparison to have a GRADE quality of evidence of high was a subgroup analysis of LIS versus any medical therapy (OR 0.12; CI 0.07-0.21). Most of the other studies were downgraded in GRADE due to imprecision.

CONCLUSIONS

LIS is superior to non-surgical therapies in achieving sustained cure of fissure. Calcium channel blockers were more effective than GTN and with less risk of headache, but with only a low quality of evidence. Anal incontinence, once thought to be a frequent risk with LIS, was found in various subgroups in this review to have a risk between 3.4 and 4.4%. Among the surgical studies, manual anal stretch performed worse than LIS in the treatment of chronic anal fissure in adults. For those patients requiring surgery for anal fissure, open LIS and closed LIS appear to be equally efficacious, with a moderate GRADE quality of evidence. All other GRADE evaluations of procedures were low to very low due mostly to imprecision.