Protocol of a randomised, controlled trial comparing immediate curative therapy with conservative treatment in men aged ≥75 years with non-metastatic high-risk prostate cancer (SPCG 19/GRand-P)

BACKGROUND

Older men (aged ≥75 years) with high risk, non-metastatic prostate cancer (PCa) are increasingly treated with curative therapy (surgery or radiotherapy). However, it is unclear if curative therapy prolongs life and improves health-related quality of life (HRQoL) in this age group compared to conservative therapy, which has evolved considerably during the last decade.

STUDY DESIGN

The Scandinavian Prostate Cancer Group (SPCG) 19/Norwegian Get-Randomized Research Group-Prostate (GRand-P) is a randomised, two-armed, controlled, multicentre, phase III trial carried out at study centres in Norway, Denmark, Finland, and Sweden.

ENDPOINTS

The primary endpoints are overall survival and HRQoL (burden of disease scale, European Organisation for the Research and Treatment of Cancer [EORTC] Elderly Cancer patients). Secondary endpoints are PCa-specific survival, metastasis-free survival, role-functioning scale (EORTC quality of life questionnaire 30-item core), urinary irritative/obstructive scale (26-item Expanded Prostate Cancer Index Composite [EPIC-26]), bowel scale (EPIC-26), intervention-free survival, PCa morbidity, use of secondary and tertiary systemic therapies, mean quality-adjusted life-years (QALYs), and mean total healthcare costs.

PATIENTS AND METHODS

A total of 980 men (aged ≥75 years) with non-metastatic, high-risk PCa will initially be screened with Geriatric 8 (G8) health status screening tool and Mini-COG© brief cognitive test. Participants identified by G8 as 'fit' or 'frail' will be randomised (ratio 1:1) to either immediate curative therapy (radiotherapy or prostatectomy) or conservative therapy (endocrine therapy or observation). Participants who are unable or unwilling to participate in randomisation will be enrolled in a separate observation group. Randomised patients will be followed for 10 years.

TRIAL REGISTRATION

Ethics approval has been granted in Norway (457593), Denmark (H-22051998), Finland (R23043) and Sweden (Dnr 2023-05296-01). The trial is registered on Clinicaltrials.org (NCT05448547).

Prognostic factors of renal cell cancer in elderly patients: a population-based cohort study

Mortality in renal cell cancer (RCC) is high in the elderly population. Comorbidities have a greater impact on overall prognosis of RCC among elderly patients than in younger patients. All new RCC cases were collected in people over 74 years of age between 1995 and 2018 from the Finnish cancer registry. The comorbidities were identified from the Care Registry for Healthcare. Charlson Comorbidity Index (CCI) was used to evaluate the risk of death based on comorbidities. The overall risk of death was analyzed using the Cox regression model. The risk for RCC death was analyzed using Fine and Gray regression analysis. Individual prognostic role of CCI components was evaluated by adding each component separately into the multivariable Fine and Gray regression model. Using the most prognostic comorbidities we constructed a nomogram to predict RCC mortality. Statistically significant prognostic factors of RCC death were tumor morphology (clear cell, papillary and chromophobe), sex, operative treatment, age, primary tumor extent and CCI. The strongest prognostic factors for overall mortality were tumor extent, tumor morphology and operative treatment. Among the components of CCI, the most important comorbidities predicting mortality were dementia, heart failure and kidney disease. The limitation of this study is that the comorbidities have only been recorded at inpatient and outpatient hospital contacts, which is why the prevalence of comorbidities is probably underestimated. In addition, physical performance status was not available from registry data, but it significantly affects the treatment decisions. RCC mortality is high in the elderly population. Among comorbidities, dementia and heart failure have the greatest impact on the prognosis. Curative treatment in selected elderly patients is efficient and should be considered in patients who can tolerate it and have only limited comorbidities.

Research protocol to identify progression and death amongst patients with metastatic hormone-sensitive prostate cancer treated with available treatments: PIONEER IMI's "big data for better outcomes" program

Androgen deprivation therapy-based with or without first-generation anti-androgens, was the standard of care for patients with metastatic hormone-sensitive prostate cancer (mHSPC) for decades. However, the development of docetaxel chemotherapy and new androgen receptor-targeted agents, abiraterone acetate and prednisolone, apalutamide , enzalutamide and darolutamide (in combination with docetaxel chemotherapy) has proven that combination of treatments is more effective. Recently, intensification therapy, so-called "triplets", have emerged in the armamentarium of mHSPC treatment. Metastatic disease is a clinical state that remains poorly understood. The optimal diagnostic and management of patients with mHSPC are changing thanks to the development of new imaging techniques and therapies. The primary objective of this study is to develop and validate a predictive model for the occurrence of symptomatic progression, initiation of new treatments and death amongst patients with mHSPC treated with one of the approved treatment plans, on characteristics present at admission.

