Bortezomib, lenalidomide, and dexamethasone with or without elotuzumab in patients with untreated, high-risk multiple myeloma (SWOG-1211): primary analysis of a randomised, phase 2 trial.

BACKGROUND: The introduction of immunomodulatory agents, proteasome inhibitors, and autologous haematopoietic stem-cell transplantation has improved outcomes for patients with multiple myeloma, but patients with high-risk multiple myeloma have a poor long-term prognosis. We aimed to address optimal treatment for these patients. METHODS: SWOG-1211 is a randomised phase 2 trial comparing eight cycles of lenalidomide (25 mg orally on days 1-14 every 21 days), bortezomib (1·3 mg/m2 subcutaneously on days 1, 4, 8, and 11 every 21 days), and dexamethasone (20 mg orally on days 1, 2, 4, 5, 8, 9, 11, and 12 every 21 days; RVd) induction followed by dose-attenuated RVd maintenance (bortezomib 1 mg/m2 subcutaneously on days 1, 8, and 15; lenalidomide 15 mg orally on days 1-21; dexamethasone 12 mg orally on days 1, 18, and 15 every 28 days) until disease progression with or without elotuzumab (10 mg/kg intravenously on days 1, 8, and 15 for cycles 1-2, on days 1 and 11 for cycles 3-8, and on days 1 and 15 during maintenance). Patients were randomly assigned (1:1) to either RVd or RVd-elotuzumab. High-risk multiple myeloma was defined by one of the following: gene expression profiling high risk (GEPhi), t(14;16), t(14;20), del(17p) or amp1q21, primary plasma cell leukaemia and elevated serum lactate dehydrogenase (two times the upper limit of normal or more). The primary endpoint was progression-free survival, and all analyses were done on intention-to-treat basis among eligible patients who were evaluable for response. This study is registered with ClinicalTrials.gov, NCT01668719. FINDINGS: 100 (RVd n=52, RVd-elotuzumab n=48) patients were enrolled between Oct 27, 2013, and May 15, 2016, across 26 cooperative group institutions in the USA. Median age was 64 years (IQR 57-70, range 36-85). 74 (75%) of 99 had International Staging System stage II or stage III disease, 47 (47%) of 99 had amp1q21, 37 (37%) of 100 had del17p, 11 (11%) of 100 had t(14;16), eight (9%) of 90 were GEPhi, seven (7%) of 100 had primary plasma cell leukaemia, five (5%) of 100 had t(14;20), four (4%) of 100 had elevated serum lactate dehydrogenase, and 17 (17%) had two or more features. With a median follow-up of 53 months (IQR 46-59), no difference in median progression-free survival was observed (RVd 33·64 months [95% CI 19·55-not reached], RVd-elotuzumab 31·47 months [18·56-53·98]; hazard ratio 0·968 [80% CI 0·697-1·344]; one-sided p=0·45]. 37 (71%) of 52 patients in the RVd group and 37 (77%) of 48 in the RVd-elotuzumab group had grade 3 or worse adverse events. No significant differences in the safety profile were observed, although some notable results included grade 3-5 infections (four [8%] of 52 in the RVd group, eight [17%] of 48 in the RVd-elotuzumab group), sensory neuropathy (four [8%] of 52 in the RVd group, six [13%] of 48 in the RVd-elotuzumab group), and motor neuropathy (one [2%] of 52 in the RVd group, four [8%] of 48 in the RVd-elotuzumab group). There were no treatment-related deaths in the RVd group and one death in the RVd-elotuzumab group for which study treatment was listed as possibly contributing by the investigator. INTERPRETATION: In the first randomised study of high-risk multiple myeloma reported to date, the addition of elotuzumab to RVd induction and maintenance did not improve patient outcomes. However, progression-free survival in both study groups exceeded the original statistical assumptions and supports the role for continuous proteasome inhibitors and immunomodulatory drug combination maintenance therapy for this patient population. FUNDING: National Institutes of Health, National Cancer Institute, Bristol Myers Squibb, Celgene, Leukemia and Lymphoma Society.

