Red and Processed Meat Consumption Increases Risk for Non-Hodgkin Lymphoma: A PRISMA-Compliant Meta-Analysis of Observational Studies

Approach to Lymphoma-Associated Cardiomyopathy

Cardiomyopathy is a disease of the myocardium that affects the heart structure and function, eventually resulting in heart failure, valvular regurgitation, arrhythmia, or even sudden cardiac death. Occurring following treatment of lymphoma, both Hodgkin's and Non-Hodgkin's, cardiomyopathy is a feared complication in these cancer survivors due to its significant association with morbidity and mortality. A review of the literature was conducted using a combination of keywords including "Cardiomyopathy," "Anthracycline," "Radiation," "Pathogenesis," and "Management." Anthracyclines and radiation are prominent entities explored in the discussion of lymphoma-associated cardiomyopathy, whereby the formation of reactive oxygen species following treatment with both has been seen in the pathogenesis. The current standard of care thus far for anthracycline-induced cardiomyopathy includes heart failure medications such as beta-blockers, angiotensin-converting enzyme inhibitors, aldosterone receptor antagonists, and loop-diuretics. On the other hand, radiation-induced cardiomyopathy management has not been well-established yet in literature, with agents such as antioxidants and anti-inflammatory drugs still being studied in rat models. The treatment approach to cardiotoxicity in a lymphoma patient should consist of a collaboration between the oncologist and cardiologist prior to lymphoma treatment initiation, to stratify the risk of development of cardiomyopathy in the patient, and decide the best chemotherapy or radiotherapy agent, dosing, and surveillance technique.

CD36: The Bridge between Lipids and Tumors

It has been found that the development of some cancers can be attributed to obesity, which is associated with the excessive intake of lipids. Cancer cells undergo metabolic reprogramming, shifting from utilizing glucose to fatty acids (FAs) for energy. CD36, a lipid transporter, is highly expressed in certain kinds of cancer cells. High expressions of CD36 in tumor cells triggers FA uptake and lipid accumulation, promoting rapid tumor growth and initiating metastasis. Meanwhile, immune cells in the tumor microenvironment overexpress CD36 and undergo metabolic reprogramming. CD36-mediated FA uptake leads to lipid accumulation and has immunosuppressive effects. This paper reviews the types of FAs associated with cancer, high expressions of CD36 that promote cancer development and progression, effects of CD36 on different immune cells in the tumor microenvironment, and the current status of CD36 as a therapeutic target for the treatment of tumors with high CD36 expression.

Isotretinoin Exposure and Risk of Inflammatory Bowel Disease: A Systematic Review with Meta-Analysis and Trial Sequential Analysis

BACKGROUND

Cases of inflammatory bowel disease (IBD) following isotretinoin use have been reported previously, but whether isotretinoin exposure is associated with IBD has been unclear.

OBJECTIVE

The aim was to evaluate whether isotretinoin use is associated with IBD.

METHODS

We performed a systematic review and searched MEDLINE, Embase, and CENTRAL databases from inception to January 27, 2023 for relevant case-control and cohort studies. Our outcome was the pooled odds ratio (OR) for IBD and its two subtypes (Crohn disease and ulcerative colitis) in relation to isotretinoin exposure. We conducted a random-effects model meta-analysis and a sensitivity analysis by excluding low-quality studies. A subgroup analysis was undertaken by including studies considering antibiotic use. A trial sequential analysis (TSA) was performed to test the robustness of the conclusiveness of our results.

RESULTS

We included eight studies (four case-control and four cohort studies) with a total of 2,522,422 participants. The meta-analysis found no increased odds for IBD among patients receiving isotretinoin (OR 1.01; 95% confidence interval [CI] 0.80-1.27). Nor did the meta-analysis find increased odds for either Crohn disease (OR 0.87; 95% CI 0.65-1.15) or ulcerative colitis (OR 1.27; 95% CI 0.94-1.73) associated with isotretinoin exposure. The sensitivity and subgroup analyses produced similar results. In TSA, the Z-curve reached the futility boundaries when using relative risk reduction thresholds ranging from 5% to 15%.

CONCLUSION

This meta-analysis with TSA found no evidence of an association of isotretinoin use with IBD. Isotretinoin should not be withheld because of unnecessary concerns for the development of IBD.

PROSPERO REGISTRATION NO

CRD42022298886.

