I'm not a doctor, Alex, but...somehow I don't think it's electoshock therapy. But you would know better than I would, whether that is really such a common thing for cancer patients to go through that it would be listed with such generic things. I did find, "EST (expressed sequence tag): A unique stretch of DNA within a coding region of a gene that is useful for identifying full-length genes and serves as a landmark for mapping. An EST is a sequence tagged site (STS) derived from cDNA.", but that's way too detailed, isn't it, to fit in with the rest on the list?

Edit: I see I was beaten to posting what my quote was about, while I was making this one.