Are you Harmar D Brereton?

Claim your profile

Publications (2)2.78 Total impact

  • Article: Vitamin D deficiency is widespread in cancer patients and correlates with advanced stage disease: a community oncology experience.
    [show abstract] [hide abstract]
    ABSTRACT: The purpose of this study was to correlate serum vitamin D levels with potential clinical variables and to determine the extent of vitamin D deficiency in a large, outpatient oncology practice. One hundred ninety-five consecutive patients referred for consultation at a community radiation oncology center from October 8, 2008 to March 17, 2010 had vitamin D levels ordered. Patients who were deficient in vitamin D were treated with replacement therapy. Demographic and medical data were collected prospectively and subsequently analyzed. Pretreatment baseline patient and tumor characteristics were evaluated with respect to vitamin D concentrations. One hundred and sixty patients were analyzed. A total of 74% of patients had 25-hydroxyvitamin D concentrations considered either deficient (<20 ng/mL) or suboptimal (20-30 ng/mL). Replacement therapy raised serum vitamin D levels by an average of 15 ng/mL (95% CI = 11-18, P < 0.01). Lower than median serum vitamin D levels were associated with stage III disease in univariate analysis [OR = 2.6 (95% CI = 1.1-6.2), p = 0.04] as well as multivariate analysis adjusted for age, sex, body mass index, and season of draw [OR = 3.3 (95% CI = 1.1-9.7), P = 0.03]. Three-quarters of patients in our series had suboptimal or deficient circulating concentrations of 25-hydroxyvitamin D. Low serum vitamin D levels, independent of age, sex, and body mass index, predicted advanced stage disease.
    Nutrition and Cancer 03/2012; 64(4):521-5. · 2.78 Impact Factor
  • Source
    Article: Serum vitamin D levels among patients in a clinical oncology practice compared to primary care patients in the same community: a case-control study.
    [show abstract] [hide abstract]
    ABSTRACT: Objectives Low serum vitamin D levels have been associated with risk for certain malignancies, but studies have not directly analysed levels between community oncology and primary care practices. The purpose of this study was to compare serum vitamin D levels in patients at a community oncology practice with non-cancer patients at a primary care practice. Design Retrospective case-control study. 25-Hydroxyvitamin D levels were ordered for screening in both cancer and non-cancer patients. Levels were compared in univariate and multivariate analyses adjusted for age, body mass index and season of blood draw. Setting A community-based radiation oncology centre and a community-based primary care practice: both located in Northeastern Pennsylvania, USA. Participants 170 newly diagnosed cancer patients referred for initial consultation at the community oncology centre from 21 November 2008 to 18 May 2010, and 170 non-cancer patients of the primary care practice who underwent screening for hypovitaminosis D for the first time from 1 January 2009 to 31 December 2009. Primary and secondary outcome measures The primary outcome measure was mean serum vitamin D level, and the secondary outcome measures were frequencies of patients with vitamin D levels <20 ng/ml and levels <30 ng/ml. Results The oncology patients had a significantly lower mean serum vitamin D level (24.9 ng/ml) relative to a cohort of non-cancer primary care patients (30.6 ng/ml, p<0.001) from the same geographical region. The relationship retained significance after adjustment for age, body mass index and season of blood draw in multivariate analysis (p=0.001). Levels <20 and <30 ng/ml were more frequent in the oncology patients (OR (95% CI)=2.59 (1.44 to 4.67) and 2.04 (1.20 to 3.46), respectively) in multivariate analysis. Conclusions Cancer patients were found to have low vitamin D levels relative to a similar cohort of non-cancer primary care patients from the same geographical region.
    BMJ open. 01/2011; 1(2):e000397.