This is a test version of Biostars. For the public version, visit https://www.biostars.org.
TCGA survival analysis with z-scores all samples altered

Hi all

I'm trying to do my own survival analysis with TCGA clinical data for PRAD in the following way:

  • downloaded latest RNASeq V2 RSEM normalized for all samples
  • calculated z-scores as z = (expression in tumor sample) - (mean expression in diploid samples) / (standard deviation of expression in diploid samples)
  • downloaded latest clinical data
  • followed "tutorial" here

...however, using a threshold of +/- 1.96 for zscores, which should correspond to a p = 0.05, I have all the tumor samples that present at least one alteration in my gene signature...this means that I cannot really build a kaplain meier plot of altered vs non-altered samples...

How would you handle this situation?!

kaplan-meier rna-seq tcga survival

1 answer

Hi, TriS

I also encounter same problem, all of my samples are tumor. Did you resolve this problem and if so, please let me know.

Thank you
Keunsuu

Thank you.

This link seems that z score was calculated between tumor and normal samples.

When I have just tumor samples, how can I do?

you can do the following:

z = [(value gene X in tumor Y)-(mean gene X in tumor)]/(standard deviation X in tumor)

Log in to answer this question.