Ronac Mamtani

Pioglitazone Use and Risk of Bladder Cancer and Other Common Cancers in Persons With Diabetes

IMPORTANCE Studies suggest pioglitazone use may increase risk of cancers. OBJECTIVE To examine whether pioglitazone use for diabetes is associated with risk of bladder and 10 additional cancers. DESIGN, SETTING, AND PARTICIPANTS Cohort and nested case-control analyses among persons with diabetes. A bladder cancer cohort followed 193,099 persons aged 40 years or older in 1997-2002 until December 2012; 464 case patients and 464 matched controls were surveyed about additional confounders. A cohort analysis of 10 additional cancers included 236,507 persons aged 40 years or older in 1997-2005 and followed until June 2012. Cohorts were from Kaiser Permanente Northern California. EXPOSURES Ever use, duration, cumulative dose, and time since initiation of pioglitazone as time dependent. MAIN OUTCOMES AND MEASURES Incident cancer, including bladder, prostate, female breast, lung/bronchus, endometrial, colon, non-Hodgkin lymphoma, pancreas, kidney/renal pelvis, rectum, and melanoma. RESULTS Among 193,099 persons in the bladder cancer cohort, 34,181 (18%) received pioglitazone (median duration, 2.8 years; range, 0.2-13.2 years) and 1261 had incident bladder cancer. Crude incidences of bladder cancer in pioglitazone users and nonusers were 89.8 and 75.9 per 100,000 person-years, respectively. Ever use of pioglitazone was not associated with bladder cancer risk (adjusted hazard ratio [HR], 1.06; 95% CI, 0.89-1.26). Results were similar in case-control analyses (pioglitazone use: 19.6% among case patients and 17.5% among controls; adjusted odds ratio, 1.18; 95% CI, 0.78-1.80). In adjusted analyses, there was no association with 8 of the 10 additional cancers; ever use of pioglitazone was associated with increased risk of prostate cancer (HR, 1.13; 95% CI, 1.02-1.26) and pancreatic cancer (HR, 1.41; 95% CI, 1.16-1.71). Crude incidences of prostate and pancreatic cancer in pioglitazone users vs nonusers were 453.3 vs 449.3 and 81.1 vs 48.4 per 100,000 person-years, respectively. No clear patterns of risk for any cancer were observed for time since initiation, duration, or dose. CONCLUSIONS AND RELEVANCE Pioglitazone use was not associated with a statistically significant increased risk of bladder cancer, although an increased risk, as previously observed, could not be excluded. The increased prostate and pancreatic cancer risks associated with ever use of pioglitazone merit further investigation to assess whether they are causal or are due to chance, residual confounding, or reverse causality.

The effect of past antibiotic exposure on diabetes risk

OBJECTIVE Gut microbiota influence metabolic pathways related to the pathogenesis of obesity, insulin-resistance and diabetes. Antibiotic therapy can alter the microbiota, and is commonly used in western countries. We sought to evaluate whether past antibiotic exposure increases diabetes risk. RESEARCH DESIGN AND METHODS We conducted a nested case-control study using a large population-based database from the UK. The cases were defined as those with incident diagnosis of diabetes. For every case, four eligible controls matched on age, sex, practice-site, and duration of follow-up before index-date were selected using incidence-density sampling. Exposure of interest was antibiotic therapy >1 year before index-date. Odds ratios (ORs) and 95% CIs were estimated using conditional logistic regression. The risk was adjusted for BMI, smoking, last glucose level, and number of infections before index-date, as well as past medical history of coronary artery disease and hyperlipidaemia. RESULTS The study included 208 002 diabetic cases and 815 576 matched controls. Exposure to a single antibiotic prescription was not associated with higher adjusted diabetes risk. Treatment with two to five antibiotic courses was associated with increase in diabetic risk for penicillin, cephalosporins, macrolides and quinolones with adjusted OR ranging from 1.08 (95% CI 1.05-1.11) for penicillin to 1.15 (95% CI 1.08-1.23) for quinolones. The risk increased with the number of antibiotic courses and reached 1.37 (95% CI 1.19-1.58) for more than 5 courses of quinolones. There was no association between exposure to anti-virals and anti-fungals and diabetes risk. CONCLUSIONS Exposure to certain antibiotic groups increases diabetes risk.

Antibiotic Exposure and the Risk for Depression, Anxiety, or Psychosis: A Nested Case-Control Study

