Uterine malignancy following tamoxifen use in breast cancer patients in Iran: case series and literature review

Asian Pac J Cancer Prev. 2009 Jan-Mar;10(1):163-6.


Background: This study evaluated tumor characteristics and survival in women with breast cancer who subsequently developed uterine cancer.

Methods: Information about endometrial cancer in tamoxifen users following breast cancer refered to the gynecologic oncology clinic of Vali-Asr hospital between 1997-2007 was evaluated.

Results: Among 330 patients with endometrial cancer, 5 were in women previously diagnosed with breast cancer. Two cancers were malignant mixed Mullerian tumors of the uterus (MMMT), 2 were endometrioid adenocarcinomas, and one was a papillary clear cell carcinoma. Patients received tamoxifen for 4-8 years. The endometrial cancers occurred 2-11 years after initial treatment for the breast cancers. Four of the endometrial cancers featured abnormal uterine bleeding and one of them had increased vaginal discharge and all were diagnosed on endometrial curetting. All patients received standard surgical staging for endometrial cancer and all except one were stage I. At laparotomy of one patient, an advanced stage MMMT was found with diffused peritoneal spread and ascites. In spite of the surgery, she died of disease, 3 months later. The other patients remain recurrence-free for breast cancer and uterine cancer after 6-120 months.

Conclusion: Breast cancer patients who use tamoxifen and have early stage endometrial cancers demonstrate a good prognosis. Abnormal uterine bleeding or vaginal discharge are the most important symptoms.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents, Hormonal / adverse effects*
  • Antineoplastic Agents, Hormonal / therapeutic use
  • Breast Neoplasms / drug therapy*
  • Female
  • Humans
  • Middle Aged
  • Neoplasms, Second Primary / chemically induced*
  • Selective Estrogen Receptor Modulators / adverse effects*
  • Selective Estrogen Receptor Modulators / therapeutic use
  • Tamoxifen / adverse effects*
  • Tamoxifen / therapeutic use
  • Uterine Neoplasms / chemically induced*
  • Uterine Neoplasms / diagnosis
  • Uterine Neoplasms / pathology


  • Antineoplastic Agents, Hormonal
  • Selective Estrogen Receptor Modulators
  • Tamoxifen