Pharmacokinetic Study of Islatravir and Etonogestrel Implants in Macaques

The prevention of HIV and unintended pregnancies is a public health priority. Multi-purpose prevention technologies capable of long-acting HIV and pregnancy prevention are desirable for women. Here, we utilized a preclinical macaque model to evaluate the pharmacokinetics of biodegradable ε-polycaprolactone implants delivering the antiretroviral islatravir (ISL) and the contraceptive etonogestrel (ENG). Three implants were tested: ISL-62 mg, ISL-98 mg, and ENG-33 mg. Animals received one or two ISL-eluting implants, with doses of 42, 66, or 108 µg of ISL/day with or without an additional ENG-33 mg implant (31 µg/day). Drug release increased linearly with dose with median [range] plasma ISL levels of 1.3 [1.0-2.5], 1.9 [1.2-6.3] and 2.8 [2.3-11.6], respectively. The ISL-62 and 98 mg implants demonstrated stable drug release over three months with ISL-triphosphate (ISL-TP) concentr54ations in PBMCs above levels predicted to be efficacious for PrEP. Similarly, ENG implants demonstrated sustained drug release with median [range] plasma ENG levels of 495 [229-1110] pg/mL, which suppressed progesterone within two weeks and showed no evidence of altering ISL pharmacokinetics. Two of the six ISL-98 mg implants broke during the study and induced implant-site reactions, whereas no reactions were observed with intact implants. We show that ISL and ENG biodegradable implants are safe and yield sufficient drug levels to achieve prevention targets. The evaluation of optimized implants with increased mechanical robustness is underway for improved durability and vaginal efficacy in a SHIV challenge model.

The effect of depot medroxyprogesterone acetate on tenofovir alafenamide in rhesus macaques

Prevention of HIV infection and unintended pregnancies are public health priorities. In sub-Saharan Africa, where HIV prevalence is highest, depot medroxyprogesterone acetate (DMPA) is widely used as contraception. Therefore, understanding potential interactions between DMPA and antiretrovirals is critical. Here, we use a macaque model to investigate the effect of DMPA on the pharmacology of the antiretroviral tenofovir alafenamide (TAF). Female rhesus macaques received 30 mg of DMPA (n = 9) or were untreated (n = 9). Macaques received a human equivalent dose of TAF (1.5 mg/kg) orally by gavage. Tenofovir (TFV) and TFV-diphosphate (TFV-DP) were measured in blood, secretions, and tissues over 72 h. The median area under the curve (AUC_0-72h) values for TFV-DP in peripheral blood mononuclear cells were similar in DMPA-treated (6991 fmol*h/10⁶ cells) and untreated controls (5256 fmol*h/10⁶ cells) (P = 0.174). Rectal tissue TFV-DP concentrations from DMPA+ animals [median: 20.23 fmol/mg of tissue (range: 4.94-107.95)] were higher than the DMPA- group [median: below the limit of quantification (BLOQ-11.92)], (P = 0.019). TFV-DP was not detectable in vaginal tissue from either group. A high-dose DMPA treatment in macaques was associated with increased rectal TFV-DP levels, indicating a potential tissue-specific drug-drug interaction. The lack of detectable TFV-DP in the vaginal tissue warrants further investigation of PrEP efficacy with single-agent TAF products. DMPA did not affect systemic TAF metabolism, with similar PBMC TFV-DP in both groups, suggesting that DMPA use should not alter the antiviral activity of TAF.

Training rhesus macaques to take daily oral antiretroviral therapy for preclinical evaluation of HIV prevention and treatment strategies

Background

Macaque models of simian or simian/human immunodeficiency virus (SIV or SHIV) infection are critical for the evaluation of antiretroviral (ARV)-based HIV treatment and prevention strategies. However, modelling human oral ARV administration is logistically challenging and fraught by limited adherence. Here, we developed a protocol for administering daily oral doses of ARVs to macaques with a high rate of compliance.

Methods

Parameters of positive reinforcement training (PRT), behavioral responses and optimal drug delivery foods were defined in 7 male rhesus macaques (Macaca mulatta). Animals were trained to sit in a specified cage location prior to receiving ARVs, emtricitabine (FTC) and tenofovir alafenamide (TAF), in a blended food mixture, which was followed immediately with a juice chaser. Consistency of daily oral adherence was evaluated in 4 trained macaques receiving clinically equivalent doses of FTC and TAF (20 and 1.5 mg/kg, respectively) in a short-term (1 month) and an extended (6 month) trial. Adherence was monitored using medication diaries and by quantifying intracellular FTC-triphosphate (FTC-TP) and tenofovir-diphosphate (TFV-DP) concentrations in peripheral mononuclear blood cells (PBMCs).

Results

Trained macaques quickly and consistently took daily oral ARVs for 1 month with an average 99.8% observed adherence. Intracellular concentrations of TFV-DP (median = 845.8 fmol/million cells [range, 620.8–1031.3]) and FTC-TP (median = 367.0 fmol/million cells [range, 289.5–413.5) in PBMCs were consistent with high adherence. Extended treatment with select subjects yielded similar observations for three months (99.5% adherence, 352/356 complete doses taken), although a sudden drop in adherence was observed after splenic biopsy surgery.

Conclusions

We demonstrate that trained macaques reliably adhere to a daily oral ARV regimen, although unexpected adherence issues are possible. Our approach, using clinical doses of oral FTC and TAF daily, further refines macaque models of HIV treatment and prevention by mimicking the human route and timing of ARV administration.

Abstract P4-03-03: Germline potentially pathogenic variants in breast cancer intrinsic molecular subtypes are not associated with somatic TMB

Background: Breast cancer (BC) is a heterogeneous disease. It is estimated that 5 to 10% of all BC to have a germline genetic predisposition. A 50-gene assay (PAM50) identifies 5 intrinsic molecular subtypes (IMS): Luminal A, Luminal B, HER2-enriched, Basal-like, and Normal-like. Basal-like breast cancers are enriched for BRCA1/2 germline mutations. Deleterious mutations in BRCA1/2 or other DNA-damage repair (DDR) genes may increase tumor mutational burden (TMB), a biomarker for response to checkpoint inhibition therapy. We sought to determine the spectrum of germline mutations in molecular BC subtypes (IMS), and their relation to somatic TMB. Methods: We performed a retrospective analysis of data from NantHealth database. RNAseq was used to classify breast tumors into IMS. Germline variants within putative driver genes (COSMIC v.76) were detected in analysis of 181 whole-genomes and 89 whole-exomes sequenced using Illumina chemistry. Classification of germline variants into potentially pathogenic variants (pPv) was determined using ClinVar database annotation. Patients were categorized as TMB-high by thresholding on >200 non-synonymous exonic somatic mutations as was previously reported. Results: A total of 270 BC patients with comprehensive omics profiling (germline DNAseq, somatic DNAseq, and somatic RNAseq) were available for this analysis. The mean age (±SD) was 56.4 (± 12.5) years (range 20.8-86.5). Forty-six patients (17.0%) were classified TMB-high. The IMS distribution was 40.7% Luminal A, 31.5% Luminal B, 5.9% HER2-enriched, 21.5% Basal-like, and 0.37% Normal-like. Over 200 unique germline variants were detected of which 98 were pPv according to ClinVar annotation. These pPv spanned 21 genes, 7 of which are directly related to DDR. One hundred and four patients had ≥1 pPv (78 had only 1 pPv, and 26 had >1 pPv). The most common pPv were APC (5.9%), BRCA2 (5.2%), TSC2 (4.4%), BRCA1 (3.7%), SDHB (3.3%), SDHD (3.3%), TSC1 (3.0%), PMS2 (3.0%), MUTYH (2.6%), MSH2 (1.5%) and MSH6 (1.5%). BRCA1 and especially BRCA2 pPv were mostly seen in the basal-like patients. Luminal B had distinctly more germline pPv in PMS2, BRCA1 & BRCA2 than Luminal A. TMB-high patients were not significantly enriched for germline pPv (OR 0.73, p=0.41), even when limited to pPv in DDR genes (OR 0.69, p=0.52). TMB-high patients were present in all 4 major IMS types; Her2-enriched 37.5%, Luminal B 23.5%, Basal-like 17.2%, and Luminal A 9.1%. Conclusion: We identified differential distribution of germline pPv in BC IMS. Of the pPv found, APC was the most commonly detected pPv across subtypes, while BRCA1/2 pPv were clustered in Basal-like subtype, and PMS2 in Luminal B subtype. 17% of all patients had a pPv within at least one DDR gene, that potentially may benefit from targeted therapy. Despite IMS types having distinct germline pPv profiles especially in DDR genes, there was no association with subsequent somatic TMB. This suggests that either 1. somatic events are the primary drivers of TMB, or 2. that germline variants with either unknown or benign significance need to be revisited. Future analysis in a larger demographically well-annotated dataset (commercial data, ExAC, other) or via functional studies should be considered.

Citation Format: Obeid E, Reddy SB, Goldstein LJ, Daly MB, Benz SC, Hall MJ, Szeto C. Germline potentially pathogenic variants in breast cancer intrinsic molecular subtypes are not associated with somatic TMB [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-03-03.

Abstract PD6-05: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Kehm RD, Phillips K-A, Daly MB, Andrulis IL, Liao Y, Ma X, Zeinomar N, MacInnis RJ, Dite GS, John EM, Buys SS, Milne RL, Hopper JL, Terry MB. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD6-05.

Abstract P4-09-02: Validation of iPrevent using the prospective family study cohort (ProF-SC)

Background: iPrevent (https://www.petermac.org/iprevent) provides women with highly-tailored risk management information after first estimating their breast cancer (BC) risk using the established risk prediction models, IBIS and BOADICEA. iPrevent has an internal switching algorithm that governs which model is used for each woman, depending on her risk factor data (i.e. LCIS/atypical hyperplasia status, BRCA status, and cancer family history). This study assessed the calibration and discriminatory accuracy of the 10-year BC risk estimates provided by iPrevent. Methods: Subjects were 16,574 women in the ProF-SC, aged 18-70 years and without BC or bilateral mastectomy at recruitment. After 10 years follow-up, 655 women (4%) were diagnosed with invasive BC. A “batch mode” for iPrevent is not available, so the iPrevent-assigned cumulative 10-year invasive BC risks were calculated by entering self-reported risk factors at cohort entry into either the IBIS (10,169 women) or BOADICEA (6,405 women) software packages (according to the iPrevent switching algorithm). To assess calibration, the mean iPrevent-assigned risk was compared with the mean 10-year observed invasive BC incidence, using a chi-squared goodness-of-fit statistic for the whole cohort, and by quartiles of risk. To evaluate discriminatory accuracy, the overall area under the receiver operating characteristic curve (AUC) for the development of invasive BC within 10 years was computed. Data were censored at date of invasive or in situ BC diagnosis, bilateral mastectomy, death, loss to follow-up, or at 10 years of follow-up. Results: For the whole cohort, iPrevent assigned risk was well-calibrated – 690 expected BCs (E) 655 observed (O) (E/O=1.05, 95% CI: 0.98-1.14), although for women in the highest risk quartile, i.e. >6% 10-year risk, E/O=1.19, 95% CI: 1.07-1.32. The AUC was 0.70, 95% CI: 0.68-0.72. Conclusions: iPrevent is well calibrated overall and has good discriminatory accuracy for predicting 10-year BC risk, thus justifying its clinical use.

Citation Format: Phillips K-A, Liao Y, Collins IM, Buchsbaum R, Weideman P, Bickerstaffe A, MacInnis RJ, kConFab Investigators, Cuzick J, Antoniou A, Andrulis IL, John EM, Daly MB, Buys SS, Hopper JL, Terry MB. Validation of iPrevent using the prospective family study cohort (ProF-SC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-09-02.

Abstract P6-09-04: Benign breast disease and breast cancer risk across the spectrum of familial risk using a prospective family study cohort (ProF-SC)

Background: Benign breast disease (BBD) is one of the strongest risk factors for breast cancer but it is unclear whether the strength of the association with BBD and breast cancers varies by breast cancer family history. Few studies of BBD enrich specifically for putative genetic factors by over-sampling based on family history let alone evaluate potential interactions with measures of underlying familial risk. The aim of this study was to evaluate how risk associated with BBD is modified by underlying familial risk so as to guide clinical management and risk assessment of women with BBD.

Methods: Using a prospective family study cohort of 17,154 women unaffected with breast cancer at baseline and followed by questionnaire at regular intervals, we examined the association between BBD and breast cancer risk using Cox Proportional Hazards models. We classified women as having BBD if they reported at baseline having been told by a doctor that they had BBD, such as a non-cancerous cyst or breast lump. We did not have information on histologic sub-type. We confirmed self-reported diagnosis of BBD with pathology reports in a subset of the New York cohort and found high agreement between self-reported and pathologically confirmed BBD (93.5%). We assessed multiplicative and additive interactions with underlying familial risk profile (FRP) defined as either fixed-time horizon of 1-year, or total lifetime risk, estimated from the Breast Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) model.

Results: During 176,756 person-years of follow-up (mean 10.2, maximum 23.7 years), we observed 968 incident breast cancers cases with an average age at diagnosis of 55.8 years and average age at enrollment into the cohort of 46.8 years. At baseline, 4,704 (27%) women reported having a previous diagnosis of BBD. Compared to women with no history of BBD, breast cancer risk was increased in women of all ages (HR: 1.37, 95% CI: 1.19,1.56), and in women up to age 45 years (using attained age models) (HR: 1.40, 95% CI: 1.01,1.93). In terms of recency of BBD, we found that the increased risk associated with BBD remained 21 years or more after the initial BBD diagnosis (HR: 1.37, 95% CI: 1.11, 1.68). We found no evidence for multiplicative interactions with FRP, which implies that the increase in absolute risk associated with BBD depends on a woman's FRP (Table 1).

Conclusions: Women with a history of BBD have an increased risk of breast cancer that multiplies their underlying familial risk (FRP). These results could prove to be valuable for risk counseling and clinical management.

Table 1: Cumulative Incidence of Breast Cancer to age 45, 55, and 65 by BBD and underlying FRP as measured by 10-year BOADICEA score.AgeNo BBD, <3.4 %BBD, <3.4%No BBD, ≥3.4%BBD, ≥3.4%454.6 (3.8, 5.6)6.1(4.7, 8.0)12.1 (10.2, 14.5)16.1 (13.1, 19.7)557.4 (6.3, 8.7)9.8 (7.5, 12.8)19.1 (16.6, 22.0)25.0 (21.7, 28.9)659.7 (8.2, 11.5)12.8 (9.9, 16.5)24.5 (21.8, 27.6)31.8 (28.3, 35.7)

Citation Format: Zeinomar N, Phillips KA, Liao Y, MacInnis RJ, Dite GS, Daly MB, John EM, Andrulis IL, Buys SS, Hopper JL, Terry MB. Benign breast disease and breast cancer risk across the spectrum of familial risk using a prospective family study cohort (ProF-SC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-04.

Abstract P3-10-01: Tamoxifen and contralateral breast cancer (CBC) risk for BRCA1 and BRCA2 mutation carriers: An updated analysis of data from the Kathleen Cuningham Foundation consortium for research into familial breast cancer, the International BRCA1 and BRCA2 Carrier cohort study and the breast cancer family registry

Background: Findings from an analysis published in 2013, using combined retrospective and prospective data pooled from 3 cohort studies, were consistent with tamoxifen use after 1st breast cancer (BC) being associated with reduced CBC risk for both BRCA1 and BRCA2 mutation carriers, although the analysis of prospective data alone (based on 100 incident CBCs) gave inconclusive results. The association did not differ by estrogen receptor (ER) status of the 1st BC, suggesting that tamoxifen may be a useful secondary BC prevention agent for mutation carriers regardless of the ER status of their 1st BC. The aim of this updated analysis was to assess these associations after incorporating data from an additional 1,279 mutation carriers and with further follow-up providing 153 additional prospective CBC events. Methods: Eligible women were BRCA1 and BRCA2 mutation carriers diagnosed with unilateral BC since 1970 and with no other invasive cancer or tamoxifen use before their 1st BC. They were followed up from their 1st BC (or, for the prospective analysis, from the later of recruitment and 1st BC diagnosis) to the development of CBC or censoring (at contralateral mastectomy, death or loss to follow-up). Hazard ratios (HRs) for CBC associated with tamoxifen use were estimated using Cox regression, adjusting for year and age of diagnosis, country and bilateral oophorectomy; analyses were also stratified by ER status of the 1st BC. Results: This 2017 analysis includes 3,743 mutation carriers (BRCA1 2,343; BRCA2 1,400) with 21,436 person years of follow-up. Compared with the 2013 analysis, the strengths of the inverse associations were attenuated after including the additional data.