Cancer origin tracing and timing in two high-risk prostate cancers using multisample whole genome analysis: prospects for personalized medicine

BACKGROUND

Prostate cancer (PrCa) genomic heterogeneity causes resistance to therapies such as androgen deprivation. Such heterogeneity can be deciphered in the context of evolutionary principles, but current clinical trials do not include evolution as an essential feature. Whether or not analysis of genomic data in an evolutionary context in primary prostate cancer can provide unique added value in the research and clinical domains remains an open question.

METHODS

We used novel processing techniques to obtain whole genome data together with 3D anatomic and histomorphologic analysis in two men (GP5 and GP12) with high-risk PrCa undergoing radical prostatectomy. A total of 22 whole genome-sequenced sites (16 primary cancer foci and 6 lymph node metastatic) were analyzed using evolutionary reconstruction tools and spatio-evolutionary models. Probability models were used to trace spatial and chronological origins of the primary tumor and metastases, chart their genetic drivers, and distinguish metastatic and non-metastatic subclones.

RESULTS

In patient GP5, CDK12 inactivation was among the first mutations, leading to a PrCa tandem duplicator phenotype and initiating the cancer around age 50, followed by rapid cancer evolution after age 57, and metastasis around age 59, 5 years prior to prostatectomy. In patient GP12, accelerated cancer progression was detected after age 54, and metastasis occurred around age 56, 3 years prior to prostatectomy. Multiple metastasis-originating events were identified in each patient and tracked anatomically. Metastasis from prostate to lymph nodes occurred strictly ipsilaterally in all 12 detected events. In this pilot, metastatic subclone content analysis appears to substantially enhance the identification of key drivers. Evolutionary analysis' potential impact on therapy selection appears positive in these pilot cases.

CONCLUSIONS

PrCa evolutionary analysis allows tracking of anatomic site of origin, timing of cancer origin and spread, and distinction of metastatic-capable from non-metastatic subclones. This enables better identification of actionable targets for therapy. If extended to larger cohorts, it appears likely that similar analyses could add substantial biological insight and clinically relevant value.

Prostate cancer incidence in men with prostate-specific antigen below 3 ng/mL: The Finnish Randomized Study of Screening for Prostate Cancer

Prostate-specific antigen (PSA)-based screening for prostate cancer (PCa) can reduce PCa mortality, but also involves overdetection of low-risk disease with potential adverse effects. We evaluated PCa incidence among men with PSA below 3 ng/mL and no PCa diagnosis at the first screening round of the Finnish Randomized Study of Screening for PCa. Follow-up started at the first screening attendance and ended at PCa diagnosis, emigration, death or the common closing date (December 2016), whichever came first. Cox regression analysis was used to estimate hazard ratios and their confidence intervals (CI). Among men with PSA <3 ng/mL, cumulative PCa incidence was 9.1% after 17.6 years median follow-up. Cumulative incidence was 3.6% among men with baseline PSA 0 to 0.99 ng/mL, 11.5% in those with PSA 1.0 to 1.99 ng/mL and 25.7% among men with PSA 2 to 2.99 ng/mL (hazard ratio 9.0, 95% CI: 7.9-10.2 for the latter). The differences by PSA level were most striking for low-risk disease based on Gleason score and EAU risk group. PSA values <1 ng/mL indicate a very low 20-year risk, while at PSA 2 to 2.99 ng/mL risks are materially higher, with 4- to 5-fold risk for aggressive disease. Using risk-stratification and appropriate rescreening intervals will reduce screening intensity and overdetection. Using cumulative incidence of clinically significant PCa (csPCa) as the criterion, rescreening intervals could range from approximately 3 years for men with initial PSA 2 to 2.99 ng/mL, 6 years for men with PSA 1 to 1.99 ng/mL to 10 years for men with PSA <1 ng/mL.

Visual Analogue Scale (VAS) in the Evaluation of Functional Outcomes After Three-dimensional Laparoscopic Prostatectomy

OBJECTIVE

To assess suitability of visual analog scale (VAS) in the evaluation of functional outcomes after 3D laparoscopic prostatectomy (3D LRP) METHODS: Two hundred men underwent 3D LRP for localised prostate cancer at Seinäjoki Central Hospital in Finland between December 2013 and September 2018. In October 2019, an EPIC-26 survey along with VAS scales enquiring urinary (VAS-incontinence) and sexual (VAS-sexual) symptoms was mailed to the patients, and the correlations between these 2 methods were evaluated. In the EPIC-26 survey, scores for incontinence-(EPIC-26 UI) and sexual (EPIC-26-sexual) domains were calculated using the University of Michigan scoring system. In the VAS questionnaires, patient put a mark on the 10 cm long horizontal line in place, which described his experience of continence and potency. The Spearman rank correlation coefficient was used to evaluate the correlation between methods.