Race-Dependent Differences in Risk, Genomics, and Epstein-Barr Virus Exposure in Monoclonal Gammopathies: Results of SWOG S0120.

PURPOSE: Risk of multiple myeloma is increased in African American (AA) populations compared with European American (EA) cohorts. Current estimates of risk of progression of monoclonal gammopathy of undetermined significance (MGUS) are based largely on studies in EA cohorts. Prospective analyses of this risk in AA cohorts are lacking. PATIENTS AND METHODS: Between 2003 and 2011, 331 eligible patients with IgG/A monoclonal gammopathy were enrolled in a prospective observational trial (SWOG S0120). RESULTS: Of 331 eligible patients, 57 (17%) were of AA descent. The risk of transformation to clinical malignancy in AA patients was significantly lower than in non-AA cohort (2-year risk 5% vs. 15%; 5-year risk 13% vs. 24%; log-rank P = 0.047). Differences in risk were evident for both MGUS and asymptomatic multiple myeloma. Gene expression profile (GEP) of CD138-purified plasma cells revealed that all molecular multiple myeloma subsets can be identified in both cohorts. However, the proportion of patients with high-risk GEP risk score (GEP-70 gene risk > -0.26) was lower in the AA cohort (0% vs. 33%, P = 0.01). AA cohorts also have higher levels of antibodies against Epstein-Barr nuclear antigen-1 (EBNA-1; P < 0.001). CONCLUSIONS: These data provide the first prospective evidence that multiple myeloma precursor states in AA patients may have lower risk of disease compared with non-AA counterparts with lower incidence of high-risk GEP and increased EBV seropositivity. Race-dependent differences in biology and clinical risk of gammopathy may impact optimal management of these patients.

Longer term follow-up of the randomized phase III trial SWOG S0777: bortezomib, lenalidomide and dexamethasone vs. lenalidomide and dexamethasone in patients (Pts) with previously untreated multiple myeloma without an intent for immediate autologous stem cell transplant (ASCT).

SWOG S0777, a randomized phase III trial, compared bortezomib, lenalidomide and dexamethasone (VRd) with lenalidomide and dexamethasone (Rd). This updated analysis includes 460 patients evaluable for survival endpoints: 225 eligible and analyzable patients were randomized to Rd and 235 to VRd. The 6-month induction was six 28-day cycles of Rd and eight 21-day cycles of VRd followed by Rd maintenance for all patients. Median follow up is 84 months. Median PFS is 41 months for VRd and 29 months for Rd: stratified hazard ratio (96% Wald Confidence Interval) was 0.742 (0.594, 0.928) and one-sided stratified log-rank P-value 0.003. Median OS for VRd is still not reached with median OS for Rd being 69 months: stratified hazard ratio (96% Wald Confidence Interval) was 0.709 (0.543, 0.926) and stratified two-sided P-value was 0.0114. Both PFS and OS were improved with VRd versus Rd adjusting for age (P-values: 0.013 [PFS]; 0.033 [OS])). Median duration of Rd maintenance was 17.1 months. The addition of bortezomib to lenalidomide dexamethasone for induction therapy results in a statistically significant and clinically meaningful improvement in PFS as well as better OS. VRd continues to represent an appropriate standard of care irrespective of age.

Low-dose versus High-dose Carfilzomib with Dexamethasone (S1304) in Patients with Relapsed-Refractory Multiple Myeloma.

