[Clinicopathological features and differences of p53 and Ki-67 expression in adenosquamous and squamous cell carcinomas of the stomach].

BACKGROUND/AIMS: This study reviews the clinicopathological features, prognosis, and differences in the expression of p53 and Ki-67 immunochemical staining in squamous cell and adenosquamous carcinoma of the stomach.

METHODS

From January 1995 to June 2005, 2,282 cases of gastric carcinoma were resected surgically in our hospital and 191 additional cases were resected by endoscopic mucosal resection. Retrospective pathologic review and immunochemical staining of p53 and Ki-67 were performed.

RESULTS

The study consists of eight cases (0.032%) of primary squamous cell carcinoma (one case) and adenosquamous carcinoma (seven cases) without early gastric cancer. Six cases (75.0%) were male and two cases were female. The mean age was 66 year-old. The clinical presentation and physical findings did not differ from those of adenocarcinoma. The mean tumor size was 5.2+/-1.7 cm. Macroscopically, five were Borrmann type 3 (62.5%) and three were type 2. At the initial diagnosis, six (75%) were stage IV based on TNM tumor staging. Six cases (75%) progressed despite the therapy while two cases responded to the treatment. The median survival time was 11.0 months (range 4.3+/-17.7). Overexpression of p53 was seen in five cases (62.5%) and their survival was poor when compared to the p53-negative group (p=0.04). The mean Ki-67 labeling index was 70.0+/-20.8%, and was not associated with p53 staining (p<0.05).

CONCLUSIONS

Adenosquamous and squamous cell carcinoma of the stomach are very rare. They tend to be at advanced stages on initial diagnosis, and progress rapidly. They show p53 protein overexpression and high Ki-67 labeling index, which might be related to poor prognosis.