Validation over time of a nomogram including HER2 status to predict the sentinel node positivity in early breast carcinoma.

BACKGROUND: The molecular subtypes of breast cancer have different axillary status. A nomogram including the interaction covariate between estrogen receptor (ER) and HER2 has been recently published (Reyal et al. PLOS One, May 2011) and allows to identify the patients with a high risk of positive sentinel lymph node (SLN). The purpose of our study was to validate this model on an independent population. METHODS: We studied 755 consecutive patients treated at Institut Curie for operable breast cancer with sentinel node biopsies in 2009. The multivariate model, including age, tumor size, lymphovascular invasion and interaction covariate between ER and HER2 status, was used to calculate the theoretical risk of positive sentinel lymph node (SLN) for all patients. The performance of the model on our population was then evaluated in terms of discrimination (area under the curve AUC) and of calibration (Hosmer-Lemeshow HL test). RESULTS: our population was significantly different from the training population for the following variables: median tumor size in mm, lymphovascular invasion, positive ER and age. The nomogram showed similar results in our population than in the training population in terms of discrimination (AUC=0.72 [0.68-0.76] versus 0.73 [0.7-0.75] and calibration (HL p=0.4 versus p=0.35). CONCLUSIONS: Despite significant differences between the two populations concerning variables which are part of the nomogram, the model was validated in our population. This nomogram is robust over time to predict the likelihood of positive SLN according to molecular subtypes defined by surrogate markers ER and HER2 determined by immunohistochemistry in clinical practice.

Whole body [(18) F]fluorodeoxyglucose positron emission tomography imaging for the diagnosis of pacemaker or implantable cardioverter defibrillator infection: a preliminary prospective study.

We studied the potential use of [(18) F]fluorodeoxyglucose ((18) F-FDG) whole body positron emission tomography (PET)-computed tomography for the diagnosis of device infection and extension of infection. Twenty-one patients with suspected device infection were prospectively included and compared with 14 controls free of infection. (18) F-FDG uptake on the box and on the leads was visually and quantitatively interpreted (using the maximal standard uptake value). The final diagnosis was obtained either from bacteriological data after device culture (n = 11) or by a 6-month follow-up according to modified Duke's criteria (n = 10). Ten patients finally showed infection on bacteriological study (n = 8) or during follow-up (n = 2). Sensitivity, specificity, positive predictive value and negative predictive value were, respectively, 80%, 100%, 100% and 84.6% on patient-based analysis (presence or absence of infection). They were 100%, 100%, 100% and 100% for boxes, but only 60%, 100%, 100% and 73% for leads. Quantitative analysis could be useful for boxes but not for leads, for which the presence of a mild hot spot was the best criterion of infection. The four false negatives on leads received antibiotics for longer than the six true positives (20 ± 7.2 vs. 3.2 ± 2.3 days, p <0.01). Although the study was not designed for this purpose, management could have been modified by PET results in six of 21 patients. (18) F-FDG PET imaging may be useful for the diagnosis of device infection, and could impact on clinical management. Interpretation of negative cases should be performed with caution if patients have received antibiotics.

Role of positron emission tomography (PET) in head and neck cancer.

F-18 fluorodeoxyglucose positron emission tomography is now part of the initial stage III and IV cancer work-up and each time that metastasis or the presence of a second cancer is suspected that may contraindicate major surgery. Similarly, this exam should be undertaken when the conventional work-up is negative but there is isolated metastatic adenopathy. In therapeutic follow-up, a 3- or 4-month delay must be respected to prevent false-positive exams caused by inflammation. Although FDG-PET seems very promising in determining target volumes in radiotherapy, its implementation raises a number of problems that can only be resolved through the collaboration of all of the different specialists.