Cancer Cohort Study Research Articles

Matrix metalloproteinase 2 polymorphisms and expression in lung cancer: a meta-analysis

A number of studies have investigated the role of matrix metalloproteinase 2 (MMP2) polymorphisms and expression in lung cancer, but have yielded inconsistent and inconclusive results. To derive a more precise estimate of the prognostic role of MMP2 expression and the susceptibility role of MMP2 polymorphisms in lung cancer, we reviewed published studies and carried out a meta-analysis. Eligible articles were identified in electronic databases. Case-control studies assessing the associations between MMP2 polymorphisms and lung cancer risk or cohort studies assessing the prognostic role of MMP2 expression in patients with lung cancer were included. Pooled odds ratio (OR) or hazard ratio (HR) with 95 % confidence interval (95 % CI) was used to assess the role of MMP2 polymorphisms and expression in lung cancer, respectively. Seven case-control studies (a total of 3,190 lung cancer cases and 3,013 controls) and 18 cohort studies (2,095 lung cancer patients) were eligible. Meta-analysis of seven case-control studies suggested that individuals with TT genotype of both MMP2 C735T and C1306T polymorphisms had obviously decreased risk of lung cancer compared with those with CC genotype (for MMP2 C735T, fixed effects OR = 0.69, 95 % CI 0.49-0.97, P = 0.032; for MMP2 C1306T, fixed effects OR = 0.54, 95 % CI 0.33-0.86, P = 0.010). Meta-analysis of 18 cohort studies suggested that patients with high MMP-2 expression had poorer overall survival (fixed effects HR = 1.82, 95 % CI 1.56-2.13, P < 0.001). Subgroup by study design, ethnicity and testing methods all further identified the prognostic value of MMP2 expression in lung cancer. In conclusion, MMP2 C735T and C1306T polymorphisms are both associated with lung cancer risk, and patients with high MMP2 expression levels have poorer overall survival compared with those with low MMP2 expression levels.

Vitamin D, PTH, and calcium and the risk of prostate cancer: a prospective nested case–control study

To examine the risk of prostate cancer in relation to pre-diagnostic serum levels of vitamin D (25OHD(2) and 25OHD(3)), PTH, and calcium. Nine hundred forty-three incident prostate cancer cases were identified in the Malmö Diet and Cancer Study cohort, and each was matched with one control using incidence density matching with age as the underlying timescale. We also matched for calendar time and age at inclusion. Logistic regression analysis yielded odds ratios with 95% confidence intervals for different quartiles and deciles. All analyses were repeated stratified for age and body mass index (BMI). We found a weak trend toward increasing prostate cancer risk with rising vitamin D levels (p-trend across quartiles, 0.048). Dividing the cohort into deciles showed a nonlinear association. Compared to decile one, the prostate cancer risk was highest in deciles seven and eight, which corresponded to vitamin D levels of 91-97nmol/L (1.68; 1.06-2.68), and 98-106nmol/L (1.80; 1.13-2.85). In the other deciles, there was no association between prostate cancer risk and vitamin D levels. Albumin-adjusted calcium was positively associated with an increased risk for prostate cancer among men aged 55-65 with a BMI <25 (2.07; 1.08-3.97). No association was observed between pre-diagnostic PTH and subsequent prostate cancer incidence, and the stratified analyses revealed no other convincing relationships. This study suggests a possible weak positive nonlinear association between vitamin D and the risk of prostate cancer.

Measures of birth size in relation to risk of prostate cancer: the Malmö Diet and Cancer Study, Sweden.

