Diet and serum micronutrients in relation to cervical neoplasia and cancer among low-income Brazilian women

Folate deficiency modifies the risk of CIN3+ associated with DNA methylation levels: a nested case-control study from the ASCUS-COL trial

PURPOSE

To our knowledge, there are very few studies evaluating if the levels of folate modify the risk of cervical intraepithelial neoplasia grade 2 and higher (CIN2+ and CIN3+) associated with the levels of HPV genome methylation, two cofactors related to single carbon metabolism and independently associated with cervical cancer in previous studies. We conducted a case-control study nested in a three-arm randomized clinical pragmatic trial (ASCUS-COL trial) to evaluate the risk of CIN3+ associated with methylation levels according to serum folate concentrations.

METHODS

Cases (n = 155) were women with histologically confirmed CIN2+ (113 CIN2, 38 CIN3, and 4 SCC) and controls were age and follow-up time at diagnosis-matched women with histologically confirmed ≤ CIN1 (n = 155), selected from the 1122 hrHPV + women of this trial. The concentrations of serum folate were determined by the radioimmunoassay SimulTRAC-SNB-VitaminB12/Folate-RIAKit and the methylation levels by the S5 classifier. Stepwise logistic regression models were used to estimate the association between folate or methylation levels and CIN2+ or CIN3+. The joint effect of folate levels and methylation on the risk of CIN3+ was estimated using combinations of categorical stratifications.

RESULTS

Folate levels were significantly lower in women with CIN3+ than in other diagnostic groups (p = 0.019). The risk of CIN3+ was eight times higher (OR 8.9, 95% CI 3.4-24.9) in women with folate deficiency and high methylation levels than in women with normal folate and high methylation levels (OR 1.4, 95% CI 0.4-4.6).

CONCLUSION

High methylation and deficient folate independently increased the risk of CIN3+ while deficient folate combined with high methylation was associated with a substantially elevated risk of CIN3+.

The Role of Micronutrients in Human Papillomavirus Infection, Cervical Dysplasia, and Neoplasm

There is evidence that diet and nutrition are modifiable risk factors for several cancers. In recent years, attention paid to micronutrients in gynecology has increased, especially regarding Human papillomavirus (HPV) infection. We performed a review of the literature up until December 2022, aiming to clarify the effects of micronutrients, minerals, and vitamins on the history of HPV infection and the development of cervical cancer. We included studies having as their primary objective the evaluation of dietary supplements, in particular calcium; zinc; iron; selenium; carotenoids; and vitamins A, B12, C, D, E, and K. Different oligo-elements and micronutrients demonstrated a potential protective role against cervical cancer by intervening in different stages of the natural history of HPV infection, development of cervical dysplasia, and invasive disease. Healthcare providers should be aware of and incorporate the literature evidence in counseling, although the low quality of evidence provided by available studies recommends further well-designed investigations to give clear indications for clinical practice.

Antioxidant and inflammatory potential of diet among women at risk of cervical cancer: findings from a cross-sectional study in Italy

OBJECTIVE

To evaluate the association of Composite Dietary Antioxidant Index (CDAI) and Dietary Inflammatory Index (DII) with the prevalence of high-grade cervical intraepithelial neoplasia (CIN).

DESIGN

A cross-sectional study was conducted on women with abnormal Papanicolaou test, who underwent high-risk human papillomavirus (HPV) screening and histological test through colposcopy. Dietary data were collected using a FFQ and used to assess both CDAI and DII.

SETTING

Women were recruited from 2012 to 2015 at the Cervical Cancer Screening Unit of the 'Azienda Sanitaria Provinciale' of Catania (Italy).

PARTICIPANTS

The study included 539 women with a mean age of 40·2 years, who were classified as cases (n 127 with CIN2 or more severe lesions) and controls (n 412 with normal cervical epithelium or CIN1).

RESULTS

Although we observed a lower proportion of HPV-positive women among those with higher CDAI (P < 0·001), the index was not associated with the diagnosis of CIN2 or more severe lesions. By contrast, women with medium or high DII showed higher odds to be diagnosed with CIN2 or more severe lesions than those with low DII (OR = 2·15; 95 % CI 1·11, 4·17; P = 0·024 and OR = 3·14; 95 % CI 1·50, 6·56; P = 0·002, respectively), after adjusting for age, HPV status, educational level, BMI, smoking status, parity, use of oral contraceptives and supplements.

CONCLUSIONS

Our findings suggested that a pro-inflammatory diet might be associated with an increased risk of CIN2 and more severe lesions. However, further prospective studies should be encouraged to support this evidence.

