Medicina Molecular e Genética

Significance of the Difference in the Size of Liver Tumors in the Management of Patients with Colorectal Liver Metastases

Abstract

Kosuke Ichida, Koichi Suzuki, Taro Fukui, Yuji Takayama, Nao Kakizaw, Yuta Muto, Takaharu Kato, Fumi Hasegawa, Fumiaki Watanabe, Yuji Kaneda, Rina Kikugaw, Masaaki Saito, Shingo Tsujinaka, Kazushige Futsuhara, Yasuyuki Miyakura, Hiroshi Nod, Hirokazu Kiyozaki and Toshiki Rikiyama

Background: The combination of chemotherapy and surgery is currently accepted for the treatment of patients with technically resectable colorectal liver metastases. It is, however, hard to determine which of these modalities should be the forward treatment. In this study, we assessed the usefulness of the difference in tumor size assessed in pretherapeutic imaging in the selection of chemotherapy in these patients.

Methods: We present a retrospective review of 80 consecutive colorectal liver metastases without extrahepatic tumors. The relapse-free survival (RFS), progression-free survival (PFS) and overall survival (OS) were evaluated and compared between patients who underwent surgery (n=66) and chemotherapy (n=14) according to clinical features. In particular, we addressed pretherapeutic imaging studies including the distribution and number of metastatic liver tumors. In addition, the ratio of tumor size (largest to smallest tumor) was calculated; two groups classified as R<5 (ratio <5) and R ≥ 5 (ratio ≥ 5) were compared.

Results: Univariate analysis was performed in the surgery group; significant differences in RFS were found regarding time of occurrence, the number of tumors and the ratio of tumor diameters. Multivariate analysis showed that the ratio of tumor size, R ≥ 5, was the only independent prognostic risk factor concerning both RFS and OS. We then compared the outcome of patients with prognostic risk factors between surgery and chemotherapy. Surgery achieved significantly better OS than chemotherapy, with the exception of the R ≥ 5 group. No difference in OS, in addition to RFS and PFS, was seen in the R ≥ 5 groups regardless of treatment.

Conclusion: CRC patients with resectable liver metastases with R ≥ 5 showed no significant difference in outcome using surgery or chemotherapy. Chemotherapy could be used as an alternative to forward surgery to address oncological concerns such as the presence of latent metastases or poor treatment outcome in these patients.