RESULTS

The median scores were as follows: EPIC-26-UI, 79.25 (14.5-100); EPIC-26-sexual, 36.17 (0.0-100); VAS-incontinence, 8.8 cm (1.4-10.0); and VAS-sexual, 3.2 cm (0.0-10). The correlation coefficient between EPIC-26 UI and VAS-incontinence was 0.722 (95% confidence interval [CI], 0.63-0.79; p <.0001) and 0.883 (95% CI, 0.84-0.91; p <.0001) between EPIC-26-sexual and VAS-sexual.

CONCLUSION

Our study shows a strong correlation between VAS and EPIC-26 urinary incontinence and sexual domains. In daily clinical practice VAS-scale may serve as a simple tool to evaluate the key functional outcomes of radical prostatectomy.

Abstract 401: Single-cell transcriptome and chromatin sequencing uncover gene expression and gene regulatory patterns associated with enzalutamide resistance

Resistance to androgen receptor-targeted therapy due to tumor heterogeneity and clonal evolution is a key challenge for improving prostate cancer outcomes. Despite this, the transcriptomic and chromatin accessibility changes contributing to the emergence of resistance remain incompletely understood at the level of individual cells. Using single-cell assays for transposase-accessible chromatin (ATAC) and RNA sequencing in models of early treatment response and resistance to enzalutamide, we previously identified pre-existing and persistent cell subpopulations that possess regenerative potential when subjected to treatment. Here we analyze the chromatin and transcriptomes of these single cells to characterize their gene regulation and gene expression trajectories. We present evidence of a model of enzalutamide resistance emergence in which the pre-existing and treatment-persistent cells regenerate the bulk of resistant cells. This process is underpinned by chromatin reprogramming that increases the overall relaxation of chromatin upon resistance. We show that the reprogramming of the chromatin further differentially contributes to transcription factor-mediated transcriptional reprogramming via DNA motif exposure in different cell subpopulations. For example, in the treatment-persistent cells, we identify chromatin configurations characterized by the exposure of DNA motifs for GATA2, RELA (a NFkB subunit), CREB1, and E2F1. Pre-existing and treatment-persistent cells consistently display transcriptional features of high developmental potential and RNA velocity analysis identifies them as precursors of cell populations that arise from enzalutamide treatment. We also analyze the pre-existing and treatment-persistent cells in spatial transcriptomics of prostate cancer patient specimens based on their characteristic gene expression profiles. We find these cells to be enriched in cancerous regions of the tissue but also detect them within apparent benign regions, which has potential implications for treatment choice. In summary, we show patterns of gene expression regulation in preclinical models and patient samples that uncover mechanisms of resistance to androgen receptor-targeted therapy in prostate cancer.

Citation Format: Sinja Taavitsainen, Nikolai Engedal, Shaolong Cao, Florian Handle, Andrew Erickson, Stefan Prekovic, Daniel Wetterskog, Teemu Tolonen, Elisa M. Vuorinen, Antti Kiviaho, Reetta Nätkin, Tomi Häkkinen, Wout Devlies, Sallamari Henttinen, Roosa Kaarijärvi, Mari Lahnalampi, Heidi Kaljunen, Karolina Nowakowska, Heimo Syvälä, Merja Bläuer, Paolo Cremaschi, Frank Claessens, Tapio Visakorpi, Teuvo L. Tammela, Teemu Murtola, Kirsi J. Granberg, Alastair D. Lamb, Kirsi Ketola, Ian G. Mills, Gerhardt Attard, Wenyi Wang, Matti Nykter, Alfonso Urbanucci. Single-cell transcriptome and chromatin sequencing uncover gene expression and gene regulatory patterns associated with enzalutamide resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 401.

Tumor margins that lead to reoperation in breast cancer: A retrospective register study of 4,489 patients

Background and Objectives

Optimal margins for ductal carcinoma in situ (DCIS) remain controversial in breast‐conserving surgery (BCS) and mastectomy. We examine the association of positive margins, reoperations, DCIS and age.

Methods

A retrospective study of histopathological reports (4489 patients). Margin positivity was defined as ink on tumor for invasive carcinoma. For DCIS, we applied 2 mm anterior and side margin thresholds, and ink on tumor in the posterior margin.

