如何为ggsurvplot绘制的Kaplan-Meier曲线设置透明背景？

问题说明 #

使用ggsurvplot绘制Kaplan-Meier曲线后，尝试直接添加透明背景参数未生效，同时需要高质量保存用于海报制作。相关代码如下：

原绘图代码 #

kaplan_plot365d <- ggsurvplot(kmcurve365d,
                              conf.int = TRUE,
                              legend.labs = c('Trop-T normal and Trop-I normal', 'Trop-T elevated and Trop-I normal', "Trop-T elevated and Trop-I elevated"),
                              legend.title = '',
                              title = 'Kaplan-Meier Curve for 365-Day Mortality',
                              xlab = 'Time in Days', 
                              ylab = 'Survival probability', main = 'Kaplan-Meier Model',
                              ylim=c(min(0.7), max(1)),
                              xlim=c(min(0), max(366)),
                              break.time.by = 120,
                              palette = c('#FDE725FF', "#21908CFF", "#440154FF"),
                              risk.table = TRUE,
                              risk.table.y.text = TRUE, fontsize = 4, tables.theme = clean_theme(),
                              risk.table.title = "Survivors per group") +
guides(colour = guide_legend(nrow = 2))

kaplan_plot365d

无效的透明背景参数 #

panel.background = element_rect(fill='transparent'), #transparent panel bg
plot.background = element_rect(fill='transparent', color=NA), #transparent plot bg
panel.grid.major = element_blank(), #remove major gridlines
panel.grid.minor = element_blank(), #remove minor gridlines
legend.background = element_rect(fill='transparent'), #transparent legend bg
legend.box.background = element_rect(fill='transparent') #transparent legend panel

原保存代码 #

grid.draw.ggsurvplot <- function(x){
  survminer:::print.ggsurvplot(x, newpage = FALSE)}

ggsave("Kaplan-Meier_365d_withCI_Troponine.jpg",
         path = ("I:\Personal\Poster/"),
         plot = kaplan_plot365d,
         dpi = 300)

解决方案 #

1. 正确设置透明主题（主图+风险表） #

ggsurvplot返回的是包含主生存曲线（$plot）和风险表（$table）的列表，需分别为两部分设置透明主题：

# 定义统一的透明主题
transparent_theme <- theme(
  panel.background = element_rect(fill='transparent'),
  plot.background = element_rect(fill='transparent', color=NA),
  panel.grid.major = element_blank(),
  panel.grid.minor = element_blank(),
  legend.background = element_rect(fill='transparent'),
  legend.box.background = element_rect(fill='transparent')
)

# 绘制并应用透明主题
kaplan_plot365d <- ggsurvplot(kmcurve365d,
                              conf.int = TRUE,
                              legend.labs = c('Trop-T normal and Trop-I normal', 'Trop-T elevated and Trop-I normal', "Trop-T elevated and Trop-I elevated"),
                              legend.title = '',
                              title = 'Kaplan-Meier Curve for 365-Day Mortality',
                              xlab = 'Time in Days', 
                              ylab = 'Survival probability', main = 'Kaplan-Meier Model',
                              ylim=c(min(0.7), max(1)),
                              xlim=c(min(0), max(366)),
                              break.time.by = 120,
                              palette = c('#FDE725FF', "#21908CFF", "#440154FF"),
                              risk.table = TRUE,
                              risk.table.y.text = TRUE, fontsize = 4, 
                              tables.theme = clean_theme() + transparent_theme,  # 风险表应用透明主题
                              risk.table.title = "Survivors per group") +
  guides(colour = guide_legend(nrow = 2)) +
  transparent_theme  # 主图应用透明主题

# 额外确保风险表背景完全透明
kaplan_plot365d$table <- kaplan_plot365d$table + 
  theme(panel.background = element_rect(fill='transparent'),
        plot.background = element_rect(fill='transparent', color=NA))

2. 修正保存设置 #

• JPG格式不支持透明通道，需改用PNG格式
• ggsave需添加bg="transparent"参数，同时修正路径斜杠（Windows下用/或\\）

ggsave("Kaplan-Meier_365d_withCI_Troponine.png",
       path = "I:/Personal/Poster/",
       plot = kaplan_plot365d,
       dpi = 300,
       bg = "transparent")

内容的提问来源于stack exchange，提问作者esptang