183 (PB-084) Poster Influence of vitamin D level on breast cancer outcomes in South East Asian population M. Baig, T. Zahid, S. Zafar, S. Batool, A. Khan, Z. Chuadhary, M.A. Parvaiz. Shaukat Khanum Memorial Cancer Hospital and Research Centre, Department of Breast Surgery, Lahore, Pakistan Background: Vitamin D has been proposed to play a significant role in recurrence and survival of patients with breast cancer. The literature however shows conflicting evidence of vitamin D association with breast cancer outcomes. We aim to look at association of vitamin D level with breast cancer outcomes in our population. Material and Methods: From July 2011 to February 2012, 97 patients diagnosed with breast cancer were included in the study from a prospectively maintained electronic database. Vitamin D level was measured at the beginning of treatment. Patients were evaluated for tumor size, histopatho- logical type and grade, lymph nodal disease, and receptor status. Oncological outcomes following treatment were assessed and their association with vitamin D was evaluated. Results: In 97 patients from the study period, mean age was 49 years and risk factors were seen only in 17 patients. Mean tumors size at presentation was 31 mm. 59 patients received neo-adjuvant chemotherapy while only 8 patients were given neo-adjuvant hormonal therapy. Breast conserving surgery (BCS) was performed in most of the patients 55.2% (n = 69) and 45.6% (n = 57) patients underwent Axillary Lymph node dissection. Commonly seen histolopathological type of tumor was Invasive Ductal Carcinoma (IDCa) 56% (n = 70). 58.4% (n = 78) patients received hormonal therapy whereas 67.2%patients (n = 84) received post operative radiother- apy. Vitamin D deficiency was recorded in 73.4% patients (n = 69). Breast cancer recurrence was found in 24% patients (n = 30) whereas 13.6% (n = 17) patients died of breast cancer. Vitamin D level has no statistically significant impact on breast cancer recurrence with p value of 0.172. Conclusion: Although the association of Vitamin D with breast cancer outcomes has been unclear, we can safely conclude that Vitamin D level does not predict the breast cancer outcomes and has no influence on breast cancer recurrence. No conflict of interest 184 (PB-085) Poster The impact of lifestyle and reproductive factors on contralateral breast cancer risk: A systematic review with meta-analysis D. Akdeniz 1 , M.M. Klaver 1 , C.Z.A. Smith 1 , L.B. Koppert 2 , M.J. Hooning 1 . 1 Erasmus MC Cancer Institute, Medical Oncology, Rotterdam, Netherlands; 2 Erasmus MC Cancer Institute, Surgical Oncology, Rotterdam, Netherlands Background: As breast cancer (BC) survival improves, an increasing number of patients are at risk for developing metachronous contralateral breast cancer (CBC). Being diagnosed with CBC is an important concern among BC survivors, as can be observed from the increasing contralateral preventive mastectomy rates. Of specific interest is the impact of lifestyle and reproductive factors on CBC risk since these factors may partly be modifiable. However, literature on this topic is scarce. We aimed to quantify the impact of lifestyle and reproductive factors on metachronous CBC risk in population-based breast cancer cohorts as reported in the literature. Methods: PubMed was searched for publications on CBC risk by two reviewers. We focused on associations between metachronous CBC risk and dietary habits, exercise, body mass index (BMI), alcohol consumption, smoking, age at menarche, oral contraceptive use, gravidity, age at primiparity, parity, breastfeeding, menopausal status and age at menopause. Eligible papers were published up to March 2nd 2017, having at least twenty CBC events and relative risk (RR) estimates (i.e. relative risk, odds ratio or hazard ratio) reported. For the meta-analyses, relative risk estimates with the corresponding confidence interval were collected, log transformed and pooled per lifestyle or reproductive factor using a random effects model. Results: We identified 38 out of 556 potentially relevant publications, of which 13 publications were included in the meta-analyses. Body mass index (≥25 versus <25 kg/m 2 ; RR = 1.22; 95%CI:1.01–1.47), alcohol consumption (ever versus never; RR = 1.19; 95%CI:1.01–1.40), primiparity (≥25 versus <25 years; RR = 1.06; 95%CI:1.02–1.10) and age at menopause (≥45 versus <45 years; RR = 1.27; 95%CI:1.08–1.49) were associated with a significantly increased CBC risk, whereas parity (≥4 full-term pregnancies versus nulliparous; RR = 0.56; 95%CI:0.42–0.76 and ≥2 full-term pregnan- cies versus 1; RR = 0.86; 95%CI:0.79–0.94) was associated with a significantly decreased CBC risk. No significant association was observed Table 1 (abstract 182 PB-083): Multivariate analyses of disease free survival and overall survival Characteristic N(%) BMI < 25 BMI ≥ 25 DFS HR(95.0% CI) P OS HR(95.0% CI) P LN statue 0.000 0.000 Negative 971(56.9) 792(53.8) 1 1 Positive 736(43.1) 679(46.2) 4.036(3.213–5.071) 4.139(3.204–5.347) BMI 0.173 0.012 <25 1707(53.7) 1 1 ≥25 1471(46.3) 1.148(0.941–1.401) 1.328(1.063–1.658) Tumor size 0.045 0.125 ≤2 cm 782(45.8) 598(40.7) 1 1 2–5 cm 645(37.8) 704(47.9) 1.157(0.928–1.443) 1.124(0.880–1.437) >5 cm 57(3.3) 56(3.8) 1.761(1.163–2.666) 1.702(1.075–2.695) Unknown 223(13.1) 113(7.7) 1.284(0.900–1.831) 1.265(0.847–1.888) Histological grade 0.001 0.064 1–2 811(47.5) 750(51.0) 1 1 3 234(13.7) 194(13.2) 1.602(1.226–2.092) 1.356(0.999–1.840) Unknown 664(38.8) 527(35.8) 1.412(1.117–1.785) 1.285(0.990–1.666) ER 0.458 0.106 Negative 1205(70.6) 1090(74.1) 1 1 Positive 502(29.4) 381(25.9) 0.877(0.620–1.241) 0.723(0.488–1.072) PR 0.000 0.000 Negative 1085(63.6) 959(65.2) 1 1 Positive 622(36.4) 512(34.8) 0.479(0.357–0.644) 0.448(0.320–0.628) Her-2 0.236 0.200 Negative 916(53.7) 860(58.5) 1 1 Uncertain 428(25.1) 336(22.8) 1.344(0.916–1.970) 1.446(0.967–2.162) Positive 363(21.3) 275(18.7) 1.696(0.803–3.583) 1.409(0.560–3.541) Subtype 0.617 0.781 ER-PR-HER-2- 205(12.0) 105(10.2) 1 1 ER/PR + HER-2- 711(41.7) 710(48.3) 1.099(0.716–1.687) 1.072(0.670–1.715) HER-2 + 338(19.8) 256(17.4) 0.711(0.354–1.428) 0.733(0.303–1.774) Ki-67 0.039 0.201 Low 323(18.9) 269(18.3) 1 1 High 1384(81.1) 1202(81.7) 1.405(1.017–1.941) 1.238(0.881–1.824) European Journal of Cancer 92, Suppl. 3 (2018) S17–S160 S45 Abstracts, EBCC 11 Poster Session (Wednesday, 21 March 2018)