Body mass index, age at breast cancer diagnosis, and breast cancer subtype: a cross-sectional study.

PURPOSE: Evidence suggests that premenopausal obesity decreases and postmenopausal obesity increases breast cancer risk. Because it is not well known whether this is subtype dependent, we studied the association between body mass index (BMI) and age at breast cancer diagnosis, or the probability of being diagnosed with a specific breast cancer phenotype, by menopausal status. METHODS: All patients with non-metastatic operable breast cancer from the University Hospital Leuven diagnosed between January 1, 2000 and December 31, 2013 were included (n = 7020) in this cross-sectional study. Linear models and logistic regression were used for statistical analysis. Allowing correction for age-related BMI-increase, we used the age-adjusted BMI score which equals the difference between a patient's BMI score and the population-average BMI score corresponding to the patient's age category. RESULTS: The quadratic relationship between the age-adjusted BMI and age at breast cancer diagnosis (p = 0.0207) interacted with menopausal status (p < 0.0001); increased age at breast cancer diagnosis was observed with above-average BMI scores in postmenopausal women, and with below-average BMI scores in premenopausal women. BMI was linearly related to the probabilities of Luminal B and HER2-like breast cancer phenotypes, but only in postmenopausal women. The relative changes in probabilities between both these subtypes mirrored each other. CONCLUSION: BMI associates differently before and after menopause with age at breast cancer diagnosis and with the probability that breast cancer belongs to a certain phenotype. The opposite effect of increasing BMI on relative frequencies of Luminal B and HER2-like breast cancers suggests a common origin.

Prognostic implications of lobular breast cancer histology: new insights from a single hospital cross-sectional study and SEER data.

BACKGROUND: Invasive lobular breast cancer (ILC) is generally believed to have an increased risk for late relapse compared to invasive ductal breast cancer (IDC). However, the study most often referred to is a chemotherapy trial that mainly included node positive patients. We hypothesize that nodal status may influence the hazard of relapse since time of diagnosis differently in invasive ductal carcinoma (IDC) and ILC. METHODS: Primary operable breast cancer patients from our institution diagnosed between 2000 and 2009 were studied. Multivariable analysis and subgroup analyses were performed to assess whether ILC carries a different prognosis compared to IDC. SEER data were used for external validation. RESULTS: In lymph node negative patients, ILC carries a better prognosis regarding distant metastasis free interval (DMFI) (HR 3.242 (1.380-7.614), p = 0.0069) with a trend towards improved breast cancer specific survival (BCSS), over the entire study frame (UZ Leuven data). In lymph node positive patients, both DMFI (HR 0.466 (0.309-0.703), p = 0.0003) and BCSS (HR 0.441 (0.247-0.788), p = 0.0057) are significantly worse for ILC, especially after longer follow-up (>4-5 years) (UZ Leuven data). Similar results were found in the SEER cohort. Results remained identical when excluding screen detected cases (data not shown). CONCLUSION: The prognostic impact of lobular histology not only depends on time since diagnosis but also on nodal status. The general believe that ILC have compromised late-term outcome compared to IDC seems untrue for the majority ( = node negative) of ILCs.

Breast cancer phenotype, nodal status and palpability may be useful in the detection of overdiagnosed screening-detected breast cancers.

BACKGROUND: Breast cancer remains the leading cause of female cancer death despite improvements in treatment and screening. Screening is often criticized for leading to overdiagnosis and overtreatment. However, few have attempted to identify overdiagnosed cases. PATIENTS AND METHODS: A large, consecutive series of patients treated for primary operable, screening-detected, breast cancer (n = 1610). Details from pathology and clinical reports, treatment and follow-up were available from our prospectively managed database. Univariate and multivariate Cox proportional models were used to study the prognostic variables in screening-detected breast cancers for distant metastatic and breast cancer-specific survival. RESULTS: We included 1610 patients. The mean/median follow-up was 6.0/6.0 years. Univariate analysis: tumor size, palpability, breast cancer phenotype and nodal status were predictors of distant metastasis and breast cancer-specific death. Multivariate analysis: palpability, breast cancer phenotype and nodal status remained independent prognostic variables. Palpability differed by breast cancer phenotype. CONCLUSION: Screening-detected breast cancer is associated with excellent outcome. Palpability, nodal status and breast cancer phenotype are independent prognostic variables that may select patients at increased risk for distant metastatic relapse and breast cancer-specific death. Overdiagnosed cases reside most likely in the nonpalpable node negative subgroup with a Luminal A phenotype.

The prognostic role of preoperative and (early) postoperatively change in CA15.3 serum levels in a single hospital cohort of primary operable breast cancers.

Measuring CA15.3 serum levels in the early breast cancer setting is not recommended by current ASCO guidelines. In this large single center study, we assess the prognostic value of preoperative (n = 3746), postoperative (n = 4049) and change in (n = 3252) CA15.3, also across different breast cancer phenotypes. Preoperative, postoperative and change in CA15.3 were all significant (p = 0.0348, p < 0.0001, p < 0.0001 respectively in multivariate analysis) predictors of distant metastasis free survival. For breast cancer specific survival, only postoperative and change in CA15.3 were significant predictors (p < 0.0001 both). Multivariate prognostic models did not improve by incorporating information on preoperative CA15.3, but did improve when introducing information on postoperative CA15.3 for distant metastasis (p = 0.0365) and on change in CA15.3 for breast cancer specific survival (p = 0.0291). Change in CA15.3 impacts on prognosis (distant metastasis) differently in different breast cancer phenotypes. A decrease in CA15.3 may be informative of improved prognosis in basal like and HER2 like breast cancer.