Current Perspective of Plant-Based Diets on Communicable Diseases Caused by Viruses: A Mini Review

Communicable diseases are illnesses caused by pathogenic biological agents, including viruses, bacteria, fungi, parasites, and protozoa. Such diseases spread among people through contact with contaminated surfaces, bodily fluids, or blood products, or through the air, insect bites, or consuming contaminated food and beverages. Although some communicable diseases can be treated or prevented by taking medication and vaccines, there has been an increase in awareness of adopting a healthy diet to aid in the prevention and reversal of these diseases. One popular diet is a plant-based diet. Plant-based diets generally consist of vegetables, grains, nuts, seeds, legumes, and fruits, without any animal-source foods or artificial ingredients. Over the years, this diet has continuously increased in popularity. Reasons for following a plant-based diet are varied but include health benefits, such as improving immunity, and reducing the risk of heart disease, diabetes, and some cancers. Scientific evidence even shows that just an increased vegetable intake can decrease the occurrence of chronic diseases caused by viruses, such as hepatitis viruses, and reduce the risk of severe coronavirus disease 2019. Therefore, this mini review discusses the effectiveness of adopting a plant-based diet in ameliorating diseases caused by selected viruses and its limitations.

Natural Bioactives: Back to the Future in the Fight against Human Papillomavirus? A Narrative Review

Human papillomavirus (HPV) still represents an important threat to health worldwide. Better therapy in terms of further improvement of outcomes and attenuation of related side-effects is desirable. The pharmaceutical industry has always targeted natural substances-phytochemicals in particular-to identify lead compounds to be clinically validated and industrially produced as antiviral and anticancer drugs. In the field of HPV, numerous naturally occurring bioactives and dietary phytochemicals have been investigated as potentially valuable in vitro and in vivo. Interference with several pathways and improvement of the efficacy of chemotherapeutic agents have been demonstrated. Notably, some clinical trials have been conducted. Despite being endowed with general safety, these natural substances are in urgent need of further assessment to foresee their clinical exploitation. This review summarizes the basic research efforts conducted so far in the study of anti-HPV properties of bio-actives with insights into their mechanisms of action and highlights the variety of their natural origin in order to provide comprehensive mapping throughout the different sources. The clinical studies available are reported, as well, to highlight the need of uniformity and consistency of studies in the future to select those natural compounds that may be suited to clinical application.

The Preventive Effect of Dietary Antioxidants on Cervical Cancer Development

Cervical cancer results from a continuous process, starting from a normal cervical epithelium after human papillomavirus (HPV) infection and progressing to cervical intraepithelial neoplasia (CIN), before finally developing into invasive squamous carcinoma (ISC). In recent decades, dietary antioxidants, such as vitamins, have received much attention in relation to cancer prevention. We reviewed the relevant literature to investigate the dietary and nutrient intake on cervical cancer. The intake of vitamins A and D and carotenoids may inhibit early cervical cancer development. The intake of folate may prevent or inhibit HPV infection rom progressing to various grades of CIN. The intake of vitamins C and E may widely inhibit the process of cervical cancer development. Polyphenols are often used in cases of cervical cancer in combination chemotherapy and radiation therapy. Regarding nutrients, different antioxidants may have differing abilities to intervene in the natural history of cervical diseases associated with HPV infection. Regarding foods, the intake of both vegetables and fruits containing multiple vitamins may widely suppress cervical cancer development. Most previous papers have described epidemiological studies. Thus, further research using in vitro and in vivo approaches will be needed to clarify the effects of the dietary and nutrient intake in detail.

Association of Diet Quality and Dietary Components with Clinical Resolution of HPV

Nutrient deficits have been repeatedly linked to cervical human papillomavirus (HPV) persistence, cervical neoplasia, and cervical cancer in case-control studies. This study sought to examine the relationship between overall diet quality and dietary components with the spontaneous resolution of cervical HPV over one year. A prospective observational cohort study was performed. Women with low-grade cervical cytology and/or positive HPV test completed a 24-hour dietary recall, from which the Healthy Eating Index (HEI)-2010, a score of overall diet quality, and scores in dietary categories were calculated. Participants were managed clinically according to national management guidelines. Those whose subsequent testing demonstrated normalization of cytology and/or HPV testing ("HPV resolution") were compared to those whose abnormalities persisted or progressed ("HPV non-resolution"). Twenty-six women were included in the HPV resolution group and 38 in the non-resolution group. They were observed for a median of 428 and 412 day, respectively (p = 0.09). There was no difference in overall diet quality between the groups. Intake of total and whole fruit, and seafood/plant protein were associated with HPV resolution in a logistic regression model (all p < 0.05). These findings could have important implications for the counseling and management of individuals with HPV infection of the cervix.

Dietary Antioxidant Intake and Human Papillomavirus Infection: Evidence from a Cross-Sectional Study in Italy

Several lines of evidence suggested that antioxidants might play a protective role against high-risk human papillomavirus (hrHPV) infection and cervical cancer. However, the effect of combined intake of antioxidants has not been investigated thus far. The current cross-sectional study aimed to understand the relationship between dietary antioxidant intake and the risk of high-risk HPV (hrHPV) infection among 251 Italian women with normal cervical cytology. Women were tested for hrHPV using the Digene HC2 HPV DNA Test. Dietary antioxidant intakes were assessed using a semi-quantitative food frequency questionnaire, and a Composite Dietary Antioxidant Index (CDAI) was constructed on the basis of zinc, selenium, manganese, vitamin A, vitamin C, vitamin E, carotenoid, and flavonoid intake. Logistic regression analysis was used to assess odds ratio (OR) and 95% confidence interval (95% CI) for the associations of antioxidant intakes or CDAI with hrHPV status, adjusting for age, smoking status, body mass index, parity, educational level, marital status, and use of multivitamins and oral contraceptives. We first observed that hrHPV-positive women (n = 84) reported lower intake of zinc, manganese, and vitamins A and C than non-infected women. Specifically, we found a negative association between dietary intake of zinc and hrHPV-positive status when all antioxidants were considered simultaneously (OR = 0.46; 95% CI = 0.27–0.80; p = 0.006). With respect to cumulative dietary antioxidant intake, we demonstrated that women with high CDAI (third tertile) had lower odds of being hrHPV-positive than those with low CDAI (first tertile) (OR = 0.39; 95% CI = 0.18–0.85; p = 0.018). To our knowledge, this is the first study demonstrating that a diet based on the combined intake of nutrients with antioxidant properties might reduce the risk of hrHPV infection. However, further research is needed to understand whether dietary antioxidant intake is associated with hrHPV infection or its persistence.

Fruits and vegetables and cervical cancer: a systematic review and meta-analysis

We conducted a meta-analysis to examine the association of fruits and vegetables intake with the occurrence of cervical intraepithelial neoplasia (CIN) and invasive cancer. MEDLINE, LILACS, Scopus, Cochrane Library, and Web of Science databases and gray literature on Google Scholar were searched before December 17, 2018. Odds ratio (OR) or relative risk (RR) estimates for the highest vs. the lowest intake of intake and 95% confidence intervals (CI) from the included studies were pooled using fixed and random-effects models. We found 18 studies: 17 case-control studies (n = 9,014 cases, n = 29,088 controls) and one cohort study (n = 299,651). No association was observed for CIN. The pooled adjusted ORs (95% CI) for cervical cancer were 0.61 (95% CI 0.52-0.73) for vegetables and 0.80 (95% CI 0.70-0.93) for fruits. However, no association was observed when the pooled effect was estimated among studies that adjusted for human papillomavirus (HPV). Consumption of vegetables and fruits was not associated with incidence of cervical cancer among studies that controlled for HPV infection. The level of evidence is limited because only one cohort study was included in the analysis.

Dietary Inflammatory Index and Its Relationship with Cervical Carcinogenesis Risk in Korean Women: A Case-Control Study

Several studies have reported that diet’s inflammatory potential is related to chronic diseases such as cancer, but its relationship with cervical cancer risk has not been studied yet. The aim of this study was to investigate the association between Dietary Inflammatory Index (DII^®) and cervical cancer risk among Korean women. This study consisted of 764 cases with cervical intraepithelial neoplasia (CIN)1, 2, 3, or cervical cancer, and 729 controls from six gynecologic oncology clinics in South Korea. The DII was computed using a validated semiquantitative Food Frequency Questionnaire (FFQ). Odds ratios and 95% CI were calculated using multinomial logistic regression. Higher DII scores were associated with higher cervical carcinogenesis risk. A significant association was observed between the DII and risk among CIN2/3 [Odds Ratio (OR) = 3.14; 95% Confidence Intervals (CI) = 1.57–6.29] and cervical cancer patients (OR = 1.98; 95% CI = 1.01–3.88). Among Human Papilloma Virus (HPV)-positive women, a significant association was found between DII and cervical carcinoma risk with CIN2/3 (OR = 5.65; 95% CI = 1.38–23.2). Moreover, women with CIN2/3 and cervical cancer showed a significant association with proinflammatory diet in people without of physical activity (OR = 3.79; 95% CI = 1.81–7.93). These findings suggest that high intake of proinflammatory diets is associated with increased risk of cervical carcinogenesis among women with CIN2/3. Further evaluation in future studies to confirm this association is warranted.

Oxidative stress: therapeutic approaches for cervical cancer treatment

Oxidative stress results from an imbalance between the generation and elimination of oxidant species. This condition may result in DNA, RNA and protein damage, leading to the accumulation of genetic alterations that can favor malignant transformation. Persistent infection with high-risk human papillomavirus types is associated with inflammatory responses and reactive oxygen species production. In this context, oxidative stress, chronic inflammation and high-risk human papillomavirus can act in a synergistic manner. To counteract the harmful effects of oxidant species, protective molecules, known as antioxidant defenses, are produced by cells to maintain redox homeostasis. In recent years, the use of natural antioxidants as therapeutic strategies for cancer treatment has attracted the attention of the scientific community. This review discusses specific molecules and mechanisms that can act against or together with oxidative stress, presenting alternatives for cervical cancer prevention and treatment.

The Association of Dietary Patterns with High-Risk Human Papillomavirus Infection and Cervical Cancer: A Cross-Sectional Study in Italy

Specific foods and nutrients help prevent the progression of persistent high-risk human papillomavirus (hrHPV) infection to cervical cancer (CC). The aim of this study was to investigate dietary patterns which may be associated with hrHPV status and the risk of high-grade cervical intraepithelial neoplasia (CIN2+). Overall, 539 eligible women, including 127 with CIN2+, were enrolled in a cross-sectional study, and tested for hrHPV infection. Food intake was estimated using a food frequency questionnaire. Logistic regression models were applied. Using the Mediterranean Diet Score, we demonstrated that, among 252 women with a normal cervical epithelium, medium adherence to the Mediterranean diet decreased the odds of hrHPV infection when compared to low adherence (adjOR = 0.40, 95%CI = 0.22-0.73). Using the principal component analysis, we also identified two dietary patterns which explained 14.31% of the variance in food groups intake. Women in the third and fourth quartiles of the "Western pattern" had higher odds of hrHPV infection when compared with first quartile (adjOR = 1.77, 95% CI = 1.04-3.54 and adjOR = 1.97, 95%CI = 1.14-4.18, respectively). Adjusting for hrHPV status and age, women in the third quartile of the "prudent pattern" had lower odds of CIN2+ when compared with those in the first quartile (OR = 0.50, 95%CI = 0.26-0.98). Our study is the first to demonstrate the association of dietary patterns with hrHPV infection and CC and discourages unhealthy habits in favour of a Mediterranean-like diet.

Effect of vitamin E supplementation on uterine cervical neoplasm: A meta-analysis of case-control studies

Several epidemiological studies have suggested that vitamin E could reduce the risk of uterine cervical neoplasm. However, controversial data were presented by different reports. Hence, we conducted a meta-analysis to assess the relationship between vitamin E and the risk of cervical neoplasia. We performed a comprehensive search of the PubMed, Embase and Cochrane databases through December 31, 2016. Based on a fixed-effects or random-effects model, the odds ratio (OR) and 95% confidence intervals (CIs) were calculated to assess the combined risk. Subgroup analyses and meta-regression were done to assess the source of heterogeneity. Subgroup analyses were performed according to survey ways, types of cervical neoplasia, study populations. A protocol was registered with PROSPERO (No. CRD42016036672). In total, 15 case-control studies were included, involving 3741 cases and 6328 controls. Our study suggested that higher category of vitamin E could reduce the cervical neoplasia risk (OR = 0.58, 95% CIs = 0.47–0.72, I² = 83%). In subgroup-analysis, both vitamin E intake and blood levels of vitamin E had a significant inverse association with the risk of cervical neoplasm. Additionally, we found the same relationship between vitamin E and cervical neoplasia among different populations and types of cervical neoplasia. Meta-regression showed that none of the including covariates were significantly related to the outcomes. No evidence of publication bias was observed. In conclusion, vitamin E intake and blood vitamin E levels were inversely associated with the risk of cervical neoplasia.

Ellagic acid and Annona muricata in the chemoprevention of HPV-related pre-neoplastic lesions of the cervix

Ellagic acid is a phenolic compound naturally present in nuts and berries. Several studies have demonstrated that this bioactive compound has antioxidant, chemopreventive and antiviral activity. Annona muricata is a type of fruit tree with a long history of traditional use. A number of properties have been attributed to different parts of the plant, including anticancer and antioxidant activities. In the current study, a complex based on ellagic acid, Annona Muricata and antioxidant factors (an ellagic acid complex) was administered to a group of human papilloma virus (HPV) infected women with and without cervical lesions, for 12 months. Its effect on HPV clearance and cervical cytological outcomes was assessed and a group of women with the same clinical features who did not receive the ellagic acid complex served as a control. A positive correlation was observed between intake of ellagic acid complex and negative Pap test following 6 and 12 months of treatment (χ² test: 0.041 and 0.014, respectively). Women treated with the ellagic acid complex were less likely to be diagnosed with an abnormal Pap smear at 6 months [Odds ratio (OR): 0.39; 95% confidence interval (CI) 0.14-1.06] and 12 months (OR: 0.35; 95% CI 0.13-0.89), compared with the control group. After adjusting for confounding factors including age and smoking habit, this association remained significant. No effect was observed on HPV clearance or viral integration. The data from the current study suggest a protective effect of the ellagic acid complex on cervical cells, possibly through apoptosis, cell cycle arrest and repair mechanisms.

