Risk of Ovarian Metastasis in Colorectal Cancer-Related Carcinomatosis

BACKGROUND: In colorectal cancer (CRC)-related carcinomatosis, the risk of ovarian metastases (OM) is not well described, and practices during cytoreductive surgery (CRS) vary widely. Defining this risk is critical for counseling patients on the necessity of oophorectomy during CRS. METHODS: This retrospective study analyzed female patients with CRC-related carcinomatosis undergoing curative intent CRS with or without hyperthermic intraperitoneal chemotherapy (HIPEC) at a single center (2008-2024). RESULTS: The study identified 74 patients, 66% of whom were post-menopausal. The median Peritoneal Cancer Index (PCI) was 8 (interquartile range [IQR], 6-10), and all the patients had a complete cytoreduction (CCR 0/1). Right-sided primary tumors were the most common (57%), and the histology was most commonly non-mucinous (n = 51, 69%), moderately differentiated (n = 49, 66%), and microsatellite stable (n = 67, 90%). Neoadjuvant therapy was common (n = 58, 78%), and 25 (34%) of the patients underwent HIPEC. Four of the patients (5%) had undergone bilateral salpingo-oophorectomy (BSO) before the diagnosis of peritoneal disease. Of the 70 remaining patients, 51 (73%) had grossly abnormal-appearing ovaries. Of the 70 patients, 65 (93%) had a bilateral or completion salpingo-oophorectomy, and 2 (3%) underwent a unilateral oophorectomy. Overall, 55 (79%) of the patients had pathologically confirmed OM. Of the 16 patients with normal-appearing ovaries who underwent oophorectomy, 4 (25%) had microscopic OM. Two (40%) of the five patients with normal-appearing ovaries preserved during CRS experienced ovarian recurrence within 15 months. CONCLUSIONS: Most of the female patients undergoing CRS for CRC-related carcinomatosis had OM, including 25% of the patients with normal-appearing ovaries. Short-interval recurrence was observed with ovarian preservation. Routine BSO should be strongly considered for patients undergoing CRS with curative intent.