br MODEL br Asian Surgical Association and Taiwan
ª 2019 Asian Surgical Association and Taiwan Robotic Surgery Association. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
Colorectal cancer (CRC) is the most common cancer of the gastrointestinal tract and the second most common cause of cancer-related deaths both in the United States and in Europe.1 About half of all patients with CRC develop distant metastases, as either synchronous metastases that are diagnosed at the time of initial cancer detection or as metachronous metastases diagnosed in the follow-up period.2 The surgical resection of metastases has been widely accepted and is considered a mainstay for patients with resectable liver or lung metastases. However, despite improvements in the overall survival (OS) rate with this treatment, recurrence remains common.
The liver is the most common site for CRC recurrence. Synchronous liver metastases are present in about 15e20% of cases at the time of CRC diagnosis. Metachronous liver metastases occur in about 25e50% of cases, within 3 years after resection of the primary CRC.3 Liver resection is considered the standard management for patients with resectable liver metastases. Moreover, the curative resec-tion of liver metastases has increased significantly and has led to long-term survival rates of up to 50%.3e5 However, despite the curative intent of liver SB-431542 resections, 60e70% of such patients develop recurrence within the first 2 years after the first metastasectomy.6,7
The second most common organ for distant metastases from primary CRC is the lung, and around 10e20% of pa-tients develop pulmonary metastases.2 The 5-year survival rate of these patients, without surgery, is assumed to be below 5%. Similar to liver metastases, resections of pul-monary metastases have increased during the last decade, and 5-year survival rates of up to 68% have been observed after metastasis resections.8e10
Although several novel chemotherapeutic and biological agents have been developed, surgery is considered to be
the most effective therapy for select patients with liver or lung metastases.5,9,11,12 However, the role of aggressive
surgery among patients who present with recurrent me-tastases remains controversial.
In this study, we aimed to evaluate the oncological outcomes after repeat metastasectomies in patients who were previously treated with liver or lung resections for CRC metastases.
This study included 248 patients who underwent surgical resection with curative intent for metachronous-isolated lung and/or liver metastases, at the ASAN Medical Center, between January 2005 and December 2011. The inclusion
criteria for receiving a repeated resection were as follows: previous curative resection of the primary lesion, an achievable complete resection with clear margins, and absence of unresectable extrahepatic or extrapulmonary lesions.
The second and third recurrences were treated under the same indications as the first recurrence. All operations were performed by specialized colorectal, hepatobiliary, and thoracic surgeons. The presence of extrahepatic or extrapulmonary metastases was considered as a contrain-dication for repeated resection. However, in patients with a solitary metastasis or metastasis that was limited to an organ, such as the primary (colorectal) local site, ovaries, local lymph nodes, celiac lymph nodes, para-aortic lymph nodes, adrenal glands, or peritoneum, with or without intrahepatic and/or pulmonary recurrence, we performed a repeated resection. In principle, radiofrequency ablation (RFA) for liver metastases and stereotactic radiosurgery for pulmonary metastases were not performed in patients with resectable metastasis, except for patients with a high-risk surgery or insufficient remnant liver or lung volume. After the repeated resection, postoperative chemotherapy was recommended, except for patients with poor performance or older age.
The median follow-up duration was 66 months (range, 6e94 months). The following patient characteristics were analyzed: age, sex, primary tumor location, pathologic TNM stage, presence of lymphovascular invasion and/or peri-neural invasion, histologic differentiation, and metastasis type. After the first metastasectomy, 74% of the patients underwent postoperative chemotherapy (Table 1).
After metastasectomy, patients were routinely followed up every 3 months, and the levels of serum carcinoem-bryonic antigen (CEA) were measured at every follow-up visit. Surveillance imaging, including abdominopelvic and chest computed tomography scans, was performed every 3 months, during the first 2 years of follow-up, and every 6 months thereafter, until the disease-free interval exceeded 5 years.