The decreasing burden of gastric cancer in Japan

Global Patterns and Trends in Gastric Cancer Incidence Rates (1988-2012) and Predictions to 2030

BACKGROUND & AIMS

The long-term trend in gastric cancer rates has rarely been reported from a global perspective. We aimed to explore the past temporal trends (1988-2012) in gastric cancer incidence rates in 43 countries and to predict future trends (2012-2030).

METHODS

Data on yearly gastric cancer incidence by age group and sex were drawn from 108 cancer registries in 43 countries in the Cancer Incidence in Five Continents Time Trends (CI5plus) database. Age-standardized incidence rates per 100,000 persons were computed from 1988-2012. The number of new cases and incidence rates were predicted to 2030 using the Bayesian age-period-cohort model.

RESULTS

Persistent decreasing trends in gastric cancer incidence rates were observed from 1988-2012 worldwide, with an overall average annual percentage change of -2.1% (95% confidence interval, -2.5--1.7). The trends will continue or remain stable until 2030 in most of the selected countries except for Ecuador and Lithuania, whose gastric cancer incidence rates will experience substantially increasing trends in the next several decades.

CONCLUSION

The incidence rates of gastric cancer are expected to decrease through 2030 in most countries except Ecuador and Lithuania. Reductions in smoking and Helicobacter pylori prevalence and improvement in diet probably contributed to the decrease. Gastric cancer still represents a major cancer burden worldwide, and the large number of gastric cancer cases worldwide may still call for lifestyle interventions in terms of smoking and diet and massive efforts for H pylori screening and treatment, especially in countries with predicted increasing incidence rates of gastric cancer.

Association of the age-adjusted Charlson Comorbidity Index and systemic inflammation with survival in gastric cancer patients after radical gastrectomy

PURPOSE

To examine the associations of the Age-Adjusted Charlson Comorbidity Index (ACCI) and preoperative systemic inflammation with survival in gastric cancer (GC) patients who underwent radical gastrectomy.

METHODS

Data from patients with GC who underwent radical gastrectomy between January 2009 and December 2014 in Fujian Medical University Union Hospital were retrospectively analyzed. Univariate and multivariate Cox regression analyses were performed to identify the prognostic factors. The relationship between the ACCI and systemic inflammation of the patients was explored, and the prognostic value of a new scoring system based on the ACCI and systemic inflammation (ANLR) was evaluated.

RESULTS

A total of 2257 patients with GC were included. The ACCI and neutrophil to lymphocyte ratio (NLR) were independent prognostic factors for overall survival (both P < 0.001) by multivariate analysis. A higher ACCI was an independent predictor of the increase in preoperative NLR (P < 0.001). Based on the preoperative ACCI and NLR, we established a novel marker, ANLR. Multivariate analysis showed that the ANLR was a significant independent predictor of 5-year OS (P < 0.001). The Harrell's C-statistics (C-index) of a model combining the ANLR and pTNM was 0.744 (95% CI: 0.728-0.760), which was significantly higher than the pTNM stage (0.717, 95% CI: 0.702-0.731; P < 0.001).

CONCLUSION

The ACCI of patients with gastric cancer was associated with preoperative systemic inflammation. The ACCI combined with the NLR, which are commonly collected biomarkers, could enhance prognostication for GC patients.

Age-adjusted Charlson Comorbidity Index (ACCI) is a significant factor for predicting survival after radical gastrectomy in patients with gastric cancer

INTRODUCTION

To assess the ability of the Age-Adjusted Charlson Comorbidity Index (ACCI) to predict survival after radical gastrectomy in patients with gastric cancer (GC).

METHOD

Data from patients with GC who underwent radical gastrectomy from January 2008 to December 2012 in Fujian Medical University Union Hospital were retrospectively analyzed. Patients were categorized into either high ACCI group or low ACCI group based on the effect of ACCI on long-term GC prognosis. 1:1 propensity score matching (PSM) was used to reduce confounding bias. To further analyze the impact of ACCI on the long-term prognosis of patients after radical gastrectomy, a nomogram was built based on the Cox proportional hazards regression model.