Results

The incidence of positive side margins was 20% in BCS and 5% in mastectomies (p < 0.001). Of these patients, 68% and 14% underwent a reoperation (p < 0.001). After a positive side margin in BCS, the reoperation rates according to age groups were 74% (<49), 69% (50–64), 68% (65–79), and 42% (80+) (p = 0.013). Of BCS patients with invasive carcinoma in the side margin, 73% were reoperated on. A reoperation was performed in 70% of patients with a close (≤1 mm) DCIS side margin, compared to 43% with a wider (1.1–2 mm) margin (p = 0.002). The reoperation rates were 55% in invasive carcinoma with close DCIS, 66% in close extensive intraductal component (EIC), and 83% in close pure DCIS (p < 0.001).

Conclusions

Individual assessment as opposed to rigid adherence to guidelines was used in the decision on reoperation.

Single-cell ATAC and RNA sequencing reveal pre-existing and persistent cells associated with prostate cancer relapse

Prostate cancer is heterogeneous and patients would benefit from methods that stratify those who are likely to respond to systemic therapy. Here, we employ single-cell assays for transposase-accessible chromatin (ATAC) and RNA sequencing in models of early treatment response and resistance to enzalutamide. In doing so, we identify pre-existing and treatment-persistent cell subpopulations that possess regenerative potential when subjected to treatment. We find distinct chromatin landscapes associated with enzalutamide treatment and resistance that are linked to alternative transcriptional programs. Transcriptional profiles characteristic of persistent cells are able to stratify the treatment response of patients. Ultimately, we show that defining changes in chromatin and gene expression in single-cell populations from pre-clinical models can reveal as yet unrecognized molecular predictors of treatment response. This suggests that the application of single-cell methods with high analytical resolution in pre-clinical models may powerfully inform clinical decision-making.

Hyperuricemia Is Not an Independent Predictor of Erectile Dysfunction

INTRODUCTION

Erectile dysfunction (ED) is strongly associated with physiological and metabolic disturbances, and hyperuricemia has been proposed to predict the onset of ED.

AIM

To investigate if hyperuricemia is an independent predictor for ED when all relevant confounding factors are taken into account.

METHODS

This is a cross-sectional study of men aged between 45 and 70 years. The population was well characterized for established cardiovascular risk factors, metabolic syndrome, as well as kidney function, depression, and socioeconomic factors. Analysis was limited to 254 men with complete data and also serum uric acid (SUA) measurements were available. This included 150 men with and 104 without ED. The presence and severity of ED was evaluated using International Index of Erectile Function-5 questionnaire. Risk of ED by SUA level was calculated using univariate and multivariable-adjusted logistic regression. Effect modification by participant characteristics were evaluated in subgroup analyses.

MAIN OUTCOME MEASURES

The main outcome measures of this study are prevalence and severity of erectile dysfunction.

RESULTS

Patients with ED (59% of the study population) were older than men without ED (59 vs 54 years) and had lower serum testosterone (14.3, 95% CI 11.3-17.3 vs 15.1 nmol/l, 95% CI 12.1-18.8, respectively). Regarding all other variables, the groups were comparable. No significant difference was found for SUA by ED. SUA was not associated with ED risk in univariate or multivariable analysis (multivariable-adjusted OR 1.14, 95% CI 0.59-2.19, P = .7) for SUA level higher than median compared with median or lesser (OR 1.00, 95% CI 0.997-1.006, P = .7 for continuous variable). No subgroup analysis modified the association. After multivariable adjustment age, education level and depression were statistically significant predictors of ED.

CONCLUSIONS

Elevated SUA was not found to be an independent risk factor for ED. Metabolic syndrome, glomerular filtration rate, or cardiovascular risk factors did not modify this result. ED cannot be predicted based on the level of SUA. A Tuokko, T Murtola, P Korhonen, et al. Hyperuricemia Is Not an Independent Predictor of Erectile Dysfunction. Sex Med 2021;9:100319.

Abstract 5782: Lipophilic Statins show promise for treatment of epithelial ovarian cancer

Background: Repurposing statins for the treatment of ovarian cancer isappealing due to promising preclinical and epidemiologic data, broad access,low cost, and modest toxicity. To inform the design of a randomized clinicaltrial, we conducted a large observational study to identify subgroups ofovarian cancer (OC) patients that could benefit from statin treatment.

