Vitamin D Status and Risk of Breast Cancer in Iranian Women: A Case–Control Study

Systematic Review and Meta-Analysis of Lifestyle and Reproductive Factors Associated with Risk of Breast Cancer in Asian Women

BACKGROUND

Assessing breast cancer risks from lifestyle and reproductive factors is critical for developing population-specific risk prediction tools. However, limited studies have evaluated these risks in recent Asian birth cohorts.

METHODS

We systematically reviewed articles published from January 2010 to December 2023, examining breast cancer risk factors in Asian women. Data were described narratively, estimates pooled, and prevalence and attributable proportions compared across Asian populations.

RESULTS

Of the 128 studies reviewed, 103 reported adjusted effect sizes for meta-analysis. Lifestyle and reproductive factors were predictive of breast cancer risk in Asian women, with varying impacts on premenopausal and postmenopausal women. Relative risks were similar within Asian populations and in comparison to European populations, except for menarche, menopause, and hormone receptor therapy. However, risk factor distributions differed across populations. While alcohol intake (21%) and oral contraceptive use (20%) emerged as the most attributable modifiable risk factors in Europeans, passive smoking (24%) and higher BMI (17%, ≥24 kg/m2 among postmenopausal women) were predominant in Asians.

CONCLUSIONS

Our study shows that while the effects of lifestyle and reproductive breast cancer risk factors are largely similar across different populations, their distributions vary.

IMPACT

Our analysis underscores the importance of considering population-specific risk factor distributions when developing risk prediction tools for Asian populations.

Evidence That Increasing Serum 25(OH)D Concentrations to 30 ng/mL in the Kingdom of Saudi Arabia and the United Arab Emirates Could Greatly Improve Health Outcomes

Accumulating evidence supports the potential protective effects of vitamin D against chronic diseases such as Alzheimer's disease, autoimmune diseases, cancers, cardiovascular disease (ischaemic heart disease and stroke), type 2 diabetes, hypertension, chronic kidney disease, stroke, and infectious diseases such as acute respiratory tract diseases, COVID-19, influenza, and pneumonia, as well as adverse pregnancy outcomes. The respective evidence is based on ecological and observational studies, randomized controlled trials, mechanistic studies, and Mendelian randomization studies. However, randomized controlled trials on vitamin D supplementation have largely failed to show benefits, probably due to poor design and analysis. In this work, we aim to use the best available evidence on the potential beneficial effects of vitamin D to estimate the expected reduction in incidence and mortality rates of vitamin D-related diseases in the Kingdom of Saudi Arabia and the United Arab Emirates if minimum serum 25(OH)D concentrations were to be raised to 30 ng/mL. Estimated reductions by 25% for myocardial infarction incidence, 35% for stroke incidence, 20 to 35% for cardiovascular disease mortality, and 35% for cancer mortality rates depicted a promising potential for raising serum 25(OH)D. Methods to increase serum 25(OH)D concentrations at the population level could include food fortification with vitamin D3, vitamin D supplementation, improved dietary vitamin D intake, and sensible sun exposure.

Association of Serum 25-Hydroxyvitamin D Concentration with Breast Cancer Risk in Postmenopausal Women in the US

The association between serum 25-hydroxyvitamin D [25(OH)D] concentration and breast cancer risk in postmenopausal women is not well understood. The aim of this study was to investigate the association between serum 25(OH)D concentration and breast cancer in postmenopausal women in the United States using nationally representative sample surveys. We used the data from seven cycles of National Health and Nutrition Examination Surveys from 2001 to 2014. Participants were non-institutionalized postmenopausal women (n = 8108). In restricted cubic spline analysis, a significant, nonlinear, invert ‘U’ relationship was observed between serum 25(OH)D concentrations and breast cancer in postmenopausal women (p = 0.029). Overall, breast cancer risk was highest (OR = 1.5) between 70 nmol/L and 80 nmol/L of serum 25(OH)D concentration. Then after serum 25(OH)D 80 nmol/L concentration, the breast cancer risk declined. In multivariate-adjusted logistic regression, the risk of having breast cancer was significantly higher in serum 25(OH)D 75−˂100 nmol/L category compared to the 25(OH)D < 30 nmol/L category [OR and 95% CI: 2.4 (1.4−4.0)]. In conclusion, serum vitamin D concentrations ≥ 100 nmol/L are associated with reduced risk of breast cancer in postmenopausal women. Controlled trials are required to verify if serum 25(OH)D ≥ 100 nmol/L offers protection against breast cancer in postmenopausal women.

