The Belfast women alleged they were abused over a three-year period in the late 1990s, when they were teenagers.
They claim the case was delayed because prosecutors gave precedence to a separate court case, involving allegations made by MÃ¡iria Cahill.
The PPS said the decision had been made by the court and not them.
The women said they had been "utterly let down by the criminal justice system".
Both women, who have retained their right to anonymity, released a statement through their solicitor, outlining the background to their case and the delays they faced in bringing the matter to court.
The two women said they first reported the alleged abuse to the Police Service of Northern Ireland (PSNI) in January 2010.
They said their case was "constantly adjourned" and then postponed two days before the trial was due to begin.
In November 2012, the women's legal representatives made complaints about the handling of the prosecution case to the Public Prosecution Service (PPS), the Office of Attorney General and the Department of Justice.
The solicitor said that shortly after a meeting with police and prosecutors in December 2012, during which there was a "frank exchange of views", the two women "reluctantly withdrew their statements".
The statement issued on behalf of two women said: "They had lost all faith and trust in the criminal justice system and believed they were being exploited, merely for political point scoring."
The statement also made reference to appointment of Keir Starmer QC to lead an independent review of three prosecution cases linked to Ms Cahill's allegations.
The women questioned the independence of the review and called for clarification on its powers and terms of reference.
Five people accused in connection with the cases linked to Ms Cahill's allegations were all acquitted in court.
A PPS spokesperson said: "The Public Prosecution Service has commissioned an independent review of these interlinked cases.
"It is intended that the review will consider all aspects of the cases, which may be unprecedented in complexity as they involve not only multiple complainants but also serious charges relating to sex abuse offences and terrorist-related offences.
"We can confirm that all of the complainants in the cases have been invited to participate in the process and it is our hope that each of the individuals involved will agree to do so.
"The approach will be robust and rigorous and any lessons to be learned from the cases will be addressed openly and transparently."
Two women who claim they were sexually abused by an alleged IRA man have said they withdrew their statements because of how prosecutors dealt with the case.