Association of body mass index with risk of luminal A but not luminal B estrogen receptor-positive and HER2-negative breast cancer for postmenopausal Japanese women.

BACKGROUND: The impact of body mass index (BMI) on the risk of postmenopausal estrogen receptor (ER)-positive breast cancers has been well documented. However, the mechanism for the impact of BMI on the etiology of luminal A and luminal B subtypes has not yet been identified. METHODS: We analyzed associations between BMI and breast cancers stratified by immunohistochemically defined intrinsic subtypes, and 1,297 Japanese women (615 breast cancer patients and 682 healthy women from a breast cancer screening program) were enrolled in a case-control study. ER-positive/human epidermal growth factor receptor 2 (HER2)-negative breast cancers were classified into luminal A and B subtypes according to Ki67 expression levels. RESULTS: Higher BMI was significantly positively associated with postmenopausal breast cancer risk for one-unit increase in BMI (adjusted odds ratio (aOR) 1.09, 95 % confidence interval (CI) 1.04-1.15; P = 0.0008). Analyses of postmenopausal women revealed that BMI was consistently and exclusively associated with luminal A incidence (aOR 1.18, 95 % CI 1.10-1.26; P < 0.0001). When BMI was divided into three categories corresponding to those of controls, among postmenopausal women, the observed positive association was confined to luminal A (high vs low, aOR 2.98, 95 % CI 1.53-5.80; P < 0.005), but not luminal B (aOR 0.95, 95 % CI 0.47-1.91) subtypes. CONCLUSIONS: We observed that BMI was significantly positively associated with increased risk of postmenopausal breast cancer for Japanese women with luminal A, but not with luminal B tumor subtype.

Hepatobiliary scintigraphy after biliary reconstruction-Roux Y and RY-DJ.

BACKGROUND/AIMS: Reconstruction of extrahepatic biliary tract with benign lesion still has some unsettled problems, such as postoperative cholangitis. This study was conducted to compare bile through the remnant alimentary tract in patients undergoing Roux-Y-duodenojejunal anastomosis (RY-DJ) which was designed for decompressing the jejunal limb of R-Y and for allowing an inflow of bile into the duodenum, and those undergoing Roux-Y choledochojejunostomy (R-Y), using hepatobiliary scintigraphy. METHODOLOGY: Five normal human volunteers and 20 patients underwent R-Y (n=14), RY-DJ (n=6), using hepatobiliary scintigraphy. RESULTS: Postoperative cholangitis developed in 2 patients (14%) with R-Y and none with RY-DJ. Hepatobiliary scintigraphy showed prominent stasis of 99mTc in the proximal jejunum loop of the patients who underwent R-Y, which was not found in the upper jejunum of the patients with RY-DJ. The time taken before visualization of 99mTc at the upper jejunum in the patient who underwent R-Y (65 +/- 5 min) was significantly longer than that in the healthy control (40 +/- 5 min). On the other hand, the time taken before visualization of 99mTc at the upper jejunum in RY-DJ (45 +/- 5 min) was similar to that of healthy controls. CONCLUSIONS: These data suggested that this new method (RY-DJ) for reconstructing the extrahepatic biliary tract was more physiological with less postoperative complications than R-Y.