Serum carotenoid, retinol and tocopherol concentrations and risk of cervical cancer among Chinese women

BACKGROUND

Despite many epidemiological studies on the effects of dietary antioxidant micronutrients on risk of cervical cancer, the findings remain uncertain and little evidence is available for serum nutrient markers. The present study aimed to examine the relationship between serum carotenoid, retinol and tocopherol concentrations and risk of cervical cancer among Chinese women.

MATERIALS AND METHODS

We conducted a hospital-based case- control study in which 358 adults (158 incident cases and 200 controls) were recruited from Xinjiang, China. Serum levels of carotenoids (α-carotene, β-carotene, β-cryptoxanthin, lycopene and lutein/zeaxanthin), retinol, and tocopherols (α-tocopherol and γ-tocopherol) were assessed by reverse-phase high-performance liquid chromatography.

RESULTS

We found inverse associations between serum carotenoid (α-carotene, β-carotene, and lutein/zeaxanthin) and tocopherol (α-tocopherol) concentrations and the risk of cervical cancer after adjusting for potential confounders, but a null association for retinol. The ORs for 1-SD increase were 0.71 (95% CI: 0.56- 0.92; p=0.003) for total carotenoids and 0.75 (95% CI: 0.60-0.94; p=0.008) for total tocopherols.

CONCLUSIONS

These results show that higher serum concentrations of some carotenoids and tocopherols are associated with a lower risk of cervical cancer among Chinese women.

Associations between antioxidant vitamins and the risk of invasive cervical cancer in Chinese women: A case-control study

Previous studies on the associations between dietary antioxidant vitamins and the risk of cervical cancer remain inconsistent, and little evidence is available for serum antioxidant vitamins, which provide more accurate measurements of these nutrients. We conducted a case-control study of 458 incident cases with invasive cervical cancer and 742 controls to assess the effects of diet or serum antioxidant vitamins. Higher serum antioxidant vitamins were associated with a lower risk of cervical cancer after adjusting for potential confounders. The odds ratios (ORs) for the highest (vs. lowest) quartile were 0.66 (95% confidence interval [CI] = 0.46–0.93; P = 0.024) for α-carotene, 0.63 (95% CI = 0.45–0.90; P = 0.006) for β-carotene, 0.53 (95% CI = 0.37–0.74; P < 0.001) for vitamin E, and 0.48 (95% CI = 0.33–0.69; P < 0.001) for vitamin C. Dietary intakes of vitamins E and C were inversely associated with the risk of cervical cancer. Risk of cervical cancer from serum antioxidant vitamins was more evident in passive smokers than non-passive smokers. These findings indicated that antioxidant vitamins (mainly α-carotene, β-carotene, and vitamins E and C) might be beneficial in reducing the risk of invasive cervical cancer in Chinese women, especially in passive smokers.

HPV DNA testing with cytology triage in cervical cancer screening: Influence of revealing HPV infection status

BACKGROUND

Knowledge of cervical human papillomavirus (HPV) status might influence a cytotechnician's assessment of cellular abnormalities. The authors compared original cytotechnicians' Papanicolaou (Pap) readings for which HPV status was concealed with Pap rereads for which HPV status was revealed separately for 3 screening populations.

METHODS

Previously collected cervical Pap smears and clinical data were obtained from the Canadian Cervical Cancer Screening Trial (study A), the Democratic Republic of Congo Community-Based Screening Study (study B), and the Brazilian Investigation into Nutrition and Cervical Cancer Prevention (study C). Smears were reread with knowledge of HPV status for all HPV-positive women as well as a sample of HPV-negative women. Diagnostic performance of Pap cytology was compared between original readings and rereads.

RESULTS

A total of 1767 Pap tests were reread. Among 915 rereads for HPV-positive women, the contrast between "revealed" and "concealed" Pap readings demonstrated revisions from negative to positive results for 109 women (cutoff was atypical squamous cells of undetermined significance or worse) and 124 women (cutoff was low-grade squamous intraepithelial lesions [LSIL] or worse). For a disease threshold of cervical intraepithelial neoplasia of grade 2 or worse, specificity significantly declined at the atypical squamous cells of undetermined significance cutoff for studies A (86.6% to 75.3%) and C (42.5% to 15.5%), and at the LSIL cutoff for study C (61.9% to 37.6%). Sensitivity remained nearly unchanged between readings, except in study C, in which reread performance was superior (91.3% vs 71.9% for the LSIL cutoff).

CONCLUSIONS

A reduction in the diagnostic accuracy of Pap cytology was observed when revealing patients' cervical HPV status, possibly due to a heightened awareness of potential abnormalities, which led to more false-positive results.