Methods: Data from the Finnish national cancer registry waslinked to prescription claims on 10,062 women diagnosed with OC between 1995and 2015. A series of analyses were then conducted in OC patients to examinethe association between pre- and post-diagnostic statin use and mortality(cause-specific and all cause). Descriptive statistics were used tocharacterize patients at baseline. To address potential confounding due toindication for statin initiation we used time updated marginal structural Coxregression models with inverse probability of treatment weights to calculatehazard ratios (HR) and 95% confidence intervals (95% CIs) between users and neverusers. Analyses were adjusted for age at diagnosis, stage, OC subtype,treatments, year of diagnosis, and chronic disease medications.

Results: The median (IQR) age of diagnosis among patients was 63(53-74) years, and median (IQR) follow up time was 4 (1.5-9.3) years. A totalof 2,621 patients were statin users of which 80% took statins classified aslipophilic. Median (IQR) duration of statin use was 7.5 (3.6-11.4) years.Eighty two percent of statin users filled 90% of their prescriptions. In timeupdated models, ever use of statins was associated with a 40% reduction in OCmortality compared to never use (HR Overall = 0.60(0.57-0.63).; HR Lipophilic = 0.78 (0.64-0.83).The benefit from statin use was greater in those being treated with curativeintent (HR=0.19; 0.18-0.20) rather than palliative intent (HR =0.41; 0.39-0.4).Further, reductions in OC mortality were also observed in women who primarilytook one specific lipophilic statin: HR Atorvastatin= 0.35;(0.22-0.50) and HR Simvastatin= 0.25;(0.22-0.34). Among women taking lipophilic statins, agreater reduction in mortality was observed with increasing statin dose (ptrend = 0.06). Lipophilic statin use was also associated with a reduction in OCmortality among most OC subtypes, but the magnitude of reduction varied: HighGrade Serous Carcinoma (HR= 0.43; 0.33-0.76); Endometroid (HR =0.65;0.34-0.78); Clear cell (HR= 1.02; 0.98-1.98); Mucinous (HR=0.60; 0.45-0.95);and Borderline (HR =0.30; 0.25-0.87). A reduction in OC mortality was alsoobserved in analyses limited to women who initiated lipophilic statinspost-diagnosis.

Conclusion: Our results provide further evidence in support of theevaluation of lipophilic statins, particularly atorvastatin and/or simvastatin,for the treatment of OC in a randomized clinical trial.

Citation Format: Kala Visvanathan, Shari Modur, Miia Artama, Teemu Murtola. Lipophilic Statins show promise for treatment of epithelial ovarian cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5782.

Charlson Comorbidity Index Based On Hospital Episode Statistics Performs Adequately In Predicting Mortality, But Its Discriminative Ability Diminishes Over Time

Purpose

To evaluate the performance of Charlson Comorbidity Index (CCI) calculated using hospitalization and medication reimbursement databases in predicting mortality.

Patients and methods

Information on hospitalizations was obtained from the national Care Register for Health Care (HILMO) and on medication reimbursements and entitlements for special reimbursements for medications from the Social Insurance Institution for 77,440 men aged 56–71 years at baseline. The subjects were followed up for mortality via Statistics Finland with 20,562 deaths during a 13-year follow-up.

Results

Compared to a CCI score of 0, the age-adjusted hazard ratio for all-cause mortality associated with HILMO-based CCI scores of 1, 2 and 3 or more were 2.39 (95% CI 2.29–2.49), 2.96 (95% CI 2.81–3.13) and 6.42 (95% CI 5.95–6.93) at 13 years. The C-statistic was 0.72 at 1, 0.68 at 5 and 0.66 at 13 years, with only minor improvement over age alone (0.10, 0.06 and 0.04 accordingly). Addition of medication data did not improve predictive abilities and medication-based CCI performed poorly on its own.

Conclusion

The hospitalization-based CCI, as well as that based on both databases, predicts relative mortality adequately, but its discriminative ability diminishes over time. Conditions related to hospitalizations affect survival more than medications.

Abstract 3290: Cancer mortality by antiarrhythmic drug use in a population-based cohort of Finnish men

Introduction: In-vitro studies have suggested that antiarrhythmic drug digoxin might restrain the growth of cancer cells by inhibiting Na+/K+-ATPase. A non-selective beta-blocker sotalol has similar effect on K+-channels. We evaluated the association between cancer mortality and digoxin, sotalol and general antiarrhythmic drug use in a retrospective cohort study.

Materials and methods: The study population consists of 78,615 men originally identified for the Finnish Randomized Study for Screening of Prostate Cancer. Men were 55-69 years old at baseline. Prevalent prostate cancer cases were excluded; no exclusions were made based on other cancer types. Information on antiarrhythmic drug purchases was collected from the national prescription database. We used Cox regression method to analyze the overall cancer mortality and individually mortality from the most common causes of cancer death.

