Effects of Helicobacter pylori treatment and vitamin and garlic supplementation on gastric cancer incidence and mortality: follow-up of a randomized intervention trial

Abstract

Objective To assess the effects of Helicobacter pylori treatment, vitamin supplementation, and garlic supplementation in the prevention of gastric cancer. Design Blinded randomized placebo controlled trial. Setting Linqu County, Shandong province, China. Participants 3365 residents of a high risk region for gastric cancer. 2258 participants seropositive for antibodies to H pylori were randomly assigned to H pylori treatment, vitamin supplementation, garlic supplementation, or their placebos in a 2×2×2 factorial design, and 1107 H pylori seronegative participants were randomly assigned to vitamin supplementation, garlic supplementation, or their placebos in a 2×2 factorial design. Interventions H pylori treatment with amoxicillin and omeprazole for two weeks; vitamin (C, E, and selenium) and garlic (extract and oil) supplementation for 7.3 years (1995-2003). Main outcome measures Primary outcomes were cumulative incidence of gastric cancer identified through scheduled gastroscopies and active clinical follow-up through 2017, and deaths due to gastric cancer ascertained from death certificates and hospital records. Secondary outcomes were associations with other cause specific deaths, including cancers or cardiovascular disease. Results 151 incident cases of gastric cancer and 94 deaths from gastric cancer were identified during 1995-2017. A protective effect of H pylori treatment on gastric cancer incidence persisted 22 years post-intervention (odds ratio 0.48, 95% confidence interval 0.32 to 0.71). Incidence decreased significantly with vitamin supplementation but not with garlic supplementation (0.64, 0.46 to 0.91 and 0.81, 0.57 to 1.13, respectively). All three interventions showed significant reductions in gastric cancer mortality: fully adjusted hazard ratio for H pylori treatment was 0.62 (95% confidence interval 0.39 to 0.99), for vitamin supplementation was 0.48 (0.31 to 0.75), and for garlic supplementation was 0.66 (0.43 to 1.00). Effects of H pylori treatment on both gastric cancer incidence and mortality and of vitamin supplementation on gastric cancer mortality appeared early, but the effects of vitamin supplementation on gastric cancer incidence and of garlic supplementation only appeared later. No statistically significant associations were found between interventions and other cancers or cardiovascular disease. Conclusions H pylori treatment for two weeks and vitamin or garlic supplementation for seven years were associated with a statistically significant reduced risk of death due to gastric cancer for more than 22 years. H pylori treatment and vitamin supplementation were also associated with a statistically significantly reduced incidence of gastric cancer. Trial registration ClinicalTrials.gov NCT00339768 .

Risk Factors and Incidence of Gastric Cancer After Detection of Helicobacter pylori Infection: A Large Cohort Study

“…22,[49][50][51][52] Two recent studies from Sweden and Hong Kong suggest that, compared with the background population or matched control individuals, treatment decreases risk of future GAC, but other studies have presented limited and conflicting evidence for which populations would most benefit from treatment of HP. 16,21,33,[53][54][55][56][57][58][59][60] Our study adds to these findings and further suggests that inadequate eradication may explain disparate findings. Our findings that failed eradication is associated with future GAC also lend further credence to the importance of HP in GAC.…”

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

“…The incidence (5.7%) of GC, in which gastric adenocarcinoma (GAC) is the dominant subtype, has continued to decline worldwide due to the H pylori treatment [106], but the mortality rate (8.2%) remains the second most common cause of cancer death worldwide (Table 1). As shown in Table 1, the overall genetic alterations of PI3K/AKT pathway are observed with PIK3CA (17%) and PTEN (11%) in GC.…”

Phytochemicals for the Prevention and Treatment of Gastric Cancer: Effects and Mechanisms

“…A study reported that daily treatment of 900 mg of Rhus verniciflua Stokes extract decreased the polypoid mass and the flat elevated lesion in an old female patient with gastric adenocarcinoma [123]. Additionally, a randomized intervention trial including 3365 residents revealed that garlic (extract and oil) supplementation could also reduce the mortality of gastric cancer [124]. In a multi-institutional randomized prospective study, combined with clinical medicine tegafur and cisplatin, lentinan could prolong median survival and improve the quality of life in patients with gastric cancer [125].…”