Collapse subtitle with bquote in ggplot2

Question

I am trying change my subtitle to read "All Subjects as Treated at 5x10^7 TCID50" with the 7 superscript and the 50 subscript.

I was able to run the following plot, where there are spaces ("5 x 10"):

With the following code:

kmcurve1 <- ggsurvplot(km_p1p2_p2dose_fit, 
              palette = c("#202960", "#8CC63E"), 
              xlab = "Time (Months)", 
              legend.labs = c("Phase 1", "Phase 2"), 
              break.time.by = 6, 
              xlim = c(0,36), 
              conf.int = FALSE, 
              pval = TRUE, 
              pval.size = 5, 
              pval.method.size = 5, 
              pval.coord = c(30,0.9), 
              pval.method.coord = c(30,1), 
              pval.method = TRUE, 
              surv.median.line = "v", 
              risk.table = "abs_pct", 
              risk.table.col = "strata", 
              surv.plot.height = 2, 
              risk.table.height = 0.24, 
              censor.shape = "|", 
              censor.size = 5, 
              font.title = 28, 
              font.x = 14, 
              font.y = 14,
              font.tickslab = 12,
              risk.table.fontsize = 3.5)

kmcurve1$plot <- kmcurve1$plot +
  labs(title = "Overall Survival for Phase 1 and Phase 2",
       subtitle = bquote(All~Subjects~as~Treated~at~5.0~x~10^7~TCID[50]),
        caption = bquote(TCID[50]~-~Median~Tissue~Culture~Infectious~Dose)) +
        theme(#text = element_text(family = "serif"), #only run for PDF output
              plot.title = element_text(size = 20), 
              plot.subtitle = element_text(size = 16), 
              plot.caption = element_text(size = 12),
              legend.text = element_text(size = 12), 
              legend.title = element_text(size = 12), 
              legend.key.size = unit(16, "points"), 
              axis.title.x = element_text(size = 14), 
              axis.title.y = element_text(size = 14),
              axis.text.x = element_text(size = 12), 
              axis.text.y = element_text(size = 12))

kmcurve1

I have removed the study numbers to avoid having identifying information.

For the subtitle, I have also tried bquote(All~Subjects~as~Treated~at~5.0x10^7~TCID[50]), which gives me the following error message:

Error: unexpected symbol in: " labs(title = "Overall Survival for Phase 1 and Phase 2", subtitle = bquote(All~Subjects~as~Treated~at~5.0x10"

Let me know if it would be helpful to have a reprex of the KM fit to replicate the curve.

Answer 1

The only bit of knowledge you were missing is the need to use an asterisk to separate the tokens in an expression when you do not want a space to appear between them. A token cannot begin with digit, so your expression argument should have been:

  bquote(All~Subjects~as~Treated~at~5.0*x*10^7~TCID[50])

Using xilliam's example since it has much less material extraneous to the question. And I used teh function expression since you were not substituting or accessing values from the calling environment.

library(survminer)
library(survival)

fit<- survfit(Surv(time, status) ~ sex, data = lung)
p <- ggsurvplot(fit, data = lung)

p$plot +
    labs(title = "Overall Survival for Phase 1 and Phase 2",
         subtitle = expression(
            All~Subjects~as~Treated~at~5*x*10^7~TCID[50]),
         caption = expression(
            TCID[50]~-~Median~Tissue~Culture~Infectious~Dose))

Gives: