Analysis of metastatic patterns after curative colorectal cancer surgery based on primary tumor location
Zhang, J.; Han, G.; Jiang, Z.; Wang, D.
Zhonghua Wei Chang Wai Ke Za Zhi 19(7): 780-784
2016
ISSN/ISBN: 1671-0274 PMID: 27452756 Document Number: 689314
To evaluate metastatic patterns of colorectal cancer following curative surgery based on primary tumor location in order to provide evidence for the decision of individualized adjuvant therapy and postoperative follow-up. Clinical and follow-up data of 904 patients who underwent curative colorectal cancer in The Affiliated Tumor Hospital of Zhengzhou University from October 2004 to October 2012 with complete follow-up data were analyzed retrospectively. A total 274 patients belonged to right-sided colon cancer group (cecum, ascending, hepatic flexure, and transverse colon), 243 belonged to left-sided colon cancer group(splenic flexure, descending, and sigmoid colon), and 387 belonged to rectal cancer group. The overall rate of distal metastasis and site-specific metastasis rates (liver, lung, and peritoneum) were compared among these 3 groups. The cohort patients had a median follow-up of 37(4-122) months, and the median follow-up duration was similar in right-sided, left-sided, and rectal cancer groups with 39(5-119), 39(6-122) and 36(5-121) months(P=0.513). During the follow-up period, 44 patients (4.9%) had local recurrence alone, 137 (15.2%) distal metastasis alone, and 30(3.3%) local recurrence combined with distal metastasis. Compared to right-sided colon cancer group, rectal and left-sided cancer groups had significantly higher overall metastasis rates [23.5% (91/387), 17.3% (42/243) vs. 12.0% (33/274), P=0.000). With respect to specific regions, lung metastasis rate in rectal cancer group was 9.3%, which was significantly higher than that in left-sided(4.5%) and right-sided colon cancer group(2.6%)(P=0.001). Other sites of metastasis did not yield significant differences, including liver(P=0.130) and peritoneum(P=0.858). Cancer location may be used as a reference of personalized adjuvant therapy and postoperative follow-up surveillance programs. Lower threshold for adjuvant therapy in rectal and left-sided colon cancers, and more aggressive surveillance for lung metastasis by chest X-ray or CT should be considered.