The Analysis Of Survival And The Fragmentation Patterns Of Urinary Cell-free DNA Of Metastatic Breast Cancer Patients

Background and objective:Breast cancer is a global problem,threatening lives of women.With an unfavorable prognosis,most advanced breast cancer(ABC)is incurable.The prognosis of ABC patients varied according to different prognostic factors.There is a lack of prognostic models predicting the overall survival(OS)of ABC patients.This study aimed to establish a nomogram to predict the OS of ABC patients.Methods:Data from the China National Cancer Center database that recorded 4039 patients diagnosed with breast cancer between 1987 and 2019 were extracted and a total of 2263 ABC participants were enrolled in this study,which were further randomized 3:1 and divided into training(n=1706)and validation(n=557)groups.The nomogram was built based on independent predictors identified by univariate and multivariate cox regression analyses.The discriminatory and predictive capacities of the nomogram were assessed by Harrell’s concordance index(C-index)and calibration plots.Results:Univariate and multivariate analyses found that age,Eastern Cooperative Oncology Group score,T-stage,N-stage,tumor subtype,the presence of distant lymph node/liver/brain metastasis,local therapy,efficacy of first-line therapy and metastatic-free interval were significantly related to OS(all p<0.05).These variables were incorporated into a nomogram to predict the 2-year and 3-year OS of ABC patients.The C-indexes of the nomogram were 0.700(95%confidence interval[CI]:0.683-0.717)for the training set and 0.686(95%CI:0.652-0.719)for the validation set.The calibration curves revealed satisfactory consistency between actual survival and nomogram prediction in both the internal and external validations.The nomogram was capable of stratifying patients into different risk cohorts.Conclusions:We constructed and validated a nomogram that might serve as an efficient tool to provide prognostic prediction for ABC patients and guide the physicians to make personalized treatment decisions.Background and Objective:Liver metastasis is one of the most frequent distant metastases of breast cancer.Patients with breast cancer liver metastases(BCLM)have poor outcomes.We aimed to investigate the clinicopathological characteristics and survival of BCLM patients at initial diagnosis of metastatic breast cancer(MBC).Materials and Methods:Data of 3,161 female patients who were initially diagnosed with MBC from December 1991 to September 2019 and treated in the China National Cancer Center were extracted and a total of 2,263 MBC patients were included in our study,among which 550(24.3%)patients had liver metastases.Multivariable logistic regression was performed to identify risk factors for the presence of liver metastases at initial MBC diagnosis.Univariable and multivariable Cox proportional hazards regression analyses were conducted to determine prognostic factors for the survival of BCLM patients.KaplanMeier analysis and log rank test were used to estimate the cumulative overall survival of BCLM patients.Results:Patients with hormone receptor(HR)-negative,human epidermal growth factor receptor 2(HER2)-positive(35.0%of the entire population)subtype had the highest incidence of liver metastases.De novo stage Ⅳ breast cancer,HR-/HER2+and HR+/HER2+subtypes were associated with higher odds of liver metastases,while triplenegative subtype and patients with lung metastases had lower risk of liver metastases at initial MBC diagnosis.The median overall survival of BCLM patients was 31.4 months and BCLM patients with HR+/HER2-subtype had the longest survival of 38.2 months.Older age,worse performance status,later stage of initial breast cancer,triple-negative subtype and lung metastases were significantly associated with a poorer prognosis in BCLM patients.Conclusions:Our study offers insights into the incidence and risk factors of BCLM patients at initial MBC diagnosis.We also characterized clinicopathological features and survival outcomes of BCLM patients according to breast cancer subtype.Background and Objective:As a completely noninvasive form of liquid biopsy,urinary cell-free DNA(ucfDNA)has attracted more and more attention from scientists in recent years.UcfDNA has shown its potential in tumor screening and diagnosis,disease assessment,efficacy evaluation,drug resistance monitoring and prognosis judgment.Fragmentomics is a new omics that focuses on various physical characteristics of cfDNA fragments,such as fragment size,preferred DNA end and end motif frequency.Our study aimed to describe and analyze the fragmentation patterns of ucfDNA in patients with metastatic breast cancer(MBC),and to identify somatic mutations from ucfDNA,attempting to explore the application of ucfDNA in MBC.Materials and Methods:We prospectively enrolled 45 MBC patients form China National Cancer Center,collected the baseline urine and blood samples before treatments and dynamically obtained urine samples after 2-3 cycles of treatments from 16/45 patients.We also collected urine samples from 5 healthy adult women as blank controls.We randomly choose 10/45 patients to test the somatic mutations and tumor mutational burdens(TMBs)using next-generation sequencing.Fragmentation patterns of cfDNA in urine and plasma were presented by electropherogram.Chi-square test was used to compare variable differences among different fragmentation patterns of ucfDNA.Wilcoxon test of paired samples was conducted to compare the differences of extracted amounts of cfDNA,length of cfDNA fragments and TMBs between urine and plasma.Heatmap was used to show somatic mutations in urine and plasma.Results:The fragmentation patterns of ucfDNA in 45 MBC patients were categorized as:(1)profile A(accounting for 57.8%),presenting as bimodal pattern,contained both a short peak between 100 bp and 200 bp and a long peak longer than 1500 bp;(2)profile B(accounting for 17.8%),presenting as unimodal pattern,contained only a long peak longer than 1500 bp;(3)profile C(accounting for 24.4%)was flat pattern with no peak.In profile A,the short-peaked ucfDNA might circulate from the bloodstream and crosse the glomerular barrier,with a median size of 149 bp(range 96-182 bp),the long-peaked ucflDNA might arise from the cells of urinary tract or/and the white blood cells in urine,with a median size of4676 bp(range 1537-15697 bp).The fragmentation pattern of cfDNA in plasma was unimodal,with a median size of 170 bp(range 157-180 bp).In patients with profile A,the fragment size of cfDNA in plasma was much longer than that of short-peaked ucfDNA(171bp vs.149bp,Wilcoxontest,p=0.023).The ucfDNA fragmentation patterns of 5 healthy female adults were all profile C.The ucfDNA fragmentation patterns of patients with lung metastases were more likely to be profile C(p=0.002).After 2-3 cycles of treatment,87.5%(14/16)of patients showed consistent ucfDNA fragmentation patterns.The concordance rate of somatic mutations in plasma and urine was 30%(3/10),and patient P07 had a consistent mutation in urine and plasma(DNMT3Ap.R882C).With no significant difference,the median TMBs of urine and plasma were 2.95 muts/Mb and 4.01 muts/Mb,respectively.Conclusions:This study described the fragmentation patterns of ucfDNA in MBC patients,simultaneously comparing with that of cfDNA in plasma.In addition,we explored the potential of detecting somatic mutations in urine.Although the study was in early stage,the sample size was small,and the results needed further validation,it offered a possibility for the application of ucfDNA in MBC.