Results: A total of 8,064 men (10.3%) had used antiarrhythmic drugs. Of these 5,668 had used digoxin and 2,540 had used sotalol. During the median follow-up of 16.9 years after baseline 26,790 (34.1%) men died, of these 8,225 (30.7% of deaths) due to cancer. Overall cancer mortality was elevated among antiarrhythmic drug users compared to non-users (HR 1.25, 95% CI 1.12-1.40). Similar results were observed for digoxin (HR 1.44, 95% CI 1.26-1.63) but not for sotalol (HR 0.92, 95% CI 0.68-1.24). Furthermore, the antiarrhythmic drug use was associated with elevated risk of lung-cancer death (HR 1.76 95% CI 1.46-2.14). However, the risk associations disappeared in long-term use. When we restricted the analysis to cancer cases only, no differences were observed in survival after the cancer diagnosis for any cancer type.

Conclusion: Cancer mortality was elevated among users of antiarrhythmic drugs compared to non-users. This association is probably due to the differences between users and non-users as it was related to short-term use, and disappeared in long-term use. Use of digoxin or sotalol was not associated with improved cancer-specific survival.

Citation Format: Kalle J. Kaapu, Teemu Murtola, Kirsi Talala, Kimmo Taari, Teuvo Tammela, Anssi Auvinen. Cancer mortality by antiarrhythmic drug use in a population-based cohort of Finnish men [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3290. doi:10.1158/1538-7445.AM2017-3290

Abstract 3294: Breast cancer extent and survival in diabetic women in a Finnish population based cohort

Introduction: Breast cancer and diabetes are two major health problems for women. Around 1.7 million new breast cancer cases are diagnosed each year, making breast cancer the most common cancer type in women. Number of people with diabetes is estimated to be 415 million worldwide, thus one in 11 adults have diabetes. However, evidence on the association between diabetes and breast cancer prognosis is controversial. We estimated breast cancer extent at diagnosis and survival in a Finnish population-based cohort of female breast cancer patients.

Materials and methods: All newly diagnosed breast cancer cases among women in Finland between 1995 and 2013 were identified from comprehensive national Finnish Cancer Registry. To minimize possible bias due to differing participation in cancer screening the study population was limited to women with at least one mammography screening before the diagnosis. In total 45,786 cases were included in our study cohort. Information on recorded diagnoses of diabetes, hypertension, hypercholesterolemia and obesity from in- and outpatient hospital visits during 1995-2013 were obtained from national Care Register for Health Care maintained by National Institute for Health and Welfare. Logistic regression was used to evaluate the risk of having cancer extended to axillary lymph nodes or beyond at diagnosis. Cox regression was used to evaluate risk of breast cancer death and overall mortality after the diagnosis. Analyses were adjusted for age, comorbidities and number of mammography screens before the diagnosis. Survival analyses were further adjusted for tumor extent and primary treatment.

Results: In total 1,419 women had diabetes. Compared to non-diabetic women, breast cancer was more often advanced to axillary lymph-nodes (OR 1.19; 95% CI 1.05-1.34) or metastatic at diagnosis (OR 1.58; 95% CI 1.26-1.97) in diabetic women. Nevertheless, during the median follow-up of 6.9 year after the diagnosis, risk of breast cancer death did not differ between diabetic and non-diabetic women (0.99; 95% CI 0.81-1.21). Overall risk of death was elevated among diabetic women (HR 1.34; 95% CI 1.19-1.51).

Conclusion: Diabetic women have more often advanced tumor extent at diagnosis compared to non-diabetic women. However, diabetes did not affect disease-specific survival within 6.9 years after the diagnosis.

Citation Format: Mika Murto, Miia Artama, Kala Visvanathan, Teemu Murtola. Breast cancer extent and survival in diabetic women in a Finnish population based cohort [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3294. doi:10.1158/1538-7445.AM2017-3294

Direct-Space Corrections Enable Fast and Accurate Lorentz-Berthelot Combination Rule Lennard-Jones Lattice Summation

Long-range lattice summation techniques such as the particle-mesh Ewald (PME) algorithm for electrostatics have been revolutionary to the precision and accuracy of molecular simulations in general. Despite the performance penalty associated with lattice summation electrostatics, few biomolecular simulations today are performed without it. There are increasingly strong arguments for moving in the same direction for Lennard-Jones (LJ) interactions, and by using geometric approximations of the combination rules in reciprocal space, we have been able to make a very high-performance implementation available in GROMACS. Here, we present a new way to correct for these approximations to achieve exact treatment of Lorentz-Berthelot combination rules within the cutoff, and only a very small approximation error remains outside the cutoff (a part that would be completely ignored without LJ-PME). This not only improves accuracy by almost an order of magnitude but also achieves absolute biomolecular simulation performance that is an order of magnitude faster than any other available lattice summation technique for LJ interactions. The implementation includes both CPU and GPU acceleration, and its combination with improved scaling LJ-PME simulations now provides performance close to the truncated potential methods in GROMACS but with much higher accuracy.