RESULTS

A total of 1476 patients were included in the analysis. After PSM, there was no statistically significant differences in tumor location, tumor size and tumor stage between low ACCI group (429 cases) and high ACCI group (429 cases) (all P > 0.05). Before and after PSM, the incidence of postoperative complications in high ACCI group was significantly higher than that in low ACCI group (P < 0.05). The 5-year overall survival rate (OS) in low ACCI group was significantly higher than that in high ACCI group. Multivariate analysis showed that ACCI was an independent risk factor for OS (P < 0.05). The Harrell's C-statistics (C-index) of TNMA, a prognostic evaluation system combining ACCI and TNM staging system, was significantly higher than that of TNM staging system in both the modeling and validation groups (all P < 0.05).

CONCLUSIONS

ACCI was an independent risk factor for the long-term prognosis of GC patients after radical gastrectomy that could effectively improve the predictive efficacy of the TNM staging system for GC.

Efficacy and safety of using premedication with simethicone/Pronase during upper gastrointestinal endoscopy examination with sedation: A single center, prospective, single blinded, randomized controlled trial

BACKGROUND AND AIM

To investigate the efficacy and safety of premedication with simethicone/Pronase during esophagogastroduodenoscopy (EGD) with sedation.

METHODS

Six hundred and ten patients were randomly allocated to two groups based on type of premedication given. Premedication used in the control group was 10 mL lidocaine hydrochloride mucilage (LHM, N = 314) and premedication used in the intervention group was 80 mL simethicone/Pronase solution plus 10 mL lidocaine hydrochloride mucilage (SP/LHM, N = 296). EGD was done under sedation. Visibility scores, number of mucosal areas that needed cleansing, water consumption for cleansing, time taken for examination, diminutive lesions, pathological diagnosis, patients' gag reflex and oxygenation (pulse oximetry) were recorded.

RESULTS

SP/LHM has significantly lower total visibility score than LHM (7.978 ± 1.526 vs 6.348 ± 1.097, P < 0.01). During the procedure, number of intragastric areas that needed cleansing and amount of water consumed were significantly less in the SP/LHM than in the LHM group (P < 0.01). In SP/LHM (P = 0.01), endoscopy procedure duration was significantly longer. Although there was no significant difference in rate of detection of diminutive lesions between LHM and SP/LHM, the endoscopist carried out more biopsies in SP/LHM. This led to a higher rate of diagnosis of atrophic gastritis (P = 0.014) and intestinal metaplasia (P = 0.024). There was no significant difference in gag reflex (P = 0.604) and oxygenation during the endoscopy procedure for either group of patients.

CONCLUSION

Routine use of premedication with simethicone/Pronase should be recommended during EGD with sedation.

Trends in gastrointestinal cancer incidence in Iran, 2001-2010: a joinpoint analysis

OBJECTIVES

The main purpose of this study was to evaluate changes in the time trends of stomach, colorectal, and esophageal cancer during the past decade in Iran.

METHODS

Cancer incidence data for the years 2001 to 2010 were obtained from the cancer registration of the Ministry of Health. All incidence rates were directly age-standardized to the world standard population. In order to identified significant changes in time trends, we performed a joinpoint analysis. The annual percent change (APC) for each segment of the trends was then calculated.

RESULTS

The incidence of stomach cancer increased from 4.18 and 2.41 per 100,000 population in men and women, respectively, in 2001 to 17.06 (APC, 16.7%) and 8.85 (APC, 16.2%) per 100,000 population in 2010 for men and women, respectively. The corresponding values for colorectal cancer were 2.12 and 2.00 per 100,000 population for men and women, respectively, in 2001 and 11.28 (APC, 20.0%) and 10.33 (APC, 20.0%) per 100,000 in 2010. For esophageal cancer, the corresponding increase was from 3.25 and 2.10 per 100,000 population in 2001 to 5.57 (APC, 12.0%) and 5.62 (APC, 11.2%) per 100,000 population among men and women, respectively. The incidence increased most rapidly for stomach cancer in men and women aged 80 years and older (APC, 23.7% for men; APC, 18.6% for women), for colorectal cancer in men aged 60 to 69 years (APC, 24.2%) and in women aged 50 to 59 years (APC, 25.1%), and for esophageal cancer in men and women aged 80 years and older (APC, 17.5% for men; APC,15.3% for women) over the period of the study.

CONCLUSIONS

The incidence of gastrointestinal cancer significantly increased during the past decade. Therefore, monitoring the trends of cancer incidence can assist efforts for cancer prevention and control.

Outcomes of octogenarians undergoing gastrectomy performed for malignancy

BACKGROUND

Studies on perioperative outcomes of octogenarians with gastric cancer are limited by small sample size. Our aim was to determine the outcomes of gastrectomy and the variation of treatments associated with advanced age (≥80 y).