 2017  2013   TotalCBCHR (95% CI) p-valueTotalCBCHR (95% CI) p-value NN NN BRCA1      Combined*      Tam 1st BC      No17615141.0012003381.00Yes5821290.77 (0.63-0.95) 0.01383350.38 (0.27-0.55) <0.001Prospective      Tam 1st BC      No9841321.00481541.00Yes369400.82 (0.57-1.20) 0.31176120.58 (0.29-1.13) 0.1BRCA2      Combined*      Tam1st BC      No6361661.004271151.00Yes764990.58 (0.44-0.76) <0.001454320.33 (0.22-0.50) <0.001Prospective      Tam 1st BC      No389461.00191211.00Yes497350.68 (0.40-1.15) 0.15235130.48 (0.22-1.05) 0.07*Combined = retrospective and prospective, N=number, BRCA1 & BRCA2=mutation carriers, Tam 1st BC= Tamoxifen for 1st Breast Cancer

In this updated prospective analysis, the inverse association between tamoxifen use for 1st BC and CBC risk was most apparent for women with ER positive 1st BC, especially for BRCA2 mutation carriers: BRCA1 ER positive HR=0.45 (95% CI 0.17-1.22, p=0.12), BRCA1 ER negative HR= 0.87 (95% CI 0.45-1.67, p=0.67), BRCA2 ER positive HR=0.33 (95% CI 0.15-0.74, p<0.007), BRCA2 ER negative HR=1.12 (95% CI 0.27-4.70, p=0.88).

Conclusions: Tamoxifen use for 1st BC might reduce CBC risk for mutation carriers, but predominantly for those with an ER positive 1st BC. These data do not support use of tamoxifen to prevent CBC for mutation carriers with ER negative BC.

Citation Format: Phillips K-A, Milne RL, Bassett JK, Hopper JL, Buys SS, Daly MB, Hooning MJ, Mooij TM, Andrieu N, Antoniou AC, Rookus MA, Easton DF, Mary-Beth T. Tamoxifen and contralateral breast cancer (CBC) risk for BRCA1 and BRCA2 mutation carriers: An updated analysis of data from the Kathleen Cuningham Foundation consortium for research into familial breast cancer, the International BRCA1 and BRCA2 Carrier cohort study and the breast cancer family registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-10-01.

Abstract P6-09-01: Risk-reducing oophorectomy and breast cancer risk across the spectrum of familial risk using a prospective family study cohort (ProF-SC)

Background: Whether risk-reducing salpingo oophorectomy (RRSO) reduces breast cancer risk in addition to reducing ovarian cancer risk is controversial with some arguing that the previous evidence of a reduction in breast cancer risk from RRSO was due to bias. Evidence from independent prospective cohorts of high-risk women is needed to resolve this controversy.

Methods: Using a prospective family study cohort of 17,810 women unaffected with breast cancer at baseline, we examined the association between RRSO and breast cancer risk using Cox Proportional Hazards models. We compared results estimating RRSO as a non-time-dependent variable to results treating RRSO as a time-dependent variable, because failing to account for the time-varying nature of a covariate person- time prior to RRSO, should it exist, will incorrectly attribute the cancer-free person-time to RRSO. We separately examined the association with RRSO in BRCA1 and BRCA2 mutation carriers and non-carriers, and further performed gene-stratified analyses in women with BRCA1 and BRCA2 only. We also assessed multiplicative interactions with underlying familial risk profile (FRP), defined as total lifetime risk estimated from the Breast Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (BOADICEA) model.

Results: During a median 10.7 years of follow-up (maximum 23.7 years), we observed 1,040 incident cases of breast cancer with an average age at diagnosis of 55.8 years and average age at enrollment into the cohort of 46.8 years. A total of 2434 (14%) women reported at baseline having a RRSO. We observed decreased risk of breast cancer associated with RRSO for both BRCA1(N= 650) and BRCA2(N=557) mutation carriers when RRSO was treated as a fixed covariate (HR= 0.60, 95% CI=0.40-0.92 and HR= 0.40, 95%CI = 0.23-0.69, respectively). In contrast, when we treated RRSO as a time-varying covariate, for both BRCA1 and BRCA2 carriers, we no longer observed a decreased risk for BRCA1 and BRCA2 carriers (HR= 1.67, 95% CI=1.05-2.67 and HR= 0.97, 95%CI = 0.53-1.80, respectively). There was no association between RRSO and breast cancer risk for non-carriers (N=16,603), whether we treated RRSO as a fixed or time varying covariate (HR= 0.88, 95% CI=0.72-1.08 and HR= 1.06, 95%CI = 0.85-1.30, respectively).

Conclusions: Our findings provide an independent replication that the reduced risk of breast cancer previously observed in BRCA1 and BRCA2 mutation carrier women may be from bias in counting person-time. Clinical management of high-risk women should counsel based on the reduced risk of ovarian cancer from RRSO, but not breast cancer.

Citation Format: Terry MB, Phillips KA, Daly MB, Andrulis IL, Liao Y, Ma X, Zeinomar N, MacInnis RJ, Dite GS, John EM, Buys SS, Hopper JL. Risk-reducing oophorectomy and breast cancer risk across the spectrum of familial risk using a prospective family study cohort (ProF-SC) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-09-01.

A central role for PI3K-AKT signaling pathway in linking SAMHD1-deficiency to the type I interferon signature

The autoimmune disorder Aicardi-Goutières syndrome (AGS) is characterized by a constitutive type I interferon response. SAMHD1 possesses both dNTPase and RNase activities and mutations in SAMHD1 cause AGS; however, how SAMHD1-deficiency causes the type I interferon response in patients with AGS remains unknown. Here, we show that endogenous RNA substrates accumulated in the absence of SAMHD1 act as a major immunogenic source for the type I interferon response. Reconstitution of SAMHD1-negative human cells with wild-type but not RNase-defective SAMHD1 abolishes spontaneous type I interferon induction. We further identify that the PI3K/AKT/IRF3 signaling pathway is essential for the type I interferon response in SAMHD1-deficient human monocytic cells. Treatment of PI3K or AKT inhibitors dramatically reduces the type I interferon signatures in SAMHD1-deficient cells. Moreover, SAMHD1/AKT1 double knockout relieves the type I interferon signatures to the levels observed for wild-type cells. Identification of AGS-related RNA sensing pathway provides critical insights into the molecular pathogenesis of the type I interferonopathies such as AGS and overlapping autoimmune disorders.

Abstract P2-06-01: Non-genetic risk factors improve accuracy of breast cancer risk assessment for women at high familial risk: Comparison of risk estimation models using the prospective family study cohort (ProF-SC)

This abstract was withdrawn by the authors.

Abstract P5-08-05: Prospective family cohort analyses of gene-environment interactions in breast cancer: Body mass index

This abstract was not presented at the symposium.

Synergistic reduction of HIV-1 infectivity by 5-azacytidine and inhibitors of ribonucleotide reductase

Although many compounds have been approved for the treatment of human immunodeficiency type-1 (HIV-1) infection, additional anti-HIV-1 drugs (particularly those belonging to new drug classes) are still needed due to issues such as long-term drug-associated toxicities, transmission of drug-resistant variants, and development of multi-class resistance. Lethal mutagenesis represents an antiviral strategy that has not yet been clinically translated for HIV-1 and is based on the use of small molecules to induce excessive levels of deleterious mutations within the viral genome. Here, we show that 5-azacytidine (5-aza-C), a ribonucleoside analog that induces the lethal mutagenesis of HIV-1, and multiple inhibitors of the enzyme ribonucleotide reductase (RNR) interact in a synergistic fashion to more effectively reduce the infectivity of HIV-1. In these drug combinations, RNR inhibitors failed to significantly inhibit the conversion of 5-aza-C to 5-aza-2'-deoxycytidine, suggesting that 5-aza-C acts primarily as a deoxyribonucleoside even in the presence of RNR inhibitors. The mechanism of antiviral synergy was further investigated for the combination of 5-aza-C and one specific RNR inhibitor, resveratrol, as this combination improved the selectivity index of 5-aza-C to the greatest extent. Antiviral synergy was found to be primarily due to the reduced accumulation of reverse transcription products rather than the enhancement of viral mutagenesis. To our knowledge, these observations represent the first demonstration of antiretroviral synergy between a ribonucleoside analog and RNR inhibitors, and encourage the development of additional ribonucleoside analogs and RNR inhibitors with improved antiretroviral activity.