Consumption of Food Components of the Mediterranean Diet Decreases the Risk of Breast Cancer in the Makkah Region, Saudi Arabia: A Case-Control Study

Background

Breast cancer is one of the leading causes of death worldwide, it affects both men and women. In Saudi Arabia, breast cancer has been the most prevalent type of cancer in women, for the past few years. Dietary habits and cultural beliefs vary according to region, and further studies are required to demonstrate the relationship between these dietary habits and cultural beliefs and the risk of developing breast cancer. This study is aimed to discover the relationship between preventive dietary factors of the Mediterranean diet and rates of breast cancer among postmenopausal women in the Makkah region of Saudi Arabia.

Methods

A case-control study was conducted in King Abdulla Medical City Hospital, Makkah, Saudi Arabia and included 432 Saudi female participants: 218 in the control group and 214 breast cancer patients. All participants were postmenopausal, around the same age, and all were ethnically Arab Saudis. Data were obtained using a self-administered validated questionnaire.

Results

Study results showed that a diet that includes 1-2 servings of legumes weekly, 1-5 servings of fish weekly, 1-5 servings of dairy products daily, 3-5 servings of fruits and vegetables daily, and more than one cup of black tea and coffee per day significantly (p < 0.05) reduces the risk of breast cancer.

Conclusion

This study demonstrates that consuming a Mediterranean diet, which includes legumes, fish, fruits and vegetables, black tea, coffee, and low intake of dairy products, works as a preventive factor against breast cancer in postmenopausal females from the Makkah region.

Serum 25-Hydroxyvitamin D and the risk of breast cancer in women from Southern Morocco: A case-control study

OBJECTIVES: Assessing Vitamin-D status and checking if low serum 25(OH)D is a factor in breast cancer (BC) for Southern Moroccan women. MATERIALS/METHODS: Study conducted in Morocco about women with BC (n = 90) and controls (n = 90). 25-hydroxy-vitamin-D Biological analyzes executed during the first consultation. Social data and anthropometric parameters were collected for all participants. RESULTS: These women constituted 67.78 % for the cases and 85.6% for the controls. The average age was 48.72±9.71 (cases) and 46.40±12.52 (controls). We found that 53.33% of cases and 40% of controls were postmenopausal and that hypovitaminosis-D affected 80 and 64.4% of cases and controls, respectively. Statistical analysis showed that hypovitaminosis-D was a significative risk factor for BC in Southern Moroccan women. The Odds Ratio was of 5 (p <  0.0001). The BC subtypes had Odds Ratios greater than 1. The highest value was obtained with Luminal B subtype (Odds ratio = 6.25; p = 0.0007). CONCLUSION: This study reinforces the evidence implicating hypovitaminosis-D among modifiable risk factors for BC. Further studies are needed to assess the extent of hypovitaminosis-D in Moroccan women with BC.

Circulating osteocyte-related biomarkers (vitamin D, sclerostin, dickkopf-1), hepcidin, and oxidative stress markers in early breast cancer: Their impact in disease progression and outcome