Association between dietary folate intake and serum insulin-like growth factor-1 levels in healthy old women

OBJECTIVE

High serum levels of insulin-like growth factor-1 (IGF-1) seem to coincide with higher rates of some types of cancer and the risk of all-cause mortality in old people. Eating vegetables seems to reduce IGF-1 levels because they are rich in micronutrients such as vitamins. This study investigates the possible association between vitamin intake and IGF-1 levels in a representative group of healthy elderly women with Mediterranean dietary habits.

DESIGN

This cross-sectional study included 124 healthy women with a mean age of 71.3 ± 4.2 years and a mean body mass index (BMI) of 27.37 ± 3.48 kg/m(2) attending a mild fitness program twice a week at public gyms in Padova. The main parameters considered were IGF-1 (measured by chemiluminescence) and diet, assessed on the basis of a 3-day record and a questionnaire on the frequency with which they usually ate certain foods.

RESULTS

The mean IGF-1 level for the sample as a whole was 136.2 ± 38.9 μg/l, and was significantly lower in women with a higher folate intake (p = 0.04). On simple linear analysis, the vitamins found associated with serum IGF-1 levels were: folates (r: -0.25; p = 0.003); vitamin E (r: -0.21; p = 0.01); vitamin D (r: -0.17; p = 0.03); and riboflavin (r: -0.16; p=0.03). After removing the effect of calorie, protein, carbohydrate and fat intake, and other known potential confounders (age, BMI, alcohol intake), only folate intake correlated with IGF-1 levels (r = -0.17; p = 0.04).

CONCLUSION

A folate-rich diet could have the effect of lowering circulating IGF-1 levels in elderly women.

Polymorphisms in genes involved in folate metabolism modify the association of dietary and circulating folate and vitamin B-6 with cervical neoplasia

High folate intake has been suggested as an important factor in cancer prevention; however, previous studies on the relation among folate intake, serum folate, and plasma homocysteine (hcy) are controversial. We conducted a hospital-based, case-control study in Brazil investigating associations between dietary and circulating vitamins B-6 and B-12 and folate, hcy, genotypes of folate-metabolizing enzyme methylenetetrahydrofolate reductase (MTHFR C677T, A1298C), 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR A2756G), methionine synthase reductase (MTRR A66G), and reduced folate carrier (RFC1 G80A) and risk of cervical intraepithelial neoplasia (CIN) grades 1 (CIN1), 2 (CIN2), and 3 (CIN3). The study was composed by 453 controls, 140 CIN1, 126 CIN2, and 231 CIN3. We investigated the joint effects of genetic variants of folate-related genes using genetic risk scores (GRSs) by summing the number of risk alleles for CIN1 and CIN2+ (CIN2 and CIN3 cases). The OR (95% CI) for CIN1 and CIN2+ per each risk allele were 1.29 (1.01, 1.65) and 1.22 (1.01, 1.46), respectively. An association between folate intake and CIN2+ was observed only after stratification according to GRS: crude OR (95% CI) for lower folate intake and GRS ≥ 4 was 1.67 (0.92, 3.04) (P-trend < 0.001) compared with higher folate intake (above the median) and GRS ≤ 3. The CIN2+ risk of lower serum vitamin B-6 and GRS ≥ 4 was 2.14 (0.92, 5.02) (P-trend = 0.05) and lower serum folate (below the median) and GRS ≥ 4 was 0.49 (0.20, 1.17) (P-trend = 0.05) after adjustment for confounding variables and human papillomavirus infection. Our data suggest that polymorphisms in genes related to folate metabolism modify the association of dietary and circulating folate and vitamin B-6 with cervical neoplasia.

A review of dietary prevention of human papillomavirus-related infection of the cervix and cervical intraepithelial neoplasia

The natural history of cervical cancer suggests that prevention can be achieved by modification of the host's immune system through a nutrient-mediated program. This study reviews the preventive role of dietary intake on cervical intraepithelial neoplasia (CIN) induced by human papillomavirus (HPV). Electronic databases were searched using relevant keywords such as, but not limited to, human papillomavirus infection, cervical intraepithelial neoplasia, lifestyle factors, nutrients intake, and diet. High consumption of fruit and vegetables appears to be protective against CIN. The findings also highlight the possibility of consuming high levels of specific nutrients, vitamins, and minerals, and retaining sufficient level of these elements in the body, especially those with high antioxidants and antiviral properties, to prevent progression of transient and persistent HPV infections to high-grade CIN 2 and 3 (including in situ cervical cancer). The protective effect is not significant for high-risk HPV persistent infections and invasive cervical cancer. Although it appears that intake of specific nutrients, vitamins, and minerals may be good in CIN prevention, there is lack of evidence from controlled trial to confirm this. Health professionals shall focus on implementation of a balanced-diet prevention strategy at an early stage for cervical cancer prevention.