There is some evidence that perinatal factors, specifically birth weight (BW), may be related to the onset of prostate cancer (PRCA). This case-control study, nested within the Malmö Diet and Cancer Cohort Study, used archived birth record data from 308 incident PRCA cases diagnosed between 1991 and 2005, and 637 age-matched controls among 4781 men born (1923-1945) in Malmö and Lund, Sweden. We applied conditional logistic regression to examine the birth size-PRCA association, including tumour subtypes, adjusting for perinatal and adult factors. Compared with controls, cases had a non-significantly higher mean BW and were more likely to have high (>4000 g) BW (21% v. 18%), but did not differ in other birth size measures, nor in mean adult body mass index . We observed a non-linear association between BW and PRCA risk. Compared with BWs between 3000 and 3500 g (reference), the fully adjusted odds ratios (OR, 95% CI) were 0.55 (0.33-0.91) for <3000 g, 0.86 (0.61-1.22) for 3500-4000 g and 0.98 (0.64-1.50) for >4000 g. Among men with aggressive tumours, the reduction in risk for those with BWs <3000 g (OR 0.26, 95% CI 0.09-0.72) was stronger than the rate of risk for PRCA overall. Crude risk estimates were minimally attenuated when adjusted for gestational age, maternal age, birth order and adult factors. Birth length, head circumference and placental weight were not associated with prostate cancer. Our results indicate a protective effect of lower BW on risk of total and aggressive prostate cancer, rather than any direct effect of larger birth size.

Validity of the diagnoses atrial fibrillation and atrial flutter in a Danish patient registry

Objectives. To assess the validity of the diagnoses of atrial fibrillation (AF) and atrial flutter (AFL) for men and women recorded in the Danish National Patient Registry, and to assess the relative distribution of AF and AFL. Design. Review of medical records for incident cases of AF and/or AFL in the Diet, Cancer, and Health cohort study. Participants were enrolled in 1993–97 with 13.6 years of follow-up until 30 December, 2009. Results. The positive predictive value of the combined diagnosis of AF and/or AFL was 92.6% (95% CI 88.8%; 95.2%) with no significant difference between sexes (men 93.7% (133/142), women 90.8% (129/142)). The proportion of AFL either alone or in combination with AF was significantly higher in men than in women (13.5% (18/133) vs. 5.4% (7/129), p =0.03). The positive predictive value of the specified diagnosis of AFL was 57.5% for men (46/80) and 29.6% for women (8/27). Conclusions. This study shows that the validity of the diagnosis of AF and/or AFL is high and may be used for registry-based studies. A specified diagnosis of AFL was rarely used and was not reliable to distinguish between cases of AF and AFL.

γ-glutamyl transferase and risk of breast cancer

g-glutamyl transferase (GGT), which is found in both serum and cell plasma membrane, has an important antioxidant effect through the metabolism of glutathione [1]. Conversely, pro-oxidant species, including superoxide and hydrogen peroxide, are produced during glutathione catabolism as a result of interaction with trace levels of cellular iron ions [2]. Because of its protective role in oxidative stress, serum GGT has been found to be elevated in many pathological processes, including liver disease, cardiovascular disease, renal disease, diabetes, kidney disease and cancer [3]. There is also mounting evidence to suggest that elevated GGT may be associated with an increase in risk of breast cancer. In a population-based cohort of over 90,000 Austrian women, serial serum GGT levels were measured and the participants were followed for a median of 13.5 years [4]. During this time, 4884 cancers were diagnosed. When women with low normal GGT levels (<18 U/l) were compared with all higher categories, there was a highly significant elevation of cancer risk (p < 0.0001). Elevated GGT was associated with a significant increase in risk for breast and female genital cancers along with digestive organs, respiratory and hematological malignancies. The Guernsey Breast Cancer Cohort Study, which has been in progress for over 50 years, recently reported a follow-up of up to 20 years of 1803 healthy women who had serum GGT measured [5]. Data were adjusted for age at entry, height, weight, age at menarche and first birth with nulliparity within the normal range. There was a highly significant relationship between elevated GGT and breast cancer risk. In the highest quartile, the hazard ratio was 2.17 (95% CI: 1.19–3.93). However, when subdivided by menopausal status there was a reduced nonsignificant effect in the postmenopausal women, whereas among the premenopausal women in the highest quartile, the hazard ratio was 3.81 (95% CI: 1.37–10.59). These findings were confirmed in the Swedish AMORIS study, which included 545,460 people [6]. After a mean followup of 12.26 years, 37,809 individuals developed cancer. When divided by categories of GGT (<18, 18–36, 36–72 and

Observer agreement comparing the use of virtual slides with glass slides in the pathology review component of the POSH breast cancer cohort study

Aims(1) To compare the use of scanned virtual slide images (virtual microscopy) with glass slides (conventional microscopy) in the assessment of morphological characteristics of breast cancers within the setting of...

