Leanness and squamous cell oesophageal cancer

Health examination results and work environment factors affecting urinary 8-hydroxy-2'-deoxyguanosine levels

OBJECTIVE

Oxidative stress is considered to cause lifestyle-related diseases, including cancer. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) is widely analyzed as an oxidative stress marker. We extensively scrutinized the relationships between 8-OHdG levels and lifestyle choices as carcinogenic factors.

METHODS

In this study, we investigated health examination results and working conditions affecting urinary 8-OHdG levels in 503 male workers.

RESULTS

The urinary 8-OHdG level was positively associated with high blood sugar and leanness in smokers. In addition, urinary 8-OHdG tended to increase with organic solvent or hydrochloric acid exposure, as well as long working hours. On the other hand, the urinary 8-OHdG level was negatively associated with high plasma LDL-cholesterol levels in non-smokers and anemia.

CONCLUSION

According to the results, anemia decreased the oxidative stress, regardless of smoking status, while leanness or high blood sugar increased the oxidative stress in smokers, and the presence of plasma cholesterol contributed to the lower oxidative stress in non-smokers. Certain types of occupational exposure may cause oxidative stress. The measurement of urinary 8-OHdG at annual health checks may be a useful biomarker for preventing lifestyle- and work-related diseases.

Adult height, body mass index change, and body shape change in relation to esophageal squamous cell carcinoma risk: A population-based case-control study in China

The relationship between risk of esophageal squamous cell carcinoma (ESCC) and adult height, changes in individual body mass index (BMI) and body shape is not established. We performed a large population‐based case‐control study, which enrolled a total of 1414 ESCC cases and 1989 controls in a high‐incidence area in China. Using face‐to‐face interview with a structured questionnaire, information on participants' heights, weights, and perceived body shapes at 20 years of age was collected. Additionally, data on weight and perceived body shape among the same participants 10 years prior to ascertainment were collected using the same method. Odd ratios (ORs) of ESCC risk in relation to BMI and body shape were estimated using unconditional logistic regression models. The adjusted results indicated that ESCC risk in adults rapidly rose as height increased, plateauing at 170 cm among men and 157 cm among women. Among participants who were underweight, normal weight, or thinner than body shape 4, body weight loss was associated with increased risk of ESCC, and body weight gain was associated with decreased incidence of ESCC (ORs ranging from 0.40 to 0.76). Notably, however, changes in body weight did not significantly affect ESCC risk among participants who were overweight, obese, or larger than body shape 3. Maintaining a fit body shape and a reasonable BMI is advisable and of vital importance to reduce the risk of ESCC, especially in high‐risk areas.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

Joint Effects of Low Body Mass Index and Alcohol Consumption on Developing Esophageal Squamous Cell Cancer: a Korean Nationwide Population-Based Cohort Study

Objective:

In Korea, 95% of esophageal cancer (EC) was the squamous cell-type. We sought to determine the combined risk of alcohol consumption on developing esophageal squamous cell carcinoma (ESCC) in pre-diagnostic underweight subjects using Korean national data.

Methods:

We analyzed the clinical data from a total of 264,084 individuals aged 40 years or older, who received healthcare checkups arranged by the national insurance program, between 2003 and 2008 in Korea. Cox proportional hazards regression was used after adjusting confounding factors.

Result:

Newly diagnosed 278 EC was identified using the claims data during a median follow-up duration of 7.9 years. It was determined that underweight and obesity-compared with normal weight-were significantly associated with 73% increased risk and 30% decreased risk of EC, respectively. Weight gain reduced the risk of EC. Alcohol consumption increased risk for EC in a dose-dependent manner. Heavy alcohol consumption in individuals with underweight increased the risk of developing EC dramatically.

Conclusion:

Underweight was a risk factor for ESCC and alcohol consumption raised the risk synergistically with low BMI. Achieving normal range of BMI could reduce the risk of ESCC.