Case-control study of diet in patients with cervical cancer or precancerosis in Wufeng, a high incidence region in China

PURPOSE

To investigate the diet of patients with cervical cancer and precancerosis in the Wufeng area, a high- incidence region in China.

METHODS

In the case group, 104 patients diagnosed with cervical cancer or cervical intraepithelial neoplasias (CINII/III) were recruited from the Wufeng area. Nine hundred thirty-six healthy women were selected from the same area as the matched controls. A questionnaire, which included questions about general lifestyle conditions, smoking and alcohol status, source of drinking water, green tea intake, and diet in the past year, was presented to all participants.

RESULTS

Green tea intake (P=0.022, OR=0.551, 95% CI=0.330-0.919) and vegetable intake (P=0.035, OR=0.896, 95% CI=0.809-0.993) were identified as protective factors against cervical cancer or CINII/III. There was no indication of any associations of other lifestyle factors (smoking status, alcohol status, source of drinking water) or diet (intake of fruit, meat/egg/milk, soybean food, onion/garlic, staple food and pickled food) with cervical cancer.

CONCLUSIONS

The results suggest that eating more fresh vegetables and drinking more green tea may help to reduce the risk of cervical cancer or CINII/III in people of the Wufeng area.

Associations between human herpesvirus-6, human papillomavirus and cervical cancer

Cervical cancer (CxCa) is the second most common cancer among women globally. Human papillomavirus (HPV) infection is thought to be a necessary, but not sufficient, causal factor in CxCa development. Why some women are able to clear HPV infection with no adverse effects, whereas others develop cancer, remains unclear. HHV-6 has demonstrated transformative abilities and has been shown to be present in the genital tract. However, based on the current evidence, we cannot conclude that HHV-6 is a co-factor in HPV-associated carcinogenesis. Nonetheless, future research is warranted because of several crucial gaps in the literature.

Association between carotenoids and outcome of cervical intraepithelial neoplasia: a prospective cohort study

BACKGROUND

It has been suggested that micronutrients such as alpha-tocopherol, retinol, lutein, cryptoxanthin, lycopene, and alpha- and beta-carotene may help in the prevention of cervical cancer. Our aim was to investigate whether serum concentrations and/or dietary intake of micronutrients influence the regression or progression of low-grade cervical abnormalities.

METHODS

In a prospective cohort study of 391 patients with cervical intraepithelial neoplasia (CIN) grade 1-2 lesions, we measured serum micronutrient concentrations in addition to a self-administered questionnaire about dietary intake. We evaluated the hazard ratio (HR) adjusted for CIN grade, human papillomavirus genotype, total energy intake and smoking status.

RESULTS

In non-smoking regression subjects, regression was significantly associated with serum levels of zeaxanthin/lutein (HR 1.25, 0.78-2.01, p = 0.024). This benefit was abolished in current smokers. Regression was inhibited by high serum levels of alpha-tocopherol in smokers (p = 0.042). In progression subjects, a significant protective effect against progression to CIN3 was observed in individuals with a medium level of serum beta-carotene [HR 0.28, 95 % confidence interval (CI) 0.11-0.71, p = 0.007), although any protective effect from a higher level of serum beta-carotene was weaker or abolished (HR 0.52, 95 % CI 0.24-1.13, p = 0.098). Increasing beta-carotene intake did not show a protective effect (HR 2.30, 95 % CI 0.97-5.42, p = 0.058).

CONCLUSIONS

Measurements of serum levels of carotenoids suggest that regression is modulated by smoking status. Maintaining a medium serum level of beta-carotene has a protective effect for progression; however, carotene intake is not correlated with serum levels of carotenoids.

Highly active antiretroviral therapy and cervical dysplasia in HIV-positive women in South Africa

BACKGROUND

The risk of squamous intra-epithelial lesions (SIL) is higher in HIV-positive women. As these women begin to live longer due to highly active antiretroviral therapy (HAART), their risk of cervical cancer may increase. Few data exist regarding the effect of HAART on the incidence and progression of SIL in HIV-positive African women. The aim of this study was to evaluate the effect of HAART on the incidence and progression of SIL in HIV-positive women in South Africa.

METHODS

A prospective observational study of HIV-seropositive women was conducted over 5 years in an HIV treatment clinic in Johannesburg, South Africa. The participants consisted of 601 women on and off HAART who had repeat Pap smears greater than 6 months apart. The effect of HAART use on incidence and progression rates of SIL was determined using multivariate Poisson regression to obtain incidence rate ratios (IRRs), adjusted for age, CD4 count and other potential confounders.