The Anyang Esophageal Cancer Cohort Study: Study Design, Implementation of Fieldwork, and Use of Computer-Aided Survey System

BackgroundHuman papillomavirus (HPV) has been observed repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, the causal relationship between HPV infection and the onset of ESCC remains unknown. A large cohort study focusing on this topic is being carried out in rural Anyang, China.Methodology/Principal FindingsThe Anyang Esophageal Cancer Cohort Study (AECCS) is a population-based prospective endoscopic cohort study designed to investigate the association of HPV infection and ESCC. This paper provides information regarding the design and implementation of this study. In particular we describe the recruitment strategies and quality control procedures which have been put into place, and the custom designed computer-aided survey system (CASS) used for this project. This system integrates barcode technology and unique identification numbers, and has been developed to facilitate real-time data management throughout the workflow using a wireless local area network. A total of 8,112 (75.3%) of invited subjects participated in the baseline endoscopic examination; of those invited two years later to take part in the first cycle of follow-up, 91.9% have complied.Conclusions/SignificanceThe AECCS study has high potential for evaluating the causal relationship between HPV infection and the occurrence of ESCC. The experience in setting up the AECCS may be beneficial for others planning to initiate similar epidemiological studies in developing countries.

Translational Genomics is Not a Spectator Sport: A Call to Action

Translational Genomics is Not a Spectator Sport: A Call to Action

Family History and Women With Ovarian Cancer

<h3>Objective</h3> The objective of the study was to determine how many women in an ovarian cancer (OC) study cohort had a family history (FH) recorded in their case notes and whether appropriate action was taken on the basis of that FH. <h3>Methods</h3> This was a review of patient case-note data of women in a randomized controlled trial of follow-up after primary treatment for OC. Available case notes of 114 women recruited at 3 UK gynecologic cancer centers in a 2-year period between January 2006 and 2008 were examined. Case-note entries for the period from first hospital consultation to 2 years after completion of primary treatment were included. Outcome measures were (1) recording of an FH of cancer in the case notes, (2) whether appropriate action had been taken on the basis of the FH in those women with affected relatives, and (3) characterizing insufficient FH records. <h3>Results</h3> Family history was not consistently recorded. Although FH was recorded in the majority of women, 14 women had no FH recorded. In 63 women, the FH was recorded as not significant, and in 15 cases, FH information was insufficient to complete a risk assessment. Twenty-two women had significant FH meeting criteria for specialist genetics referral. In 15 of these 22 cases, the relevant history suggestive of hereditary breast cancer and OC (due to BRCA1 or BRCA2 mutations) or Lynch syndrome had been documented, but no action was recorded, and its significance was not appreciated. <h3>Conclusions</h3> These data indicate that training in recognizing relevant FH is needed for clinicians looking after women with OC. Research is necessary to determine the barriers in taking and interpreting an FH and to determine the optimal time for broaching FH issues during a woman’s care pathway. This will improve the accuracy of FH recording and ensure families with OC have access to appropriate surveillance and genetic testing.

Stroke and mortality in patients with incident heart failure: the Diet, Cancer and Health (DCH) cohort study

ObjectiveThe objective was to test the hypothesis that the risk of stroke, death and the composite of ‘stroke and death’ would be increased among patients with incident heart failure (HF)....