Breast cancer (BC) is a major concern to female health worldwide. We assessed the circulating osteocyte-related biomarkers, hepcidin, and oxidative stress status among early-stage BC patients in aspects of clinical severity and impact on the outcome. The study incorporated 73 patients categorized into 57 early-stage BC and 16 benign breast diseases and 30 healthy controls. Serum 25-hydroxyvitamin D [25(OH)D], sclerostin (SOST), dickkopf-1(DKK1), and hepcidin were measured using ELISA, while, serum oxidative stress markers were assessed by spectrophotometry. Our results show that patients with BC showed significant increase in the mean levels of DKK1, SOST, hepcidin, and LPER and significant decrease in the mean levels of 25(OH)D, SOD, GPx, and Hb when compared with controls and benign breast diseases. Significantly higher DKK1, hepcidin, and SOD levels among benign breast diseases were found in comparison to control group. There were significantly lower levels of 25(OH)D, SOD, and Hb and significantly higher levels of SOST, DKK1, hepcidin, No, and LPER with advanced grade. Lower levels of 25(OH)D, SOD and higher levels of SOST, hepcidin were observed with increasing the malignant stage. Reduced levels of 25(OH)D, and SOD were significantly associated with poor prognosis and were strong predictors among BC. There were significant negative correlations between 25(OH)D with LPER, SOST, and hepicidin. We conclude that low 25(OH)D, high SOST, DKK1, and hepcidin, and dysregulated oxidative stress could be helpful in early detection and assessment of BC. 25(OH)D, and SOD were the most relevant to tumor progression and prognosis which indicate a significant role in the BC pathogenesis and could be promising targets in management. Our research paves the way to disrupt vicious circle between these biomarkers to obtain the best care of BC.

The Intake of Some Nutrients is Associated with the Risk of Breast Cancer: Results from Jordanian Case-Control Study

Breast cancer (BC) is the most commonly diagnosed cancer and is considered the leading cause of cancer deaths in women globally. The aim of this study is to evaluate the relationship between macro- and micronutrient intake and BC risk among Jordanian women. A case-control design was used in this study, and BC patients were recruited from the main two hospitals provide cancer therapy in Jordan. Four hundred women aged 20-65 years of age were enrolled in the study. For the cases, 200 recently diagnosed BC women were selected from the two hospitals and matched in age and marital status to 200 BC-free women. Dietary data were collected through face-to-face interview using a validated food frequency questionnaire between October 2016 and September 2017. To calculate odds ratio (OR), logistic regression was used; while for p-trend the linear regression was performed. The study results demonstrated that increasing the intake of total energy and percentage of fat was significantly and positively associated with BC (p-= 0.001). The risk of BC increased significantly and positively as carbohydrate, sugar, fat, saturated fat and polyunsaturated and monounsaturated fatty acids intake increased. A significant trend in BC risk was found for cholesterol (p-= 0.005). The ORs for higher intakes of vitamins E, B1, B2, and B3, folate and phosphorus showed a significant association with the risk of BC (p-trend =0.001). A significant inverse effect was detected between iron intake and BC risk (p-=0.001). The study findings resulted in insight of the associations between the total energy intake and some macro/micronutrients intake can be an increasing risk of BC.

A multicenter case control study of association of vitamin D with breast cancer among women in Karachi, Pakistan

Background

The prevalence of vitamin D inadequacy and breast cancer are both high among women living in Karachi, Pakistan.

Methods

A matched case control study was conducted in two hospitals of Karachi, Pakistan to evaluate the association of vitamin D (serum 25-hydroxyvitamin D) concentrations, vitamin D supplementation and sun exposure with breast cancer among Pakistani women. A total of 411 newly diagnosed histologically confirmed primary breast cancer cases were enrolled and 784 controls, free of breast and any other cancers, were matched by age (year of birth ± 5 years), residence in the same geographic area and study site. Information was collected on sociodemographic history, history of vitamin D supplementation, past medical and obstetrical history, family history of breast cancer, sun exposure history, histopathology reports and anthropometric measurement and venous blood was collected to measure serum 25-hydroxyvitamin D (25(OH)D) concentration.

Results

Compared to patients with sufficient serum vitamin D (>30 ng/ml), women with serum vitamin D deficiency (<20ng/ml), had a higher risk of breast cancer (OR = 1.65, 95%CI: 1.10, 2.50). Women with history of vitamin D supplementation one year prior to enrollment, had significant protective effect against breast cancer (OR = 0.32, 95% CI: 0.24, 0.43).