Prognostic impact of body mass index stratified by smoking status in patients with esophageal squamous cell carcinoma

Background

As smoking affects the body mass index (BMI) and causes the risk of esophageal squamous cell carcinoma (ESCC), the prognostic impact of BMI in ESCC could be stratified by smoking status. We investigated the true prognostic effect of BMI and its potential modification by smoking status in ESCC.

Methods

We retrospectively analyzed 459 patients who underwent curative treatment at a single institution between January 2007 and December 2010. BMI was calculated using the measured height and weight before surgery. Chi-square test was used to evaluate the relationships between smoking status and other clinicopathological variables. The Cox proportional hazard models were used for univariate and multivariate analyses of variables related to overall survival.

Results

BMI <18.5 kg/m² was a significantly independent predictor of poor survival in the overall population and never smokers after adjusting for covariates, but not in ever smokers. Among never smokers, underweight patients (BMI <18.5 kg/m²) had a 2.218 times greater risk of mortality than non-underweight (BMI ≥18.5 kg/m²) patients (P=0.015). Among ever smokers, BMI <18 kg/m² increased the risk of mortality to 1.656 (P=0.019), compared to those having BMI ≥18 kg/m².

Conclusion

Our study is likely the first to show that the prognostic effect of BMI was substantial in ESCC, even after stratifying by smoking status. Furthermore, the risk of death due to low BMI would be significantly increased in never smokers. We believe that the prognostic impact of BMI is modified but not eliminated by the smoking status in ESCC.

Analysis of TP53 polymorphisms in North Indian sporadic esophageal cancer patients

BACKGROUND

To investigate the relationship of five TP53 polymorphisms (p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a) with the esophageal cancer (EC) risk in North Indians.

MATERIALS AND METHODS

Genotyping of p.P47S, p.R72P, PIN3 ins16bp, p.R213R and r.13494g>a polymorphisms of TP53 in 136 sporadic EC patients and 136 controls using polymerase chain reaction and PCR-RFLP.

RESULTS

The frequencies of genotype RR, RP and PP of p.R72P polymorphism were 16.91 vs 26.47%, 58.82 vs 49.27% and 24.27 vs 24.27% among patients and controls respectively. We observed significantly increased frequency of RP genotype in cases as compared to controls (OR=1.87, 95% CI, 1.01-3.46, p=0.05). The frequencies of genotype A1A1, A1A2 and A2A2 of PIN3 ins16bp polymorphism were 69.12 vs 70.59%, 27.20 vs 25% and 3.68 vs 4.41% among patients and controls. There was no significant difference among genotype and allele distribution between patients and controls. The frequencies of genotype GG, GA and AA of r.13494g>a polymorphism were 62.50 vs 64.70%, 34.56 vs 30.15% and 2.94 vs 5.15% among patients and controls respectively. No significant difference between genotype and allele frequency was observed in the patients and controls. For p.P47S and p.R213R polymorphisms, all the cases and controls had homozygous wild type genotype. The RP-A1A1-GG genotype combination shows significant risk for EC (OR=2.01, 95%CI: 1.01-3.99, p=0.05).

CONCLUSIONS

Among the five TP53 polymorphisms investigated, only p.R72P polymorphism may contributes to EC susceptibility.

Prognostic value of body mass index for patients undergoing esophagectomy for esophageal squamous cell carcinoma

OBJECTIVE

The correlation between high body mass index and outcomes after esophagectomy has not been systematically addressed. Some studies have shown that patients with a high body mass index had better overall survival and disease-free survival compared with those with a normal/low body mass index, whereas others have shown that the body mass index was not of prognostic value.

METHODS

Ninety-nine patients with esophageal squamous cell carcinoma were retrospectively reviewed in this study. Patients' postoperative overall and disease-free survivals were compared between the two groups (body mass index <24.00 kg/m(2) and body mass index ≥24.00 kg/m(2)).