Identifying patients with suspected lung cancer in primary care: derivation and validation of an algorithm

Lung cancer has one of the lowest survival outcomes of any cancer because more then two-thirds of patients are diagnosed when curative treatment is not possible. The challenge is to help earlier diagnosis of lung cancer and hence improve prognosis. To derive and validate an algorithm incorporating information on symptoms, to estimate the absolute risk of having lung cancer Cohort study of 375 UK QResearch® general practices for development, and 189 for validation. Selected patients were aged 30-84 years and free of lung cancer at baseline and haemoptysis, loss of appetite, or weight loss in previous 12 months. Primary outcome was incident diagnosis of lung cancer recorded in the next 2 years. Risk factors examined were: haemoptysis, appetite loss, weight loss, cough, dyspnoea, tiredness, hoarseness, smoking, body mass index, deprivation score, family history of lung cancer, other cancers, asthma, chronic obstructive airways disease, pneumonia, asbestos exposure, and anaemia. Cox proportional hazards models with age as the underlying time variable were used to develop separate risk equations in males and females. Measures of calibration and discrimination assessed performance in the validation cohort. There were 3785 incident cases of lung cancer arising from 4 289 282 person-years in the derivation cohort. Independent predictors were haemoptysis, appetite loss, weight loss, cough, body mass index, deprivation score, smoking status, chronic obstructive airways disease, anaemia, and prior cancer (females only). On validation, the algorithms explained 72% of the variation. The receiver operating characteristic (ROC) statistics were 0.92 for both females and males. The D statistic was 3.25 for females and 3.29 for males. The 10% of patients with the highest predicted risks included 77% of all lung cancers diagnosed over the subsequent 2 years. The algorithm has good discrimination and calibration and could potentially be used to identify those at highest risk of lung cancer, to facilitate early referral and investigation.

Physical and mental health status and health behaviors of childhood cancer survivors: Findings from the 2009 BRFSS survey

The growing number of childhood cancer survivors makes examination of their current physical and mental health status and health behaviors an important concern. Much of what is known about the long-term outcomes of childhood cancer survivors comes from the Childhood Cancer Cohort Study (CCSS) which uses sibling controls. Using data from the 2009 Behavioral Risk Factor Surveillance System survey, 651 childhood cancer survivors and 142,932 non-cancer peer controls were identified. The two groups were compared on a variety of physical and mental health status and health behavior variables using ANCOVA and binary logistic regression. While controlling for differences in age, sex, and minority status, survivors significantly (P ≤ 0.001) had poorer socioeconomic outcomes, more comorbid conditions, lower life satisfaction, less social and emotional support, poorer general health, and reported more days per month of poor physical and mental health than non-cancer individuals. Survivors were more likely to report being a current smoker [odds ratio (OR) = 2.33; 95% confidence interval (CI), 1.98-2.73; P < 0.001]; tested for human immunodeficiency virus (HIV) (OR = 1.79; 95% CI, 1.52-2.11; P < 0.001); and that at least one HIV situation applied to them (OR = 2.06; 95% CI, 1.55-2.74; P < 0.001). No significant differences were found between groups in regards alcohol use and diet. Results support and extend previous findings reported by the CCSS. New findings regarding survivors' increased likelihood to engage in risky behaviors proposes new directions for future research.

A case–cohort study of lung cancer in poultry and control workers: occupational findings

ObjectivesWe conducted a mortality study of members of the United Food and Commercial Workers International Union who worked in poultry slaughtering/processing plants, and controls. Excess deaths from cancer at 11...

Abstract A86: Interaction of nitrate and folate on the risk of breast cancer among postmenopausal women