PURPOSE: Treatment of multiple myeloma has evolved tremendously and optimal utilization of available therapies will ensure maximal patient benefits. PATIENTS AND METHODS: We report the Southwest Oncology Group randomized phase II trial (S1304) comparing twice weekly low-dose (27 mg/m2; arm 1) to high-dose carfilzomib (56 mg/m2; arm 2), both with dexamethasone, administered for 12 cycles (11 months) for relapsed and/or refractory multiple myeloma with up to six prior lines of therapy (NCT01903811). The primary endpoint was progression-free survival (PFS), and patients on arm 1 could cross-over to arm 2 after progression on treatment. RESULTS: Among 143 enrolled patients, of whom 121 were eligible and analyzable, the overall response rate was 42.8%, with no significant difference between the arms (P = 0.113). Also, neither the median PFS [5 months and 8 months, respectively; HR, 1.061; 80% Wald confidence interval (CI), 0.821-1.370; P = 0.384] nor the median overall survival were significantly different (26 and 22 months, respectively; HR, 1.149, 80% Wald CI, 0.841-.571; P = 0.284). Sixteen patients crossed over to arm 2 with a median PFS benefit of 3 months. Certain adverse events (AE) were more frequent in arm 2, including fatigue, thrombocytopenia, and peripheral neuropathy, but there was no significant difference in cardiopulmonary AEs. CONCLUSIONS: This randomized trial did not support a benefit of fixed duration, twice weekly 56 mg/m2 dosing of carfilzomib over the 27 mg/m2 dose for the treatment of relapsed and/or refractory multiple myeloma. However, treatment to progression in earlier patient populations with high-dose carfilzomib using different schedules should still be considered as part of the standard of care.

Disease and outcome disparities in multiple myeloma: exploring the role of race/ethnicity in the Cooperative Group clinical trials.

Multiple myeloma (MM) is an incurable hematologic malignancy with disparities in outcomes noted among racial-ethnic subgroups, likely due to disparities in access to effective treatment modalities. Clinical trials can provide access to evidence-based medicine but representation of minorities on therapeutic clinical trials has been dismal. We evaluated the impact of patient race-ethnicity in pooled data from nine large national cooperative group clinical trials in newly diagnosed MM. Among 2896 patients enrolled over more than two decades, only 18% were non-White and enrollment of minorities actually decreased in most recent years (2002-2011). African-Americans were younger and had more frequent poor-risk markers, including anemia and increased lactate dehydrogenase. Hispanics had the smallest proportion of patients on trials utilizing novel therapeutic agents. While adverse demographic (increased age) and clinical (performance status, stage, anemia, kidney dysfunction) factors were associated with inferior survival, patient race-ethnicity did not have an effect on objective response rates, progression-free, or overall survival. While there are significant disparities in MM incidence and outcomes among patients of different racial-ethnic groups, this disparity seems to be mitigated by access to appropriate therapeutic options, for example, as offered by clinical trials. Improved minority accrual in therapeutic clinical trials needs to be a priority.

Antigen-mediated regulation in monoclonal gammopathies and myeloma.

A role for antigen-driven stimulation has been proposed in the pathogenesis of monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) based largely on the binding properties of monoclonal Ig. However, insights into antigen binding to clonal B cell receptors and in vivo responsiveness of the malignant clone to antigen-mediated stimulation are needed to understand the role of antigenic stimulation in tumor growth. Lysolipid-reactive clonal Ig were detected in Gaucher disease (GD) and some sporadic gammopathies. Here, we show that recombinant Ig (rIg) cloned from sort-purified single tumor cells from lipid-reactive sporadic and GD-associated gammopathy specifically bound lysolipids. Liposome sedimentation and binding assays confirmed specific interaction of lipid-reactive monoclonal Ig with lysolipids. The clonal nature of lysolipid-binding Ig was validated by protein sequencing. Gene expression profiling and cytogenetic analyses from 2 patient cohorts showed enrichment of nonhyperdiploid tumors in lipid-reactive patients. In vivo antigen-mediated stimulation led to an increase in clonal Ig and plasma cells (PCs) in GD gammopathy and also reactivated previously suppressed antigenically related nonclonal PCs. These data support a model wherein antigenic stimulation mediates an initial polyclonal phase, followed by evolution of monoclonal tumors enriched in nonhyperdiploid genomes, responsive to underlying antigen. Targeting underlying antigens may therefore prevent clinical MM.

Riluzole synergizes with paclitaxel to inhibit cell growth and induce apoptosis in triple-negative breast cancer.