RESULTS

There were 66 patients in the low/normal body mass index group (body mass index <24.00 kg/m(2)) and 28 patients in the high body mass index group (body mass index ≥24.00 kg/m(2)). Although disease recurrence were more frequent in the high body mass index group vs. the low/normal body mass index group, there was no significant difference noted (60.7%, 40.9%, P = 0.078). The 3-year overall survival rates were 60.6% in the low/normal body mass index group and 57.1% in the high body mass index group (P = 0.392). The 3-year disease-free survival rates were higher in the low/normal body mass index group vs. the high body mass index group (56.1%, 39.3%, P = 0.048). On multivariate analysis, the number of lymph node metastases (hazard ratio: 1.192, 95% confidence interval: 1.076-1.320, P = 0.001) was recognized as an independent prognostic factor for overall survival. Both body weight loss (hazard ratio: 2.153, 95% confidence interval: 1.027-4.511, P = 0.042) and the number of lymph node metastases (hazard ratio: 1.669, 95% confidence interval: 1.297-2.146, P < 0.001) were significantly and independently associated with disease-free survival.

CONCLUSIONS

Our results suggest that high body mass index appears to shorten disease-free survival in esophageal squamous cell carcinoma patients and further studies are needed to detect the mechanism.

Body mass index change in adulthood and lung and upper aerodigestive tract cancers

Body mass index (BMI) has been inversely associated with lung and upper aerodigestive tract (UADT) cancers. However, only a few studies have assessed BMI change in adulthood in relation to cancer. To understand the relationship between BMI change and these cancers in both men and women, we analyzed data from a population-based case-control study conducted in Los Angeles County. Adulthood BMI change was measured as the proportional change in BMI between age 21 and 1 year before interview or diagnosis. Five categories of BMI change were included, and individuals with no more than a 5% loss or gain were defined as having a stable BMI (reference group). Adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated using logistic regression models. Potential confounders included age, gender, ethnicity, education, tobacco smoking and energy intake. For UADT cancers, we also adjusted for alcohol drinking status and frequency. A BMI gain of 25% or higher in adulthood was inversely associated with lung cancer (OR 0.53, 95% CI 0.33-0.84) and UADT cancers (OR 0.44, 95% CI 0.27-0.71). In subgroup analyses, a BMI gain of ≥25% was inversely associated with lung and UADT cancers among current and former smokers, as well as among current and former alcohol drinkers. The inverse association persisted among moderate and heavy smokers (≥20 pack-years). The observed inverse associations between adulthood BMI gain and lung and UADT cancers indicate a potential role for body weight-related biological pathways in the development of lung and UADT cancers.

Large body size and sedentary lifestyle during childhood and early adulthood and esophageal squamous cell carcinoma in a high-risk population

BACKGROUND

Little is known about the association of obesity and physical activity at young ages with subsequent risk of esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Between 2003 and 2007, we conducted a case-control study in a high-risk population in northeastern Iran. Three hundred ESCC cases and 571 matched controls were recruited. Each individual was shown a standard pictogram, to report body size at ages 15 and 30. Demographic and health-related information, including physical activity at these ages was also collected.

RESULTS

In the fully adjusted models, very obese body size (last two pictograms) at age 15 [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.3-7.7] and age 30 (OR 3.1; 95% CI 1.1-8.5) were associated with ESCC in women, but not in men. Sedentary work at age 15 (OR 3.3, 95% CI 1.3-8.3) and 30 (OR 18.2, 95% CI 3.9-86.2) were also associated with ESCC risk in women only. The increased risk in women at age 15 remained high after later reduction in body size, while women who became very obese only at age 30 did not show a significantly increased risk.

CONCLUSION

These results highlight the importance of early lifestyle modifications in the context of cancer prevention, particularly in women.

