To the Editor: The article by Rossing et al. (Sept. 22 issue)1 may have generated undue anxiety in many women undergoing treatment for infertility. Although this study does prompt some interesting hypotheses about the future risks of ovarian cancer in patients with ovulatory dysfunction, it does not convincingly link any risk to the use of clomiphene. There are several confounding variables and biases that weaken the validity of the authors’ conclusions. Patients undergoing treatment for infertility, especially those who take medication to induce ovulation, undergo far more surveillance with ultrasound studies than other patients, solely because of their treatment. Furthermore,.