Conclusions and recommendation

Serum vitamin D deficiency was associated with increased risk of breast cancer, while vitamin D supplementation was associated with decreased risk of breast cancer. In Pakistani women, where vitamin D deficiency is common, raising and maintaining serum vitamin D at population level is a safe and affordable strategy. It may play a role in reducing the incidence of both vitamin D deficiency and breast cancer, particularly among poor women where the breast cancer mortality is highest due to limited resources for early detection, diagnosis, and treatment. The effects of vitamin D with regard to breast cancer risk in Karachi Pakistan should be further evaluated.

Vitamin D intake, blood vitamin D levels, and the risk of breast cancer: a dose-response meta-analysis of observational studies

Epidemiological studies have indicated that blood vitamin D levels are linked to cancer. Here we conducted a dose-response meta-analysis based on published observational studies to evaluate the association of vitamin D intake and blood vitamin D levels with breast cancer susceptibility. PubMed, EMBASE, and Web of Science databases were searched up to January 2019. The pooled odds ratio (OR) and 95% confidence intervals (CIs) were extracted to estimate the risk. We identified 70 relevant studies on blood vitamin D levels (50 studies) and vitamin D intake (20 studies), respectively. Linear and nonlinear trend analyses were performed and showed that an increase in blood vitamin D levels by 5 nmol/l was associated with a 6% decrease in breast cancer risk (OR = 0.94, 95% CI = 0.93-0.96). Similar results were obtained for premenopausal (OR = 0.96, 95% CI = 0.93-0.99) and postmenopausal women (OR = 0.96, 95% CI = 0.94-0.98). The pooled OR of breast cancer risk for a 400IU/day increase in vitamin D intake was 0.97 (95% CI = 0.92-1.02). In conclusion, we found that breast cancer risk was inversely related to blood vitamin D levels; however, no significant association was observed in vitamin D intake.

A higher circulating concentration of 25-hydroxyvitamin-D decreases the risk of renal cell carcinoma: a case-control study

OBJECTIVE

To investigate the relationship between vitamin D status, using circulating 25-hydroxyvitamin D [25 (OH) D], and renal cell carcinoma (RCC) risk in a case-control study, because the association between the two is unclear in China.

MATERIALS AND METHODS

A total of 135 incident RCC cases were matched with 135 controls by age and sex. The blood samples were collected on the first day of hospitalization before surgery to measure plasma 25 (OH) D. Logistic regression analyses were used to calculate odds ratios (ORs) and 95% confi dence intervals (95% CIs) with adjustment for several confounders (e.g. age, gender, smoking and season of blood draw). Furthermore, the association of RCC with 25 (OH) D in units of 10 ng / mL as a continuous variable were also examined.

RESULTS

The average plasma 25 (OH) D concentrations in RCC were signifi cantly lower compared with those of the controls (21.5 ± 7.4 ng / mL vs. 24.1 ± 6.6 ng / mL, respectively; P = 0.003). In the adjusted model, inverse associations were observed between circulating 25 (OH) D levels and RCC risk for 25 (OH) D insuffi ciency (20-30 ng / mL) with OR of 0.50 (95% CI: 0.29-0.88; P = 0.015) and a normal 25 (OH) D level (≥ 30 ng / mL) with OR of 0.30 (95% CI: 0.13-0.72; P = 0.007), compared with 25 (OH) D deficiency (< 20 ng / mL). Furthermore, results with 25 (OH) D as a linear variable indicated that each 10 ng / mL increment of plasma 25 (OH) D corresponded to a 12% decrease in RCC risk.

CONCLUSIONS

This case-control study on a Chinese Han population supports the protective effect of a higher circulating concentration of 25 (OH) against RCC, whether the confounding factors are adjusted or not.

Serum vitamin D level, sun-exposed area, dietary factors, and physical activity as predictors of invasive breast cancer risk among Sudanese women: A case-control study

Background:

The role of vitamin D in the development, progression, and prognosis of breast cancer, though widely studied worldwide, has been inconclusive. This study intended to assess the role of some factors (including serum vitamin D level, sun-exposed area, dietary factors, and physical activity) as predictors of the development of invasive breast cancer (IBC) among Sudanese women.

