***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background Recently , serum 25-hydroxyvitamin D ( 25OHD ) levels were shown to be associated with the survival of patients with colorectal cancer . However , 25OHD levels were measured a median of 6 years before diagnosis or were predicted levels . In this study , we directly measured serum 25OHD levels at surgery and examined the association with survival among patients with colorectal cancer . Methods We started a prospect i ve cohort study to find prognostic factors in patients with colorectal cancer from 2003 to 2008 and stored serum sample s and clinical data . As part of a post-hoc analysis ,  serum 25OHD levels  were measured by radioimmunoassay . Association between overall survival and serum 25OHD levels were computed using the Cox proportional hazard model adjusted for month of serum sampling as well as age at diagnosis , gender , cancer stage , residual tumor after surgery , time period of surgery , location of tumor , adjuvant chemotherapy and number of lymph nodes with metastasis at surgery . Unadjusted and adjusted hazard ratios ( HR ) and 95 % confidence intervals ( 95 % CI ) were determined . Results Serum 25OHD levels were measured in 257 patients . Only 3 % had sufficient levels ( 30 ng/ml and greater ) . Based on month of blood sampling , an annual oscillation of 25OHD levels was seen , with levels being lower in spring and higher in late summer . Higher 25OHD levels were associated with better overall survival under multi-variate analysis ( HR , 0.91 : 95 % CI , 0.84 to 0.99 , P = 0.027 ) . Conclusions These results suggest that higher 25OHD levels at surgery may be associated with a better survival rate of patients with colorectal cancer Prospect i ve cohort studies have provided some evidence that circulating vitamin D is associated with risk of , and survival from , renal cell carcinoma ( RCC ) , but it is unclear whether concentrations of vitamin D at the time of diagnosis of RCC are associated with prognosis . We conducted a case – cohort study of 630 RCC cases , including 203 deaths , from a multicenter case – control study in Eastern Europe .  Vitamin D was assessed as 25-hydroxyvitamin D3 [ 25(OH)D3 ] , and we used weighted Cox models to estimate hazard ratios ( HR ) and 95 % confidence intervals ( CI ) by categories of season-adjusted 25(OH)D3 . Higher concentrations of 25(OH)D3 were associated with lower risk of death after adjusting for stage , age , sex , and country ( HR highest vs. lowest category 0.57 ; 95 % CI , 0.34–0.97 ) . The inverse associations of 25(OH)D3 with death were most notable among those who died from non-RCC causes and those diagnosed with early-stage disease . In summary , 25(OH)D3 concentration at diagnosis of RCC was inversely associated with all-cause mortality rates , but not specifically with RCC outcome . Cancer Epidemiol Biomarkers Prev ; 24(8 ) ; 1277–81 . © 2015 AACR Experimental and epidemiological data suggest that vitamin D play a role in pathogenesis and progression of cancer , but prospect i ve data on head and neck cancer ( HNC ) and oesophagus cancer are limited . The European Prospect i ve Investigation into Cancer and Nutrition ( EPIC ) study recruited 385,747 participants with blood sample s between 1992 and 2000 . This analysis includes 497 case-control pairs of the head and neck and oesophagus , as well as 443 additional controls .  Circulating 25(OH)D3  were measured in pre-diagnostic sample s and evaluated in relation to HNC and oesophagus cancer risk and post-diagnosis all-cause mortality . After controlling for risk factors , a doubling of 25(OH)D3 was associated with 30 % lower odds of HNC ( OR 0.70 , 95 % confidence interval [ 95 % CI ] 0.56–0.88 , Ptrend = 0.001 ) . Subsequent analyses by anatomical sub-site indicated clear inverse associations with risk of larynx and hypopharynx cancer combined ( OR 0.55 , 95CI% 0.39–0.78 ) and oral cavity cancer ( OR 0.60 , 95CI% 0.42–0.87 ) . Low 25(OH)D3 concentrations were also associated with higher risk of death from any cause among HNC cases . No clear association was