OBJECTIVE Changes in the microbiota (dysbiosis) were suggested to increase the risk of several psychiatric conditions through neurologic, metabolic, and immunologic pathways. Our aim was to assess whether exposure to specific antibiotic groups increases the risk for depression, anxiety, or psychosis. METHOD We conducted 3 nested case-control studies during the years 1995-2013 using a large population-based medical record database from the United Kingdom. The study included 202,974 patients with depression, 14,570 with anxiety, and 2,690 with psychosis and 803,961, 57,862, and 10,644 matched controls, respectively. Cases were defined as individuals aged 15-65 years with any medical Read code for depression, anxiety, or psychosis. Subjects with diagnosis-specific psychotropic prescriptions > 90 days before index date were excluded. For every case, 4 controls were selected using incidence density sampling, matching on age, sex, practice site, calendar time, and duration of follow-up before index date. The primary exposure of interest was therapy with 1 of 7 antibiotic classes > 1 year before index date. Odds ratios (ORs) and 95% CIs were calculated for the association between each psychiatric disorder and exposure to individual classes of antibiotics using conditional logistic regression analysis. The risk was adjusted for obesity, smoking history, alcohol consumption, socioeconomic status, and number of infectious events before diagnosis. RESULTS Treatment with a single antibiotic course was associated with higher risk for depression with all antibiotic groups, with an adjusted OR (AOR) of 1.23 for penicillins (95% CI, 1.18-1.29) and 1.25 (95% CI, 1.15-1.35) for quinolones. The risk increased with recurrent antibiotic exposures to 1.40 (95% CI, 1.35-1.46) and 1.56 (95% CI, 1.46-1.65) for 2-5 and > 5 courses of penicillin, respectively. Similar association was observed for anxiety and was most prominent with exposures to penicillins and sulfonamides, with an AOR of 1.17 (95% CI, 1.01-1.36) for a single course of penicillin and 1.44 (95% CI, 1.18-1.75) for > 5 courses. There was no change in risk for psychosis with any antibiotic group. There was a mild increase in the risk of depression and anxiety with a single course of antifungals; however, there was no increase in risk with repeated exposures. CONCLUSION Recurrent antibiotic exposure is associated with increased risk for depression and anxiety but not for psychosis.

Risk of Nonmelanoma Skin Cancer Associated With the Use of Immunosuppressant and Biologic Agents in Patients With a History of Autoimmune Disease and Nonmelanoma Skin Cancer

IMPORTANCE Immune dysfunction underlies the pathogenesis of rheumatoid arthritis (RA) and inflammatory bowel disease (IBD). Immunosuppressive therapy is the standard of care for these diseases. Both immune dysfunction and therapy-related immunosuppression can inhibit cancer-related immune surveillance in this population. Drug-induced immunosuppression is a risk factor for nonmelanoma skin cancer (NMSC), particularly squamous cell tumors. For patients with a history of NMSC, data are limited on the effect of these drugs on the risk of additional NMSCs. OBJECTIVE To determine the relative hazard of a second NMSC in patients with RA or IBD who use methotrexate, anti-tumor necrosis factor (anti-TNF) therapy, or thiopurines after an initial NMSC. DESIGN, SETTING, AND PARTICIPANTS In this retrospective cohort study, we studied 9460 individuals with RA or IBD enrolled in Medicare from January 1, 2006, through December 31, 2012. EXPOSURES Exposure to methotrexate, thiopurines, anti-TNFs, sulfasalazine, hydroxychloroquine, abatacept, or rituximab after the incident NMSC surgery. MAIN OUTCOMES AND MEASURES A second NMSC occurring 1 year or more after the incident NMSC using Cox proportional hazards regression models. RESULTS Among 9460 individuals (6841 with RA and 2788 with IBD), the incidence rate of a second NMSC per 1000 person-years was 58.2 (95% CI, 54.5-62.1) and 58.9 (95% CI, 53.2-65.2) in patients with RA and IBD, respectively. Among patients with RA, methotrexate used in conjunction with other medications was associated with an increased risk of a second NMSC (hazard ratio [HR], 1.60; 95% CI, 1.08-2.37). Adjusted for other medications, the risk of NMSC increased with 1 year or more of methotrexate use (HR, 1.24; 95% CI, 1.04-1.48). Compared with methotrexate alone, the addition of anti-TNF drugs was significantly associated with risk of NMSC (HR, 1.49; 95% CI, 1.03-2.16). Abatacept and rituximab were not associated with increased NMSC risk. The nonsignificant HRs for 1 year or more of thiopurine and anti-TNF use for IBD were 1.49 (95% CI, 0.98-2.27) and 1.36 (95% CI, 0.76-2.44), respectively. CONCLUSIONS AND RELEVANCE Methotrexate use is associated with an increased risk of a second NMSC. Anti-TNF use may increase the risk of a second NMSC when used with methotrexate for RA. Further long-term studies are required before one can conclude that thiopurine and/or anti-TNF do not increase the risk of a second NMSC in patients with IBD.

Incidence of Bladder Cancer in Patients With Type 2 Diabetes Treated With Metformin or Sulfonylureas

OBJECTIVE Previous studies evaluating the effect of metformin on cancer risk have been impacted by time-related biases. To avoid these biases, we examined the incidence of bladder cancer in new users of metformin and sulfonylureas (SUs). RESEARCH DESIGN AND METHODS This cohort study included 87,600 patients with type 2 diabetes in The Health Improvement Network database. Use of metformin or an SU was treated as a time-dependent variable. Cox regression–generated hazard ratios (HRs) compared metformin use with SU use, adjusted for age, sex, smoking, obesity, and HbA1c level. RESULTS We identified 196 incident bladder cancers in the metformin cohort and 66 cancers in the SU cohort. Use of metformin was not associated with decreased bladder cancer risk (HR 0.81 [95% CI 0.60–1.09]). This association did not differ by sex (P for interaction = 0.20). We observed no association with duration of metformin relative to SU use (3 to <4 years of use: 0.57 [0.25–1.34]; 4 to <5 years of use: 0.93 [0.30–2.85; ≥5 years of use: 1.18 [0.44–3.19]; P for trend = 0.26). CONCLUSIONS Use of metformin is not associated with a decreased incidence of bladder cancer. Similar methods should be used to study other cancers that have previously been identified as potentially preventable with metformin.