Methods:

A case–control study was conducted on 200 Sudanese women (100 with newly diagnosed IBC and 100 matched healthy females). Serum 25-hydroxyvitamin D was measured through a competitive electrochemiluminescence immunoassay. Matching analysis was adopted by R version 3.4.1 making use of the “MatchIt” package for calculating propensity scores to build a confounder-adjusted, multiple generalized, linear logistic regression model.

Results:

Participants’ age ranged from 28 to 85 years with a mean [±standard deviation (SD)] of 48.10 (±12.11) years. The mean (±SD) serum vitamin D level was 12.97 (±8.60) and 13.79 (±6.79) ng/mL in breast cancer and noncancer Sudanese women, respectively [P = 0.013; odds ratio (OR) 0.862; 95% confidence interval (CI) 0.766–0.969; β = 0.149)]. Sun-exposed area (P = 0.038; OR 0.013; 95% CI 0.000–0.782; β = 4.339) is significantly and negatively associated with breast cancer development. While moderate physical activity (P = 0.0008; OR 2625.430; 95% CI 26.647–258673.001; β = 7.873) is significantly and positively associated with IBC risk. Occasional consumption of milk, dairy products, eggs, and fish reduces the risk of developing IBC by 78.1%, 75.0%, 78.4%, and 76.4%, respectively.

Conclusion:

The higher the plasma vitamin D level by one unit, the lower the risk of breast cancer by 13.84%. Sedentary lifestyle, reduced sun-exposed skin area, and low serum vitamin D levels can be considered as predictors of IBC. Encouraging moderate physical activity and consumption of certain foods may, in part, decrease the precipitating risks of breast cancer. More studies and research are needed to confirm these findings.

Vitamin D exposure and Risk of Breast Cancer: a meta-analysis

The relationship between vitamin D and breast cancer is still controversial. The present meta-analysis examines the effects of the 25(OH)D, 1,25(OH)2D and vitamin D intake on breast cancer risk. For this purpose, a PubMed, Scopus and Web of Science-databases search was conducted including all papers published with the keywords “breast cancer” and “vitamin D” with at least one reported relative risk (RR) or odds ratio (OR). In total sixty eight studies published between 1998 and 2018 were analyzed. Information about type of study, hormonal receptors and menopausal status was retrieved. Pooled OR or RR were estimated by weighting individual OR/RR by the inverse of their variance Our study showed a protective effect between 25 (OH) D and breast cancer in both cohort studies (RR = 0.85, 95%CI:0.74–0.98) and case-control studies (OR = 0.65, 95%CI: 0.56–0.76). However, analyzing by menopausal status, the protective vitamin D – breast cancer association persisted only in the premenopausal group (OR = 0.67, 95%CI: 0.49–0.92) when restricting the analysis to nested case-control studies. No significant association was found for vitamin D intake or 1,25(OH)2D. Conclusion: This systematic review suggests a protective relationship between circulating vitamin D (measured as 25(OH) D) and breast cancer development in premenopausal women.

Reproductive factors, nutritional status and serum 25(OH)D levels in women with breast cancer: A case control study

The study was conducted with an objective to investigate the association between reproductive factors, nutritional status and serum 25(OH)D levels among women diagnosed with breast cancer (BC). A total of 200 women with BC attending a tertiary healthcare institute of Delhi, India matched with 200 healthy women for age (±2years) and socio economic status were included in the study. Data was collected on socio-demographic profile, reproductive factors, physical activity and dietary intake (24h dietary recall and food frequency questionnaire) using interviewer administered structured questionnaires and standard tools. Non fasting blood samples (5ml) were collected for the biochemical estimation of serum 25(OH)D and calcium levels by chemiluminescent immunoassay and colorimetric assay technique. Data was analyzed by univariable conditional logistic regression and significant variables with (p<0.05), were analyzed in final model by conditional multivariable logistic regression analysis. The mean age of patients at diagnosis of BC was 45±10years. Results of multivariable conditional logistic regression analysis revealed significantly higher odds of BC for reproductive factors like age at marriage (more than 23 years), number of abortions, history or current use of oral contraceptive pills (OCP), with [OR (95% CI)] of [2.4 (1.2-4.9)], [4.0 (1.6-12.6)], [2.4 (1.2-5.0)]. Women with physically light activities and occasional consumption of eggs were found to have higher odds of BC [4.6 (1.6-13.0)] and [3.2 (1.6-6.3)]. Women with serum 25(OH)D levels less than 20ng/ml and calcium levels less than 10.5mg/dl had higher odds of having BC [2.4 (1.2-5.1)] and [3.7 (1.5-8.8)]. A protective effect of urban areas as place of residence and energy intake greater than 50% of Recommended Dietary Allowance (RDA) per day against BC was observed (p<0.05). The findings of the present study revealed a significant association of reproductive and dietary factors in addition to sedentary physical activity and low serum 25(OH)D levels in women diagnosed with BC.

