--- title: "Example for Classification Data -- Breast Invasive Carcinoma" author: "Marta Lopes and André Veríssimo" date: "`r Sys.Date()`" output: BiocStyle::html_document: number_sections: yes toc: true vignette: > %\VignetteEngine{knitr::rmarkdown} %\VignetteIndexEntry{Example for Classification -- Breast Invasive Carcinoma} %\VignetteEncoding{UTF-8} params: seed: !r 29221 --- ## Instalation ```{r, eval=FALSE} if (!require("BiocManager")) { install.packages("BiocManager") } BiocManager::install("glmSparseNet") ``` # Required Packages ```{r packages, message=FALSE, warning=FALSE, results='hide'} library(dplyr) library(ggplot2) library(survival) library(futile.logger) library(curatedTCGAData) library(MultiAssayExperiment) library(TCGAutils) # library(glmSparseNet) # # Some general options for futile.logger the debugging package flog.layout(layout.format("[~l] ~m")) options( "glmSparseNet.show_message" = FALSE, "glmSparseNet.base_dir" = withr::local_tempdir() ) # Setting ggplot2 default theme as minimal theme_set(ggplot2::theme_minimal()) ``` # Load data The data is loaded from an online curated dataset downloaded from TCGA using `curatedTCGAData` bioconductor package and processed. To accelerate the process we use a very reduced dataset down to 107 variables only *(genes)*, which is stored as a data object in this package. However, the procedure to obtain the data manually is described in the following chunk. ```{r curated_data, include=FALSE, results="hide", message=FALSE, warning=FALSE} brca <- tryCatch( { curatedTCGAData( diseaseCode = "BRCA", assays = "RNASeq2GeneNorm", version = "1.1.38", dry.run = FALSE ) }, error = function(err) { NULL } ) ``` ```{r curated_data_non_eval, eval=FALSE} brca <- curatedTCGAData( diseaseCode = "BRCA", assays = "RNASeq2GeneNorm", version = "1.1.38", dry.run = FALSE ) ``` ```{r data.show, warning=FALSE, error=FALSE, eval=!is.null(brca)} brca <- TCGAutils::TCGAsplitAssays(brca, c("01", "11")) xdataRaw <- t(cbind(assay(brca[[1]]), assay(brca[[2]]))) # Get matches between survival and assay data classV <- TCGAbiospec(rownames(xdataRaw))$sample_definition |> factor() names(classV) <- rownames(xdataRaw) # keep features with standard deviation > 0 xdataRaw <- xdataRaw[, apply(xdataRaw, 2, sd) != 0] |> scale() set.seed(params$seed) smallSubset <- c( "CD5", "CSF2RB", "HSF1", "IRGC", "LRRC37A6P", "NEUROG2", "NLRC4", "PDE11A", "PIK3CB", "QARS", "RPGRIP1L", "SDC1", "TMEM31", "YME1L1", "ZBTB11", sample(colnames(xdataRaw), 100) ) xdata <- xdataRaw[, smallSubset[smallSubset %in% colnames(xdataRaw)]] ydata <- classV ``` # Fit models Fit model model penalizing by the hubs using the cross-validation function by `cv.glmHub`. ```{r fit.show, eval=!is.null(brca)} fitted <- cv.glmHub(xdata, ydata, family = "binomial", network = "correlation", nlambda = 1000, options = networkOptions( cutoff = .6, minDegree = .2 ) ) ``` # Results of Cross Validation Shows the results of `1000` different parameters used to find the optimal value in 10-fold cross-validation. The two vertical dotted lines represent the best model and a model with less variables selected *(genes)*, but within a standard error distance from the best. ```{r results, eval=!is.null(brca)} plot(fitted) ``` ## Coefficients of selected model from Cross-Validation Taking the best model described by `lambda.min` ```{r show_coefs, eval=!is.null(brca)} coefsCV <- Filter(function(.x) .x != 0, coef(fitted, s = "lambda.min")[, 1]) data.frame( ensembl.id = names(coefsCV), gene.name = geneNames(names(coefsCV))$external_gene_name, coefficient = coefsCV, stringsAsFactors = FALSE ) |> arrange(gene.name) |> knitr::kable() ``` ## Accuracy ```{r accuracy, echo=FALSE, eval=!is.null(brca)} resp <- predict(fitted, s = "lambda.min", newx = xdata, type = "class") flog.info("Misclassified (%d)", sum(ydata != resp)) flog.info( " * False primary solid tumour: %d", sum(resp != ydata & resp == "Primary Solid Tumor") ) flog.info( " * False normal : %d", sum(resp != ydata & resp == "Solid Tissue Normal") ) ``` Histogram of predicted response ```{r predict, echo=FALSE, warning=FALSE, eval=!is.null(brca)} response <- predict(fitted, s = "lambda.min", newx = xdata, type = "response") qplot(response, bins = 100) ``` ROC curve ```{r roc, echo=FALSE, eval=!is.null(brca)} rocObj <- pROC::roc(ydata, as.vector(response)) data.frame(TPR = rocObj$sensitivities, FPR = 1 - rocObj$specificities) |> ggplot() + geom_line(aes(FPR, TPR), color = 2, size = 1, alpha = 0.7) + labs( title = sprintf("ROC curve (AUC = %f)", pROC::auc(rocObj)), x = "False Positive Rate (1-Specificity)", y = "True Positive Rate (Sensitivity)" ) ``` # Session Info ```{r sessionInfo} sessionInfo() ```