[Analysis of ovarian metastasis of colorectal cancer--a comparison between ovarian metastasis and peritoneal metastasis without involving ovaries].

This retrospective study was performed to clarify whether or not ovarian metastasis from colorectal cancer should be classified into peritoneal metastasis. We compared patient background data and prognosis between patients with ovarian metastasis (ovarian group, n=16) and female patients with peritoneal metastasis without involving ovaries (peritoneal group, n=22) treated between 1998 and 2008. The two groups did not significantly differ in terms of other clinicopathological factors evaluated. The median overall survival period was 13.8 months for the ovarian group and 16.7 months for the peritoneal group (p=0.96). The 3-year overall survival rate was 48.6%, 46.9%, and 11.5% for patients with ovarian metastasis only (P2), those with minute peritoneal metastasis without involving ovaries (P1), and those with multiple (numerous) peritoneal metastasis without involving ovaries (P3) (p=0.13), respectively. These results suggest that it is valid to classify ovarian metastasis as peritoneal metastasis. However, further collection of data may be needed to conclude that solitary ovarian lesion(s) would be classified into P2.