N. Ichikawa1, S. Homma1, T. Yoshida1, F. Kawamata1, T. Mitsuhashi2, H. Iijima3, S. Shibasaki1, H. Kawamura1, K. Ogasawara4, K. Kazui5, Y. Kamiizumi6, A. Taketomi1 1Hokkaido University,Department Of Gastroenterological Surgery 1,Sapporo, HOKKAIDO, Japan 2Hokkaido University Hospital,Department Of Surgical Pathology,Sapporo, HOKKAIDO, Japan 3Hokkaido University Hospital,Clinical Research And Medical Innovation Center,Sapporo, HOKKAIDO, Japan 4Kushiro Rosai Hospital, Japan Labour Health and Welfare Organization,Department Of Surgery,Kushiro, HOKKAIDO, Japan 5Hokkaido Hospital, Japan Community Healthcare Organization,Department Of Surgery,Sapporo, HOKKAIDO, Japan 6Iwamizawa Municipal Hospital,Department Of Surgery,Iwamizawa, HOKKAIDO, Japan
Introduction: The prognostic benefit of primary tumor resection in colorectal cancer patients with unresectable distant metastasis remains unclear. We aimed to assess whether palliative primary tumor resection in colorectal cancer patients with unresectable metastasis is associated with improved survival.
Methods: The survival period of 123 colorectal cancer patients diagnosed from January 2010 to December 2015 in 4 Japanese hospitals was analyzed. Sixty-four patients with and 59 without primary tumor resection were compared, retrospectively. In the patients with primary tumor resection, the survival period of 39 patients with lymphocyte:monocyte ratio (LMR) increase after primary tumor resection (LMR-increase) and 25 patients with LMR decrease (LMR-decrease) was also compared.
Results: Eighty nine colon cancer and 34 rectal cancer patients were eligible for the analysis. The mean age was 63 years old and male to female ratio was 63: 60. In the resection group, more patients were accompanied by non-differentiated adenocarcinoma (36% vs 15%, p <0.01), obstructive symptom (80% vs 51%, p <0.01), high serum albumen (3.8 vs 3.6 mg/dL, p =0.02) and no lymph node metastasis (20% vs 2%, p <0.01) than the non-resection group. The patients who underwent primary tumor palliative resection had prolonged median survival compared with patients never resected (24.5 vs 14.5 months, p =0.01). Multivariate analysis identified possible independent prognostic variables as the pathology containing non-differentiated adenocarcinoma (Hazard Ratio, 3.7), non-resection of primary lesion (2.7), and no use of irinotecan (2.6). Moreover, in the patients with primary tumor resection, the median survival times of the LMR-increase and LMR-decrease groups were 27.3 and 20.8 months, respectively (p =0.02, Figure). The preoperative lymphocyte population and LMR in peripheral blood of the LMR-increase group were significantly less than those of LMR-decrease group. There were no differences in any other patient characteristics and the extent of metastases between the 2 groups. When assessed the resected specimen in available cases, there were more CD163+ and CD8+ cells invaded into tumor stroma, significantly. (n=5)
Conclusion: Palliative primary tumor resection in colorectal cancer patients with unresectable metastasis is possibly associated with improved survival, especially in the case with lymphocyte:monocyte ratio increase after primary tumor resection.
