Unexpected results with Guix.

[Jone]

Hello, peolpe! I cannot understand results of this simple sequence of
actions:
First, update Icecat: guix package -u icecat
and then later remove it: guix package -r icecat
and view /gnu/store:

du -hs -l -t 1M /gnu/store/* | grep -E 'rust|icecat'
274M    /gnu/store/0p4blr576rjzpyybfmvygny6ra641w0p-rust-1.37.0
157M    /gnu/store/50530hgnzkxgkqciip68dn7v23cslw1c-icecat-60.8.0-guix1
169M
/gnu/store/ngsswh27mqxpynwrw6qyjsc3iql1ma3i-icecat-68.2.0-guix0-preview2

I used to deal only with rpm package manager - there unnecessary
dependencies would be removed automatically.
How do I get the same result with Guix? I don't have much space on the
partition =)