As suggested in the comment, there are alternatives such as sex slaves, forced prostitutes or enforced prostitutes, etc. There has been much debate about whether to call them comfort women is appropriate and right because it doesn't have any connotation of forceful and cruel characteristics of the sex slavery.
In the linked Wikipedia article about Comfort women they were:
women and girls who were forced into sexual slavery by the Imperial
Japanese Army in occupied territories before and during World War II.
The word 慰安 (comfort) was also used to describe Japanese prostitute stations set up for occupying Allied troops immediately following Word War II.
The Recreation and Amusement Association (特殊慰安施設協会 Tokushu Ian
Shisetsu Kyōkai (Special Comfort Facility Association)?) (RAA) was the
largest of the organizations established by the Japanese government to
provide organized prostitution and other leisure facilities for
occupying Allied troops immediately following World War II.
The RAA established its first brothel on 28 August: the Komachien in Ōmori. By December 1945, the RAA owned 34 facilities, 16 of which were "comfort stations". The total number of prostitutes employed by the RAA amounted to 55,000 at its peak.
You could notice how inappropriate (or weird) the Recreation and Amusement Association sounds.
The same Chinese characters 慰安 [i : an ] (comfort or solace) were translated into Recreation and Amusement in the name RAA. The name 特殊慰安施設協会 should be translated word-for-word into Special (特殊), Comfort or Comfort Station (慰安), Facility or Establishment (施設), Association (協会).
It would be far mare inappropriate to call them Recreation Women or Amusement Women. Comfort women became an appellative or quasi-proper noun to describe those women forced to work as sex slaves in Asia during World War II.
The Ngram Viewer for comfort woman and comfort women shows that both terms are (relatively) new from around 1990s and this Ngram Viewer shows that the word sex slave and sex slaves are also relatively new.