Prognostic Impact of Histologic Type in Curatively Resected Stage IV Colorectal Cancer: A Japanese Multicenter Retrospective Study.
BACKGROUND
This study aimed to clarify differences in prognostic factors, metastatic features, and recurrence rates between histologic types in patients with stage 4 colorectal cancer (CRC) who had undergone curative resection.


METHODS
The data from 1131 patients with stage 4 colorectal cancer from the databases of referral institutions were analyzed. The patients were divided into two groups according to histologic types as follows: patients with poorly differentiated adenocarcinoma, mucinous adenocarcinoma, or signet-ring cell carcinoma (Por/Muc/Sig) and patients with well-differentiated or moderately differentiated adenocarcinoma (Wel/Mod). Differences in clinicopathologic features, relapse-free survival (RFS) rates, and cancer-specific survival (CSS) rates between the groups were evaluated.


RESULTS
Although RFS did not differ between the Por/Muc/Sig and Wel/Mod groups, CSS was significantly shorter in the Por/Muc/Sig group's than in the Wel/Mod group, and survival after recurrence was significantly worse in the Por/Muc/Sig group than in theWel/Mod group. The incidence of peritoneal or local recurrence was significantly higher for the Por/Muc/Sig patients, whereas the resection recurrence rate was 16.4 %. Multivariate analysis suggested that histologic type was an independent prognostic factor for survival after recurrence.


CONCLUSIONS
The patients with Por/Muc/Sig CRC synchronous metastasis had significantly shorter survival times than the patients with other CRC histologies, even if the metastases were curatively resected.
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan. shibata200101545@yahoo.co.jp.
Junichi
J
Shibata
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Kazushige
K
Kawai
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Takeshi
T
Nishikawa
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Toshiaki
T
Tanaka
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Junichiro
J
Tanaka
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Tomomichi
T
Kiyomatsu
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Keisuke
K
Hata
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Hiroaki
H
Nozawa
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Shinsuke
S
Kazama
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Hironori
H
Yamaguchi
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Soichiro
S
Ishihara
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Eiji
E
Sunami
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Joji
J
Kitayama
Department of Surgical Oncology, Tokyo Medical and Dental University, Tokyo, Japan.
Kenichi
K
Sugihara
Department of Surgical Oncology, University of Tokyo Hospital, The University of Tokyo, Tokyo, Japan.
Toshiaki
T
Watanabe
D000230:Adenocarcinoma / Q000556:secondary* / Q000601:surgery; D002288:Adenocarcinoma, Mucinous / Q000556:secondary* / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018279:Carcinoma, Signet Ring Cell / Q000556:secondary* / Q000601:surgery; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology* / Q000601:surgery; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000556:secondary* / Q000601:surgery; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D055815:Young Adult