PURPOSE: One in eight women will develop breast cancer, 15-20% of whom will have triple-negative breast cancer (TNBC), an aggressive breast cancer with no current targeted therapy. We have demonstrated that riluzole, an FDA-approved drug for treating amyotrophic lateral sclerosis, inhibits growth of TNBC. In this study, we explore potential synergism between riluzole and paclitaxel, a chemotherapeutic agent commonly used to treat TNBC, in regulating TNBC proliferation, cell cycle arrest, and apoptosis. METHODS: TNBC cells were treated with paclitaxel and/or riluzole and synergistic effects on cell proliferation were quantified via MTT assay and CompuSyn analysis. Apoptosis was observed morphologically and by measuring cleaved PARP/caspase three products. Microarray analysis was performed using MDA-MB-231 cells to examine cell cycle genes regulated by riluzole and any enhanced effects on paclitaxel-mediated cell cycle arrest, determined by FACS analysis. These results were confirmed in vivo using a MDA-MB-231 xenograft model. RESULTS: Strong enhanced or synergistic effects of riluzole on paclitaxel regulation of cell cycle progression and apoptosis was demonstrated in all TNBC cells tested as well as in the xenograft model. The MDA-MB-231, SUM149, and SUM229 cells, which are resistant to paclitaxel treatment, demonstrated the strongest synergistic or enhanced effect. Key protein kinases were shown to be upregulated in this study by riluzole as well as downstream cell cycle genes regulated by these kinases. CONCLUSIONS: All TNBC cells tested responded synergistically to riluzole and paclitaxel strongly suggesting the usefulness of this combinatorial treatment strategy in TNBC, especially for patients whose tumors are relatively resistant to paclitaxel.

Antibiotic resistance among Helicobacter pylori clinical isolates in Lima, Peru.

OBJECTIVES: Gastric carcinoma is the most common cancer and cause of cancer mortality in Peru. Helicobacter pylori, a bacterium that colonizes the human stomach, is a Group 1 carcinogen due to its causal relationship to gastric carcinoma. While eradication of H. pylori can help prevent gastric cancer, characterizing regional antibiotic resistance patterns is necessary to determine targeted treatment for each region. Thus, we examined primary antibiotic resistance in clinical isolates of H. pylori in Lima, Peru. MATERIALS AND METHODS: H. pylori strains were isolated from gastric biopsies of patients with histologically proven H. pylori infection. Primary antibiotic resistance among isolates was examined using E-test strips. Isolates were examined for the presence of the cagA pathogenicity island and the vacA m1/m2 alleles via polymerase chain reaction. RESULTS: Seventy-six isolates were recovered from gastric biopsies. Clinical isolates showed evidence of antibiotic resistance to 1 (27.6%, n=21/76), 2 (28.9%, n=22/76), or ≥3 antibiotics (40.8%). Of 76 isolates, eight (10.5%) were resistant to amoxicillin and clarithromycin, which are part of the standard triple therapy for H. pylori infection. No trends were seen between the presence of cagA, vacA m1, or vacA m2 and antibiotic resistance. CONCLUSION: The rate of antibiotic resistance among H. pylori isolates in Lima, Peru, is higher than expected and presents cause for concern. To develop more targeted eradication therapies for H. pylori in Peru, more research is needed to better characterize antibiotic resistance among a larger number of clinical isolates prospectively.

Bortezomib with lenalidomide and dexamethasone versus lenalidomide and dexamethasone alone in patients with newly diagnosed myeloma without intent for immediate autologous stem-cell transplant (SWOG S0777): a randomised, open-label, phase 3 trial.

