SECTION EDITOR: CARL E. BREDENBERG, MD
Pathologic examination of the operative specimens confirmed a primary moderately to poorly differentiated, circumferential, transverse colon adenocarcinoma with histologic and staining profiles consistent with metastases to the ovary, peritoneum, and omentum (stage IVB [T4N2M1] colorectal adenocarcinoma).
A review of ovarian malignant neoplasms estimates that in 10% of all cases the ovarian metastasis is the presenting symptom leading to diagnosis of the primary nongynecologic tumor.1 The actual incidence of ovarian metastases from colorectal cancer is not well established, ranging from less than 1% to 9% in clinical and autopsy studies; however, gastrointestinal malignant neoplasms are the most common to metastasize to the ovary, with most being a primary colorectal cancer.2- 4 In patients with an ovarian mass determined to be of nongynecologic origin, 27% to 45% are due to colon cancer metastases.2,5,6 Abdominal pain or an identified adnexal mass are the most common presenting symptoms, with the minority of patients having a more classic presentation of colorectal cancer.2 Definitive diagnosis is pathologic with histologic findings of mixed solid and cystic components, the well-described “dirty necrosis,” and immunohistochemical staining that differentiates ovarian primary disease from metastatic disease. Positive prognostic factors for patients with colon cancer and ovarian metastases include unilateral disease, disease limited to the pelvis (ie, no intra-abdominal metastases), and residual tumor volume less than 2 cm.7 Histologic grade and menopausal status have not been demonstrated as significant for prognosis.6,7 While size of the ovarian metastasis does not affect prognosis, it is common for the ovarian mass to be larger than the primary colon cancer.3
Colorectal cancer is the third most common cause of both new cancers and cancer deaths, composing approximately 10% of all cases in men and women.8 Ovarian cancer composes 3% of new cancers and 6% of cancer deaths in women. Relative survival for patients with colorectal cancer is currently 83% at 1 year and 65% at 5 years. The estimated 5-year survival for this patient is 23% to 30%.2,7 Although the ovaries are a known site of metastasis in colorectal cancer, it is not common practice to perform colonoscopy beyond standard screening recommendations when evaluating an ovarian mass. Resection of ovarian metastases is a well-accepted practice owing to its reduction of tumor burden. The role of prophylactic oophorectomy in colorectal cancer remains controversial. The proposed benefit of prophylactic oophorectomy is primarily removal of undiscovered metastases, thereby preventing development of resistant disease in a chemotherapy sanctuary site and limiting future reoperation.9,10 It may also be a preventive measure against primary ovarian cancer, as patients with colorectal cancer are at increased risk especially in association with hereditary cancer syndromes.4,10 Two retrospective studies have shown a survival benefit in women undergoing prophylactic oophorectomy, particularly those with limited primary disease where complete resection can be accomplished.4,11 The only prospective randomized trial to date examining the benefit of prophylactic oophorectomy was unable to demonstrate a statistically significant improvement in survival or recurrence rates; however, this study was underpowered and is currently still enrolling patients.12 While no clear consensus exists, several authors suggest that prophylactic oophorectomy be offered to postmenopausal women with a family history of cancer.4,9,10 Outside these parameters, the associated hormonal and psychological morbidity coupled with the low occurrence of ovarian metastases in colorectal cancer have limited its application in current therapy.13,14
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Correspondence: Clay Cothren Burlew, MD, Department of Surgery, Denver Health Medical Center, 777 Bannock St, MC 0206, Denver, CO 80204 (firstname.lastname@example.org).
Accepted for Publication: September 21, 2011.
Author Contributions:Study concept and design: Burlew and Barnett. Acquisition of data: Yi and Barnett. Analysis and interpretation of data: Yi, Burlew, Barnett, and Moore. Drafting of the manuscript: Yi and Burlew. Critical revision of the manuscript for important intellectual content: Yi, Burlew, Barnett, and Moore. Administrative, technical, and material support: Burlew, Barnett, and Moore. Study supervision: Burlew and Barnett.
Financial Disclosure: None reported.
Image of the Month—Diagnosis. Arch Surg. 2012;147(9):886. doi:10.1001/archsurg.147.9.886