METHODS

The National Surgical Quality Improvement Program database was queried from 2005 to 2011. Patients who underwent gastrectomy for malignancy were identified using International Classification of Diseases, Ninth Revision and Current Procedural Terminology codes.

RESULTS

Of 2591 cases, 487 patients were octogenarians (≥80) and 2104 were nonoctogenarians (<80). Overall, 4.9% of patients had disseminated cancer. Octogenarians had higher 30-d mortality (7.2% versus 2.5%, P < 0.01) and more major complications (31.4% versus 25.5%, P < 0.01), though fewer octogenarians underwent total gastrectomy (24.0% versus 43.2%, P < 0.01) and extended lymphadenectomy (10.1% versus 17.4%, P < 0.01) than the nonoctogenarian cohort. On multivariate analysis, age ≥80 y was associated with major complications (OR, 1.3; 95% CI, 1.03-1.6; P = 0.03) and increased mortality (OR, 3.0; 95% CI, 1.9-4.9; P < 0.01).

CONCLUSIONS

Advanced age (≥80 y) was associated with worse outcomes in patients undergoing gastrectomy for malignancy. Therefore, careful staging is necessary to reduce unnecessary operations in this population. Furthermore, surgeons must place greater attention on optimizing the octogenarian population before surgery.

Early Oral Feeding After Surgery for Upper Gastrointestinal Malignancies: A Prospective Cohort Study

OBJECTIVES

Poor nutritional status following abdominal surgeries for esophageal and gastric cancers remains a major challenge in postoperative care. Our study aimed to investigate the efficacy of starting early oral feeding (EOF) in patients undergoing surgical resection of upper gastrointestinal malignancies.

METHODS

A total of 180 consecutive patients with a diagnosis of esophageal or gastric malignancies undergoing elective surgical resection between January 2008 and February 2011 were enrolled in this prospective cohort study. Seventy-two patients were assigned to the EOF group, and 108 patients received late oral feeding (LOF). Postoperative endpoints were compared between the two groups.

RESULTS

Nasogastric tubes were removed from patients on average 3.3±1.6 days after the surgery in the EOF group and 5.2±2.5 days in the LOF group (p < 0.001). The soft diet regimen was started and tolerated significantly sooner in the EOF group (5.8±1.2 days) than the LOF group (9.5±5.5 days). Hospital stay was significantly shorter in the EOF group compared to the LOF group (6.7±3.1 days vs. 9.1±5.8 days, p < 0.001). Surgical complications and rehospitalization occurred less in EOF group compared with the LOF group. However, the differences were not significant (p > 0.050).

CONCLUSIONS

EOF is safe following esophageal and gastric cancer surgery and results in faster recovery and hospital discharge.

Study of C-MYC amplification and expression in Iranian gastric cancer samples using CISH and IHC methods

Background:

Gastric cancer is the fourth most frequent malignancy and the second cause of cancer-related mortality worldwide. It has been suggested that in gastric carcinogenesis, the C-MYC gene has an important function. The objective of this study is to establish the preference of Chromogenic in situ hybridization (CISH) and Immunohistochemistry (IHC) in the diagnosis and prognosis of gastric cancer.

Materials and Methods:

Samples comprised of 50 randomly selected patients of whom 40 were male and 10 female. To evaluate the MYC copy number and its protein expression, CISH and IHC analyses were performed for 50 gastric adenocarcinomas, in Iran.

Results:

The location of the tumor in 64% of the patients was the fundus, and in 72% of patients, the tumors were of a diffuse type; 22 samples showed no amplification, and 28 samples were with amplification. MYC immunoreactivity was observed in 13 samples. Twelve samples showed both MYC amplification and MYC immunoreactivity. In addition, among the 28 CISH+ samples, 12 samples had positive signals for IHC and 16 samples had negative signals for IHC. A majority of the IHC-negative patients had no amplification, but only one patient with IHC positive had no amplification.

Conclusion:

Our conclusion was that for the management and treatment of gastric cancer, and for special attention of clinicians, for prognosis and tumor progression, the CISH was a better and more feasible test than IHC, in regard to the sensitivity and specificity.

