Trend in gastric cancer: 35 years of surgical experience in Japan

Abstract

Aim: To investigate the trend in gastric cancer surgery in the context of rapid therapeutic advancement in Japan and East Asia.

Methods: A retrospective analysis was performed on 4163 patients who underwent gastric resection for gastric cancer with histological confirmation between 1971 and 2007 at the surgical unit in Kitasato University Hospital, to determine the trend in gastric cancer requiring surgery.

Results: Gastric cancer requiring surgical resection increased in our hospital, but the incidence adjusted for population was constant during the observed period. Interestingly, the ratio of diffuse type/intestinal type gastric cancer was unexpectedly unchanged, and that of advanced/early gastric cancer (EGC) was, however, markedly reduced, while the actual incidence of potentially curative advanced gastric cancer tended to decrease. The incidence of EGC requiring surgery tended to increase as a whole, which is consistent with increased prevalence of endoscopic surveillance. As a result, overall survival and mortality of gastric cancer requiring gastric resection has recently markedly improved.

Conclusion: In Japan, planned interventions may improve surgical gastric cancer mortality, but an unexpected trend of persistent existence of intestinal type cancer suggests the need for more robust medical intervention.

Keywords: Age factors; Clinical classification; Disease progression; Gastric cancer; Histology; Prognosis.

Figure 1

Trends in gastric cancer patients in Kitasato University Hospital. A: Trend in the numbers of patients requiring surgery, according to 3 histology categories, namely intestinal, mixed, and diffuse type; B: Trend in the proportion of intestinal type advanced gastric cancer (AGC) of stages I to III. Note that the proportion of intestinal type AGC did not decline during the time period (the final time period was 7 years only).

Figure 2

Incidence of gastric cancer treated in Kitasato University Hospital, according to the population of Sagamihara city. A: Incidence is shown between 1972 and 2006, because full annual data for 1971 and 2007 was not available. The incidence of gastric cancer requiring surgery did not decline; B: Incidence of gastric cardia cancer has been increasing until recently. Incidence is per 100 000 population.

Figure 3

Proportion of early gastric cancer and advanced gastric cancer. Early gastric cancer (EGC) was further subdivided into mucosal EGC (Early-mucosal ) and submucosal EGC (Early-submucosa), while advanced gastric cancer was subdivided into stage I-III and stage IV. Note that the proportion of EGC increased over time.

Figure 4

Trend in the number of patients according to the 4 gastric cancer categories in Kitasato University Hospital. The initial year of the critical events in endoscopic resection in Japan is designated by arrows. EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; EGC (Early-mucosal ).

Figure 5

Incidence of advanced gastric cancer treated in Kitasato University Hospital per 100 000 population of Sagamihara city. A: Incidence of advanced gastric cancer (AGC) stage I to III the observed 35 years between 1972 (corresponding to 1) and 2006 (corresponding to 35). Note that the incidence of AGC stage I to III declined during the time period; B: Incidence of AGC stage IV during the same 35 years.

Figure 6

Incidence of early gastric cancer treated in Kitasato University Hospital per 100 000 population in Sagamihara city. A: Incidence of early gastric cancer (EGC) in the 35 years between 1972 and 2006. Note that the incidence of EGC increased during the time period; B: Incidence of EGC-M and EGC-SM during the observed 35 years. The initial year of the critical events in endoscopic resection in Japan is designated by arrows. EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; EGC-M: Early-Mucosa; EGC-SM: Early-Submucosa.

Figure 7

Clinical outcome of gastric cancer requiring surgery in the Kitasato University Hospital. A: Overall survival (OS) of gastric cancer requiring surgery shown according to time period (1971-1980, 1981-1990, 1991-2000). Five-year OS was 57.2%, 67.2%, and 77.4% according to time period, and has remarkably improved; B: Mortality of gastric cancer requiring surgery shown according to time period (1971-1980, 1981-1990, 1991-2000), which is consistent with (A).