The association between change in body mass index and upper aerodigestive tract cancers in the ARCAGE project: multicenter case-control study

Previous studies reported an inverse relationship between body mass index (BMI) and upper aerodigestive tract (UADT) cancers. Examining change in BMI over time may clarify these previous observations. We used data from 2,048 cases and 2,173 hospital- and population-based controls from ten European countries (alcohol-related cancers and genetic susceptibility in Europe study) to investigate the relationship with BMI and adult change in BMI on UADT cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between BMI at three time intervals and BMI change on UADT cancer development, adjusting for center, age, sex, education, fruit and vegetable intake, smoking and alcohol consumption. We found an inverse relationship between UADT cancers and BMI at time of interview and 2 years before interview. No association was found with BMI at 30 years of age. Regarding BMI change between age 30 and 2 years before interview, BMI decrease (BMI change <-5%) vs. BMI stability (-5% ≤ BMI change <5%) showed no overall association with UADT cancers (OR = 1.15; 95% CI = 0.89, 1.49). An increase in BMI (BMI change ≥+5%) was inversely associated with UADT cancers (OR = 0.74; 95% CI = 0.62, 0.89). BMI gain remained inversely associated across all subsites except for esophageal cancer. When stratified by smoking or by drinking, association with BMI gain was detected only in drinkers and smokers. In conclusion, BMI gain is inversely associated with UADT cancers. These findings may be influenced by smoking and/or drinking behaviors and/or the development of preclinical UADT cancers and should be corroborated in studies of a prospective nature.

Body mass index and risk of colorectal cancer in Chinese Singaporeans: the Singapore Chinese Health Study

BACKGROUND

The authors chose to examine the association between body mass index (BMI) and incident colorectal cancer across the spectrum of BMI, including underweight persons, because detailed prospective cohort data on this topic in Asians is scarce, as is data on underweight persons (BMI, <18.5 kg/m(2)) in any population.

METHODS

Analysis of the Singapore Chinese Health Study included 51,251 men and women aged 45-74 years enrolled in 1993-1998 and followed through 2007. Incident cancer cases and deaths among cohort members were identified through record linkage, and 980 cases were identified. Cox regression models were used to investigate the association of baseline BMI with risk of incident colorectal cancer during a mean of 11.5 years of follow-up.

RESULTS

A significant, U-shaped, quadratic association was observed between BMI and colon cancer risk, with increased risk in BMIs ≥27.5 and <18.5 kg/m(2). The association was more pronounced in never smokers and most prominent when further limiting the sample to those free of diabetes and cases with longer than 5 years of follow-up. Localized cases had a more pronounced association in BMIs ≥27.5, whereas advanced cases had a more pronounced association in BMIs <18.5 kg/m(2) . No association was found in relation to rectal cancer risk. The association was also stronger among patients aged 65 years and older.

CONCLUSIONS

BMI displays a U-shaped, quadratic association with colon cancer risk in this Chinese population in Southeast Asia.

Body mass index and risk of head and neck cancer in a pooled analysis of case-control studies in the International Head and Neck Cancer Epidemiology (INHANCE) Consortium

BACKGROUND

Head and neck cancer (HNC) risk is elevated among lean people and reduced among overweight or obese people in some studies; however, it is unknown whether these associations differ for certain subgroups or are influenced by residual confounding from the effects of alcohol and tobacco use or by other sources of biases.

METHODS

We pooled data from 17 case-control studies including 12 716 cases and the 17 438 controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for associations between body mass index (BMI) at different ages and HNC risk, adjusted for age, sex, centre, race, education, tobacco smoking and alcohol consumption.

RESULTS

Adjusted ORs (95% CIs) were elevated for people with BMI at reference (date of diagnosis for cases and date of selection for controls) < or =18.5 kg/m(2) (2.13, 1.75-2.58) and reduced for BMI >25.0-30.0 kg/m(2) (0.52, 0.44-0.60) and BMI > or =30 kg/m(2) (0.43, 0.33-0.57), compared with BMI >18.5-25.0 kg/m(2). These associations did not differ by age, sex, tumour site or control source. Although the increased risk among people with BMI < or =18.5 kg/m(2) was not modified by tobacco smoking or alcohol drinking, the inverse association for people with BMI > 25 kg/m(2) was present only in smokers and drinkers.

