Can Histological Grade and Mitotic Index Replace Ki67 to Determine Luminal Breast Cancer Subtypes?

Introduction: Breast cancer can be classified into subtypes based on immunohistochemical markers, with Ki67 expression levels being used to divide luminal BC tumors in luminal A and B subtypes; however, Ki67 is not routinely determined due to a lack of standardization. Objective: To evaluate histological grade and Eliminate: the mitotic index to determine if they can be used as an alternative method to Ki67 staining for luminal subtype definition. Methods: We evaluated estrogen receptor positive breast cancer tissue samples. Pathological analysis included determination of Ki67. A low level of Ki67 was defined as <14% positive cells. Results: We evaluated 151 breast cancer samples; 24 (15,9%) were classified as I; 74 as HG II (49%), and 53 (35,1%) as HG III. The median value for Ki67 was 13% (range: <1% - 82%) and for MI was 2 (0-12). Histological grade I tumors exhibited Ki67 values significantly lower than HG II and III tumors (Anova, Tamhane test p=0,001). A higher Ki67 value was related to a higher MI (Rho Sperman p=0,336; R2= 0,0273). ROC curve analysis determined that a MI ≥ 3 had a sensibility of 61.9% and specificity of 66.7% in predicting a high Ki67 value (≥14%) (area under the curve: 0,691; p =0,0001). A HG I tumor or HG II-III with MI ≤2, had a high probability of corresponding to a LA tumor (76,3%), as defined using Ki67 expression, while the probability of a LB subtype was higher with HG II-III and a MI ≥3 (57.4%). Global discrimination was 68.1%. Conclusions: For the LA subtype, our predictive model showed a good correlation of HG and MI with the classification based on Ki67<14%. In the LB subtype, the model showed a weak correlation; therefore Ki67 determination seems to be needed for this group of patients.

Plethysmographic lung volumes in normal Chilean children and adolescents.

INTRODUCTION: Plethysmographic measurement is the most reliable method for evaluating lung volumes in children. Current published normative data are based on studies in primarily Caucasian children. OBJECTIVES: To establish Chilean normal values with new reference equations and to compare these results with previously published data. SUBJECTS AND METHODS: Lung function was measured [slow vital capacity (SVC), inspiratory capacity (IC), expiratory reserve volume (ERV), functional residual capacity (FRC), residual volume (RV), total lung capacity (TLC), and RV/TLC] in 245 healthy Chilean school children and adolescents, using spirometry and plethysmography; 123 girls and 122 boys were studied, aged 7-18 years. RESULTS: Almost all variables of pulmonary volume differed between boys and girls (P < 0.05). Z scores were significantly higher than zero in all age groups when compared with predicted values. We present predictive exponential equations for each variable of static lung volume; all of these variables had a strong correlation with height, but not weight. SUMMARY: Normal values of lung volumes of Chilean school children and adolescents are significantly higher than the current predictive values. These differences may be related to differences in anthropometric characteristics. We recommend using these data in our population and postulate that Latin-American populations like ours may have similar lung volumes.

[Empyema and pleural effusion in children]. / Empiema y efusión pleural en niños.

INTRODUCTION: Pleural empyema (PE) is a serious complication of community-acquired pneumonia (CAP). OBJECTIVES: To describe the clinical profile of hospitalized patients with PE in the pediatric ward of the Catholic University Hospital between 2000-2005. PATIENTS AND METHODS: Retrospectively, all pediatric admission due to CAP and pleural effusion (86 children) were identified. In 59 (70%) children > 1 thoracocentesis were performed. We considered PE as the presence in the pleural effusion of pus, and/or a positive gram strain and/ or positive culture, and/or a pH < 7.10. Children with effusions not meeting any criteria were used as controls. RESULTS: Twenty four PE and 25 controls were identified, with a global mean age of 2.9 years (range: 8 months to 14.3 years); 78% were < 5 years, with a significant difference between PE and controls [1.6 vs 3.3 years (p = 0.01)]. The mean duration of symptoms in PE patients before admission was 7 days (range: 2-21), and the most frequent symptoms were fever (100%) and cough (96%). In 15/24 cases a microorganism was identified being Streptococcus pneumoniae (n = 9) the most common. In 48 patients management was conservative and in 4 surgical procedures were required. The mean duration of hospitalization was significantly higher in the PE group vs controls group: 15 (range: 5-38) vs 9 days (range 3-16) (p < 0.01). A chest tube was inserted in 83% of children with EP compared with 36% in the control group (p = 0.002). There were no difference in number of days of oxygen use [6 vs 4.5 (p = 0.36)] or number of chest tubes per child [3 vs 2.5 (p = 0.29)]. No deaths were reported. CONCLUSION: PE in children represented an acute respiratory event associated with more prolonged hospitalization especially at younger ages; the majority of cases did not require surgical intervention.