I was able to find a reference for you:
Studies have indicated that childhood abuse characteristics are associated with different sexual behavior outcomes for men and women. For example, Senn et al. (2007) found that for men, sexual abuse with force and penetration was associated with greater frequency of sex trading than it was for those who reported abuse without force and penetration. The term sex trading has been defined as participating in sex in return for food, money, sex, or shelter (Newman, Rhodes, & Weiss, 2004). Senn et al. (2006) found that women were more likely than men were to report exchanging sex for money or drugs and a childhood sexual experience that involved force.
The periodical quoted is: http://www.faqs.org/periodicals/201004/2004709811.html
And the article used by its reference (Senn et al., 2007) can be found at:
Senn, T. E., Carey, M. P., Vanable, P. A., Coury-Doniger, P., & Urban, M. (2007). Characteristics of sexual abuse in childhood and adolescence influence sexual risk behavior in adulthood. Archives of Sexual Behavior, 36, 637-645.
Note that this links sex trade workers with sexual abuse victims. It does not suggest, as Dr. Pinsky stated, that most people in sex-related industries experienced abuse.