seen with risk or survival for oesophageal cancer . Study participants with elevated circulating concentrations of 25(OH)D3 had decreased risk of HNC , as well as improved survival following diagnosis Background : Vitamin D , from diet and sunlight exposure , may be associated with reduced breast-cancer risk . This study investigated if c and i date gene variants in vitamin D pathways are associated with breast cancer risk , or modify the associations between breast cancer and vitamin D exposure . Methods : Breast cancer cases aged 25 to 74 years were identified from the Ontario Cancer Registry ( histopathologically confirmed and diagnosed 2002–2003 ) and population -based controls were identified through r and om digit dialing of Ontario households .  Saliva ( DNA ) was available for 1,777 cases and 1,839 controls .  Multivariate logistic regression was used to evaluate associations between 19 single nucleotide polymorphisms ( SNP ) in vitamin D related genes , including vitamin D binding protein ( GC ) , vitamin D receptor ( VDR ) , and cytochrome P450 type 24A1 ( CYP24A1 ) . Statistical interactions were assessed using the likelihood ratio test . Results : Some SNPs were found to be significantly associated with breast cancer risk . For example , breast cancer risk was associated with the GC rs7041 TT genotype ( age-adjusted odds ratio ( OR ) = 1.23 ; 95 % CI : 1.01 , 1.51 ) and inversely with the VDR Fok1 ( rs2228570 ) ff genotype ( OR = 0.71 ; 95 % CI : 0.57 , 0.88 ) . Few significant gene-environment interactions were observed between dietary vitamin D and genetic variants . Conclusion : Our study suggests certain vitamin D related genetic variants may influence breast-cancer risk and we found limited evidence that genetic variants modify the associations between vitamin D exposure and breast cancer risk . Impact : Variation in vitamin D-related genotypes may help to explain inconsistent results from previous epidemiologic studies and may lead to targeted prevention strategies . Cancer Epidemiol Biomarkers Prev ; 20(8 ) ; 1708–17 . © 2011 AACR Introduction Vitamin D has been postulated to be involved in cancer prognosis . Thus far , only two studies reported on its association with recurrence and survival after breast cancer diagnosis yielding inconsistent results . Therefore , the aim of our study was to assess the effect of post-diagnostic serum 25-hydroxyvitamin D [ 25(OH)D ] concentrations on overall survival and distant disease-free survival . Methods We conducted a prospect i ve cohort study in Germany including 1,295 incident postmenopausal breast cancer patients aged 50 - 74 years . Patients were diagnosed between 2002 and 2005 and median follow-up was 5.8 years . Cox proportional hazards models were stratified by age at diagnosis and season of blood collection and adjusted for other prognostic factors . Fractional polynomials were used to assess the true dose-response relation for 25(OH)D. Results Lower concentrations of 25(OH)D were linearly associated with higher risk of death ( hazard ratio ( HR ) = 1.08 per 10 nmol/L decrement ; 95 % confidence interval ( CI ) , 1.00 to 1.17 ) and significantly higher risk of distant recurrence ( HR = 1.14 per 10 nmol/L decrement ; 95%CI , 1.05 to 1.24 ) . Compared with the highest tertile ( ≥ 55 nmol/L ) , patients within the lowest tertile ( < 35 nmol/L ) of 25(OH)D had a HR for overall survival of 1.55 ( 95%CI , 1.00 to 2.39 ) and a HR for distant disease-free survival of 2.09 ( 95%CI , 1.29 to 3.41 ) . In addition , the association with overall survival was found to be statistically significant only for 25(OH)D levels of blood sample s collected before start of chemotherapy but not for those of sample s taken after start of chemotherapy ( P for interaction = 0.06 ) . Conclusions In conclusion , lower serum 25(OH)D concentrations may be associated with poorer overall survival and distant disease-free survival in postmenopausal breast cancer patients BACKGROUND There is a paucity of research evaluating the relation between  vitamin D  and recurrence of breast cancer after treatment . OBJECTIVE