BACKGROUND: Lenalidomide plus dexamethasone is a reference treatment for patients with newly diagnosed myeloma. The combination of the proteasome inhibitor bortezomib with lenalidomide and dexamethasone has shown significant efficacy in the setting of newly diagnosed myeloma. We aimed to study whether the addition of bortezomib to lenalidomide and dexamethasone would improve progression-free survival and provide better response rates in patients with previously untreated multiple myeloma who were not planned for immediate autologous stem-cell transplant. METHODS: In this randomised, open-label, phase 3 trial, we recruited patients with newly diagnosed multiple myeloma aged 18 years and older from participating Southwest Oncology Group (SWOG) and National Clinical Trial Network (NCTN) institutions (both inpatient and outpatient settings). Key inclusion criteria were presence of CRAB (C=calcium elevation; R=renal impairment; A=anaemia; B=bone involvement) criteria with measurable disease (measured by assessment of free light chains), Eastern Cooperative Oncology Group (ECOG) performance status of 0-3, haemoglobin concentration 9 g/dL or higher, absolute neutrophil count 1 × 103 cells per mm3 or higher, and a platelet count of 80 000/mm3 or higher. We randomly assigned (1:1) patients to receive either an initial treatment of bortezomib with lenalidomide and dexamethasone (VRd group) or lenalidomide and dexamethasone alone (Rd group). Randomisation was stratified based on International Staging System stage (I, II, or III) and intent to transplant (yes vs no). The VRd regimen was given as eight 21-day cycles. Bortezomib was given at 1·3 mg/m2 intravenously on days 1, 4, 8, and 11, combined with oral lenalidomide 25 mg daily on days 1-14 plus oral dexamethasone 20 mg daily on days 1, 2, 4, 5, 8, 9, 11, and 12. The Rd regimen was given as six 28-day cycles. The standard Rd regimen consisted of 25 mg oral lenalidomide once a day for days 1-21 plus 40 mg oral dexamethasone once a day on days 1, 8, 15, and 22. The primary endpoint was progression-free survival using a prespecified one-sided stratified log rank test at a significance level of 0·02. Analyses were intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00644228. FINDINGS: Between April, 2008, and February, 2012, we randomly assigned 525 patients at 139 participating institutions (264 to VRd and 261 to Rd). In the randomly assigned patients, 21 patients in the VRd group and 31 in the Rd group were deemed ineligible based mainly on missing, insufficient, or early or late baseline laboratory data. Median progression-free survival was significantly improved in the VRd group (43 months vs 30 months in the Rd group; stratified hazard ratio [HR] 0·712, 96% CI 0·56-0·906; one-sided p value 0·0018). The median overall survival was also significantly improved in the VRd group (75 months vs 64 months in the Rd group, HR 0·709, 95% CI 0·524-0·959; two-sided p value 0·025). The rates of overall response (partial response or better) were 82% (176/216) in the VRd group and 72% (153/214) in the Rd group, and 16% (34/216) and 8% (18/214) of patients who were assessable for response in these respective groups had a complete response or better. Adverse events of grade 3 or higher were reported in 198 (82%) of 241 patients in the VRd group and 169 (75%) of 226 patients in the Rd group; 55 (23%) and 22 (10%) patients discontinued induction treatment because of adverse events, respectively. There were no treatment-related deaths in the Rd group, and two in the VRd group. INTERPRETATION: In patients with newly diagnosed myeloma, the addition of bortezomib to lenalidomide and dexamethasone resulted in significantly improved progression-free and overall survival and had an acceptable risk-benefit profile. FUNDING: NIH, NCI, NCTN, Millennium Pharmaceuticals, Takeda Oncology Company, and Celgene Corporation.

Prospective analysis of antigen-specific immunity, stem-cell antigens, and immune checkpoints in monoclonal gammopathy.

Blockade of immune checkpoints (ICPs) has led to impressive responses in cancer patients. However, the impact of preexisting immunity and ICPs on the risk of malignant transformation in human preneoplasia has not been prospectively studied. We prospectively analyzed antigen-specific B/T-cell immunity, immune composition of the tumor microenvironment, and the expression of a panel of ICPs on tumor and tumor-infiltrating immune cells in 305 patients with asymptomatic monoclonal gammopathy enrolled in S0120 under the auspices of SWOG. T-cell immunity against stem-cell antigen SOX2 and preserved humoral responses at study entry independently correlated with reduced risk of progression to clinical myeloma. Among the ICPs analyzed, expression of programmed death-ligand 1 (PD-L1) on tumor and infiltrating T cells correlated with increased risk of clinical malignancy, and blockade of this pathway boosted anti-SOX2 immunity in culture. These data suggest that stem-cell antigens and PD-L1 may be targeted for immunoprevention of myeloma. This trial was registered at www.clinicaltrials.gov as #NCT00900263.