SAMHD1 controls cell cycle status, apoptosis and HIV-1 infection in monocytic THP-1 cells

SAMHD1 limits HIV-1 infection in non-dividing myeloid cells by decreasing intracellular dNTP pools. HIV-1 restriction by SAMHD1 in these cells likely prevents activation of antiviral immune responses and modulates viral pathogenesis, thus highlighting a critical role of SAMHD1 in HIV-1 physiopathology. Here, we explored the function of SAMHD1 in regulating cell proliferation, cell cycle progression and apoptosis in monocytic THP-1 cells. Using the CRISPR/Cas9 technology, we generated THP-1 cells with stable SAMHD1 knockout. We found that silencing of SAMHD1 in cycling cells stimulates cell proliferation, redistributes cell cycle population in the G1/G0 phase and reduces apoptosis. These alterations correlated with increased dNTP levels and more efficient HIV-1 infection in dividing SAMHD1 knockout cells relative to control. Our results suggest that SAMHD1, through its dNTPase activity, affects cell proliferation, cell cycle distribution and apoptosis, and emphasize a key role of SAMHD1 in the interplay between cell cycle regulation and HIV-1 infection.

Dual anti-HIV mechanism of clofarabine

BACKGROUND

HIV-1 replication kinetics inherently depends on the availability of cellular dNTPs for viral DNA synthesis. In activated CD4(+) T cells and other rapidly dividing cells, the concentrations of dNTPs are high and HIV-1 reverse transcription occurs in an efficient manner. In contrast, nondividing cells such as macrophages have lower dNTP pools, which restricts efficient reverse transcription. Clofarabine is an FDA approved ribonucleotide reductase inhibitor, which has shown potent antiretroviral activity in transformed cell lines. Here, we explore the potency, toxicity and mechanism of action of clofarabine in the human primary HIV-1 target cells: activated CD4(+) T cells and macrophages.

RESULTS

Clofarabine is a potent HIV-1 inhibitor in both activated CD4(+) T cells and macrophages. Due to its minimal toxicity in macrophages, clofarabine displays a selectivity index over 300 in this nondividing cell type. The anti-HIV-1 activity of clofarabine correlated with a significant decrease in both cellular dNTP levels and viral DNA synthesis. Additionally, we observed that clofarabine triphosphate was directly incorporated into DNA by HIV-1 reverse transcriptase and blocked processive DNA synthesis, particularly at the low dNTP levels found in macrophages.

CONCLUSIONS

Taken together, these data provide strong mechanistic evidence that clofarabine is a dual action inhibitor of HIV-1 replication that both limits dNTP substrates for viral DNA synthesis and directly inhibits the DNA polymerase activity of HIV-1 reverse transcriptase.

Genetic testing for hereditary cancer predisposition: BRCA1/2, Lynch syndrome, and beyond

Obstetrician/gynecologists and gynecologic oncologists serve an integral role in the care of women at increased hereditary risk of cancer. Their contribution includes initial identification of high risk patients, screening procedures like bimanual exam, trans-vaginal ultrasound and endometrial biopsy, prophylaxis via TAH and/or BSO, and chemoprevention. Further, gynecologists also serve a central role in the management of the secondary repercussions of efforts to mitigate increased cancer risks, including vasomotor symptoms, sexual function, bone health, cardiovascular disease, and mental health. The past several years has seen multiple new high and moderate penetrance genes introduced into the clinical care of women at increased risk of gynecologic malignancy. Awareness of these new genes and the availability of new multi-gene panel tests is critical for providers on the front-line of women's health.

Genetic counselors' (GC) knowledge, awareness, understanding of clinical next-generation sequencing (NGS) genomic testing

Genomic tests are increasingly complex, less expensive, and more widely available with the advent of next-generation sequencing (NGS). We assessed knowledge and perceptions among genetic counselors pertaining to NGS genomic testing via an online survey. Associations between selected characteristics and perceptions were examined. Recent education on NGS testing was common, but practical experience limited. Perceived understanding of clinical NGS was modest, specifically concerning tumor testing. Greater perceived understanding of clinical NGS testing correlated with more time spent in cancer-related counseling, exposure to NGS testing, and NGS-focused education. Substantial disagreement about the role of counseling for tumor-based testing was seen. Finally, a majority of counselors agreed with the need for more education about clinical NGS testing, supporting this approach to optimizing implementation.

Host SAMHD1 protein promotes HIV-1 recombination in macrophages

Template switching can occur during the reverse transcription of HIV-1. Deoxynucleotide triphosphate (dNTP) concentrations have been biochemically shown to impact HIV-1 reverse transcriptase (RT)-mediated strand transfer. Lowering the dNTP concentrations promotes RT pausing and RNA template degradation by RNase H activity of the RT, subsequently leading to strand transfer. Terminally differentiated/nondividing macrophages, which serve as a key HIV-1 reservoir, contain extremely low dNTP concentrations (20-50 nm), which results from the cellular dNTP hydrolyzing sterile α motif and histidine aspartic domain containing protein 1 (SAMHD1) protein, when compared with activated CD4(+) T cells (2-5 μm). In this study, we first observed that HIV-1 template switching efficiency was nearly doubled in human primary macrophages when compared with activated CD4(+) T cells. Second, SAMHD1 degradation by viral protein X (Vpx), which elevates cellular dNTP concentrations, decreased HIV-1 template switching efficiency in macrophages to the levels comparable with CD4(+) T cells. Third, differentiated SAMHD1 shRNA THP-1 cells have a 2-fold increase in HIV-1 template switching efficiency. Fourth, SAMHD1 degradation by Vpx did not alter HIV-1 template switching efficiency in activated CD4(+) T cells. Finally, the HIV-1 V148I RT mutant that is defective in dNTP binding and has DNA synthesis delay promoted RT stand transfer when compared with wild type RT, particularly at low dNTP concentrations. Here, we report that SAMHD1 regulation of the dNTP concentrations influences HIV-1 template switching efficiency, particularly in macrophages.

Restricted 5'-end gap repair of HIV-1 integration due to limited cellular dNTP concentrations in human primary macrophages

HIV-1 proviral DNA integration into host chromosomal DNA is only partially completed by the viral integrase, leaving two single-stranded DNA gaps with 5'-end mismatched viral DNA flaps. It has been inferred that these gaps are repaired by the cellular DNA repair machinery. Here, we investigated the efficiency of gap repair at integration sites in different HIV-1 target cell types. First, we found that the general gap repair machinery in macrophages was attenuated compared with that in dividing CD4(+) T cells. In fact, the repair in macrophages was heavily reliant upon host DNA polymerase β (Pol β). Second, we tested whether the poor dNTP availability found in macrophages is responsible for the delayed HIV-1 proviral DNA integration in this cell type because the Km value of Pol β is much higher than the dNTP concentrations found in macrophages. Indeed, with the use of a modified quantitative AluI PCR assay, we demonstrated that the elevation of cellular dNTP concentrations accelerated DNA gap repair in macrophages at HIV-1 proviral DNA integration sites. Finally, we found that human monocytes, which are resistant to HIV-1 infection, exhibited severely restricted gap repair capacity due not only to the very low levels of dNTPs detected but also to the significantly reduced expression of Pol β. Taken together, these results suggest that the low dNTP concentrations found in macrophages and monocytes can restrict the repair steps necessary for HIV-1 integration.