Recurrent antibiotic exposure may promote cancer formation – Another step in understanding the role of the human microbiota?

BACKGROUND Bacterial dysbiosis was previously described in human malignancies. In a recent animal model, tumour susceptibility was transmitted using faecal transplantation. Our aim was to evaluate possible association between antibiotic exposure and cancer risk. METHODS We conducted nested case-control studies for 15 common malignancies using a large population-based electronic medical record database. Cases were defined as those with any medical code for the specific malignancy. Individuals with familial cancer syndromes were excluded. For every case, four eligible controls matched on age, sex, practice site and duration of follow-up before index-date were selected using incidence-density sampling. Exposure of interest was antibiotic therapy >1 year before index-date. Adjusted odds-ratios (AORs) and 95% confidence intervals (CIs) were estimated for each antibiotic type using conditional logistic regression. RESULTS 125,441 cases and 490,510 matched controls were analysed. For gastro-intestinal malignancies, the use of penicillin was associated with an elevated risk of oesophageal, gastric and pancreatic cancers. The association increased with the number of antibiotic courses and reached 1.4 for gastric cancers associated with >5 courses of penicillin (95% CI 1.2-1.8). Lung cancer risk increased with the use of penicillin, cephalosporins, or macrolides (AOR for >5 courses of penicillin: 1.4 95% CI 1.3-1.6). The risk of prostate cancer increased modestly with the use of penicillin, quinolones, sulphonamides and tetracyclines. The risk of breast cancer was modestly associated with exposure to sulphonamides. There was no association between the use of anti-virals and anti-fungals and cancer risk. CONCLUSION Recurrent exposure to certain antibiotics may be associated with cancer risk in specific organ sites.

Implications of inadequate lymph node staging in resectable gastric cancer: A contemporary analysis using the National Cancer Data Base

National guidelines recommend examination of ≥ 15 lymph nodes for adequate staging of resectable gastric adenocarcinoma (GA). The relevance of these guidelines, which were established before the increasing use of multimodality therapy, and the impact of inadequate lymph node staging (LNS) in a contemporary cohort have not been extensively explored.

Efficacy of adjuvant chemotherapy for small bowel adenocarcinoma: A propensity score–matched analysis

The role of adjuvant chemotherapy (AC) in the treatment of small bowel adenocarcinoma is poorly defined. Previous analyses have been limited by small sample sizes and have failed to demonstrate a survival advantage.

Impact of antibiotic exposure on the risk of colorectal cancer

Gut microbiota has been postulated to serve as a significant promoter of CRC formation, and colonic dysbiosis was previously reported in CRC tissue. Our aim was to evaluate the association between the type and cumulative duration of antibiotic exposure and CRC risk.

The Benefit to Risk Balance of Combining Infliximab with Azathioprine Varies With Age: A Markov Model

BACKGROUND & AIMS Combination therapy with infliximab and azathioprine has demonstrated benefit over monotherapy for moderate-to-severe Crohns disease. Clinical trials and models have not accounted for age-specific risks associated with these therapies, including the risk of immunosuppression-related cancer and infection. After accounting for these risks, the strategy yielding the greatest benefit may vary with age. METHODS We assessed age-specific risks and benefits of combination therapy compared with infliximab monotherapy by using Markov modeling. The base case was a 35-year-old male patient with a 1-year time horizon. We assumed the incidence of lymphoma to be 5.28-fold higher with combination therapy. Secondary analyses accounted for life expectancy, therapy beyond 1 year, and age-specific surgical and infection risks. Quality-adjusted life years (QALYs) were calculated for 25- to 75-year old individuals. RESULTS Combination therapy was found to be of greater benefit in the base case (0.7522 QALYs for combination therapy vs 0.7426 QALYs for monotherapy). Accounting for life years lost, monotherapy was the best approach if the hazard ratio for lymphoma with combination therapy was >8.1 patients who were 75 years old. Monotherapy provided greater net benefit to patients 55, 65, or 75 years old if therapy was extended for 9, 7, or 5 years, respectively. For 25-year-old men, monotherapy resulted in fewer deaths but only yielded greater QALYs if the annual incidence of hepatosplenic T-cell lymphoma exceeded 36/100,000 persons. CONCLUSIONS After accounting for age-specific risks of lymphoma, infection, and surgical complications, benefits of combination therapy outweighed the risks as a short-term and intermediate-term strategy for most patients with moderate-to-severe Crohns disease who were younger than 65 years. For young male patients, combination therapy yields greater QALYs but at cost of an increased risk of death from lymphoma.