Clinical, genomic, and imaging predictors of myeloma progression from asymptomatic monoclonal gammopathies (SWOG S0120).

All cases of clinical myeloma (CMM) are preceded by an asymptomatic monoclonal gammopathy (AMG), classified as either monoclonal gammopathy of undetermined significance (MGUS) or asymptomatic multiple myeloma (AMM). We analyzed data from AMG patients (n = 331) enrolled in a prospective, observational clinical trial (S0120). Baseline data from clinical variables, gene expression profiles (GEP) of purified tumor cells, and findings of magnetic resonance imaging (MRI) were correlated with the risk of progression to CMM requiring therapy. GEP of purified tumor cells revealed that all molecular subtypes of CMM are also represented in the AMG phase. An increased risk score (>-0.26) (based on a 70-gene signature, GEP70) was an independent predictor of the risk of progression to CMM. Combination of elevated serum free light chain, M-spike, and GEP70 risk score identified a subset with high risk (67% at 2 years) of progression to CMM requiring therapy. Importantly, absence of these factors in AMM patients predicted low risk similar to MGUS. Detection of multiple (>1) focal lesions by MRI also conferred an increased risk of progression. These data demonstrate that signatures associated with high-risk CMM impact disease risk and support inclusion of genomic analysis in the clinical management of AMGs.

Risk factors for MDS and acute leukemia following total therapy 2 and 3 for multiple myeloma.

Lenalidomide has been linked to myelodysplastic syndrome (MDS) after autotransplants for myeloma. Total therapy trials (TT; TT2(-/+) thalidomide) and TT3 (TT3a with bortezomib, thalidomide; TT3b with additional lenalidomide) offered the opportunity to examine the contribution of these immune-modulatory agents to MDS-associated cytogenetic abnormalities (MDS-CA) and clinical MDS or acute leukemia ("clinical MDS/AL"). Of 1080 patients with serial cytogenetic studies, MDS-CA occurred in 11% and clinical MDS/AL in 3%. Risk features of MDS-CA included TT3b, age ≥65 years, male gender, levels of ß-2-microglobulin >5.5 mg/L, and multiple myeloma relapse. Clinical MDS/AL occurred less frequently in the control arm of TT2 and more often with TT3a and TT3b. Since MDS-CA often antedated clinical disease, periodic cytogenetic monitoring is recommended. Larger CD34 quantities should be collected upfront as the risk of MDS could be reduced by applying higher CD34 doses with transplant. Thus, treatment, host, and myeloma features could be linked to MDS development after therapy for this malignancy. This trial was registered at www.clinicaltrials.gov: TT3A: NCT00081939, TT3B: NCT00572169.

Risk of recurrent Helicobacter pylori infection 1 year after initial eradication therapy in 7 Latin American communities.