Characteristics of gastric cancer in Asia

Gastric cancer (GC) is the fourth most common cancer in the world with more than 70% of cases occur in the developing world. More than 50% of cases occur in Eastern Asia. GC is the second leading cause of cancer death in both sexes worldwide. In Asia, GC is the third most common cancer after breast and lung and is the second most common cause of cancer death after lung cancer. Although the incidence and mortality rates are slowly declining in many countries of Asia, GC still remains a significant public health problem. The incidence and mortality varies according to the geographic area in Asia. These variations are closely related to the prevalence of GC risk factors; especially Helicobacter pylori (H. pylori) and its molecular virulent characteristics. The gradual and consistent improvements in socioeconomic conditions in Asia have lowered the H. pylori seroprevalence rates leading to a reduction in the GC incidence. However, GC remains a significant public health and an economic burden in Asia. There has been no recent systemic review of GC incidence, mortality, and H. pylori molecular epidemiology in Asia. The aim of this report is to review the GC incidence, mortality, and linkage to H. pylori in Asia.

Age, period, and cohort effects on gastric cancer mortality

BACKGROUND

The incidence of gastric cancer varies both within and among populations and can change rapidly without a corresponding decline in Helicobacter pylori prevalence. Here, we describe the changes in gastric cancer mortality in Japan in relation to age-period-cohort effects as well as the decline in H. pylori prevalence.

METHODS

We used data from Japanese for men and women aged 30-94 for birth years 1875-1970 (calendar time 1950-2000) to observe the age, period and cohort effects on gastric cancer mortality rates. Additionally, we used Poisson regression to simultaneously adjust for concurrent age, period and cohort effects as well as for declining H. pylori prevalence in the Japanese population.

RESULTS

There was an approximate 60 % decline in gastric cancer mortality between 1965 and 1995. Detailed age, period and cohort analyses and Poisson regression analysis showed these factors interact in complex ways, analyses focused on one or two of these effects, such as birth cohort without considering concurrent age and period would obscure important interactions that affected different age groups at different times to produce this composite effect.

CONCLUSION

The underlying complexity in population-disease dynamics requires population-specific descriptions of trends using multiple methods to provide an in-depth analysis while simultaneously allowing for necessary statistical adjustments as well as identification of interactions. More thorough descriptions of the population-specific general trends in relation to changes in the population structure (age-period-cohort) enable better prevention and health care policy planning, and further, the descriptions enable hypothesis generation regarding causes of population-specific disease patterns.

Characteristics of gastric cancer in Asia

Gastric cancer (GC) is the fourth most common cancer in the world with more than 70% of cases occur in the developing world. More than 50% of cases occur in Eastern Asia. GC is the second leading cause of cancer death in both sexes worldwide. In Asia, GC is the third most common cancer after breast and lung and is the second most common cause of cancer death after lung cancer. Although the incidence and mortality rates are slowly declining in many countries of Asia, GC still remains a significant public health problem. The incidence and mortality varies according to the geographic area in Asia. These variations are closely related to the prevalence of GC risk factors; especially Helicobacter pylori (H. pylori) and its molecular virulent characteristics. The gradual and consistent improvements in socioeconomic conditions in Asia have lowered the H. pylori seroprevalence rates leading to a reduction in the GC incidence. However, GC remains a significant public health and an economic burden in Asia. There has been no recent systemic review of GC incidence, mortality, and H. pylori molecular epidemiology in Asia. The aim of this report is to review the GC incidence, mortality, and linkage to H. pylori in Asia.

Negative impact of leakage on survival of patients undergoing curative resection for advanced gastric cancer

BACKGROUND AND OBJECTIVES

Leakage has been shown to adversely affect survival in patients undergoing surgery for gastrointestinal malignancies. However, the effect of leakage following radical gastrectomy in patients with gastric cancer remains unclear.

METHODS

In total, 478 patients with advanced gastric cancer who underwent surgery with curative intent were reviewed. Anastomosis or duodenal stump leakage was diagnosed clinically or radiologically. Risk factors for leakage were evaluated by univariate and multivariate analyses. The impact of leakage on patient survival was analyzed using the Kaplan-Meier method.

RESULTS

Leakage was diagnosed in 32 of 478 patients (6.7%); 14 patients (2.9%) exhibited esophagojejunal anastomotic leakage, 14 (2.9%) showed duodenal stump leakage, and four (0.8%) showed gastroduodenal anastomotic leakage. Poor performance status [odds ratio (OR): 4.01, 95% confidence interval (CI): 1.80-8.93] and tumor location (OR: 3.74, 95% CI: 1.56-8.89) were risk factors for postoperative leakage. Overall mean survival of patients with leakage was significantly lower than that of patients without leakage (30.5 vs. 96.2 months; P < 0.001). Leakage was one of the independent predictive factor for overall survival [hazard ratio (HR): 3.58, 95% CI: 2.29-5.59].