Dietary intake of animal-based products and likelihood of follicular lymphoma and survival: A population-based family case-control study

Background

The association between dietary intake of foods of animal origin and follicular lymphoma (FL) risk and survival is uncertain. In this study, we examined the relationship between dietary intake of dairy foods and fats, meat, fish and seafoods, and the likelihood of FL and survival.

Methods

We conducted a population-based family case-control study in Australia between 2011 and 2016 and included 710 cases, 303 siblings and 186 spouse/partner controls. We assessed dietary intake of animal products prior to diagnosis (the year before last) using a structured food frequency questionnaire and followed-up cases over a median of 6.9 years using record linkage to national death data. We examined associations with the likelihood of FL using logistic regression and used Cox regression to assess association with all-cause and FL-specific mortality among cases.

Results

We observed an increased likelihood of FL with increasing daily quantity of oily fish consumption in the year before last (highest category OR = 1.96, CI = 1.02-3.77; p-trend 0.06) among cases and sibling controls, but no associations with spouse/partner controls. We found no association between the likelihood of FL and the consumption of other types of fish or seafood, meats or dairy foods and fats. In FL cases, we found no association between meat or oily fish intake and all-cause or FL-specific mortality.

Conclusion

Our study showed suggestive evidence of a positive association between oily fish intake and the likelihood of FL, but findings varied by control type. Further investigation of the potential role of environmental contaminants in oily fish on FL etiology is warranted.

Association between Osteoprotegerin rs2073618 polymorphism and peri-implantitis susceptibility: a meta-analysis

OBJECTIVES

Peri-implantitis was an inflammatory progress on the tissue around the implant. The Osteoprotegerin G1181C (rs2073618) polymorphism was reported to be related to the increased risk of the peri-implantitis, whereas another found no relationship. The present study was conducted to research the relationship between Osteoprotegerin rs2073618 polymorphism and peri-implantitis susceptibility.

MATERIALS AND METHODS

The meta-analysis was performed according to the Preferred Reporting Items for Systematic reviews. Electronic databases including PubMed, Web of science, Springer Link and Embase (updated to April 15, 2022) were retrieved. The cohort study, case-control study or cross-sectional study focusing on the Osteoprotegerin rs2073618 polymorphism and peri-implantitis were retrieved. The data included basic information of each study and the genotype and allele frequencies of the cases and controls.

RESULTS

Three studies were finally included, including 160 cases and 271 controls. Allelic model, homozygote model, recessive model, dominant model, and heterozygous model were established to assess the relationship between OPG rs2073618 polymorphism and peri-implantitis susceptibility. The Osteoprotegerin rs2073618 polymorphism was significantly associated with peri-implantitis in Recessive model and Homozygote model.

CONCLUSION

OPG rs2073618 polymorphism in Recessive model and Homozygote model was highly likely related to the risk of peri-implantitis. PROSPERO registration number: CRD42022320812.

A prospective analysis of red blood cell membrane polyunsaturated fatty acid levels and risk of non-Hodgkin lymphoma

Published studies report inconsistent associations of polyunsaturated fatty acid (PUFA) intake with non-Hodgkin lymphoma (NHL) risk. We conducted a nested case-control study in Nurses' Health Study and Health Professionals Follow-Up Study participants to evaluate a hypothesis of inverse association of pre-diagnosis red blood cell (RBC) membrane PUFA levels with risk of NHL endpoints. We confirmed 583 NHL cases and matched 583 controls by cohort/sex, age, race and blood draw date/time. We estimated odds ratios (OR) and 95% confidence intervals (CI) for risk of NHL endpoints using logistic regression. RBC PUFA levels were not associated with all NHL risk; cis 20:2n-6 was associated with follicular lymphoma risk (OR [95% CI] per one standard deviation increase: 1.35 [1.03-1.77]), and the omega-6/omega-3 PUFA ratio was associated with diffuse large B-cell lymphoma risk (2.33 [1.23-4.43]). Overall, PUFA did not demonstrate a role in NHL etiology; the two unexpected positive associations lack clear biologic explanations.

Association between Meat, Fish, and Fatty Acid Intake and Non-Hodgkin Lymphoma Incidence: The Japan Public Health Center-Based Prospective Study

BACKGROUND

Meat, fish, and fatty acid intakes have been reported to be associated with non-Hodgkin lymphoma (NHL), although results have been inconclusive. We hypothesized that red meat and SFA intakes increase NHL risk, and fish and PUFA intakes decrease NHL risk.

OBJECTIVES

We investigated the association between NHL incidence and meat, fish, and various fatty acid type intakes using the Japan Public Health Center-based Prospective Study.

