Although many children who were sexually abused become prostitutes, not all sexually abused children enter this profession. as such, the relationship between sexual abuse and prostitution involves:

The relationship between sexual abuse and prostitution involves:  Correlation

When a victim of sexual abuse choose a career of them, they will correlate their past experience with the type of career that they wanted to take.

Those who correlate themselves as someone whose value as human being has been taken, tend to follow the similar path of sexual occupations.
Those who still correlate themselves as valuable human being, will choose other occupation that stray away from it.