Cancelling Solicitaiton - Sole Source

What prohibits a PCO from rescinding RFPs in sole source environments?

to me, 15.206(e) addresses cancellation in a competitive situation but does not address sole source. 15.206(a) seems to imply amending if there is a change in requirements/terms and conditions.

Are you suggesting that a contracting officer CANNOT cancel or rescind a sole source solicitation?  That would be a very bold suggestion!

FAR 1.102-4(e) says a procedure (canceling a solicitation?) may be used if it is in the Government's best interest and is not prohibited anywhere.  So Matthew's question is on target -- is there any citation prohibiting a contracting officer from canceling a solicitation?

No there is not, good point