METHODS

The current cohort study included 93,366 participants aged 45-74 y who were eligible for analysis; they were followed up until December 2012. Participants answered an FFQ between 1995 and 1999. We analyzed the effects of meat, fish, total fatty acid, SFA, and PUFA intakes on NHL incidence using the Cox proportional hazard model.

RESULTS

The median age was 57 y (IQR: 51-63 y), and 46.5% of the participants were men. Participants were followed up for 1,345,001 person-years, and 230 patients with NHL were identified. Total fatty acid and SFA intakes were associated with an increased incidence of NHL, with an adjusted HR of 1.56 (95% CI: 1.04, 2.34 highest compared with lowest quartile; P-trend = 0.062), and 1.63 (95% CI: 1.11, 2.41; P-trend = 0.074), respectively. In subtype analysis, total fatty acid and SFA intakes were also associated with increased incidence of follicular lymphoma but were not significantly associated with diffuse large B-cell lymphoma. Conversely, total meat, processed meat, unprocessed meat, red meat, poultry, fish, MUFA, PUFA, n-3 (ω-3) PUFA, and n-6 (ω-6) PUFA intakes were not significantly associated with the incidence of NHL or its subtypes.

CONCLUSIONS

Total fatty acid and SFA intakes were associated with increased incidence of NHL in the Japanese adult population. Further large-scale studies are warranted to test whether fatty acid intakes affect the development of NHL.

Total, red and processed meat consumption and human health: an umbrella review of observational studies

Meat consumption has represented an important evolutionary step for humans. However, modern patterns of consumption, including excess intake, type of meat and cooking method have been the focus of attention as a potential cause of rise in non-communicable diseases. The aim of this study was to investigate the association between total, red and processed meat with health outcomes and to assess the level of evidence by performing a systematic search of meta-analyses of prospective cohort studies. Convincing evidence of the association between increased risk of (i) colorectal adenoma, lung cancer, CHD and stroke, (ii) colorectal adenoma, ovarian, prostate, renal and stomach cancers, CHD and stroke and (iii) colon and bladder cancer was found for excess intake of total, red and processed meat, respectively. Possible negative associations with other health outcomes have been reported. Excess meat consumption may be detrimental to health, with a major impact on cardiometabolic and cancer risk.

Association of rs2910164 in miR-146a with type 2 diabetes mellitus: A case-control and meta-analysis study

OBJECTIVE

Several studies have shown that miR-146a rs2910164 (C > G) is associated with type 2 diabetes mellitus (T2DM) susceptibility, but the results are still controversial. This study is divided into two parts, and one is to explore the relationship between miR-146a rs2910164 polymorphism and the genetic susceptibility of T2DM in Chinese Han population. Second, a meta-analysis on the basis of a larger sample size was used to determine whether this is a susceptibility gene for T2DM.

METHODS

A case-control study including 574 T2DM patients and 596 controls was used to evaluate the association of miR-146a rs2910164 polymorphism with the risk of T2DM in Chinese Han People. Then, we systematically searched studies investigating the correlation between miR-146a rs2910164 polymorphism and T2DM susceptibility published before April 2022 from PubMed, Web of Science, Wanfang, and China National Knowledge Infrastructure database, and a meta-analysis including six studies was carried out. The results were expressed by odds ratio (OR) and its 95% confidence interval (95% CI).

RESULTS

In a case-control study, we found that there were no statistical differences in genotype frequencies between T2DM and control group. Subgroup analysis showed that, compared with the CC genotype, CG + GG genotype was associated with a decreased risk of T2DM in the subgroup of individuals ≥ 65 years old (OR = 0.75; 95% CI: 0.58-0.98; P _adjusted = 0.032) and BMI < 18.5 (OR = 0.16; 95% CI: 0.03-0.89; P _adjusted = 0.037). In overall meta-analysis, significant heterogeneity was detected. No significant association between miR-146a rs2910164 polymorphism and T2DM was observed in all genetic models under random effects models. Subgroup analysis revealed that there was a significant difference in genotype frequencies between the T2DM and control group in recessive model (CC vs. CG + GG: OR = 1.79; 95% CI: 1.08-2.96; P_Q = 0.307, I ² = 4.0%) and homozygote model (CC vs. GG: OR = 1.79; 95% CI: 1.07-3.00; P_Q = 0.216, I ² = 34.7%) in Caucasians.

