The Risk of Gastrointestinal and other Primary Malignant Diseases Following Gastric Cancer

Abstract

The risk of developing a second primary cancer was studied among 34,506 gastric cancer patients identified through the Swedish Cancer Registry. A second cancer was reported in 962 patients compared to an expected number of 826 (relative risk = 1.16, 95% confidence limits = 1.09-1.24). The slightly but significantly elevated risk was largely confined to the first year after the gastric cancer diagnosis, and to patients under 70 years old at the time of diagnosis. The risk was significantly increased for cancer in the small intestine, colon, rectum, kidney, breast and prostate. A closer look at the data, however, revealed that a substantial proportion of the second cancers were diagnosed within one month after the gastric cancer diagnosis, or at autopsy. We recalculated the relative risk estimates under the assumption that only 75% of the cancers incidentally detected in connection with diagnosis/treatment of the gastric cancer would have become clinically manifest during the relatively short observation time. and that 20% of the cancers revealed at autopsy in the gastric cancer patients would have been detected if the death and autopsy rates in this group had been equal to those in the general population (matched for age and gender). Under those assumptions the risk of having a second primary cancer among gastric cancer patients was close to what would be expected. The increased risk reported in some previous studies could be the result of closer patient surveillance.

Synchronous and metachronous cancers in patients with gastric cancer

“…In that study, the incidence of synchronous and metachronous cancer in patients with gastric cancer was 2.0% in Japan. Since then, other studies have reported an incidence of 1.1-4.7% [11][12][13][14][15][16][17]. In this study, the incidence was 3.4%, but it seems to be underestimated, as the study excluded those patients who were not operated on for gastric cancer due to the inoperability of their advanced gastric cancer stage.…”

Clinicopathological features of gastric carcinoma patients with other primary carcinomas

“…In patients with gastric carcinoma, the prevalence of associated primary carcinomas reported by several authors varies between 2.8% [18] and 6.8% [5]. In Japan, Yoshino et al [19] found multiple primary carcinomas combined with gastric carcinomas in 2.1% of patients with apparently single gastric carcinomas.…”

Loss of protein expression of hMLH1 and hMSH2 with double primary carcinomas of the stomach and colorectum

“…In particular, a metachronous CRC after surgery for GC, and a metachronous GC after surgery for CRC were often found (23,24). There have been no reports to our knowledge on the biological nature or characteristics of any specified carcinoma with double carcinomas of the stomach and colorectum.…”