Roux-en-Y gastric bypass is a gastric reduction duodenal switch with a combination of restrictive and malabsorptive procedures. It is the most common gastric bypass procedure performed in the United States. Malabsorption causing nutritional deficiencies does occur, yet a PubMed literature search (1955-2009) returned no reports of malabsorption of anticancer agents after gastric bypass. To our knowledge, this is the first report of three cases of malabsorption of the anticancer agent tamoxifen after this procedure. The first patient was a 58-year-old woman who underwent Roux-en-Y bypass for morbid obesity. Two years later, she developed estrogen receptor-positive ductal carcinoma in situ of the breast, underwent lumpectomy and irradiation, and tamoxifen was started. Two years after that, she presented with concerns of potential malabsorption of the drug. Her plasma tamoxifen level was 28 ng/ml, which was below the lower limit of the therapeutic range (77-274 ng/ml for 10-30-mg/day regimens). The second patient was a 51-year-old woman who sought medical advice on risk reduction for breast cancer after receiving a diagnosis of atypical ductal hyperplasia of the breast. She also had a history of morbid obesity and underwent Roux-en-Y bypass. Tamoxifen was started to reduce her risk of breast cancer; her plasma tamoxifen level was subtherapeutic at 14 ng/ml. The third patient was a 53-year-old woman with estrogen receptor-positive breast cancer who underwent lumpectomy and was prescribed anastrozole, an aromatase inhibitor. She also underwent Roux-en-Y bypass for morbid obesity. As she experienced adverse effects while receiving anastrozole, the drug was discontinued, and tamoxifen 20 mg/day was started. Her tamoxifen plasma level was 52 ng/ml. Therefore, her tamoxifen dosage was increased to 20 mg twice/day. Six weeks later, her tamoxifen level was 120 ng/ml (therapeutic range 95-520 ng/ml for the increased dosage). These three cases suggest that steady-state serum tamoxifen levels should be evaluated in patients who have undergone Roux-en-Y gastric bypass. Until adequate data suggest otherwise, parenteral anticancer alternatives should be considered when systemic therapy is needed in a patient with malabsorption.
Observational studies have reported an inverse association between vitamin D intake and breast cancer risk. We examined whether vitamin D supplementation in high-risk premenopausal women reduces mammographic density (MD), an established breast cancer risk factor. We conducted a multicenter randomized double-blind placebo-controlled trial in premenopausal women at high risk for breast cancer [5-year risk ! 1.67%, lifetime risk ! 20%, lobular carcinoma in situ, prior stage 0-II breast cancer, hereditary breast cancer syndrome, or high MD (heterogeneously/extremely dense)], with a baseline serum 25-hydroxyvitamin D [25(OH)D] 32 ng/mL. Participants were randomized to 12 months of vitamin D3 20,000 IU/week or matching placebo. The primary endpoint was change in MD from baseline to 12 months using the Cumulus technique. Secondary endpoints included serial blood bio-markers [25(OH)D, 1,25-dihydroxyvitamin D (1,25 (OH)D), insulin-like growth factor (IGF)-1, IGFbinding protein-3] and MD change at 24 months. Among 208 women randomized, median age was 44.6 years, 84% were white, 33% had baseline 25 (OH)D < 20 ng/mL, and 78% had high baseline MD. Comparing the active and placebo groups at 12 months, MD changes were small and did not significantly differ. Mean MD changes at 12 and 24 months were À0.3% and À1.2%, respectively, in the active arm and þ1.5% and þ1.6% with placebo (P > 0.05). We observed a mean change in serum 25(OH)D of þ18.9 versus þ2.8 ng/mL (P < 0.01) and IGF-1 of À9.8 versus À1.8 ng/mL (P ¼ 0.28), respectively. At 12 months, MD was positively correlated with serum IGF-1 and IGF-1/IGFBP-3 (P < 0.01). This trial does not support the use of vitamin D supplementation for breast cancer risk reduction.
The rate of lymphedema was higher in delayed ALND but not statistically significant. Comparison, however, is difficult, given the limited sample size. We urge the other centers of NSABP-B32 to validate this, by contacting the node-positive patients for measurements. The lymphedema rate for SLNB alone was 0% and approached statistical significance when compared with node-negative ALND.
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