Abstract Background: Ingested nitrate can form N-nitroso compounds endogenously, which may lead to DNA adducts and activating mutations in oncogenes. However, previous studies have reported null or inverse associations between dietary nitrate intake and cancer risk, while nitrate intake from drinking water has shown null or positive associations with cancer risk. These associations may be confounded by protective effects of dietary folate, which provides methyl groups for nucleotide synthesis, and thus plays a vital role in the DNA repair system. In a small case-control study, an increased risk of breast cancer was observed among individuals with high dietary nitrate relative to folate intake. We therefore evaluated interaction of total folate with nitrate intake from diet and drinking water on breast cancer risk in the Iowa Women's Health Study (IWHS). Methods: The IWHS is a prospective cohort study of cancer among 41,836 women in Iowa, initiated in 1986. Dietary intake was assessed at study baseline using a food frequency questionnaire (FFQ). Nitrate intake from foods and total folate intake from foods and dietary supplements were computed using consumption frequencies collected by the FFQ. Nitrate intake from drinking water was assessed using a historical analytical database on Iowa municipal water supplies in 15,151 women using municipal water supply. We evaluated the interaction of nitrate and total folate intake with breast cancer risk using Cox proportional hazard regression modeling, adjusting for potential confounders (age, body mass index, waist-hip-ratio, education, smoking, family history of breast cancer, age at menopause, age at first live birth, estrogen use, total energy intake, and intake of vitamin C and E and flavonoids). Results: After baseline exclusions (history of cancer at baseline, previous mastectomy or partial breast resection, implausible energy intake, or ≥30 missing responses on the FFQ), there were 34,388 postmenopausal women in the analytic cohort. Through 2008, 2,875 incident breast cancer cases were identified. Nitrate intake from diet or drinking water was not associated with breast cancer risk. After stratification by total folate intake, high dietary nitrate intake (&amp;gt;106.1 mg/day) was associated with a marginally decreased risk of breast cancer compared to those with low nitrate intake (≤106.1 mg/day) (HR=0.90, 95% confidence interval=0.81–1.00) only among women with folate intake &amp;lt;400 μg/day (p for interaction = 0.65). There was no interaction of nitrate intake from drinking water and total folate intake on breast cancer risk. Conclusions: Our findings do not support the previously reported increased risk of breast cancer risk among individuals with high dietary nitrate and low folate intake. The inverse association between nitrate intake and breast cancer risk observed among women with low folate intake in the present study may be attributed to residual confounding due to high correlation among intakes of nitrate, folate and antioxidants. Citation Information: Cancer Prev Res 2011;4(10 Suppl):A86.

Association Between Smoking and Risk of Bladder Cancer Among Men and Women

Previous studies indicate that the population attributable risk (PAR) of bladder cancer for tobacco smoking is 50% to 65% in men and 20% to 30% in women and that current cigarette smoking triples bladder cancer risk relative to never smoking. During the last 30 years, incidence rates have remained stable in the United States in men (123.8 per 100,000 person-years to 142.2 per 100,000 person-years) and women (32.5 per 100,000 person-years to 33.2 per 100,000 person-years); however, changing smoking prevalence and cigarette composition warrant revisiting risk estimates for smoking and bladder cancer. To evaluate the association between tobacco smoking and bladder cancer. Men (n = 281,394) and women (n = 186,134) of the National Institutes of Health-AARP (NIH-AARP) Diet and Health Study cohort completed a lifestyle questionnaire and were followed up between October 25, 1995, and December 31, 2006. Previous prospective cohort studies of smoking and incident bladder cancer were identified by systematic review and relative risks were estimated from fixed-effects models with heterogeneity assessed by the I(2) statistic. Hazard ratios (HRs), PARs, and number needed to harm (NNH). During 4,518,941 person-years of follow-up, incident bladder cancer occurred in 3896 men (144.0 per 100,000 person-years) and 627 women (34.5 per 100,000 person-years). Former smokers (119.8 per 100,000 person-years; HR, 2.22; 95% confidence interval [CI], 2.03-2.44; NNH, 1250) and current smokers (177.3 per 100,000 person-years; HR, 4.06; 95% CI, 3.66-4.50; NNH, 727) had higher risks of bladder cancer than never smokers (39.8 per 100,000 person-years). In contrast, the summary risk estimate for current smoking in 7 previous studies (initiated between 1963 and 1987) was 2.94 (95% CI, 2.45-3.54; I(2) = 0.0%). The PAR for ever smoking in our study was 0.50 (95% CI, 0.45-0.54) in men and 0.52 (95% CI, 0.45-0.59) in women. Compared with a pooled estimate of US data from cohorts initiated between 1963 and 1987, relative risks for smoking in the more recent NIH-AARP Diet and Health Study cohort were higher, with PARs for women comparable with those for men.