CONCLUSIONS

In our large pooled analysis, leanness was associated with increased HNC risk regardless of smoking and drinking status, although reverse causality cannot be excluded. The reduced risk among overweight or obese people may indicate body size is a modifier of the risk associated with smoking and drinking. Further clarification may be provided by analyses of prospective cohort and mechanistic studies.

Anthropometry and esophageal cancer risk in the European prospective investigation into cancer and nutrition

BACKGROUND

Increasing evidence suggests that general obesity [measured by body mass index (BMI)] is positively associated with risk of esophageal adenocarcinoma (EAC). In contrast, previous studies have shown inverse relations with esophageal squamous cell carcinoma (ESCC). However, it is still unclear whether body fat distribution, particularly abdominal obesity, is associated with each type of esophageal cancer.

METHODS

We applied multivariable adjusted Cox proportional hazards regression to investigate the association between anthropometric measures and risk of EAC and ESCC among 346,554 men and women participating in the European Prospective Investigation into Cancer and Nutrition. All statistical tests were two sided.

RESULTS

During 8.9 years of follow-up, we documented 88 incident cases of EAC and 110 cases of ESCC. BMI, waist circumference, and waist-to-hip ratio (WHR) were positively associated with EAC risk [highest versus lowest quintile; relative risk (RR), 2.60; 95% confidence interval (95% CI), 1.23-5.51; P(trend) < 0.01; RR, 3.07; 95% CI, 1.35-6.98; P(trend) < 0.003; and RR, 2.12; 95% CI, 0.98-4.57; P(trend) < 0.004]. In contrast, BMI and waist circumference were inversely related to ESCC risk, whereas WHR showed no association with ESCC. In stratified analyses, BMI and waist circumference were significantly inversely related to ESCC only among smokers but not among nonsmokers. However, when controlled for BMI, we found positive associations for waist circumference and WHR with ESCC, and these associations were observed among smokers and nonsmokers.

CONCLUSION

General and abdominal obesity were associated with higher EAC risk. Further, our study suggests that particularly an abdominal body fat distribution might also be a risk factor for ESCC.

[Risk factors for esophageal cancer, and possible genetic background]

Esophageal cancer is the sixth most common cancer mortality, with increasing incidence. 95% of the esophageal cancer is squamous cell carcinoma or adenocarcinoma. Although they differ in histology and epidemiology, some of their risk factors (smoking, dietary factors) and their pathogenesis are the same. More than 90% of esophageal cancer is diagnosed in late stage. Despite the development of diagnostic and therapeutic techniques, esophageal cancer has poor prognosis, with 5-year survival rates between 10-13%. Understanding the exact pathogenesis can help the prevention of this highly aggressive cancer, with the use of natural substances and nonsteroid inflammatory drugs.

Esophageal cancer and body mass index: results from a prospective study of 220,000 men in China and a meta-analysis of published studies

Several epidemiological studies have reported on the association between body mass index (BMI) and risk of esophageal cancer, but these were mostly in Western populations where many are overweight or obese. There is little direct evidence about the relationship in China where the mean BMI is relatively low and the disease rate is high. We examined the data from a population-based prospective study of 220,000 Chinese men aged 40-79 without a previous history of cancer (mean BMI 21.7 kg/m(2)), which included 1,082 esophageal cancer deaths during 10 years of follow-up. Adjusted hazard ratios for death from esophageal cancer by baseline BMI category were calculated using Cox proportional hazards models. Even among men with good self-assessed health and BMI >or= 18.5 kg/m(2), there was a strong inverse association between BMI and death from esophageal cancer, with each 5 kg/m(2) higher BMI associated with 25% (95%CI: 11-36%) lower esophageal cancer mortality. This inverse association persisted when analysis was restricted to men who had never smoked or when the first 5 years of follow-up were excluded. The strength of the relationship was consistent with the pooled estimate for squamous cell carcinoma of the esophagus in a meta-analysis of prospective studies (31% lower relative risk per 5 kg/m(2) higher BMI; 95% CI: 25-37%), but contrasted with that for adenocarcinoma which showed a positive association with BMI. Together, these data provide reliable evidence that in many populations low BMI is associated with an increased risk of squamous cell carcinoma of the esophagus.

