The risk of cancer at all sites following gastric operation for benign disease. A cohort study of 4,224 patients

Long-term risk of gastric cancer by subsite in operated and unoperated patients hospitalized for peptic ulcer

OBJECTIVE

We aimed to investigate whether the elevated risk of gastric cancer among patients with gastric ulcer (GU) and the enigmatic low risk among patients with duodenal ulcer (DU) pertain to both cardia and noncardia cancer. We also studied the risks among operated patients while taking the disparate baseline risks into consideration.

METHODS

Retrospective cohorts of 59,550 and 79,412 unoperated patients with DU and GU, respectively, plus 12,840 patients with partial gastric resection and 8,105 with vagotomy, recorded in the Swedish Inpatient Register since 1970, were followed from the first hospitalization (date of operation for the surgery cohort) until occurrence of any cancer, death, emigration, definitive surgery, or December 31, 2003. Standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) expressed relative risk (RR), compared to the age-, sex-, and calendar period-matched Swedish population. Cox regression produced adjusted RR estimates among operated patients, relative to unoperated ones with the same ulcer type.

RESULTS

While unoperated DU patients had a halved risk of noncardia cancer (SIR=0.5, 95% CI 0.4-0.7), their risk of cardia cancer was slightly above expectation (SIR=1.2, 95% CI 0.8-1.7). Unoperated GU patients had doubled risks for both cancers (SIR=2.1, 95% CI 2.0-2.4 and SIR=1.9, 95% CI 1.4-2.3, respectively). DU patients who underwent gastric resection had a 60% risk elevation (RR=1.6, 95% CI 1.0-2.5) compared to unoperated ones. Vagotomy was associated with a greater risk in the first 10 yr, but this excess disappeared with further follow-up. Resected GU patients had a 40% risk reduction relative to their unoperated peers (RR=0.6, 95% CI 0.5-0.8). This reduction persisted well beyond the first postoperative decade.

CONCLUSION

The DU-related protection against gastric cancer does not seem to pertain to cardia cancer. With gastric resection, risks are shifted toward normality, regardless of underlying ulcer type.

Etiology of pancreatic cancer, with a hypothesis concerning the role of N-nitroso compounds and excess gastric acidity

In the United States, pancreatic cancer is the fourth most frequent cause of cancer death in males as well as females, after lung, prostate or breast, and colorectal cancer. Each year, approximately 30 000 Americans are diagnosed with pancreatic cancer and about the same number die of it. Germline mutations in a few genes including p16 and BRCA2 have been implicated in a small fraction of cases, as has chronic pancreatitis. The one established risk factor for pancreatic cancer is cigarette smoking: current smokers have two to three times the risk of nonsmokers. Studies of dietary factors have not been entirely consistent but do suggest associations of higher risk with consumption of smoked or processed meats or with animal foods in general and lower risk with consumption of fruits and vegetables. Colonization by Helicobacter pylori appears to increase risk, and a history of diabetes mellitus may also increase risk. The purpose of this epidemiologic review is to consider the possibility that risk of pancreatic cancer is increased by factors associated with pancreatic N-nitrosamine or N-nitrosamide exposures and with chronic excess gastric or duodenal acidity. Host genetic variation in inflammatory cytokine mechanisms may also be involved in this process. Many features of the evidence bearing on the pathophysiology of pancreatic cancer appear to support connections with N-nitroso compounds and with gastric acidity.

Diabetes mellitus, other medical conditions and familial history of cancer as risk factors for pancreatic cancer

In a population-based case-control study of pancreatic cancer conducted in three areas of the USA, 484 cases and 2099 controls were interviewed to evaluate the aetiologic role of several medical conditions/interventions, including diabetes mellitus, cholecystectomy, ulcer/gastrectomy and allergic states. We also evaluated risk associated with family history of cancer. Our findings support previous studies indicating that diabetes is a risk factor for pancreatic cancer, as well as a possible complication of the tumour. A significant positive trend in risk with increasing years prior to diagnosis of pancreatic cancer was apparent (P-value for test of trend = 0.016), with diabetics diagnosed at least 10 years prior to diagnosis having a significant 50% increased risk. Those treated with insulin had risks similar to those not treated with insulin (odds ratio (OR) = 1.6 and 1.5 respectively), and no trend in risk was associated with increasing duration of insulin treatment. Cholecystectomy also appeared to be a risk factor, as well as a consequence of the malignancy. Subjects with a cholecystectomy at least 20 years prior to the diagnosis of pancreatic cancer experienced a 70% increased risk, which was marginally significant. In contrast, subjects with a history of duodenal or gastric ulcer had little or no elevated risk (OR = 1.2; confidence interval = 0.9-1.6). Those treated by gastrectomy had the same risk as those not receiving surgery, providing little support for the hypothesis that gastrectomy is a risk factor for pancreatic cancer. A significant 40% reduced risk was associated with hay fever, a non-significant 50% decreased risk with allergies to animals, and a non-significant 40% reduced risk with allergies to dust/moulds. These associations, however, may be due to chance since no risk reductions were apparent for asthma or several other types of allergies. In addition, we observed significantly increased risks for subjects reporting a first-degree relative with cancers of the pancreas (OR = 3.2), colon (OR = 1.7) or ovary (OR = 5.3) and non-significantly increased risks for cancers of the endometrium (OR = 1.5) or breast (OR = 1.3). The pattern is consistent with the familial predisposition reported for pancreatic cancer and with the array of tumours associated with hereditary non-polyposis colon cancer.

Gastrectomy and subsequent risk of oesophageal cancer in Milan

STUDY OBJECTIVE

To analyse quantitatively the relationship between gastrectomy and oesophageal cancer risk.

DESIGN

This was a case-control study, based on a structured questionnaire that included a problem-oriented medical history.

SETTING

A network of hospitals in the Greater Milan area between 1984 and 1992.

SUBJECTS

Subjects were 316 incident, histologically confirmed cases of oesophageal cancer (258 males and 58 females), and 1408 controls (1031 males, 377 females), admitted to hospital for acute, non-neoplastic, non-digestive tract conditions.

MEASUREMENTS AND MAIN RESULTS

Relative risks (RR) and the corresponding 95% confidence intervals (CI) adjusted for age and sex, plus area of residence, education, tobacco, and alcohol consumption. There was an association of borderline significance of oesophageal cancer with gastric ulcer (RR = 1.6), but not with duodenal ulcer (RR = 0.9). Among cases, 25 (7.9%) reported a history of gastrectomy, versus 29 (2.1%) of the controls. The corresponding multivariate RR was 3.8 (95% CI 2.0, 7.0). The RR of oesophageal cancer was significantly raised (RR = 3.6) within 20 years after gastrectomy, and the association seemed stronger with increasing time since gastrectomy (RR = 4.2).

CONCLUSIONS

Since gastrectomy may cause gastric hypoacidity and favour oesophageal reflux, and hence oesophagitis, the results of this study, if confirmed, are of interest to a better understanding of the mechanisms of oesophageal carcinogenesis.