Ovarian Cysts in Breast Cancer Patients Receiving Tamoxifen


  • Musaab R. Al-Bayati MB.Ch.B, FICMS, MRCP, ESMO C. Thiqar Oncology center, Thiqar, Iraq
  • AL- Saaedi Fadhil Ghadhban Atshan M.B.Ch.B, C.A.B.S, Consultant Surgeon, College of Medicine - Alayen University – Iraq
  • Maitham Fadhil Hassan MBChB, FICMS& CABMS in General Surgery, Suq Al-Shuyukh /Thi Qar Health Directorate


Ovarian Cysts, Breast cancer, Tamoxifen


Background : Tamoxifen, a selective estrogen receptor modulator is commonly used to treat
hormone receptor positive breast cancer. Prolonged tamoxifen treatment in breast cancer have been
reported to increase the incidence of functional ovarian cysts.
Aim : To study the frequency and characteristics of ovarian cysts in patients with hormone
receptor positive breast cancer taking tamoxifen.
Methods : A cross sectional study that included 183 patients with hormone receptor positive
breast cancer receiving tamoxifen for at least 6 months. Patients were examined by transvaginal
ultrasound to look for ovarian cysts which are defined as sonolucencies in the ovary with a diameter
of >30 mm
Results : The study shows that 22.4% (29/129) of patients taking tamoxifen have ovarian cysts.
Cysts size ranged from 30 – 66 mm., 62% of patients have single cyst, and, 69% have unilateral
cysts. All cysts are asymptomatic and have benign features on ultrasound. The cysts were most
commonly seen in young, premenopausal patients, and, in those who maintained menstruation
during treatment (p < 0.05).
Conclusions : Tamoxifen treatment for breast cancer is associated with increased incidence of
ovarian cysts which are mostly benign functional cysts and seen mostly in young premenopausal


Sung H, Ferlay J, Siegel RL. et al. Global cancer statistics 2020: GLOBOCAN estimates of

incidence and mortality worldwide for 36 cancers in 185 countries. CA A Cancer J Clin


Santa-Maria CA, Gradishar WJ. Changing Treatment Paradigms in Metastatic Breast Cancer:

Lessons Learned. JAMA Oncol 2015 Jul;1(4):528-34.

Chuanxu Luo, Xiaorong Zhong, Yu Fan et al. Clinical characteristics and survival outcome of

patients with estrogen receptor low positive breast cancer. Breast. 2022 Jun; 63: 24–28.

Early Breast Cancer Trialists Group. Effects of chemotherapy and hormonal therapy for early

breast cancer on recurrence and 15-year survival: an overview of the randomised trials. Lancet


Van Leeuwen FE, Benraadt J, Coebergh JW et al. Risk of endometrial cancer following breast

cancer treatment with tamoxifen. Lancet 1994;343:448-52.

Jolles CJ, Smotkin D, Ford KL et al. Cystic ovarian necrosis complicating tamoxifen therapy

for breast cancer in a premenopausal woman: a case report. J Reprod Med 1990;35:299–300.

Mourits MJ, de Vries EG, Willemse PH et al. Ovarian cysts in women receiving tamoxifen for

breast cancer. Br J Cancer. 1999 Apr;79(11-12):1761-4.

Metindir J, Aslan S, Bilir G. Ovarian cyst formation in patients using tamoxifen for breast

cancer. Jpn J Clin Oncol. 2005 Oct;35(10):607-11.

Kim HS, Jeon YT, Kim YB. The effect of adjuvant hormonal therapy on the endometrium and

ovary of breast cancer patients. J Gynecol Oncol. 2008 Dec;19(4):256-60.

Mofrad MH, Shandiz FH, Roodsare FV et al. Evaluation of ovarian cysts in breast cancer cases

on tamoxifen. Asian Pac J Cancer Prev. 2010;11(1):161-4.

Cohen I, Rosen DJD, Altaras MM et al. Tamoxifen treatment in premenopausal breast cancer

patients may be associated with ovarian overstimulation, cystic formations and fibroid

overgrowth. Br J Cancer. 1994 Mar; 69(3): 620–621.

Seoud M, El-saghir N, Salem Z et al. Tamoxifen and ovarian cysts: a prospective study. Eur J

Obstet Gynecol Reprod Biol. 2001 Dec 10;100(1):77-80.

Inal MM, Incebiyik A, Sanci M et al. Ovarian cysts in tamoxifen-treated women with breast

cancer. Eur J Obstet Gynecol Reprod Biol. 2005 May 1;120(1):104-6.

Cohen I, Beyth Y, Tepper R et al. Ovarian tumors in postmenopausal breast cancer patients

treated with tamoxifen. Gynecol Oncol. 1996 Jan;60(1):54-8.

Christensen JT, Boldsen JL, Westergaard JG. Functional ovarian cysts in premenopausal and

gynecologically healthy women. Contraception 2002;66:153-7.

Shushan A, Peretz T, Uziely B et al. Ovarian cysts in premenopausal and postmenopausal

tamoxifen-treated women with breast cancer. Am J Obstet Gynecol. 1996 Jan;174(1 Pt 1):141-

Cohen I, Potlog-Nahari C, Shapira J et al. Simple ovarian cysts in postmenopausal patients with

breast carcinoma treated with tamoxifen: long-term follow-up. Radiology. 2003


Barbieri RL, Ferracci AL, Droesch JN et al. Ovarian torsion in a premenopausal woman treated

for breast cancer. Fertil Steril 1993;59:459–460.

Oren H, Baltali E, Guler N, et al. A retrospective study of gynecologic complications associated

with tamoxifen therapy in breast cancer patients. In: Proceedings of the 7th International

Congress on Anti- Cancer Treatment; Paris, France 1997