CONCLUSION

The results of our study demonstrate that the miR-146a rs2910164 polymorphism might have ethnicity-dependent effects in T2DM and may be related to T2DM susceptibility in Caucasians.

Drug Survival of Biologics in Treating Ankylosing Spondylitis: A Systematic Review and Meta-analysis of Real-World Evidence

BACKGROUND

The last decade has witnessed the increasing use of biologics for the treatment of ankylosing spondylitis (AS). Drug survival is an outcome incorporating real-world effectiveness and safety. However, the drug survival of biologics in treating AS is unclear.

OBJECTIVE

The aim was to assess the drug survival of biologics (tumor necrosis factor inhibitors and anti-interleukin-17 monoclonal antibodies) in treating AS.

METHODS

We conducted a systematic review and meta-analysis and searched the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase databases up to 13th May 2020. Studies that analyzed the drug survival of biologics for AS and reported the respective annual data for each biologic for at least 1 year were included. Two authors independently screened and selected studies and assessed their risk of bias. A third author was available for arbitrating discrepancies. The Newcastle-Ottawa Scale was employed to evaluate the risk of bias of included studies. We conducted a random-effects model meta-analysis to obtain pooled drug survival from year 1 to 5. We performed subgroup analyses for biologic-naïve patients, first-line versus second- and third-line biologics, discontinuation due to loss of effectiveness and adverse effects, and high-quality studies.

RESULTS

We included 39 studies with 32,493 patients. The drug survival decreased from 76% at year 1 to 51% at year 5 for etanercept, from 75 to 51% for adalimumab, from 76 to 53% for infliximab, from 72 to 49% for golimumab, and from 63 to 57% for certolizumab pegol. The drug survival rate for secukinumab was 0.77 (95% confidence interval 0.64‒0.90) at year 1. Subgroup analyses on biologic-naïve patients and discontinuation due to adverse effects found no differences in the drug survival of various biologics except for a lower drug survival of infliximab in biologic-naïve patients. The drug survival for first-line biologics was higher than for second- and third-line biologics.

CONCLUSION

To the best of our knowledge, this study is the first systematic review and meta-analysis on the drug survival of biological therapies for AS patients. The drug survival of all biologics in treating AS appeared comparable, but is higher in first-line biologics than second- and third-line biologics. To date there are scarce data on the drug survival of newly available biologics, for example, anti-interleukin-17 biologics.

PROSPERO REGISTRATION NO

CRD42018114204.

Red and processed meat consumption and cancer outcomes: Umbrella review

The purpose of this umbrella review was to evaluate the quality of evidence, validity and biases of the associations between red and processed meat consumption and multiple cancer outcomes according to existing systematic reviews and meta-analyses. The umbrella review identified 72 meta-analyses with 20 unique outcomes for red meat and 19 unique outcomes for processed meat. Red meat consumption was associated with increased risk of overall cancer mortality, non-Hodgkin lymphoma (NHL), bladder, breast, colorectal, endometrial, esophageal, gastric, lung and nasopharyngeal cancer. Processed meat consumption might increase the risk of overall cancer mortality, NHL, bladder, breast, colorectal, esophageal, gastric, nasopharyngeal, oral cavity and oropharynx and prostate cancer. Dose-response analyses revealed that 100 g/d increment of red meat and 50 g/d increment of processed meat consumption were associated with 11%-51% and 8%-72% higher risk of multiple cancer outcomes, respectively, and seemed to be not correlated with any benefit.

Non-coding RNAs (miRNAs and lncRNAs) and their roles in lymphogenesis in all types of lymphomas and lymphoid malignancies

Contemporary developments in molecular biology have been combined with discoveries on the analysis of the role of all non-coding RNAs (ncRNAs) in human diseases, particularly in cancer, by examining their roles in cells. Currently, included among these common types of cancer, are all the lymphomas and lymphoid malignancies, which represent a diverse group of neoplasms and malignant disorders. Initial data suggest that non-coding RNAs, particularly long ncRNAs (lncRNAs), play key roles in oncogenesis and that lncRNA-mediated biology is an important key pathway to cancer progression. Other non-coding RNAs, termed microRNAs (miRNAs or miRs), are very promising cancer molecular biomarkers. They can be detected in tissues, cell lines, biopsy material and all biological fluids, such as blood. With the number of well-characterized cancer-related lncRNAs and miRNAs increasing, the study of the roles of non-coding RNAs in cancer is bringing forth new hypotheses of the biology of cancerous cells. For the first time, to the best of our knowledge, the present review provides an up-to-date summary of the recent literature referring to all diagnosed ncRNAs that mediate the pathogenesis of all types of lymphomas and lymphoid malignancies.