Vitamin D and Breast Cancer: Latest Evidence and Future Steps

Vitamin D (the sunshine vitamin) plays a vital role in calcium homeostasis, skeletal metabolism, and immune, cardiovascular, and reproductive systems’ functions. The worldwide prevalence of vitamin D deficiency is approximately 1 billion. Vitamin D deficiency is a serious health problem with numerous health consequences; it is associated with diabetes, rheumatic arthritis, Parkinson, Alzheimer diseases, osteomalacia, osteoporosis, and fractures in adults and cancers. Many reports showed an inverse association between serum vitamin D concentration and incidence of several cancers, including breast, colorectal, kidney, lung, and pancreatic. About 20 different cancers have incidence rates inversely related to solar UV-B doses and serum vitamin D concentration. Considering the rising incidence of breast cancer and high prevalence of vitamin D deficiency, this review aimed to reflect an association between serum vitamin D concentration and breast cancer risk, reveal the link between vitamin D receptor genetic polymorphisms and breast cancer risk, and review the relationship between vitamin D level, breast cancer risk, and prognostic factors such as tumor stage, grade, size, lymph node involvement, and hormone receptor status.

Metformin use and its effect on gastric cancer in patients with type 2 diabetes: A systematic review of observational studies

Increasing evidence suggests that metformin use is associated with a decreased risk of cancer. The traditional therapies for gastric cancer (GC) are gastrectomy and chemoradiotherapy; however, these therapies may cause certain adverse effects, which affect a patient's quality of life, and the overall survival rate is low. At present, little is known about whether the use of metformin decreases the risk of GC in patients with type 2 diabetes. Therefore, in the present study, a systematic review was performed to analyze the effect of metformin on GC. A literature search was conducted in PubMed, EMBASE, and the Cochrane Library databases for articles published up to June 30th, 2016. The studies that evaluated GC patients treated with metformin and compared them with GC patients treated with other antidiabetic drugs were reviewed. Eligible studies were evaluated using the Newcastle-Ottawa Scale. Adjusted hazard ratio and 95% confidence intervals were determined to evaluate the effect of metformin on GC. From the 422 articles evaluated, 5 studies involving a total of 1,804,479 patients met the inclusion criteria and were qualitatively analyzed. The quality of all selected articles was classified as moderate. These studies reported that the long-term use of metformin was associated with a lower risk of GC compared with the lack of use of metformin or the use of other hypoglycemic drugs. In GC patients with diabetes who were subjected to gastrectomy, the cumulative use of metformin reduced the rates of disease recurrence and of all-cause and cancer-specific mortality. Despite the limited number of studies on this subject, currently available evidence indicates that metformin is associated with a decreased risk of GC and improves survival in patients with type 2 diabetes. However, more well-designed trials are required to elucidate this association.