Host factor SAMHD1 restricts DNA viruses in non-dividing myeloid cells

SAMHD1 is a newly identified anti-HIV host factor that has a dNTP triphosphohydrolase activity and depletes intracellular dNTP pools in non-dividing myeloid cells. Since DNA viruses utilize cellular dNTPs, we investigated whether SAMHD1 limits the replication of DNA viruses in non-dividing myeloid target cells. Indeed, two double stranded DNA viruses, vaccinia and herpes simplex virus type 1, are subject to SAMHD1 restriction in non-dividing target cells in a dNTP dependent manner. Using a thymidine kinase deficient strain of vaccinia virus, we demonstrate a greater restriction of viral replication in non-dividing cells expressing SAMHD1. Therefore, this study suggests that SAMHD1 is a potential innate anti-viral player that suppresses the replication of a wide range of DNA viruses, as well as retroviruses, which infect non-dividing myeloid cells.

Various viral pathogens such as HIV-1, herpes simplex virus (HSV) and vaccinia virus infect terminally-differentiated/non-dividing macrophages during the course of viral pathogenesis. Unlike dividing cells, non-dividing cells lack chromosomal DNA replication, do not enter the cell cycle, and harbor very low levels of cellular dNTPs, which are substrates of viral DNA polymerases. A series of recent studies revealed that the host protein SAMHD1 is dNTP triphosphohydrolase, which contributes to the poor dNTP abundance in non-dividing myeloid cells, and restricts proviral DNA synthesis of HIV-1 and other lentiviruses in macrophages, dendritic cells, and resting T cells. In this report, we demonstrate that SAMHD1 also controls the replication of large dsDNA viruses: vaccinia virus and HSV-1, in primary human monocyte-derived macrophages. SAMHD1 suppresses the replication of these DNA viruses to an even greater extent in the absence of viral genes that are involved in dNTP metabolism such as thymidine kinase. Therefore, this study supports that dsDNA viruses evolved to express enzymes necessary to increase the levels of dNTPs as a mechanism to overcome the restriction induced by SAMHD1 in myeloid cells.

Anti-HIV host factor SAMHD1 regulates viral sensitivity to nucleoside reverse transcriptase inhibitors via modulation of cellular deoxyribonucleoside triphosphate (dNTP) levels

Newly identified anti-HIV host factor, SAMHD1, restricts replication of lentiviruses such as HIV-1, HIV-2, and simian immunodeficiency virus in macrophages by enzymatically hydrolyzing and depleting cellular dNTPs, which are the substrates of viral DNA polymerases. HIV-2 and some simian immunodeficiency viruses express viral protein X (VPX), which counteracts SAMHD1 and elevates cellular dNTPs, enhancing viral replication in macrophages. Because nucleoside reverse transcriptase inhibitors (NRTIs), the most commonly used anti-HIV drugs, compete against cellular dNTPs for incorporation into proviral DNA, we tested whether SAMHD1 directly affects the efficacy of NRTIs in inhibiting HIV-1. We found that reduction of SAMHD1 levels with the use of virus-like particles expressing Vpx- and SAMHD1-specific shRNA subsequently elevates cellular dNTPs and significantly decreases HIV-1 sensitivity to various NRTIs in macrophages. However, virus-like particles +Vpx treatment of activated CD4(+) T cells only minimally reduced NRTI efficacy. Furthermore, with the use of HPLC, we could not detect SAMHD1-mediated hydrolysis of NRTI-triphosphates, verifying that the reduced sensitivity of HIV-1 to NRTIs upon SAMHD1 degradation is most likely caused by the elevation in cellular dNTPs.

Genetic counselor opinions of, and experiences with telephone communication of BRCA1/2 test results

BRCA1/2 test disclosure has, historically, been conducted in-person by genetics professionals. Given increasing demand for, and access to, genetic testing, interest in telephone and Internet genetic services, including disclosure of test results, has increased. Semi-structured interviews with genetic counselors were conducted to determine interest in, and experiences with telephone disclosure of BRCA1/2 test results. Descriptive data are summarized with response proportions. One hundred and ninety-four genetic counselors completed self-administered surveys via the web. Although 98% had provided BRCA1/2 results by telephone, 77% had never provided pre-test counseling by telephone. Genetic counselors reported perceived advantages and disadvantages to telephone disclosure. Thirty-two percent of participants described experiences that made them question this practice. Genetic counselors more frequently reported discomfort with telephone disclosure of a positive result or variant of uncertain significance (p < 0.01) than other results. Overall, 73% of participants reported interest in telephone disclosure. Many genetic counselors have provided telephone disclosure, however, most, infrequently. Genetic counselors identify potential advantages and disadvantages to telephone disclosure, and recognize the potential for testing and patient factors to impact patient outcomes. Further research evaluating the impact of testing and patient factors on cognitive, affective, social and behavioral outcomes of alternative models of communicating genetic information is warranted.

Measuring, and identifying predictors of women's perceptions of three types of breast cancer risk: population risk, absolute risk and comparative risk

Although a key function of cancer genetics services is to provide risk information, to date there has been little consistency in the way in which breast cancer risk perception has been measured. The aims of the study were to measure estimates of (i) population risk, (ii) absolute risk and (iii) comparative risk of developing breast cancer for Ashkenazi Jewish women, and to determine predictors of breast cancer risk perception. Of 152 women, 107 (70%) completed all questions. The mean (s.d.) estimates for population risk, absolute risk and comparative risk were 22.7% (15.9), 31.8% (20.6) and 1.9-fold (1.9), respectively. Most women overestimated population risk. Women at population risk generally overestimated the population risk and their own absolute risk, yet understood they are at the same risk as the population. Those with a family history understood that they are at increased risk, but underestimated the extent to which their familial risk is increased. Anxiety, high estimation of population risk and lesser family history predicted overestimation of absolute risk, whereas high estimation of population risk and a strong family history predicted underestimation of comparative risk.

Validation study of the LAMBDA model for predicting the BRCA1 or BRCA2 mutation carrier status of North American Ashkenazi Jewish women

LAMBDA is a model that estimates the probability an Ashkenazi Jewish (AJ) woman carries an ancestral BRCA1 or BRCA2 mutation from her personal and family cancer history. LAMBDA is relevant to clinical practice, and its implementation does not require a computer. It was developed principally from Australian and UK data. We conducted a validation study using 1286 North American AJ women tested for the mutations 185delAG and 5382insC in BRCA1 and 6174delT in BRCA2. Most had a personal or family history of breast cancer. We observed 197 carriers. The area under the receiver operator characteristic (ROC) curve (a measure of ranking) was 0.79 [95% confidence interval (CI) = 0.77-0.81], similar to that for the model-generating data (0.78; 95% CI = 0.75-0.82). LAMBDA predicted 232 carriers (18% more than observed; p = 0.002) and was overdispersed (p = 0.009). The Bayesian computer program BRCAPRO gave a similar area under the ROC curve (0.78; 95% CI = 0.76-0.80), but predicted 367 carriers (86% more than observed; p < 0.0001), and was substantially overdispersed (p < 0.0001). Therefore, LAMBDA is comparable to BRCAPRO for ranking AJ women according to their probability of being a BRCA1 or BRCA2 mutation carrier and is more accurate than brcapro which substantially overpredicts carriers in this population.

A discrete choice experiment of preferences for genetic counselling among Jewish women seeking cancer genetics services

To determine which aspects of breast cancer genetic counselling are important to Ashkenazi Jewish women, a discrete choice experiment was conducted. Participants consisted of 339 Australian Ashkenazi Jewish women who provided a blood sample for research used to test for Ashkenazi Jewish ancestral mutations in the genes BRCA1 and BRCA2, and were offered their genetic test result through a cancer genetics service. Main outcome measures were women's preferences for, and trade-offs between, the genetic counselling aspects of providing cancer, gene, and risk information (information); giving advice about cancer surveillance (surveillance); preparing for genetic testing (preparation); and, assistance with decision-making (direction). Respondents most valued information, about twice as much as advice about surveillance, four times as much as preparation for testing, and nine times as much as assistance with decision-making, which was least valued. Women's preferences were consistent with the major goals of genetic counselling, which include providing information and surveillance advice, and avoiding direction by facilitating autonomous decision-making. There were differences between the women in which aspects they most favoured, suggesting that counselling that elicits and responds to clients’ preferences is more likely to meet clients’ needs.