Body mass index and oxidative DNA damage: a longitudinal study

Leanness has been shown to be related to an increased risk of some cancer forms, including lung cancer. However, biological evidence supporting a causal link between leanness and carcinogenesis is limited. The authors investigated longitudinally the association between body mass index (BMI) and levels of urinary 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage, using data from 174 healthy employees who participated in a lifestyle intervention study. 8-OHdG levels were measured using automated high-performance liquid chromatography and adjusted for urinary creatinine levels. Analysis of repeated measurements using a random effects model detected a statistically significant inverse association between BMI and 8-OHdG levels (P = 0.003); one unit decrease in BMI was associated with a 2.7% (95% confidence interval 0.9-4.4) increase in 8-OHdG levels. The association was pronounced among men consuming less than 20 cigarettes per day (8.8% increase per unit decrease in BMI) and among non-smoking men (3.7% increase). The results based on a longitudinal observation suggest that weight loss is associated with increased oxidative DNA damage, a state presumably related to an increased risk of cancer.

The economic consequences of health shocks: evidence from Vietnam

This paper finds that the incomes of urban households are more vulnerable to health shocks than rural households, that health shocks may precipitate increases in unearned income that partially offset reductions in earned income and large increases in medical spending even among insured households. It also finds that households spend less on food following a health shock, but more on budget items such as housing and electricity. Measures of household health shocks used include a recent death of a working-age household member, a long inpatient spell, and a recent sizeable drop in the body mass index of the household head.

Body size and laryngeal cancer risk

BACKGROUND

A few studies have analyzed the role of lifetime anthropometric measures on laryngeal cancer risk.

PATIENT AND METHODS

This relation was investigated using a multicentre case-control study from Italy, conducted between 1992 and 2000, and including 460 incident, histologically confirmed laryngeal cancer cases, and 1088 controls admitted to the same network of hospitals as cases for acute, non neoplastic condition. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were obtained from multiple logistic regression, including terms for major confounding factors, such as physical activity and energy intake.

RESULTS

An inverse association with laryngeal cancer risk was found for body mass index (BMI) in both sexes (OR for the lowest compared to the highest quintile was 1.47, 95% CI 0.93-2.33 in men and 8.11, 95% CI 1.38-47.66 in women) and for BMI at age 50 years (OR=1.65, 95% CI 0.88-3.11) in men and 7.84, 95% CI 0.69-88.58 in women). An inverse association was also observed with waist-to-hip ratio (WHR) at diagnosis in men only (OR=4.56, 95% CI 2.62-7.95 for the lowest compared to the highest quintile).

CONCLUSIONS

This study supports the existence of a relation between leanness and laryngeal cancer risk. In particular, men with less abdominal fat (characterized by a lower WHR) had an increased risk of laryngeal cancer.

