Birth cohort trends for breast cancer among women in Europe and North America

The birth cohort pattern of risk for breast cancer among European women is remarkably similar to that observed among women in the United States and Canada.  A sharp decrease in risk for women born after World War II is particularly intriguing, and warrants further epidemiological investigation in order to identify etiologic factors potentially responsible for the unexpected and unexplained declining risk

Visualizing Rank Deficient Models: A Row Equation Geometry of Rank Deficient Matrices and Constrained-Regression

Situations often arise in which the matrix of independent variables is not of full column rank. That is, there are one or more linear dependencies among the independent variables. This paper covers in detail the situation in which the rank is one less than full column rank and extends this coverage to include cases of even greater rank deficiency. The emphasis is on the row geometry of the solutions based on the normal equations. The author shows geometrically how constrained-regression/generalized-inverses work in this situation to provide a solution in the face of rank deficiency

Epidemiologic characteristics and risk factors for renal cell cancer

Loren Lipworth1,2, Robert E Tarone1,2, Lars Lund2,3, Joseph K McLaughlin1,21International Epidemiology Institute, Rockville, MD, USA; 2Department of Medicine (JKM, RET) and Preventive Medicine (LL), Vanderbilt University Medical Center and Vanderbilt-Ingram Cancer Center, Nashville, TN, USA; 3Department of Urology, Viborg Hospital, Viborg, DenmarkAbstract: Incidence rates of renal cell cancer, which accounts for 85% of kidney cancers, have been rising in the United States and in most European countries for several decades. Family history is associated with a two- to four-fold increase in risk, but the major forms of inherited predisposition together account for less than 4% of renal cell cancers. Cigarette smoking, obesity, and hypertension are the most consistently established risk factors. Analgesics have not been convincingly linked with renal cell cancer risk. A reduced risk of renal cell cancer among statin users has been hypothesized but has not been adequately studied. A possible protective effect of fruit and vegetable consumption is the only moderately consistently reported dietary finding, and, with the exception of a positive association with parity, evidence for a role of hormonal or reproductive factors in the etiology of renal cell cancer in humans is limited. A recent hypothesis that moderate levels of alcohol consumption may be protective for renal cell cancer is not strongly supported by epidemiologic results, which are inconsistent with respect to the categories of alcohol consumption and the amount of alcohol intake reportedly associated with decreased risk. For occupational factors, the weight of the evidence does not provide consistent support for the hypotheses that renal cell cancer may be caused by asbestos, gasoline, or trichloroethylene exposure. The established determinants of renal cell cancer, cigarette smoking, obesity, and hypertension, account for less than half of these cancers. Novel epidemiologic approaches, including evaluation of gene–environment interactions and epigenetic mechanisms of inherited and acquired increased risk, are needed to explain the increasing incidence of renal cell cancer.Keywords: renal cell cancer, epidemiology, risk factor, revie