Communicating genetic test results to the family: a six-step, skills-building strategy

As the availability of tests to identify hereditary predisposition to chronic diseases continues to grow, a need has arisen to prepare individuals receiving genetic test results to share this highly sophisticated and value-laden information with other at-risk family members. Responding to this need, a communication skills-building intervention, based on Buckman's model of "Breaking Bad News," was developed for use in the setting of genetic testing for BRCA1 and BRCA2 mutations. Outcomes will include knowledge, attitudes, and health behavior on the part of both the proband and her first-degree relatives.

Modification of BRCA1- and BRCA2-associated breast cancer risk by AIB1 genotype and reproductive history

Women who have inherited a germ-line mutation in the BRCA1 or BRCA2 (BRCA1/2) genes have a greatly increased risk of developing breast cancer compared with the general population. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1/2 mutation carriers. We hypothesize that genes involved in endocrine signaling may modify the BRCA1/2-associated age-specific breast cancer penetrance. We studied the effect of alleles at the AIB1 gene using a matched case-control sample of 448 women with germ-line BRCA1/2 mutations. We found that these women were at significantly higher breast cancer risk if they carried alleles with at least 28 or 29 polyglutamine repeats at AIB1, compared with women who carried alleles with fewer polyglutamine repeats [odds ratio (OR), 1.59; 95% confidence interval (CI), 1.03-2.47 and OR, 2.85; 95% CI, 1.64-4.96, respectively]. Late age at first live birth and nulliparity have been associated with increased breast cancer risk. We observed increases in BRCA1/2-associated breast cancer risk in women who were either nulliparous or had their first live birth after age 30 (OR, 3.06; 95% CI, 1.52-6.16). Women were at significantly increased risk if they were nulliparous or had a late age at first live birth and had AIB1 alleles no shorter than 28 or 29 or more AIB1 polyglutamine repeats (OR, 4.62; 95% CI, 2.02-10.56 and OR, 6.97; 95% CI, 1.71-28.43, respectively) than women with none of these risk factors. Our results support the hypothesis that pathways involving endocrine signaling, as measured through AIB1 genotype and reproductive history, may have a substantial effect on BRCA1/2-associated breast cancer risk.

Anxiety/uncertainty reduction as a motivation for interest in prophylactic oophorectomy in women with a family history of ovarian cancer

Most women at familial risk for ovarian cancer must decide about prophylactic oophorectomy without conclusive genotypic information about their risk level. Some women with relatively low-risk profiles seek prophylactic oophorectomy or are recommended the procedure by their physicians, if they appear "cancerphobic." This study investigated the desire to reduce anxiety in relation to other factors associated with interest in prophylactic oophorectomy in a group of women with varying degrees of familial risk for ovarian cancer. Ninety-four women enrolled in an ongoing program for women with a family history of ovarian cancer received personalized risk counseling and were classified as having a sporadic, familial, or putative hereditary pedigree by a genetics counselor. Eligible enrollees were interviewed by telephone about current and future interest in prophylactic oophorectomy, perceived risk of ovarian cancer, severity of cancer anxiety, stress-related ideation, and reasons for and against surgery. Reduction of anxiety/uncertainty was the factor most strongly associated with current interest in prophylactic oophorectomy, independent of objective risk classification, perceived risk, severity of cancer anxiety, intrusive ideation, or other variables. Future interest in prophylactic oophorectomy was predicted by other perceived benefits of surgery. Current, but not future, interest in prophylactic oophorectomy appears motivated in part by seeking immediate relief from anxiety. Interest in prophylactic oophorectomy may fluctuate based on varying exposure to cues that trigger anxiety. Women seeking prophylactic oophorectomy, particularly those with lower-risk family pedigrees, should be offered options for anxiety management as part of informed consent for prophylactic oophorectomy.

Quantitative studies of the vasculature of the carotid body in the chronically hypoxic rat

The carotid bodies of rats made chronically hypoxic by breathing 12% O2 in a normobaric chamber (inspired PO2 91 mmHg) were compared with those of controls. Serial 5-microm sections of the organs were examined using an interactive image analysis system. The total volume of the carotid bodies was increased by 64%. The total vascular volume rose by 103% and was likely due to an increase in size of the large vessels (>12 microm lumen diameter) because the small vessel (5-12 microm lumen diameter) volume did not increase significantly while the small vessel density tended to decrease. The extravascular volume was increased by 57%. Expressed as a percentage of the total volume of the organ, the total vascular volume did not change, but the small vessel volume was significantly decreased from 7.83 to 6.06%. The large vessel volume must therefore have been increased. The proportion occupied by the extravascular volume was virtually unchanged (84 vs 82%). In accordance with these findings, the small vessel endothelial surface area per unit carotid body volume was diminished from 95.2 to 76.5 mm-1, while the extravascular area per small vessel was increased from 493 to 641 microm(2) or by 30%. In conclusion, the enlargement of the carotid body in chronic hypoxia is most likely due to an increase in total vascular volume, mainly involving the "large" vessels, and to an increase in extravascular volume. This is in contrast to our previously published findings indicating that in the spontaneous insulin-dependent diabetic rat the enlargement of the carotid body is due solely to an increase in extravascular volume.

Decision making about prophylactic oophorectomy among at-risk women: psychological influences and implications

OBJECTIVE

Women with a family history of ovarian cancer are confronted with difficult decisions regarding the management of their risk status. Currently, the main preventive option available is prophylactic oophorectomy. The objective of the present paper is to review research and theory on psychological factors that influence decision making about preventive surgery and discuss the implications for patient management.

METHODS

Guided by a cognitive-social framework, the literature on decision making about preventive surgery is reviewed and integrated.

RESULTS

The available studies show that women are more likely to opt for surgery if they feel more vulnerable to cancer, believe that surgery will prevent cancer, and are worried about developing cancer. Further, the response to ovarian risk is influenced by the individual's characteristic psychological style: monitors (who typically scan for and amplify threatening cues) tend to feel more vulnerable to cancer and more distressed about their cancer risk than blunters (who typically distract from threatening cues) do.

CONCLUSION

On the basis of prior research, monitors may be more likely to choose surgical intervention to reduce their distress, without fully anticipating the psychological and medical consequences of that decision. In order to facilitate informed decision making, counseling protocols should be designed to enable the patient to understand and take account of the psychological consequences of the available medical options. Future studies are needed to systematically extend and explore the proposed theory-based relationships.

Breast cancer risk after bilateral prophylactic oophorectomy in BRCA1 mutation carriers

BACKGROUND

The availability of genetic testing for inherited mutations in the BRCA1 gene provides potentially valuable information to women at high risk of breast or ovarian cancer; however, carriers of BRCA1 mutations have few clinical management options to reduce their cancer risk. Decreases in ovarian hormone exposure following bilateral prophylactic oophorectomy (i.e., surgical removal of the ovaries) may alter cancer risk in BRCA1 mutation carriers. This study was undertaken to evaluate whether bilateral prophylactic oophorectomy is associated with a reduction in breast cancer risk in BRCA1 mutation carriers.

METHODS

We studied a cohort of women with disease-associated germline BRCA1 mutations who were assembled from five North American centers. Surgery subjects (n = 43) included women with BRCA1 mutations who underwent bilateral prophylactic oophorectomy but had no history of breast or ovarian cancer and had not had a prophylactic mastectomy. Control subjects included women with BRCA1 mutations who had no history of oophorectomy and no history of breast or ovarian cancer (n = 79). Control subjects were matched to the surgery subjects according to center and year of birth.

RESULTS

We found a statistically significant reduction in breast cancer risk after bilateral prophylactic oophorectomy, with an adjusted hazard ratio (HR) of 0.53 (95% confidence interval [CI] = 0.33-0.84). This risk reduction was even greater in women who were followed 5-10 (HR = 0. 28; 95% CI = 0.08-0.94) or at least 10 (HR = 0.33; 95% CI = 0.12-0.91) years after surgery. Use of hormone replacement therapy did not negate the reduction in breast cancer risk after surgery.

CONCLUSIONS

Bilateral prophylactic oophorectomy is associated with a reduced breast cancer risk in women who carry a BRCA1 mutation. The likely mechanism is reduction of ovarian hormone exposure. These findings have implications for the management of breast cancer risk in women who carry BRCA1 mutations.