This study was design ed to evaluate the associations between circulating concentrations of  25-hydroxyvitamin D [ 25(OH)D ]  and dietary , supplemental , and total intake of vitamin D  and recurrent or new breast cancer events within the Women 's Healthy Eating and Living ( WHEL ) Study . DESIGN A prospect i ve cohort study design ( n = 3085 ) was used to evaluate the relation between dietary , supplemental , and total vitamin D intake and recurrent breast cancer , and a nested case-control study with 512 matched pairs was used for analysis of the association between 25(OH)D and breast cancer recurrence . RESULTS No relation between 25(OH)D and breast cancer recurrence was observed . Compared with women with serum concentrations of 25(OH)D ≥ 30 ng/mL , adjusted odds ratios ( 95 % CI ) for breast cancer recurrence were 1.14 ( 0.57 , 2.31 ) for those with concentrations < 10 ng/mL , 1.00 ( 0.68 - 1.48 ) for concentrations ≥ 10 and < 20 ng/mL , and 1.05 ( 0.76 , 1.47 ) for concentrations ≥ 20 and < 30 ng/mL. No significant associations were observed when analyses were stratified by pre- and postmenopausal status or for local , regional , or distant recurrence or death . Vitamin D intake was not related to breast cancer recurrence overall , although for premenopausal women there was a significant inverse association between dietary vitamin D intake and recurrence ( P for trend = 0.02 ) . CONCLUSION These results do not provide support for a relation between concentrations of 25(OH)D after treatment and the recurrence of breast cancer . This trial is registered at clinical trials.gov for the WHEL Study as NCT00003787 Low vitamin D levels have been associated with poor breast cancer outcomes in observational studies . We examined the association of  vitamin D  blood levels with  relapse-free survival ( RFS ) , breast cancer-specific survival ( BCSS ) , and overall survival ( OS ) in the MA.21 r and omized clinical trial . Fasting blood was collected pre-chemotherapy in 934/2104 ( 44.4 % ) of subjects ;  25 hydroxy vitamin D was measured ( radioimmunoassay , Diasorin ) in one batch . Vitamin D was assessed as a transformed continuous factor , and categorically ( quartiles and clinical classifications ) . Univariate and multivariate prognostic analyses ( adjusted for treatment , stratification factors , and baseline imbalances ) were performed using Cox models . Most patients were young ( median 47.8 years ) , white ( 91.6 % ) and premenopausal ( 69.4 % ) with grade III ( 52 % ) , HER2 negative or missing ( 89.5 % ) , ER positive ( 61.9 % ) , T1 - 2 ( 89.4 % ) , N + ( 72.7 % ) breast cancer . Compared to the full population , those with vitamin D levels were more likely to be white , PS 1 or 2 , to have undergone mastectomy , and to have an ER + tumor . Mean vitamin D was 69.7 nmol/L ( 27.9 ng/ml ) and did not vary by tumor subtype . The majority ( 80.5 % ) had levels > 50 nmol/L ( 20 ng/ml ) , considered adequate by Institute of Medicine . Continuous  vitamin D  was not multivariately associated with RFS , BCSS , or OS ( p = 0.36 , 0.26 , 0.33 , respectively ) ; categorical  vitamin D  was also not associated with outcome .  Vitamin D associations with RFS did not differ within ER/HER2 subgroups . There was no evidence that  vitamin D blood level was associated with RFS , BCSS , and OS in MA.21 ; the majority of subjects had adequate vitamin D levels at study entry Background Vitamin D plays a role in cancer development and acts through the vitamin D receptor ( VDR ) . Although African-Americans have the lowest levels of serum vitamin D , there is a dearth of information on VDR gene polymorphisms and breast cancer among African-Americans and Hispanics . This study examines whether VDR gene polymorphisms are associated with breast cancer in these cohorts . Methods Blood was collected from 232 breast cancer patients ( Cases ) and 349 
    Output:
    
Conclusions : Higher 25OHD concentration is associated with better cancer outcome , and the observed association of functional variants in vitamin D pathway genes with outcome supports a causal link .