A critical review why assessment of steroid hormone receptors in breast cancer should be quantitative.

Steroid receptors have been around in the field of breast cancer for decades now. Still, controversy remains on how best to report steroid receptors. In this review, we will convince the reader why benefits outweigh pitfalls, when reporting steroid receptors in a quantitative rather than qualitative way. Summarizing decades of research in this field, we will explore the evidence why quantitative reporting is superior in all settings (neoadjuvant, adjuvant and metastatic settings). Furthermore, we will also summarize different staining methods, definitions and pitfalls that have shown to be important points of discussion in earlier debates. Although the molecular unraveling of breast cancer in the past decade has revolutionized the way we think about breast cancer, we should not easily abandon the classical pathological variables such as steroid receptors in favor of molecular tools.

Applying the 2011 St Gallen panel of prognostic markers on a large single hospital cohort of consecutively treated primary operable breast cancers.

BACKGROUND: Many easily measurable and readily available factors are now established as being prognostic in primary operable breast cancer. We here applied the 2011 St Gallen surrogate definition for breast cancer subclassification using tumor grade instead of Ki67. PATIENTS AND METHODS: Four thousand three hundred and eighteen consecutive patients who had surgery for primary operable breast cancer (1 January 2000 and 31 December 2009) in UZ Leuven excluding primary metastastic male breast cancers and those receiving neoadjuvant therapy. Five different surrogate phenotypes were created using the combined expression of estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2 together with tumor grade. Disease-free interval (DFI), distant metastastis-free interval (DMFI), locoregional relapse-free interval (LRRFI), breast cancer-specific survival (BCSS) and overall survival (OS) were calculated. RESULTS: Surrogate phenotypes present with significant differences in DFI, DMFI, LRRFI, BCSS and OS. 'Luminal A' tumors presented with the best outcome parameters but the effect weakened at longer follow-up. CONCLUSIONS: The four surrogate markers, agreed upon by the 2011 St Gallen consensus, defined five prognostic surrogate phenotypes in a large series of consecutively treated breast cancer patients. Their prognostic value changed with longer follow-up. The added value of gene expression profile over classical pathological assessment remains to be defined.

Lobular and non-lobular breast cancers differ regarding axillary lymph node metastasis: a cross-sectional study on 4,292 consecutive patients.

Invasive lobular carcinoma (ILC) accounts for 8-14% of all breast cancers and carries distinct prognostic and biologic implications. The goal of our study was to investigate the impact of lobular histology on axillary lymph node (ALN) involvement. This is a cross-sectional study of 4,292 consecutive patients surgically treated for breast carcinoma at the University Hospitals Leuven. Logistic regression analysis was used to relate ILC to lymph node involvement while controlling for the following clinicopathologic features: tumor size, multifocal disease, tumor grade, lobular subtype and the combined steroid, and Her-2 status. Odds ratios (ORs) and 95% confidence intervals (CIS) were computed. A subgroup analysis was performed for patients that underwent a sentinel lymph node (SLN) procedure. The observed incidence of ILC was 13%. ILCs were larger, were more often grade II, multifocal, steroid receptor positive and Her-2 negative, and tended to be present in older patients. Incidence of ALN involvement was 42.0% for ILCs versus 38.3% for other tumors (OR 1.17, 95% CI 0.97-1.40). For the SLN subgroup, ILCs were less often ALN positive than non-ILCs (20.5% versus 28.3%, OR 0.66, 95% CI: 0.41-1.00). In the multivariable analysis, the lobular subtype was identified as less likely to have ALN involvement (adjusted OR 0.66, 95% CI 0.53-0.82). The analysis for the SLN subgroup showed comparable results (adjusted OR 0.49, 95% CI 0.30-0.78). This study has demonstrated that the lobular subtype is an independent predictor of lymph node involvement with ILC having a lower incidence of involved lymph nodes. The mildly higher incidence of ALN metastasis in lobular cancers in univariable analysis is not due to the lobular subtype, but due to confounding factors that interact with lymph node involvement.

Short-Term Prognostic Index for Breast Cancer: NPI or Lpi.

Axillary lymph node involvement is an important prognostic factor for breast cancer survival but is confounded by the number of nodes examined. We compare the performance of the log odds prognostic index (Lpi), using a ratio of the positive versus negative lymph nodes, with the Nottingham Prognostic Index (NPI) for short-term breast cancer specific disease free survival. A total of 1818 operable breast cancer patients treated in the University Hospital of Leuven between 2000 and 2005 were included. The performance of the NPI and Lpi were compared on two levels: calibration and discrimination. The latter was evaluated using the concordance index (cindex), the number of patients in the extreme groups, and difference in event rates between these. The NPI had a significant higher cindex, but a significant lower percentage of patients in the extreme risk groups. After updating both indices, no significant differences between NPI and Lpi were noted.