Association between TNF-α G-308A (rs1800629) polymorphism and susceptibility to chronic periodontitis and type 2 diabetes mellitus: A meta-analysis

BACKGROUND AND OBJECTIVE

Although the association between tumor necrosis factor-α (TNF-α) G-308A (rs1800629) polymorphism and chronic periodontitis (CP), chronic periodontitis with type 2 diabetes mellitus (DP) is assumed, results of this association have been contradictory. The aim of this study was to assess the relationship between rs1800629 polymorphism and CP/DP susceptibility.

METHODS

We searched for studies on PubMed, Web of Science, MEDLINE, Chinese National Infrastructure, and WanFang databases. Study selection was performed using specific inclusion and exclusion criteria and fulfilled the PECO (participant, exposure, comparison, and outcome) format. The relationship between rs1800629 polymorphism and CP/DP susceptibility was evaluated by the effect summary odds ratio (OR) and 95% confidence intervals (CIs). Allele, dominant, and recessive genetic models were computed to assess the strength of the association.

RESULTS

A total of 25 case-control studies were included in the analysis. In the Asian population, TNF-α rs1800629 polymorphism was found to be significantly associated with CP in the overall analyses and for all genetic contrasts, while no significant risks were found among Caucasian populations for all genetic contrasts. The TNF-α rs1800629 polymorphism was also associated with increased DP risk in Asians under the fixed-effects model, but not in the recessive comparison.

CONCLUSION

The meta-analysis suggested that TNF-α rs1800629 polymorphism might affect the risk of CP and DP, particularly in individuals of Asian descent.

Processed meat intake and chronic disease morbidity and mortality: An overview of systematic reviews and meta-analyses

Despite the nutritional value of meat, a large volume of reviews and meta-analyses suggests that processed meat intake is associated with an increased risk of chronic diseases. However, assessments of the quality of these published reviews internal validity are generally lacking. We systematically reviewed and assessed the quality alongside summarizing the results of previously published systematic reviews and meta-analyses that examined the association between processed meat intake and cancers, type II diabetes (T2D), and cardiovascular diseases (CVD). Reviews and meta-analyses published until May 2018 were identified through a systematic literature search in the databases MEDLINE and EMBASE, and reference lists of included reviews. The quality of the systematic reviews and meta-analyses was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). All eligible reviews had to comply with two quality requirements: providing sufficient information on quality assessment of the primary studies and a comprehensive search. The results were summarized for T2D, CVD, and each of the different cancer types. The certainty in the estimates of the individual outcomes was rated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. In total, 22 systematic reviews were eligible and thus included in this review. More than 100 reviews were excluded because quality assessment of the primary studies had not been performed. The AMSTAR score of the included reviews ranged from 5 to 8 indicating moderate quality. Overall, the quality assessments of primary studies of the reviews are generally lacking; the scientific quality of the systematic reviews reporting positive associations between processed meat intake and risk of various cancers, T2D and CVD is moderate, and the results from case-control studies suggest more often a positive association than the results from cohort studies. The overall certainty in the evidence was very low across all individual outcomes, due to serious risk of bias and imprecision.

Meat, fish, dairy products and risk of hematological malignancies in adults - a systematic review and meta-analysis of prospective studies

This systematic review and meta-analysis of cohort studies examine the association of meat, fish, and dairy product consumption with the risk of hematological neoplasms in adults. Thirteen studies encompassing 1,480,986 participants and 10,442 incident cases were included. Red or processed meat consumption was not associated with the risk of leukemia, acute myeloid leukemia, non-Hodgkin lymphoma (NHL) and small lymphocytic lymphoma/chronic lymphocytic leukemia (CLL/SLL). Poultry consumption did not seem to affect the risk of leukemia, NHL, CLL/SLL, and multiple myeloma (MM). Fish consumption was not associated with leukemia, NHL, CLL/SLL, and MM risk. Interestingly though, fish consumption was positively associated with myeloid leukemia risk (pooled RR = 1.74, 95% CI: 1.22-2.47, random effects, highest vs. lowest category). Milk and dairy product consumption was not associated with NHL and leukemia risk. In conclusion, methodologically strict prospective studies are mandatory, in order to extract reliable conclusions concerning the role of these dietary factors in hematological malignancies.

