Flora E van Leeuwen

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BACKGROUND Immunohistochemical markers are often used to classify breast cancer into subtypes that are biologically distinct and behave differently. The aim of this study was to estimate mortality for patients with the major subtypes of breast cancer as classified using five immunohistochemical markers, to investigate patterns of mortality over time, and to(More)
BACKGROUND Many epidemiologic studies have found an association between physical activity and breast cancer risk, although this has not been a consistent finding. METHODS Studies were identified through a systematic review of literature available on PubMed through February 2006. We included all cohort and case-control studies that assessed total or(More)
BACKGROUND Tamoxifen increases the risk of endometrial cancer. However, few studies have produced reliable risk estimates by duration, dose, and recency of use, or addressed the prognosis of endometrial cancers in tamoxifen-treated women. METHODS We did a nationwide case-control study on the risk and prognosis of endometrial cancer after tamoxifen use for(More)
CONTEXT Second cancer is the leading cause of death in long-term survivors of Hodgkin disease (HD), with exceptionally high risks of breast cancer among women treated at a young age. Quantitative associations between radiotherapy dose delivered to the breast and administered chemotherapy have not been reported to date in large series, nor has the influence(More)
BACKGROUND Female survivors of Hodgkin's disease (HD) have a strongly elevated risk of breast cancer, but factors responsible for the increased risk are not well known. METHODS We investigated the effects of radiation dose, chemotherapy (CT), and reproductive factors on breast cancer risk in a nested case-control study in The Netherlands in a cohort of(More)
BACKGROUND Previous studies have suggested that breast cancer risk factors are associated with estrogen receptor (ER) and progesterone receptor (PR) expression status of the tumors. METHODS We pooled tumor marker and epidemiological risk factor data from 35,568 invasive breast cancer case patients from 34 studies participating in the Breast Cancer(More)
PURPOSE To compare radiotherapy and chemotherapy effects on long-term risks of second malignant neoplasms (SMNs) and cardiovascular diseases (CVDs) in testicular cancer (TC) survivors. PATIENTS AND METHODS In our nationwide cohort comprising 2,707 5-year TC survivors, incidences of SMNs and CVDs were compared with general-population rates by calculating(More)
PURPOSE To quantify the relative and absolute excess risks (AER) of site-specific second cancers, in particular solid tumors, among long-term survivors of Hodgkin's disease (HD) and to assess risks according to age at HD diagnosis, attained age, and time since initial treatment. PATIENTS AND METHODS Data from 32,591 HD patients (1,111 25-year survivors)(More)
PURPOSE To quantify the risk of second cancers among long-term survivors of Hodgkin's disease (HD) diagnosed before 21 years of age and to explore sex-, age-, and site-related differences. PATIENTS AND METHODS We analyzed data from 5,925 pediatric HD patients, including 2,646 10-year and 755 20-year survivors, who were reported to 16 population-based(More)
BACKGROUND Survivors of hereditary retinoblastoma have an elevated risk of developing second malignancies, but data on the risk in middle-aged retinoblastoma survivors (ie, those with more than 40 years of follow-up) are scarce. METHODS Data from the Dutch retinoblastoma registry were used to analyze risks of second malignancies in 668 retinoblastoma(More)