title: Up-front systemic chemotherapy is a feasible option compared to primary tumor resection followed by chemotherapy for colorectal cancer with unresectable synchronous metastases.
abstract: BACKGROUND
  In stage IV colorectal cancer (CRC) with unresectable metastases, whether or not resection of the primary tumor should be indicated remains controversial. We aim to determine the impact of primary tumor resection on the survival of stage IV CRC patients with unresectable metastases.
  
  
  METHODS
  We retrospectively investigated 103 CRC patients with stage IV colorectal cancer with metastases, treated at Hiroshima University Hospital between 2007 and 2013. Of these, those who had resectable primary tumor but unresectable metastases and received any chemotherapy were included in the study. We analyzed the overall survival (OS) and short-term outcomes between the patients who received up-front systemic chemotherapy (USC group) and those who received primary tumor resection followed by chemotherapy (PTR group).
  
  
  RESULTS
  Of the 57 included patients, 15 underwent USC and 42 PTR. The median survival times were 13.4 and 23.9 months in the USC and PTR groups, respectively (P = 0.093), but multivariate analysis for the overall survival showed no significant difference between the two groups (hazard ratio, 1.30; 95% confidence interval (CI), 0.60 to 2.73, P = 0.495). In the USC group, the disease control rate of primary tumor was observed in 12 patients (80.0%), but emergency laparotomy was required for 1 patient. Morbidity in the PTR group was observed in 18 cases (42.9%).
  
  
  CONCLUSIONS
  The overall survival did not differ significantly between the USC and PTR groups. USC may help avoid unnecessary resection and consequently the high morbidity rate associated with primary tumor resection for stage IV CRC with unresectable metastases.
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. hiroaki.niitsu0310@gmail.com.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Niitsu
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. thinoi@hiroshima-u.ac.jp.
authors.forename: Takao
authors.initials: T
authors.lastname: Hinoi
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. manabus@fuga.ocn.ne.jp.
authors.forename: Manabu
authors.initials: M
authors.lastname: Shimomura
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. hiroegi@yahoo.co.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Egi
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. m-hattori@hiroshima-u.ac.jp.
authors.forename: Minoru
authors.initials: M
authors.lastname: Hattori
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. ishizaki.y@do2.enjoy.ne.jp.
authors.forename: Yasuyo
authors.initials: Y
authors.lastname: Ishizaki
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. adachitomohiro@hotmail.com.
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Adachi
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. ngywc515@ybb.ne.jp.
authors.forename: Yasufumi
authors.initials: Y
authors.lastname: Saito
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. miguchima0815@gmail.com.
authors.forename: Masashi
authors.initials: M
authors.lastname: Miguchi
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. dannte5426@yahoo.co.jp.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sawada
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. masatoshi-m5@hotmail.co.jp.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Kochi
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. silentman1087@yahoo.co.jp.
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Mukai
authors.affiliation: Department of Gastroenterological and Transplant Surgery, Applied Life Sciences, Institute of Biomedical & Health Sciences, Hiroshima University, 1-2-3 Kasumi, Minamiku, Hiroshima, 734-8551, Japan. hohdan@hiroshima-u.ac.jp.
authors.forename: Hideki
authors.initials: H
authors.lastname: Ohdan
mesh_terms: D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D003131:Combined Modality Therapy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D016609:Neoplasms, Second Primary / Q000188:drug therapy* / Q000401:mortality / Q000556:secondary; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate