A clinicopathological and immunohistochemical study of gastric cancer with squamous cell carcinoma components: a clinically aggressive tumor.
OBJECTIVE
Adenosquamous carcinoma originating in the stomach is an unusual neoplasm with few existing histological studies. This study was aimed to gain insight into the histogenetic and clinicopathological characteristics of gastric cancer with squamous cell carcinoma (SCC) components.


METHODS
From January 2001 to June 2010 a total of 1735 patients underwent a resection of gastric cancer. Histopathologically, eight patients had adenocarcinoma containing SCC components, in which the proportion of SCC components was above 25% of the total tumor mass in four patients. The immunohistochemical and clinicopathological characteristics of these eight patients were analyzed.


RESULTS
The median survival duration was 22 months. Adenocarcinoma was present at the superficial layer of all tumors and SCC was primarily present at sites with deep invasion. Immunohistochemically, adenocarcinoma components were positive for cytokeratin (CK) 8/18/19 and CK7 in all cases. SCC components were positive for carcinoembryonic antigen and CK7 in more than 60% of patients. Expression patterns of p53 product were identical in both components. SCC components were positive for 34βE12 and adenocarcinoma components were negative for 34βE12 in all patients.


CONCLUSIONS
SCC components are derived from squamous metaplasia in a pre-existing adenocarcinoma. A gastric adenocarcinoma with SCC components is associated with various patterns of metastasis and both SCC and adenocarcinoma components have the potential for metastasis. Gastric cancer with SCC components is a clinically aggressive tumor.
Department of Surgery             Clinical Oncology             Pathology, Jichi Medical University, Tochigi, Japan.
Shin
S
Saito
Yoshinori
Y
Hosoya
Kazue
K
Morishima
Takashi
T
Ui
Hidenori
H
Haruta
Kentaro
K
Kurashina
Yoshiyuki
Y
Meguro
Toru
T
Zuiki
Naohiro
N
Sata
Hirofumi
H
Fujii
Daisuke
D
Matsubara
Toshiro
T
Niki
Alan T
AT
Lefor
Yoshikazu
Y
Yasuda
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D000369:Aged, 80 and over; D015820:Cadherins / Q000378:metabolism; D002272:Carcinoembryonic Antigen / Q000378:metabolism; D018196:Carcinoma, Adenosquamous / Q000378:metabolism / Q000473:pathology*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053538:Keratin-18 / Q000378:metabolism; D053539:Keratin-19 / Q000378:metabolism; D053552:Keratin-7 / Q000378:metabolism; D053533:Keratin-8 / Q000378:metabolism; D007633:Keratins / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology*; D016019:Survival Analysis; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
C121278:CK-34 beta E12; D015820:Cadherins; D002272:Carcinoembryonic Antigen; D053538:Keratin-18; D053539:Keratin-19; D053552:Keratin-7; D053533:Keratin-8; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53; D007633:Keratins