Leanness, Smoking, and Enhanced Oxidative DNA Damage

An increased risk of some forms of cancer, including lung cancer, among lean individuals has been consistent; however, there is a paucity of biological evidence supporting this relation. Subjects analyzed were 177 healthy Japanese workers who participated in a lifestyle intervention study. The levels of urinary 8-hydroxydeoxyguanosine (8-OHdG), a marker of oxidative DNA damage, were measured using an automated high-pressure liquid chromatography and urinary creatinine levels were adjusted for before statistical analysis. A clear inverse association was found between body mass index (BMI) and 8-OHdG levels among smokers [Pearson correlation coefficient (r) = -0.48], and the association did not materially change after adjustment for potential confounding factors. In contrast, no apparent relation was observed between BMI and 8-OHdG levels among nonsmokers (r = -0.12), although lean nonsmokers had a slightly higher mean of 8-OHdG levels compared with nonlean nonsmokers. The interaction of smoking and BMI reached statistical significance (P = 0.04). Leanness may enhance oxidative DNA damage induced by smoking and thus serve as a marker of host susceptibility to smoking-related cancers.

Energy, macronutrients and laryngeal cancer risk

BACKGROUND

A role for diet in laryngeal carcinogenesis has been suggested, but only a few studies have examined the potential relationship with a wide variety of macronutrients.

PATIENTS AND METHODS

A case-control study was conducted between 1992 and 2000 in Italy and Switzerland, including 527 incident cases of laryngeal cancer, and 1297 controls hospitalized for acute, non-neoplastic conditions. The subjects' usual diet was investigated through a validated food frequency questionnaire, including 78 foods and beverages. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using unconditional multiple logistic regression models.

RESULTS

Cases reported higher energy intake than controls. The continuous OR for 100 kcal/day was 1.16 (95% CI 1.12-1.21) for alcohol energy, and 1.02 (95% CI 1.01-1.04) for non-alcohol energy. A significantly increased risk of laryngeal cancer was observed for animal protein (continuous OR = 1.21, 95% CI 1.03-1.41), polyunsaturated fats other than linoleic and linolenic fatty acids (OR = 1.43, 95% CI 1.19-1.70), and cholesterol intake (OR = 1.43, 95% CI 1.19-1.71). Laryngeal cancer risk was slightly reduced with increasing vegetable protein (OR = 0.75, 95% CI 0.62-0.91), sugar (OR = 0.84, 95% CI 0.71-1.00) and monounsaturated fatty acid intake (OR = 0.83, 95% CI 0.70-0.99).

CONCLUSIONS

Laryngeal cancer cases have a higher energy intake than control subjects, and report a higher intake of animal protein and cholesterol.

Cigarette tar yield and risk of upper digestive tract cancers: case-control studies from Italy and Switzerland

BACKGROUND

Tobacco smoking is one of the main risk factors for oral, pharyngeal and oesophageal cancers in developed countries. Information on the role of the tar yield of cigarettes in upper digestive tract carcinogenesis is sparse and needs to be updated because the tar yield of cigarettes has steadily decreased over the last few decades.

PATIENTS AND METHODS

We analysed two case-control studies, from Italy and Switzerland, conducted between 1992 and 1999, involving 749 cases of oral and pharyngeal cancer and 1770 controls, and 395 cases of squamous-cell oesophageal carcinoma and 1066 matched controls. Odds ratios (ORs) were estimated by unconditional multiple logistic regression models, including terms for age, sex, study centre, education and alcohol consumption.

RESULTS

Based on the brand of cigarettes smoked for the longest time, the multivariate ORs for current smokers compared with never smokers were 6.1 for <20 mg and 9.8 for >or=20 mg tar for oral and pharyngeal neoplasms, and 4.8 and 5.4 for oesophageal cancer, respectively. For the cigarette brand smoked in the previous six months, the ORs for >or=10 mg compared with <10 mg were 1.9 for cancer of the oral cavity and pharynx and 1.8 for oesophageal cancer, after allowance for number of cigarettes and duration of smoking.

CONCLUSIONS

The present study confirms the direct relationship between the tar yield of cigarettes and upper digestive tract neoplasms, and provides innovative information on lower tar cigarettes, which imply reduced risks compared with higher tar ones. However, significant excess risks were observed even in the lower tar category, thus giving unequivocal indications for stopping smoking as a priority for prevention of upper digestive tract neoplasms.