Specific worry about breast cancer predicts mammography use in women at risk for breast and ovarian cancer

This longitudinal study examined predictors of mammography use among women with a family history of breast cancer participating in a risk assessment and surveillance program (N = 213). Assessed were background variables (age, prior mammography utilization), cognitive variables (perceived vulnerability), and affective variables (cancer worry and general distress). Results of logistic regression analyses predicting adherence 1 year after baseline contact, in which variables of prior utilization, feelings of vulnerability, and general distress were controlled for, indicated that cancer worry and age were significant predictors of mammography adherence. Results suggest that moderate levels of cancer worry facilitate, rather than undermine, adherence. The results have implications for the construction of educational messages that should be designed to acknowledge feelings of cancer-specific worry and to provide guidance in health protective behaviors.

Modification of BRCA1-associated breast cancer risk by the polymorphic androgen-receptor CAG repeat

Compared with the general population, women who have inherited a germline mutation in the BRCA1 gene have a greatly increased risk of developing breast cancer. However, there is also substantial interindividual variability in the occurrence of breast cancer among BRCA1 mutation carriers. We hypothesize that other genes, particularly those involved in endocrine signaling, may modify the BRCA1-associated age-specific breast cancer risk. We studied the effect of the CAG repeat-length polymorphism found in exon 1 of the androgen-receptor (AR) gene (AR-CAG). AR alleles containing longer CAG repeat lengths are associated with a decreased ability to activate androgen-responsive genes. Using a sample of women who inherited germline BRCA1 mutations, we compared AR-CAG repeat length in 165 women with and 139 women without breast cancer. We found that women were at significantly increased risk of breast cancer if they carried at least one AR allele with >/=28 CAG repeats. Women who carried an AR-CAG allele of >/=28, >/=29, or >/=30 repeats were given a diagnosis 0.8, 1.8, or 6.3 years earlier than women who did not carry at least one such allele. All 11 women in our sample who carried at least one AR-CAG allele with >/=29 repeats had breast cancer. Our results support the hypothesis that age at breast cancer diagnosis is earlier among BRCA1 mutation carriers who carry very long AR-CAG repeats. These results suggest that pathways involving androgen signaling may affect the risk of BRCA1-associated breast cancer.

The central action of the 5-HT2 receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) on cardiac inotropy and vascular resistance in the anaesthetized cat

Experiments were carried out to determine the effects of the application of the selective 5-HT2 receptor agonist DOI intravenously (in the presence of the peripherally acting 5-HT2 receptor antagonist, BW501C67, 1 mg kg(-1), i.v.) or to the 'glycine sensitive area' of the ventral surface (30 microg each side) on the left ventricular inotropic (left ventricular dP/dt max) and vascularly isolated hindlimb responses in anaesthetized cats. For the ventral surface experiments, NMDA (10 microg each side) was applied to act as a positive control. In all experiments heart rate and mean arterial blood pressure were held constant to exclude any secondary effects caused by changes in these variables. DOI (n=6) i.v or on the ventral surface had no effect on left ventricular dP/dt max but caused a significant increase in hindlimb perfusion pressure of 40+/-9 and 50+/-14 mmHg, respectively. Respiration was unaffected. NMDA (n=6), applied to the ventral surface, caused significant increases in both left ventricular dP/dt max and hindlimb perfusion pressure of 1,950+/-349 mmHg s(-1) and 69+/-17 mmHg respectively, with no associated change in left ventricular end-diastolic pressure. The amplitude of respiratory movements increased. It is concluded that activation of 5-HT2 receptors at the level of the rostral ventrolateral medulla (RVLM) excites sympathetic premotor neurons and/or their antecedents controlling hindlimb vascular resistance but not those controlling the inotropic effects on the left ventricle.

Is hereditary site-specific ovarian cancer a distinct genetic condition?

It is not clear if hereditary site-specific ovarian cancer exists as a genetic entity distinct from the hereditary breast-ovarian cancer syndrome. We have identified a large Ashkenazi Jewish kindred with 8 cases of ovarian carcinoma and no cases of breast cancer. Initially, linkage analysis for this kindred generated a negative LOD score to BRCA1, but subsequent mutation and haplotype analysis of key individuals demonstrated a BRCA1 185delAG mutation segregating with all but 1 of the ovarian cancer cases. This observation has important implications for genetic counselling of families with site-specific ovarian cancer. Hereditary site-specific ovarian cancer is likely to be a variant of the hereditary breast-ovarian cancer syndrome, attributable to either BRCA1 or BRCA2. We consider women from these families to be at increased risk of breast cancer and counsel them accordingly.

Genetic testing for susceptibility to adult-onset cancer. The process and content of informed consent

OBJECTIVE

To provide guidance on informed consent to clinicians offering cancer susceptibility testing.

PARTICIPANTS

The Task Force on Informed Consent is part of the Cancer Genetics Studies Consortium (CGSC), whose members were recipients of National Institutes of Health grants to assess the implications of cancer susceptibility testing. The 10 task force members represent a range of relevant backgrounds, including various medical specialties, social science, genetic counseling, and consumer advocacy.

EVIDENCE

The CGSC held 3 public meetings from 1994 to 1996. At its first meeting, the task force jointly established a list of topics. The cochairs (G.G. and J.R.B) then developed an outline and assigned each topic to an appropriate writer and reviewer. Writers summarized the literature on their topics and drafted recommendations, which were then revised by the reviewers. The cochairs compiled and edited the entire manuscript. All members were involved in writing this report.

CONSENSUS PROCESS

The first draft was distributed to task force members, after which a meeting was held to discuss its content and organization. Consensus was reached by voting. A subsequent draft was presented to the entire CGSC at its third meeting, and comments were incorporated.

CONCLUSIONS

The task force recommends that informed consent for cancer susceptibility testing be an ongoing process of education and counseling in which (1) providers elicit participant, family, and community values and disclose their own, (2) decision making is shared, (3) the style of information disclosure is individualized, and (4) specific content areas are discussed.

Microscopic benign and invasive malignant neoplasms and a cancer-prone phenotype in prophylactic oophorectomies

BACKGROUND

The occurrence of approximately 5% of common epithelial malignant tumors of the ovary can be traced to inheritance of risk. One prophylactic strategy to decrease the probability of development of disease in individuals within families where this mendelian-dominant pattern of occurrence is apparent is to remove the ovaries of individuals at risk for ovarian cancer. The procedure, when done for this purpose, is recommended soon after completion of childbearing.

PURPOSE

Our goal was to compare the histologic features of the ovaries of women at increased risk for ovarian cancer to those at no known increased risk for the disease.

METHODS

Ovaries removed for prophylaxis from 20 women considered to be at increased risk for developing ovarian cancer were examined histologically. During the course of this work, it seemed apparent that these ovaries contained numerous atypical features compared with the expected appearance of normal ovaries. Hence, we expanded the study to include a control group whose ovaries were removed for reasons unrelated to cancer. The study, therefore, was not blinded. The increased risk in the cancer-prone individuals was determined by family history, specifically the presence of at least one first-degree relative and one second-degree relative with ovarian and/or breast cancer and positive linkage or mutational analysis of BRCA1 in some. The difference in mean ages of patients in the control and high-risk groups was not statistically significant. The difference among both groups with respect to the number of atypical features as well as the intensity of those features was ascertained by computing probabilities using Fisher's exact test (two-sided) for rows x columns contingency tables.

RESULTS

Two unanticipated microscopic or near-microscopic malignant neoplasms and other benign and borderline tumors were discovered in the ovaries of the high-risk individuals. Of substantial interest was the finding that among the ovaries of high-risk women, 85% presented two or more and 75% presented three or more of the following histologic features: surface epithelial pseudostratification; surface papillomatosis; deep cortical invaginations of the surface epithelium, frequently with multiple papillary projections within small cystic spaces (microscopic papillary cystadenomas); epithelial inclusion cysts, frequently with epithelial hyperplasia and papillary formations; cortical stromal hyperplasia and hyperthecosis; increased follicular activity; corpus luteum hyperplasia; or hilar cell hyperplasia. Two or more or three or more such changes were observed in a lesser percentage (30% or 10%, respectively) of ovaries obtained from the control individuals, with a statistically significant difference (P = .001 or P = .00007, respectively), particularly considering that a detailed determination of a family history of cancer in the control group was not possible.

