Incidence of metastatic tumors to ovary (Krukenberg) versus primary ovarian neoplasms associated with colorectal cancer surgery

Background

An ovarian mass in the setting of colorectal cancer (CRC) can be concerning due to the uncertainty of it being metastatic disease or primary ovarian neoplasm, leading to different referral and treatment options. Our objective was to determine the incidence of ovarian metastasis compared to primary ovarian pathology in women diagnosed with CRC.

Methods

Women aged 18 years or older, diagnosed with CRC in 2014 were included. 806 records were screened for findings of an ovarian mass until 2023. Pathology was determined via resection, biopsy, or imaging with follow-up.

Results

Forty women (5.0 %) had an ovarian mass; 11 at index surgery and 29 on follow-up. Median age at CRC diagnosis was 62.7 years. The incidence of Krukenberg tumour (KT) was 3.2 % accounting for 65 % of ovarian masses. Approximately 20 % presented with synchronous KTs (n = 5) and 53.8 % had synchronous peritoneal carcinomatosis (n = 14). On follow-up, KTs were found in 72.4 % of the patients (n = 21). The Overall Survival (OS) in the KT group was 7.8 % with median survival of 30.4 months. The median time to developing KTs was 20.8 months with 2-year disease-free survival of 19.2 %. Synchronous KT presentation was the only factor associated with worse OS on univariate and multivariate analysis (HR 7.23, 95 % CI 1.57–33.28, P < 0.05).

Conclusion

The risk of developing KT in women with CRC is 3.2 %, of which most (72.4 %) present with metachronous disease within 2 years of CRC diagnosis. Initial evaluation by a gastrointestinal tumor group is warranted.

Synopsis

In this multicenter study involving 806 women diagnosed with colorectal cancer, most ovarian masses that were detected during or following surgery are colorectal metastases and not primary ovarian pathology.