Phytotherapy and Nutritional Supplements on Breast Cancer

Breast cancer is the most frequent type of nonskin malignancy among women worldwide. In general, conventional cancer treatment options (i.e., surgery, radiotherapy, chemotherapy, biological therapy, and hormone therapy) are not completely effective. Recurrence and other pathologic situations are still an issue in breast cancer patients due to side effects, toxicity of drugs in normal cells, and aggressive behaviour of the tumours. From this point of view, breast cancer therapy and adjuvant methods represent a promising and challenging field for researchers. In the last few years, the use of some types of complementary medicines by women with a history of breast cancer has significantly increased such as phytotherapeutic products and nutritional supplements. Despite this, the use of such approaches in oncologic processes may be problematic and patient's health risks can arise such as interference with the efficacy of standard cancer treatment. The present review gives an overview of the most usual phytotherapeutic products and nutritional supplements with application in breast cancer patients as adjuvant approach. Regardless of the contradictory results of scientific evidence, we demonstrated the need to perform additional investigation, mainly well-designed clinical trials in order to establish correlations and allow for further validated outcomes concerning the efficacy, safety, and clinical evidence-based recommendation of these products.

The association between the Index of Nutritional Quality (INQ) and breast cancer and the evaluation of nutrient intake of breast cancer patients: A case-control study

OBJECTIVE

Breast cancer (BrCa) is the most frequently diagnosed cancer among females and second cancer after lung cancer in many societies. In Iran, the risk for BrCa is 1 in 35 and each year, 8000 new patients have been diagnosed with BrCa. Studies have shown that dietary components are implicated in the etiology of BrCa. The Index of Nutritional Quality (INQ) is a method of quantitative and qualitative analysis of single foods, meals, and diets. The aim of this study was to determine the usefulness of INQs in predicting BrCa risk.

METHODS

Our case-control study was conducted from March 2015 to February 2016. The study included 145 cases and 148 controls who attended the Shahid Beheshti University of Medical Sciences Cancer Research Center. INQ scores were computed based on dietary intake using a validated 168-item food frequency questionnaire. Logistic regression models were used to estimate multivariable odds ratios adjusted body mass index, education, employment, marital status, menarche age, childbirth number, smoking, menopause status, and physical activity.

RESULTS

Vitamins A, C, B₁, B₂, and B₁₂ and selenium INQs as a continuous variable in relation to risk for BrCa showed a significant association after multivariate adjustment (odds ratio [OR]_vitA, 0.41 [0.27-0.64]; OR_vitC, 0.30 [0.20-0.47]; OR_vitB1, 0.08 [0.04-0.17]; OR_vitB2, 0.19 [0.11-0.34]; OR_vitB12, 0.44 [0.31-0.61]; and OR_selenium, 0.42 [0.26-0.67]).

CONCLUSION

Women who consumed a healthier diet including vitamin A, β-carotene, vitamin C, and folate and low-fat milk were at decreased risk for developing BrCa compared with those whose diet included more high fat and lamb meat.

Circulating 25-hydroxyvitamin D level and prognosis of lung cancer patients: A systematic review and meta-analysis

BACKGROUND

Previous studies suggested a possible influence of circulating 25-hydroxyvitamin D [25(OH)D] level on the prognosis of lung cancer patients, but conflicting findings were reported. A systematic review and meta-analysis was thus conducted to comprehensively assess the influence of circulating 25(OH)D level on the prognosis of lung cancer patients.

METHODS

Prospective or retrospective cohort studies assessing the influence of circulating 25(OH)D level on the prognosis of lung cancer patients were considered eligible. Hazard Ratios (HR) were pooled using meta-analysis.

RESULTS

Eight studies with 2166 lung cancer patients were included. Meta-analysis of unadjusted HRs from four studies showed low circulating 25(OH)D level was significantly correlated with poor overall survival in lung cancer (HR=1.30, 95%CI 1.08-1.55, P=0.004). Meta-analysis of adjusted HRs from eight studies suggested that low circulating 25(OH)D level was not significantly correlated with poor overall survival (HR=1.25; P=0.13). However, sensitivity analysis suggested an obvious change in the pooled HRs when excluding single study by turns. When the study by Liu et al. was omitted, low circulating 25(OH)D level was significantly correlated with poor overall survival (HR=1.34; P=0.04).

CONCLUSION

The present systematic review and meta-analysis suggested a correlation between low circulating 25(OH)D level and poor overall survival in lung cancer. More studies are needed to further validate the finding above.