CONCLUSIONS

Postoperative inflammation due to leakage is a negative prognostic factor for patients with advanced gastric cancer.

A randomized controlled trial of rebamipide plus rabeprazole for the healing of artificial ulcers after endoscopic submucosal dissection

BACKGROUND

Endoscopic submucosal dissection (ESD) is an increasingly common technique for the resection of early gastric cancers. Although 8 weeks of treatment with a proton pump inhibitor (PPI) reportedly heals most patients with ESD-derived artificial ulcers, it does not heal those with severe atrophic gastritis, for whom there is little data. This study examined whether healing rates of the latter especially were improved by the addition of the non-PPI mucosal healing agent rebamipide after ESD.

METHODS

Patients were randomly assigned to two treatment groups for 8 weeks following ESD: patients in the PPI group received daily rabeprazole alone (20 mg), whereas those in the combination group received daily rabeprazole (20 mg) and rebamipide (300 mg). At the primary endpoint (56 days after ESD) we determined the proportion of patients in whom ulcers had healed to scar-stage (S-stage, complete healing). A pre-specified subgroup analysis examined ulcer healing in patients with severe atrophic gastritis.

RESULTS

Overall, progression to S-stage occurred in 54.8% in the PPI group, and 86.7% in the combination group (odds ratio 5.3, 95% confidence interval 1.50-19.02, p = 0.006). Among those patients with severe atrophic gastritis, healing to S-stage occurred in 30.0% in the PPI group, and in 92.9% in the combination group (odds ratio 30.3, 95% confidence interval 2.63-348.91, p = 0.0023).

CONCLUSION

Treatment with a PPI plus rebamipide improved healing rates at 8 weeks for patients with ESD-derived artificial ulcer, and appeared to be particularly effective for patients with severe atrophic gastritis.

Population-based differences in treatment outcome following anticancer drug therapies

Population-based differences in toxicity and clinical outcome following treatment with anticancer drugs have an important effect on oncology practice and drug development. These differences arise from complex interactions between biological and environmental factors, which include genetic diversity affecting drug metabolism and the expression of drug targets, variations in tumour biology and host physiology, socioeconomic disparities, and regional preferences in treatment standards. Some well-known examples include the high prevalence of activating epidermal growth factor receptor (EGFR) mutations in pulmonary adenocarcinoma among northeast (China, Japan, Korea) and parts of southeast Asia (excluding India) non-smokers, which predict sensitivity to EGFR kinase inhibitors, and the sharp contrast between Japan and the west in the management and survival outcome of gastric cancer. This review is a critical overview of population-based differences in the four most prevalent cancers in the world: lung, breast, colorectal, and stomach cancer. Particular attention is given to the clinical relevance of such knowledge in terms of the individualisation of drug therapy and in the design of clinical trials.

Effects of early oral feeding on surgical outcomes and recovery after curative surgery for gastric cancer: pilot study results

BACKGROUND

The aim of the present study was to determine whether early oral feeding after curative resection for gastric cancer can be tolerated and whether it has an effect on recovery.

METHODS

From September 2007 to January 2008, we provided early postoperative oral feeding for 35 patients who underwent curative distal gastrectomy for gastric cancer. These patients began a liquid diet on the second postoperative day (POD), followed by a soft diet beginning on the third POD until they were discharged. From April to August 2007, we enrolled 31 patients with a conventional diet schedule as a control group. We compared the clinicopathologic features and surgical outcomes, including morbidity, laboratory results, and hospitalized days between the two groups.

RESULTS

There were no significant differences in the clinical and operative factors between the two groups. Although there was no difference in the morbidity rate (P = 0.331), the early group was hospitalized for fewer days (8.03 +/- 1.43 vs. 9.97 +/- 2.07 days; P < 0.001) and had a faster onset of flatus (1.96 +/- 0.58 vs. 2.97 +/- 0.66 day; P < 0.001) than the control group. The laboratory findings showed that the early feeding group tended to have a lymphocyte count that recovered faster than the control group, although the difference was not statistically significant.

CONCLUSIONS

Early oral feeding following a gastrectomy for gastric cancer is feasible and can result in faster recovery of bowel function and a shorter hospitalization.