CONCLUSIONS

The frequency of these changes in the high-risk ovaries compared with control ovaries suggests a characteristic histologic preneoplastic phenotype defined by an increased frequency and intensity of the above-described histologic features in the high-risk ovaries. Limited access to numerous small (stage I) ovarian cancers or cancer-prone ovaries by any one pathologist may explain the failure to identify the phenotype in the past.

IMPLICATIONS

We suggest that the ovaries removed from ovarian cancer-prone individuals as a preventative measure should be thoroughly examined histologically to identify or rule out microscopic or near-microscopic invasive neoplasms.

The impact of tamoxifen on breast recurrence, cosmesis, complications, and survival in estrogen receptor-positive early-stage breast cancer

PURPOSE

To evaluate the impact of tamoxifen on breast recurrence, cosmesis, complications, overall and cause-specific survival in women with Stage I-II breast cancer and estrogen receptor positive tumors undergoing conservative surgery and radiation.

METHODS AND MATERIALS

From 1982 to 1991, 491 women with estrogen receptor positive Stage I-II breast cancer underwent excisional biopsy, axillary dissection, and radiation. The median age of patient population was 60 years with 21% < 50 years of age. The median follow-up was 5.3 years (range 0.1 to 12.8). Sixty-nine percent had T1 tumors and 83% had histologically negative axillary nodes. Re-excision was performed in 49% and the final margin of resection was negative in 64%. One hundred fifty-four patients received tamoxifen and 337 patients received no adjuvant therapy. None of the patients received adjuvant chemotherapy.

RESULTS

There were no significant differences between the two groups for age, race, clinical tumor size, histology, the use of re-excision, or median total dose to the primary. Patients who received tamoxifen were more often axillary node positive (44% tamoxifen vs. 5% no tamoxifen), and, therefore, a greater percentage received treatment to the breast and regional nodes. The tamoxifen patients less often had unknown margins of resection (9% tamoxifen vs. 22% no tamoxifen). The 5-year actuarial breast recurrence rate was 4% for the tamoxifen patients compared to 7% for patients not receiving tamoxifen (p = 0.21). Tamoxifen resulted in a modest decrease in the 5-year actuarial risk of a breast recurrence in axillary node-negative patients, in those with unknown or close margins of resection, and in those who underwent a single excision. Axillary node-positive patients had a clinically significant decrease in the 5-year actuarial breast recurrence rate (21 vs. 4%; p = 0.08). The 5-year actuarial rate of distant metastasis was not significantly decreased by the addition of adjuvant tamoxifen in all patients or pathologic node-negative patients. Pathologically node-positive patients had a significant decrease in distant metastasis (35 vs. 11%; p = 0.02). There were no significant differences in cause-specific survival for patients receiving tamoxifen when compared to observation (95% no tamoxifen vs. 89% tamoxifen; p = 0.24). Similar findings were noted for pathologically node-negative patients. However, axillary node-positive patients receiving tamoxifen had an improvement in 5-year actuarial cause-specific survival (90% tamoxifen vs. 70% no tamoxifen; p = 0.10). Cosmesis (physician assessment) was good to excellent in 85% of the tamoxifen patients compared to 88% of the patients who did not receive tamoxifen.

CONCLUSION

The addition of tamoxifen to conservative surgery and radiation in women with Stage I-II breast cancer and estrogen receptor positive tumors resulted in a modest but not statistically significant decrease in the 5-year actuarial risk of a breast recurrence. Tamoxifen significantly decreased the 5-year actuarial risk of distant metastasis in axillary node-positive patients and there was a trend towards improvement in cause-specific survival that was not statistically significant. Tamoxifen did not decrease the 5-year actuarial rate of distant metastasis in axillary node negative, patients and in this group, there was no improvement in cause-specific survival. Tamoxifen did not have an adverse effect on cosmesis or complications.

Breast cancer and mammography: an American Cancer Society profile of Philadelphia and Montgomery Counties

The American Cancer Society, Philadelphia Division, has completed a comprehensive profile of breast cancer and mammography in Philadelphia and Montgomery Counties. The profile consists of three segments: (1) data on incidence of breast cancer and trends in stage at diagnosis; (2) estimates of breast cancer screening practices based on surveys of the population; and (3) results from a survey of mammography providers assessing the region's capacity for and access to mammography. The profile demonstrated that the Philadelphia Division is already close to achieving the national American Cancer Society's goals for breast cancer detection for the year 2000 for the percent of women screened and percent of cancers diagnosed in early stages. New and more ambitious goals for the Division must be set. Although capacity for mammography is high, outreach programs by mammography providers represent only 1% to 2% of all mammograms performed. The profile has been the cornerstone of new programmatic initiatives for the Division.

Gail model breast cancer risk components are poor predictors of risk perception and screening behavior

The Gail model is being used increasingly to determine individual breast cancer risk and to tailor preventive health recommendations accordingly. Although widely known to the medical and biostatistical communities, the risk factors included in the model may not be salient to the women to whom the model is being applied. This study explored the relationship of the individual Gail model risk factors to perceived risk of breast cancer and prior breast cancer screening among women with a family history of breast cancer. Data from baseline interviews with 969 women found a striking disparity between the objective risk factors included in the model and the accuracy of perceived risk and screening behaviors of this population, particularly among women over the age of 50 years. Risk perception accuracy was unrelated to all of the Gail model risk factors for all age groups. Reported mammography adherence was only associated with having had a breast biopsy in both age groups. Breast self examination (BSE) practice was independent of all measured factors for both age groups. These findings support the need for further research to identify additional determinants of risk perception and motivators of screening behavior.

Urinary bladder distension: its effects on carotid baroreceptor reflex left ventricular inotropic response in the dog

1. The effects of distension of the urinary bladder on heart rate, maximum rate of change of left ventricular pressure (dP/dt max) and hindlimb vascular resistance together with their modulation at different carotid sinus pressures were studied in dogs anaesthetized with a mixture of chloralose and urethane and artificially ventilated. 2. When the carotid sinus mean perfusion pressure was raised in randomly selected steps from 60 to 210 mmHg, it caused a progressive bradycardia, and a reduction in left ventricular dP/dt max and in arterial blood pressure, together with vasodilatation in the perfused hindlimb. Distension of the bladder at each level of carotid sinus pressure resulted in tachycardia, a small but significant increase in left ventricular dP/dt max (160 +/- 30 mmHg s-1) and hindlimb vasoconstriction. 3. When heart rate and arterial blood pressure were held constant to exclude these secondary effects on left ventricular dP/dt max, raising the carotid sinus pressure caused a progressive reduction in left ventricular dP/dt max and hindlimb vasodilatation. Superimposition of tests of bladder distension at each level of sinus pressure resulted in variable responses, but overall there was a significant increase in left ventricular dP/dt max of 190 +/- 54 mmHg s-1. Hindlimb vasocontriction, however, was a consistent finding. 4. The gain of the relationship between the carotid sinus perfusion pressure and left ventricular dP/dt max was unaffected by distension of the bladder. 5. It is concluded that, when changes secondary to increases in heart rate and blood pressure are prevented, distension of the bladder causes a small but significant reflex increase in left ventricular dP/dt max. The responses, however, are variable and the possible reasons for this are discussed.

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

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

Ovarian cancer risk counseling: a guide for the practitioner

Epithelial ovarian cancer is the most common gynecologic cancer diagnosed in women in the United States, with over 20,000 newly diagnosed cases per year. Over 70% of these patients present with advanced, stage III or IV disease, resulting in more than 13,000 deaths each year. This figure is all the more tragic given the long-term disease-free survival of approximately 85% for early stage disease. The natural history of the disease is poorly understood but is characterized by an insidious onset with vague, non-specific symptoms (which are commonly overlooked), and a high but often transient response to current surgical and chemotherapeutic approaches. It is commonly associated with a prolonged and painful death accompanied by repeat bowel obstructions, malnutrition, and immunologic compromise. In addition to the pain and suffering and loss of life of those affected with the disease, there is a profound and long-lasting impact on the entire family who experience the loss.