Long Term Effects of Tyrosine Kinase Inhibitor Therapy on Ovarian Reserve and Fertility in Patients With Chronic Myeloid Leukemia or Gastrointestinal Stromal Tumor

Inclusion Criteria: * Diagnosed with chronic myeloid leukemia (CML), gastrointestinal stromal tumor (GIST), non metastatic cancer where TKI is the first line agent * Premenopausal (has had menses at any time in the preceding 12 consecutive months) * Has not undergone a hysterectomy or bilateral oophorectomy * Willing to use non-hormonal (ie: barrier method or abstinence) as form of contraception during the one year of study Exclusion Criteria: * Patients who have had chemotherapy or radiotherapy in the past * Patients may not be receiving any other investigational agents * Patients must not be pregnant or nursing * Other medical conditions or treatments that affect hormonal levels (potentially confounding interpretation of results) * Patients with ongoing hormonal contraception or unwilling or unable to discontinue will not eligible