Multiscale modeling of emergent materials: biological and soft matter

In this review, we focus on four current related issues in multiscale modeling of soft and biological matter. First, we discuss how to use structural information from detailed models (or experiments) to construct coarse-grained ones in a hierarchical and systematic way. This is discussed in the context of the so-called Henderson theorem and the inverse Monte Carlo method of Lyubartsev and Laaksonen. In the second part, we take a different look at coarse graining by analyzing conformations of molecules. This is done by the application of self-organizing maps, i.e., a neural network type approach. Such an approach can be used to guide the selection of the relevant degrees of freedom. Then, we discuss technical issues related to the popular dissipative particle dynamics (DPD) method. Importantly, the potentials derived using the inverse Monte Carlo method can be used together with the DPD thermostat. In the final part we focus on solvent-free modeling which offers a different route to coarse graining by integrating out the degrees of freedom associated with solvent.

Insights into activation and RNA binding of trp RNA-binding attenuation protein (TRAP) through all-atom simulations

Tryptophan biosynthesis in Bacillus stearothermophilus is regulated by a trp RNA binding attenuation protein (TRAP). It is a ring-shaped 11-mer of identical 74 residue subunits. Tryptophan binding pockets are located between adjacent subunits, and tryptophan binding activates TRAP to bind RNA. Here, we report results from all-atom molecular dynamics simulations of the system, complementing existing extensive experimental studies. We focus on two questions. First, we look at the activation mechanism, of which relatively little is known experimentally. We find that the absence of tryptophan allows larger motions close to the tryptophan binding site, and we see indication of a conformational change in the BC loop. However, complete deactivation seems to occur on much longer time scales than the 40 ns studied here. Second, we study the TRAP-RNA interactions. We look at the relative flexibilities of the different bases in the complex and analyze the hydrogen bonds between the protein and RNA. We also study the role of Lys37, Lys56, and Arg58, which have been experimentally identified as essential for RNA binding. Hydrophobic stacking of Lys37 with the nearby RNA base is confirmed, but we do not see direct hydrogen bonding between RNA and the other two residues, in contrast to the crystal structure. Rather, these residues seem to stabilize the RNA-binding surface, and their positive charge may also play a role in RNA binding. Simulations also indicate that TRAP is able to attract RNA nonspecifically, and the interactions are quantified in more detail using binding energy calculations. The formation of the final binding complex is a very slow process: within the simulation time scale of 40 ns, only two guanine bases become bound (and no others), indicating that the binding initiates at these positions. In general, our results are in good agreement with experimental studies, and provide atomic-scale insights into the processes.

Conformational analysis of lipid molecules by self-organizing maps

The authors have studied the use of the self-organizing map (SOM) in the analysis of lipid conformations produced by atomic-scale molecular dynamics simulations. First, focusing on the methodological aspects, they have systematically studied how the SOM can be employed in the analysis of lipid conformations in a controlled and reliable fashion. For this purpose, they have used a previously reported 50 ns atomistic molecular dynamics simulation of a 1-palmitoyl-2-linoeayl-sn-glycero-3-phosphatidylcholine (PLPC) lipid bilayer and analyzed separately the conformations of the headgroup and the glycerol regions, as well as the diunsaturated fatty acid chain. They have elucidated the effect of training parameters on the quality of the results, as well as the effect of the size of the SOM. It turns out that the main conformational states of each region in the molecule are easily distinguished together with a variety of other typical structural features. As a second topic, the authors applied the SOM to the PLPC data to demonstrate how it can be used in the analysis that goes beyond the standard methods commonly used to study the structure and dynamics of lipid membranes. Overall, the results suggest that the SOM method provides a relatively simple and robust tool for quickly gaining a qualitative understanding of the most important features of the conformations of the system, without a priori knowledge. It seems plausible that the insight given by the SOM could be applied to a variety of biomolecular systems and the design of coarse-grained models for these systems.