The association between height and prostate cancer grade in the Early Stage Prostate Cancer Cohort Study

We examined the relationship between height and prostate cancer grade. The Early Stage Prostate Cancer Cohort Study is an observational cohort of 1,037 men diagnosed with early-stage prostate cancer, T(0-3)N(x)M(0). High-grade prostate cancer was defined as a biopsy Gleason score≥7 (4+3). Logistic regression models were created to calculate odds ratios (OR) and 95% confidence intervals (CI) for the cross-sectional relationship between height and prostate cancer grade in the overall cohort and subpopulations. We identified 939 participants with a biopsy Gleason score. High-grade prostate cancer was diagnosed in 138 participants. Overall, participants in the highest quartile of height were more than twice as likely to have a Gleason score≥7 (4+3) than participants in the lowest quartile of height, OR 2.14 (95% CI 1.11, 4.14), after multivariate adjustment. Participants in the highest quartile of height were more likely to be diagnosed with high-grade prostate cancer than participants in the lowest quartile of height among participants who were black, OR 8.00 (95% CI 1.99, 32.18), and participants who had diabetes mellitus, OR 5.09 (95% CI 1.30, 19.98). Height is associated with increased risk of high-grade prostate cancer overall and perhaps among certain subpopulations.

Impact of vascular disease in predicting stroke and death in patients with atrial fibrillation: the Danish Diet, Cancer and Health cohort study

The presence of vascular disease (peripheral artery disease [PAD] and/or myocardial infarction [MI]) may impact on the risk of stroke and death among patients with incident atrial fibrillation (AF). To test this hypothesis, we analyzed data from a large Danish prospective cohort, the Danish Diet, Cancer and Health (DCH) study, to assess the risk of stroke or death among those who developed AF according to concomitant presence of vascular disease. A prospective cohort study of 57, 053 persons (27, 178 men and 29, 876 women, respectively), aged between 50 and 64 years. The risk of stroke or death for patients with vascular disease was assessed amongst 3315 patients with incident AF (mean age, 67.1years; 2130 men, 1185 women) using Cox proportional hazard models, after a median follow-up of 4.8 years. Of the subjects with AF, 417 (12.6%) had 'vascular disease' (PAD and/or prior MI). The risk of the primary endpoint (stroke or death) was significantly higher in patients with vascular disease at 1-year follow-up (crude hazard ratio [HR] 2.51 [1.91-3.29]), with corresponding crude HRs for PAD and MI being 3.51 (2.40-5.13), and 1.99 (1.46-2.72), respectively. For the secondary endpoints of death or stroke individually, these risk estimates were similar (crude HR 2.48 [1.89-3.26] and 1.77 [1.18-2.66], respectively). After adjustment for risk factors within the CHADS(2) score, the adjusted HR for the primary endpoint (stroke or death) in patients with vascular disease was 1.91 (1.44-2.54), which was also significant for death (1.97 [1.48-2.62]). Vascular disease (prior MI and PAD) is an independent risk factor for the primary endpoint of 'stroke or death' in patients with AF, even after adjustment for the CHADS(2) risk score, although this is driven by the impact on mortality. This reaffirms that patients with vascular disease represent a 'high-risk' population, which necessitates proactive management of all cardiovascular risk factors and effective thromboprophylaxis (i.e. oral anticoagulation), which has been shown to significantly reduce the risk of stroke and death in AF.

