This trial compares two chemotherapy agents for the treatment of recurrent ovarian, fallopian or primary peritoneal cancer in patients that have received and are no longer responding to Platinum based treatment. The purpose of this trial is to compare progression free survival between gemcitabine and liposomal doxorubicin. Progression free survival (PFS) is defined as the period from study entry until disease progression

Inclusion Criteria:

• All patients must have a documented pathologic diagnosis of epithelial ovarian (FIGO Stage I-IV), Fallopian tube or primary peritoneal carcinoma
• Patients must have received platinum-based, first-line chemotherapy but no more than one additional prior chemotherapy regimen. Patients must have recovered from the acute side effects of prior chemotherapy prior to enrollment in this trial.
• Patients must be considered to have platinum resistant disease based on the most recent platinum-based regimen given, i.e., have had a treatment-free interval in response to platinum of less than six months, or have progressed during platinum-based therapy
• Presence of measurable disease or CA-125 > or = to 100 on two separate occasions at least one week apart is required for this study
• Patient must have a Zubrod Performance Status of 0, 1 or 2

Exclusion

• Patients with a current diagnosis of epithelial ovarian tumor of low malignant potential (borderline carcinomas) are not eligible. Patients with a prior diagnosis of a low malignant potential tumor that was surgically resected and who have subsequently developed invasive adenocarcinoma are eligible.
• Patients who are currently undergoing abdominal or pelvic radiation therapy or patients who have received prior abdominal or pelvic radiation therapy are excluded.
• Patients with unstable angina or who have had a heart attack within the past six months are not eligible to participate.
• Patients who have received prior Gemzar or Doxil therapy are ineligible.