Coarse-grained model for phospholipid/cholesterol bilayer employing inverse Monte Carlo with thermodynamic constraints

The authors introduce a coarse-grained (CG) model for a lipid membrane comprised of phospholipids and cholesterol at different molar concentrations, which allows them to study systems that are approximately 100 nm in linear size. The systems are studied in the fluid phase above the main transition temperature. The effective interactions for the CG model are extracted from atomic-scale molecular dynamics simulations using the inverse Monte Carlo (IMC) technique, an approach similar to the one the authors used earlier to construct another CG bilayer model [T. Murtola et al., J. Chem. Phys. 121, 9156 (2004)]. Here, the authors improve their original CG model by employing a more accurate description of the molecular structure for the phospholipid molecules. Further, they include a thermodynamic constraint in the IMC procedure to yield area compressibilities in line with experimental data. The more realistic description of the molecular structure of phospholipids and a more accurate representation of the interaction between cholesterols and phospholipid tails are shown to improve the behavior of the model significantly. In particular, the new model predicts the formation of denser transient regions in a pure phospholipid system, a finding that the authors have verified through large scale atomistic simulations. They also find that the model predicts the formation of cholesterol-rich and cholesterol-poor domains at intermediate cholesterol concentrations, in agreement with the original model and the experimental phase diagram. However, the domains observed here are much more distinct compared to the previous model. Finally, the authors also explore the limitations of the model, discussing its advantages and disadvantages.

Coarse-grained model for phospholipid/cholesterol bilayer

We construct a coarse-grained (CG) model for dipalmitoylphosphatidylcholine (DPPC)/cholesterol bilayers and apply it to large-scale simulation studies of lipid membranes. Our CG model is a two-dimensional representation of the membrane, where the individual lipid and sterol molecules are described by pointlike particles. The effective intermolecular interactions used in the model are systematically derived from detailed atomic-scale molecular dynamics simulations using the Inverse Monte Carlo technique, which guarantees that the radial distribution properties of the CG model are consistent with those given by the corresponding atomistic system. We find that the coarse-grained model for the DPPC/cholesterol bilayer is substantially more efficient than atomistic models, providing a speedup of approximately eight orders of magnitude. The results are in favor of formation of cholesterol-rich and cholesterol-poor domains at intermediate cholesterol concentrations, in agreement with the experimental phase diagram of the system. We also explore the limits of the coarse-grained model, and discuss the general validity and applicability of the present approach.

Transient ordered domains in single-component phospholipid bilayers

We report evidence of dense, ordered nanodomains in single-component fluid lipid bilayers. Our atomic-scale molecular dynamics simulations suggest that the area available to a lipid acyl chain exhibits large fluctuations, resulting in denser and sparser domains. The sizes of the dense domains can be up to approximately 10 nm, and their lifetimes are of the order of approximately 10 ns. In addition, our simulations suggest that domains of lipids with highly ordered acyl chains form predominantly within the dense regions, their sizes ranging from a few chains up to a few nanometers, and with lifetimes between approximately 10 ps-10 ns. These observations shed light on the origin of experimentally observed fluctuations, as well as on the mechanisms of phase transitions in lipid membranes.

Regulation of aromatase and 5alpha-reductase by 25-hydroxyvitamin D(3), 1alpha,25-dihydroxyvitamin D(3), dexamethasone and progesterone in prostate cancer cells

Estrogens and androgens are proposed to play a role in the pathogenesis of prostate cancer. The effective metabolites, estradiol and 5alpha-dihydrotestosterone are produced from testosterone by aromatase and 5alpha-reductase, respectively. Metabolites of vitamin D have shown to inhibit the growth of prostate cancer cells. The aim of the present study was to verify whether 25-hydroxyvitamin D(3) (25OHD(3)), 1alpha,25-dihydroxyvitamin D(3) [1alpha,25-(OH)(2)D(3)], dexamethasone, and progesterone regulate the expression of aromatase and 5alpha-reductase in human prostate cancer cells. LNCaP and PC3 cells were treated with 25OHD(3), 1alpha,25-(OH)(2)D(3), dexamethasone, or progesterone. Aromatase and 5alpha-reductase mRNA was quantified by real-time RT-PCR and aromatase enzyme activity was measured by the [(3)H] water assay. Aromatase enzyme activity in LNCaP and PC3 cells was increased by both 10nM dexamethasone, 1-100 nM 1alpha,25-(OH)(2)D(3) and 100 nM-10 microM progesterone. The induction was enhanced when hormones were used synergistically. Real-time RT-PCR analysis showed no regulation of the expression of aromatase mRNA by any steroids tested in either LNCaP or PC3 cells. The expression of 5alpha-reductase type I mRNA was not regulated by 1alpha,25-(OH)(2)D(3) and no expression of 5alpha-reductase type II was detected in LNCaP.