Complementary and Integrative Medicine in Hematologic Malignancies: Questions and Challenges

Hematologic malignancies represent 9.7% of all cancers, making them the fourth most common type of cancer in the United States. The aggressive and complex treatments administered in hematologic malignancies result in a high burden of psychological needs. Complementary and integrative medicine (CIM) is becoming one of the options that patients use to address their distress during and after cancer treatments. It is not clear whether appropriate CIM can relieve distress in patients affected by these malignancies. This review covers the potential benefits of CIM as relates to nutrition, nutritional supplements, exercise, circadian rhythm, methods for reducing distress during bone marrow aspiration, massage therapy, and acupuncture, in treating patients with hematological malignancies. This review may provide a framework to enhance patient-doctor dialogue regarding CIM use in hematologic malignancies.

Human T lymphocytes bioactivate heterocyclic aromatic amines by forming DNA adducts

Heterocyclic aromatic amines (HAA) are formed in cooked meat, poultry and fish but also arise in tobacco smoke and exhaust gases. HAA are potential human carcinogens, which require metabolic activation to exert their genotoxicity. Human tissues can bioactivate HAA to produce reactive intermediates that bind to DNA. HAA DNA adduct formation occurs in human hepatocytes; however, the potential of HAA to form DNA adducts has not been investigated in human T lymphocytes. In this study, we investigated the ability of human T lymphocytes activated with PMA/Ionomycin or CD3/CD28 to express functional CYP1 activity and bioactivate three major HAA: 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), and 2-amino-9H-pyrido[2,3-b]indole (AαC) to form DNA adducts. Adducts were measured by ultraperformance liquid chromatography-electrospray ionization/multistage scan mass spectrometry. The highest level of DNA adducts occurred for AαC (16 adducts per 10⁹ nucleotides), followed by PhIP (9 adducts per 10⁹ nucleotides). In contrast, DNA adducts formed from MeIQx and the structurally related aromatic amine 4-aminobiphenyl, a known human carcinogen, were below the limit of detection (< 3 adducts per 10⁹ nucleotides). Moreover, we demonstrate that AαC is a potent inducer of CYP1A1 and CYP1B1 activity through a transcriptional mechanism involving the AhR pathway. Overall, our results highlight the capacity of activated human T lymphocytes to more efficiently bioactivate AαC to form DNA adducts than other prominent HAA or 4-ABP. Environ. Mol. Mutagen. 57:656-667, 2016. © 2016 Wiley Periodicals, Inc.

Association of Cancer Incidence and Duration of Residence in Geothermal Heating Area in Iceland: An Extended Follow-Up

BACKGROUND

Residents of geothermal areas have higher incidence of non-Hodgkin's lymphoma, breast cancer, prostate cancer, and kidney cancers than others. These populations are exposed to chronic low-level ground gas emissions and various pollutants from geothermal water. The aim was to assess whether habitation in geothermal areas and utilisation of geothermal water is associated with risk of cancer according to duration of residence.

METHODS

The cohort obtained from the census 1981 was followed to the end of 2013. Personal identifier was used in record linkage with nation-wide emigration, death, and cancer registries. The exposed population, defined by community codes, was located on young bedrock and had utilised geothermal water supply systems since 1972. Two reference populations were located by community codes on older bedrock or had not utilised geothermal water supply systems for as long a period as had the exposed population. Adjusted hazard ratio (HR), 95% confidence intervals (CI) non-stratified and stratified on cumulative years of residence were estimated in Cox-model.

RESULTS

The HR for all cancer was 1.21 (95% CI 1.12-1.30) as compared with the first reference area. The HR for pancreatic cancer was 1.93 (1.22-3.06), breast cancer, 1.48 (1.23-1.80), prostate cancer 1.47 (1.22-1.77), kidney cancer 1.46 (1.03-2.05), lymphoid and haematopoietic tissue 1.54 (1.21-1.97), non-Hodgkin´s lymphoma 2.08 (1.38-3.15) and basal cell carcinoma of the skin 1.62 (1.35-1.94). Positive dose-response relationship was observed between incidence of cancers and duration of residence, and between incidence of cancer and degree of geothermal/volcanic activity in the comparison areas.

CONCLUSIONS

The higher cancer incidence in geothermal areas than in reference areas is consistent with previous findings. As the dose-response relationships were positive between incidence of cancers and duration of residence, it is now more urgent than before to investigate the chemical and physical content of the geothermal water and of the ambient air of the areas to detect recognized or new carcinogens.