Intake of whole-grain products and risk of prostate cancer among men in the Danish Diet, Cancer and Health cohort study

High intake of whole-grain products may protect against prostate cancer, but overall evidence is limited and inconclusive. The aim of the present study was to investigate the relationship between the intake of whole-grain products and risk of prostate cancer in a large prospective cohort. A total of 26,691 men aged 50-64years participated in the Diet, Cancer and Health cohort study and provided information about diet and potential prostate cancer risk factors. During a median follow-up of 12.4years, we identified 1,081 prostate cancer cases. Associations between whole-grain product intake and prostate cancer incidence were analyzed using Cox's regression model. Overall, there was no association between total intake of whole-grain products and prostate cancer risk (adjusted incidence rate ratio per 50gday(-1): 1.00 (95% confidence interval: 0.96, 1.05)) as well as between intake of the specific whole-grain products: whole-grain rye bread, whole-grain bread, and oatmeal, and risk of prostate cancer. No risk estimates did differ according to either stage or grade of disease. Results from this prospective study suggest that higher intakes of total or specific whole-grain products are not associated with risk of prostate cancer in a population of Danish middle-aged men.

Assessment of follow-up, and the completeness and accuracy of cancer case ascertainment in three areas of India

Background: A prospective study of diet and cancer has not been conducted in India; consequently, little is known regarding follow-up rates or the completeness and accuracy of cancer case ascertainment. Methods: We assessed follow-up in the India Health Study (IHS; 4671 participants aged 35–69 residing in New Delhi, Mumbai, or Trivandrum). We evaluated the impact of medical care access and relocation, re-contacted the IHS participants to estimate follow-up rates, and conducted separate studies of cancer cases to evaluate registry coverage (604 cases in Trivandrum) and the accuracy of self- and proxy-reporting (1600 cases in New Delhi and Trivandrum). Results: Over 97% of people reported seeing a doctor and 85% had lived in their current residence for over six years. The 2-year follow-up rate was 91% for Trivandrum and 53% for New Delhi. No cancer cases were missed among public institutions participating in the surveillance program in Trivandrum during 2003–2004; but there are likely to be unmatched cases (ranging from 5 to 13% of total cases) from private hospitals in the Trivandrum registry, as there are no mandatory reporting requirements. Vital status was obtained for 36% of cancer cases in New Delhi as compared to 78% in Trivandrum after a period of 4 years. Conclusions: A prospective cohort study of cancer may be feasible in some centers in India with active follow-up to supplement registry data. Inclusion of cancers diagnosed at private institutions, unique identifiers for individuals, and computerized medical information would likely improve cancer registries.

Multi-center feasibility study evaluating recruitment, variability in risk factors and biomarkers for a diet and cancer cohort in India.

BackgroundIndia's population exhibits diverse dietary habits and chronic disease patterns. Nutritional epidemiologic studies in India are primarily of cross-sectional or case-control design and subject to biases, including differential recall of past diet. The aim of this feasibility study was to evaluate whether a diet-focused cohort study of cancer could be established in India, providing insight into potentially unique diet and lifestyle exposures.MethodsField staff contacted 7,064 households within three regions of India (New Delhi, Mumbai, and Trivandrum) and found 4,671 eligible adults aged 35-69 years. Participants completed interviewer-administered questionnaires (demographic, diet history, physical activity, medical/reproductive history, tobacco/alcohol use, and occupational history), and staff collected biological samples (blood, urine, and toenail clippings), anthropometric measurements (weight, standing and sitting height; waist, hip, and thigh circumference; triceps, sub-scapula and supra-patella skin fold), and blood pressure measurements.ResultsEighty-eight percent of eligible subjects completed all questionnaires and 67% provided biological samples. Unique protein sources by region were fish in Trivandrum, dairy in New Delhi, and pulses (legumes) in Mumbai. Consumption of meat, alcohol, fast food, and soft drinks was scarce in all three regions. A large percentage of the participants were centrally obese and had elevated blood glucose levels. New Delhi participants were also the least physically active and had elevated lipids levels, suggesting a high prevalence of metabolic syndrome.ConclusionsA high percentage of participants complied with study procedures including biological sample collection. Epidemiologic expertise and sufficient infrastructure exists at these three sites in India to successfully carry out a modest sized population-based study; however, we identified some potential problems in conducting a cohort study, such as limited number of facilities to handle biological samples.