Follow-up strategy after curative resection of gastric cancer: a nationwide survey in Korea

BACKGROUND

To date, guidelines for follow-up after curative resection in patients with gastric cancer have not been reported. Thus, most centers have managed the process according to institution-specific protocols. We investigated current follow-up practices after curative resection of gastric cancer using a nationwide survey in Korea, where gastric cancer is epidemic.

METHODS

From July to September 2007, questionnaires were sent out to 205 members of the Korean Gastric Cancer Association (KGCA). The questionnaire packet contained a covering letter, general information, and a questionnaire about follow-up schedules and methodologies.

RESULTS

Forty-six percent (96/205) of the members of the KGCA returned the survey. The majority of responders indicated that patients with early gastric cancer were followed up every 6 months (64.4%) for the first year, every 12 months (47.9%) for the next 4 years, and every 12 months (68.8%) from the fifth year after surgery on. For patients with advanced gastric cancer, follow-up studies were carried out every 3 months (43.8%) for the first year, every 6 months for the next 4 years, and every 12 months (75.0%) from the fifth year onward. After surgery, most responders used computed tomography for imaging, carcinoembryonic antigen (CEA) and carbohydrate antigen (CA)19-9 as tumor markers, and serum iron among follow-up measures.

CONCLUSIONS

Clinicians have a variety of approaches regarding the extent of follow-up and methodologies used after curative resection for gastric cancer. Therefore, a multicenter randomized trial will be needed to compare routine follow-up with intensive schedules. Our results could facilitate the design of such studies.

The impact of comorbidity on surgical outcomes in laparoscopy-assisted distal gastrectomy: a retrospective analysis of multicenter results

OBJECTIVE

The purpose of this study was to evaluate the impact of comorbidities on the surgical outcomes in laparoscopy-assisted distal gastrectomy (LADG).

SUMMARY BACKGROUND DATA

Although laparoscopic gastrectomy is less invasive than conventional open surgery, surgeons are still concerned with surgical outcomes associated with comorbidity.

METHODS

We retrospectively collected data on 1324 patients who underwent LADG between April 1998 and December 2005 by 10 surgeons in 10 hospitals. After excluding 87 patients who had an unusual medical history or surgical methods, 1237 patients were enrolled for analysis to evaluate the effect of comorbidities on the surgical outcomes.

RESULTS

Seven patients (0.6%) died during their hospitalization, and postoperative complications occurred in 162 (13.1%) of 1237 patients. According to univariate analysis, gender, number of comorbidities, reconstruction type, and the surgeon's experience in laparoscopy-assisted gastrectomy (LAG) were related to postoperative local complications; age and comorbidity were related to systemic complications; and comorbidity was the only variable related to hospital mortality. Comorbidity was a predictive risk factor for local complications (odds ratio (OR): 1.79) and systemic complications (OR: 2.89) in multivariate analysis. The patients with pulmonary comorbidity were related to most types of immediate postoperative complications compared with other comorbidities.

CONCLUSIONS

Our study suggests that comorbidities of patients could be a predictive risk factor for surgical complication after LADG. Therefore, patients with early gastric cancer having comorbidity should be considered for one of the limited surgeries. In addition, surgeons should carefully assess patients with comorbidities with full perioperative attention.

Anisakis simplex: from obscure infectious worm to inducer of immune hypersensitivity

Infection of humans with the nematode worm parasite Anisakis simplex was first described in the 1960s in association with the consumption of raw or undercooked fish. During the 1990s it was realized that even the ingestion of dead worms in food fish can cause severe hypersensitivity reactions, that these may be more prevalent than infection itself, and that this outcome could be associated with food preparations previously considered safe. Not only may allergic symptoms arise from infection by the parasites ("gastroallergic anisakiasis"), but true anaphylactic reactions can also occur following exposure to allergens from dead worms by food-borne, airborne, or skin contact routes. This review discusses A. simplex pathogenesis in humans, covering immune hypersensitivity reactions both in the context of a living infection and in terms of exposure to its allergens by other routes. Over the last 20 years, several studies have concentrated on A. simplex antigen characterization and innate as well as adaptive immune response to this parasite. Molecular characterization of Anisakis allergens and isolation of their encoding cDNAs is now an active field of research that should provide improved diagnostic tools in addition to tools with which to enhance our understanding of pathogenesis and controversial aspects of A. simplex allergy. We also discuss the potential relevance of parasite products such as allergens, proteinases, and proteinase inhibitors and the activation of basophils, eosinophils, and mast cells in the induction of A. simplex-related immune hypersensitivity states induced by exposure to the parasite, dead or alive.