IMPORTANCE: The long-term effectiveness of Helicobacter pylori eradication programs for preventing gastric cancer will depend on recurrence risk and individual and community factors. OBJECTIVE: To estimate risk of H. pylori recurrence and assess factors associated with successful eradication 1 year after treatment. DESIGN, SETTING, AND PARTICIPANTS: Cohort analysis of 1463 randomized trial participants aged 21 to 65 years from 7 Latin American communities, who were treated for H. pylori and observed between September 2009 and July 2011. INTERVENTIONS: Randomization to 1 of 3 treatment groups: 14-day lansoprazole, amoxicillin, and clarithromycin (triple therapy); 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential); or 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant). Participants with a positive (13)C-urea breath test (UBT) 6 to 8 weeks posttreatment were offered voluntary re-treatment with 14-day bismuth-based quadruple therapy. MEASUREMENTS: Recurrent infection after a negative posttreatment UBT and factors associated with successful eradication at 1-year follow-up. RESULTS: Among participants with UBT-negative results who had a 1-year follow-up UBT (n=1091), 125 tested UBT positive, a recurrence risk of 11.5% (95% CI, 9.6%-13.5%). Recurrence was significantly associated with study site (P = .03), nonadherence to initial therapy (adjusted odds ratio [AOR], 2.94; 95% CI, 1.31-6.13; P = .01), and children in the household (AOR, 1.17; 95% CI, 1.01-1.35 per child; P = .03). Of the 281 with positive posttreatment UBT results, 138 completed re-treatment, of whom 93 tested UBT negative at 1 year. Among the 1340 who had a 1-year UBT, 80.4% (95% CI, 76.4%-83.9%), 79.8% (95% CI, 75.8%-83.5%), and 77.8% (95% CI, 73.6%-81.6%) had UBT-negative results in the triple, sequential, and concomitant groups, respectively (P = .61), with 79.3% overall effectiveness (95% CI, 77.1%-81.5%). In a single-treatment course analysis that ignored the effects of re-treatment, the percentage of UBT-negative results at 1 year was 72.4% (95% CI, 69.9%-74.8%) and was significantly associated with study site (P < .001), adherence to initial therapy (AOR, 0.26; 95% CI, 0.15-0.42; P < .001), male sex (AOR, 1.63; 95% CI, 1.25-2.13; P < .001), and age (AOR, 1.14; 95% CI, 1.02-1.27 per decade; P = .02). One-year effectiveness among all 1463 enrolled participants, considering all missing UBT results as positive, was 72.7% (95% CI, 70.3%-74.9%). CONCLUSIONS AND RELEVANCE: One year after treatment for H. pylori infection, recurrence occurred in 11.5% of participants who had negative posttreatment UBT results. Recurrence determinants (ie, nonadherence and demographics) may be as important as specific antibiotic regimen in determining the long-term success of H. pylori eradication interventions. Study findings are relevant to the feasibility of programs for the primary prevention of gastric cancer in high-incidence regions of Latin America. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01061437.

Epidemiology of Helicobacter pylori infection in six Latin American countries (SWOG Trial S0701).

OBJECTIVE: To investigate the potential determinants of Helicobacter pylori infection between adults 21-65 years old. METHODS: Data are from the initial screening visit of a randomized clinical trial of three antibiotic regimens to eradicate H. pylori, conducted in seven sites (Santiago-Chile, Túquerres-Colombia, Guanacaste-Costa Rica, Copán-Honduras, Obregón and Tapachula-México, León-Nicaragua). Thousand eight hundred and fifty-nine adults from the general population were screened for H. pylori infection using an urea breath test (UBT) and were interviewed to assess socioeconomic-, demographic-, and symptom-related characteristics. Logistic regression was used to assess the relationship between these characteristics and H. pylori positivity at enrollment. RESULTS: Among the 1,852 eligible participants for whom a conclusive UBT result was obtained, H. pylori prevalence was 79.4 %, ranging from 70.1 to 84.7 % among the seven centers. Prevalence did not differ by sex (female: 78.4, male: 80.9; p = 0.20) or age (p = 0.08). H. pylori positivity increased with increasing number of siblings (p trend <0.0001). Participants with education beyond 12 years were less likely to be UBT-positive (OR 0.4: 0.3-0.6, compared to participants with 0-6 years of schooling) as were those employed outside the home (OR 0.7: 0.6-1.0). Odds of H. pylori infection increased with the presence of certain living conditions during childhood including having lived in a household with an earth floor (OR 1.8: 1.4-2.4), lack of indoor plumbing (OR 1.3: 1.0-1.8) and crowding (OR 1.4: 1.0-1.8, for having more than two persons per bedroom). Regarding current household conditions, living with more than 3 children in the household (OR 1.7: 1.2-2.5) and crowding (OR 1.8: 1.3-2.3) were associated with H. pylori infection. CONCLUSIONS: The prevalence of H. pylori in adults was high and differed significantly among the six Latin American countries studied (p < 0.001). Our findings confirm the strong link between poor socioeconomic conditions and H. pylori infection.