RESULTS

Median follow-up time was 445 days (inter-quartile range 383, 671). The crude rate of incidence of any SIL was 15.9 episodes (95% confidence limit (CL) 12.7, 19.9) per 100 person-years; the crude rate of all progression of cervical dysplasia among women was 13.5 episodes (95% CL 11.3, 16.1) per 100 person-years. HAART use was associated with a robust reduction in the rate of incidence and progression of cervical lesions, adjusted IRR=0.55 (95% CL 0.37, 0.80). Sensitivity analyses confirmed this main association held for incidence and progression when they were considered separately, and that the result was not dependent on the length of HAART exposure.

CONCLUSION

HAART use was associated with a reduction in the rate of both incidence and progression of cervical lesions among HIV-positive women.

Vitamin A and risk of cervical cancer: a meta-analysis

OBJECTIVE

To conduct a systematic review with meta-analysis of studies assessing the association of vitamin A (retinol, carotene and other carotenoids) intake or blood (serum or plasma) levels of vitamin A (retinol and carotene) with risk of cervical cancer.

METHODS

We evaluated the studies published in English and Chinese on diet or blood vitamin A for the risk of cervical cancer. We also reviewed reference lists from retrieved articles. Meta-analysis was applied to calculate the combined effect values and their 95% confidence intervals. The risk of bias was assessed by the Egger regression asymmetry test.

RESULTS

As many as 11 articles on dietary vitamin A and 4 articles on blood vitamin A were selected according to the eligibility criteria and were included in the meta-analysis, for a total of 12,136 participants. The pooled odds ratios (ORs) of cervical cancer were 0.59 (95% CI, 0.49-0.72) for total vitamin A intake and 0.60 (95% CI, 0.41-0.89) for blood vitamin A levels. The combined ORs of cervical cancer were 0.80 (95% CI, 0.64-1.00), 0.51 (95% CI, 0.35-0.73) and 0.60 (95% CI, 0.43-0.84) for retinol, carotene and other carotenoid intake, and 1.14 (95% CI, 0.83-1.56) and 0.48 (95% CI, 0.30-0.77) for blood retinol and carotene.

CONCLUSIONS

Vitamin A intake and blood vitamin A levels were inversely associated with the risk of cervical cancer in this meta-analysis.

Assessing the validity of a food frequency questionnaire among low-income women in São Paulo, southeastern Brazil

This study describes the validity of a food frequency questionnaire (FFQ) in 93 low-income women (20-65 years), participating in a case-control study in São Paulo, Brazil. Two FFQ (FFQ1 and FFQ2, 12 months apart) and three 24-hour dietary recalls (24hR) were conducted between 2003 and 2004 to estimate dietary intake during the past year. The Pearson correlation coefficients (crude, energy-adjusted and de-attenuated) were used for comparisons between FFQ and 24hR. The agreement between the methods was further examined by the Bland-Altman analysis. For the assessment of long-term reliability, the energy-adjusted intra-class correlation coefficients were mostly around 0.40, but higher for vitamin A and folate (0.50-0.56). Energy-adjusted, attenuation-corrected Pearson validity correlations between FFQ and DR ranged from 0.30-0.54 for macronutrients to 0.20-0.48 for micronutrients, with higher value for calcium (0.75). There were small proportions of grossly misclassified nutrient intakes, while Bland-Altman plots indicated that the FFQ is accurate in assessing nutrient intake at a group level.

Associations of dietary dark-green and deep-yellow vegetables and fruits with cervical intraepithelial neoplasia: modification by smoking

Smoking has been positively and fruit and vegetable intake has been negatively associated with cervical cancer, the second most common cancer among women worldwide. However, a lower consumption of fruits and reduced serum carotenoids have been observed among smokers. It is not known whether the smoking effect on the risk of cervical neoplasia is modified by a low intake of fruits and vegetables. The present study examined the combined effects of tobacco smoking and diet using a validated FFQ and serum carotenoid and tocopherol levels on cervical intraepithelial neoplasia grade 3 (CIN3) risk in a hospital-based case–control study conducted in São Paulo, Brazil, between 2003 and 2005. The sample comprised 231 incident, histologically confirmed cases of CIN3 and 453 controls. A low intake ( ≤ 39 g) of dark-green and deep-yellow vegetables and fruits without tobacco smoking had a lesser effect on CIN3 (OR 1·14; 95 % CI 0·49, 2·65) than among smokers with higher intake ( ≥ 40 g; OR 1·83; 95 % CI 0·73, 4·62) after adjusting for confounders. The OR for the joint exposure of tobacco smoking and low intake of vegetables and fruits was greater (3·86; 95 % CI 1·74, 8·57; P for trend < 0·001) compared with non-smokers with higher intake after adjusting for confounding variables and human papillomavirus status. Similar results were observed for total fruit, serum total carotene (including β-, α- and γ-carotene) and tocopherols. These findings suggest that the effect of nutritional factors on CIN3 is modified by smoking.