Journal of Clinical Oncology, Vol 25, No 35 (December 10), 2007: pp. 5657-5658
© 2007 American Society of Clinical Oncology.
Detection of Early-Stage Ovarian Cancer by FDG-PET-CT in a Patient With BRCA2-Positive Breast Cancer
R. Ashley Milam,
Michael R. Milam,
Revathy B. Iyer
The University of Texas M.D. Anderson Cancer Center, Houston, TX
A 53-year-old postmenopausal woman with newly diagnosed invasive ductal carcinoma of the breast underwent positron emission tomography–computed tomography (PET-CT) for further evaluation of abnormal bone scan results. No osseous metastases were evident on the PET-CT. However, a small complex mass was visible in the left adnexa that contained areas of abnormal [18F]fluorodeoxyglucose (FDG) avidity (arrows in Figs 1 and 2). These adnexal findings were not recognized as being significant at the time of the examination, and therefore no further evaluation was performed. Thirteen months later, after having undergone segmental mastectomy, chemotherapy, and irradiation, the patient presented to the emergency department with severe abdominal pain and peritoneal signs. A CT of the abdomen and pelvis demonstrated large bilateral ovarian masses (arrows in Fig 3) and suspected left-sided adnexal torsion (double arrow in Fig 3). The patient underwent an urgent exploratory laparotomy, total abdominal hysterectomy, bilateral salpingo-oophorectomy, and operative staging. Intraoperative findings included bilateral complex cystic ovarian masses and left adnexal torsion. Serum CA-125 on the day of surgery was elevated at 134.2 U/mL (normal defined as < 35 U/mL). Final pathology revealed bilateral ovarian cystadenomas with foci of high-grade serous carcinoma, distinct from the breast primary. Pelvic washings, lymph nodes, and omental biopsies were negative for carcinoma, and the patient was surgically staged as IB and subsequently treated with adjuvant chemotherapy. BRCA1 and BRCA2 genetic testing revealed a deleterious mutation in BRCA2, a tumor suppressor gene implicated in hereditary breast ovarian cancer syndrome.5 Though our case is somewhat limited by the 13-month interval between the PET scan and surgical confirmation of malignancy, the patient was reportedly asymptomatic during this interval with no clinical evidence of any other confounding process (such as pelvic inflammatory disease). Therefore, we believe the PET-CT abnormality reflected early asymptomatic malignant or premalignant changes within the left ovary.
FDG uptake within the adnexa is often dismissed as "physiologic." In a woman of reproductive age, this assumption is valid. Many authors have reported FDG uptake within benign physiologic ovarian structures such as dominant follicles and corpora lutea2,3; however, areas of hypermetabolism within the ovaries of a postmenopausal woman cannot be presumed to be innocuous. In two series of postmenopausal women who underwent PET, no patients demonstrated areas of adnexal FDG avidity.2,3 In a 2004 retrospective study of 1,750 PET scans of cancer patients, there was a 3.3% incidence of foci of unexpected FDG accumulation. One of these foci was adnexal and proved to represent ovarian adenocarcinoma.1 In the gynecologic oncology and radiology literature, PET-CT has been reported to be of value in evaluating the response of advanced ovarian cancer to therapy, in the early detection of recurrent disease and, more recently, for the prospective characterization of suspicious adnexal masses as benign or malignant.4,6 To our knowledge, no one has yet reported the detection of asymptomatic early-stage ovarian cancer by fusion PET-CT. If the significance of the finding had been recognized at the time of the original PET examination, the patient could have been evaluated and treated earlier in a controlled rather than emergent setting and, perhaps, diagnosed at an earlier stage of disease. The interpretation of FDG accumulation within the adnexa of premenopausal women is complicated by physiologic uptake within benign structures. However, FDG avidity is not observed within the normal postmenopausal ovary. The presence of FDG uptake within the ovary of a postmenopausal woman therefore raises the question of ovarian cancer. This is particularly true in patients undergoing PET-CT for the evaluation of malignancies that may confer an increased risk of ovarian cancer such as breast (hereditary breast ovarian cancer syndrome) or colorectal (Lynch syndrome) cancer. As our case demonstrates, careful assessment of FDG distribution in the adnexa is warranted in these patients. Areas of hypermetabolism within the postmenopausal adnexa require further evaluation.
AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST
The author(s) indicated no potential conflicts of interest.
1. Agress H, Cooper B: Detection of clinically unexpected malignant and premalignant tumors with whole-body FDG PET: Histopathologic comparison. Radiology 230:417-422, 2004[Abstract/Free Full Text]
2. Lerman H, Metser U, Grisaru D, et al: Normal and abnormal 18F-FDG endometrial and ovarian uptake in pre- and postmenopausal patients: Assessment by PET/CT. J Nucl Med 45:266-271, 2004[Abstract/Free Full Text]
3. Nishizawa S, Inubushi M, Okada H: Physiological 18F-FDG uptake in the ovaries and uterus of healthy female volunteers. Eur J Nucl Med Mol Imaging 32:549-556, 2005[CrossRef][Medline]
4. Risum S, Hogdall C, Loft A, et al: The diagnostic value of PET/CT for primary ovarian cancer: A prospective study. Gynecol Oncol 105:145-149, 2007[CrossRef][Medline]
5. Sowter HM, Ashworth A: BRCA1 and BRCA2 as ovarian cancer susceptibility genes. Carcinogenesis 26:1651-1656, 2005[Abstract/Free Full Text]
6. Subhas N, Patel PV, Pannu HK, et al: Imaging of pelvic malignancies with in-line FDG PET-CT: Case examples and common pitfalls of FDG PET. Radiographics 25:1031-1043, 2005[Abstract/Free Full Text]
CiteULike Complore Connotea Delicious Digg Facebook Reddit Technorati Twitter What's this?