Prediction of Pathologic Complete Response in Breast Cancer Patients Comparing Magnetic Resonance Imaging with Ultrasound in Neoadjuvant Setting.

BACKGROUND: Some subgroups of breast cancer patients receiving neoadjuvant chemotherapy (NACT) show high rates of pathologic complete response (pCR) in the breast, proposing the possibility of omitting surgery. Prediction of pCR is dependent on accurate imaging methods. This study investigated whether magnetic resonance imaging (MRI) is better than ultrasound (US) in predicting pCR in breast cancer patients receiving NACT. METHODS: This institutional, retrospective study enrolled breast cancer patients receiving NACT who were examined by either MRI or combined US and mammography before surgery from 2016 to 2019. Imaging findings were compared with pathologic response evaluation of the tumor. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for prediction of pCR were calculated and compared between MRI and US. RESULTS: Among 307 patients, 151 were examined by MRI and 156 by US. In the MRI group, 37 patients (24.5 %) had a pCR compared with 51 patients (32.7 %) in the US group. Radiologic complete response (rCR) was found in 35 patients (23.2 %) in the MRI group and 26 patients (16.7 %) in the US group. In the MRI and US groups, estimates were calculated respectively for sensitivity (87.7 % vs 91.4 %), specificity (56.8 % vs 33.3 %), PPV (86.2 % vs 73.8 %), NPV (60.0 % vs 65.4 %), and accuracy (80.1 % vs 72.4 %). CONCLUSIONS: In predicting pCR, MRI was more specific than US, but not sufficiently specific enough to be a valid predictor of pCR for omission of surgery. As an imaging method, MRI should be preferred when future studies investigating prediction of pCR in NACT patients are planned.

Diagnostic challenges in clinical, radiological and histopathological tests regarding papillomatous lesions of the breast.

Papillomas of the female breast is a relatively frequent lesion, and the majority are benign when excised. However, some may host malignant or premalignant areas. Consequently, it is a worldwide accepted principle to excise the lesion whenever diagnosed. However, this leads to a large number of patients having an unnecessary operation. The present study was designed to investigate whether we could find clinical, radiological and pathological factors in the preoperative, diagnostic setting that could identify patients hosting a benign papilloma in order to avoid operation. The patient material consisted of 260 patients, all with a preoperative diagnosis of a papillomatous process in core biopsy. The lesion was excised, and 71% had a benign lesion. The rest had lesions ranging from premalignant to malignant. In the clinical, radiological and histopathological investigations conducted, we were not able to identify factors that statistically significant could predict whether the lesion was benign or malignant. However, our data showed a higher prevalence of malignant and premalignant lesions for older patient, larger lesions, and lesions found at a longer distance from the papilla. We conclude that, since almost 30% of the patients in our study ended up with a premalignant or malignant diagnosis, where no statistically significant preoperative factors could indicate a benign outcome, operation is warranted in all patients with a preoperative diagnosis of a papillomatous lesion.

A pig model of acute Staphylococcus aureus induced pyemia.

BACKGROUND: Sepsis caused by Staphylococcus aureus constitutes an important cause of morbidity and mortality in humans, and the incidence of this disease-entity is increasing. In this paper we describe the initial microbial dynamics and lesions in pigs experimentally infected with S. aureus, with the aim of mimicking human sepsis and pyemia. METHODS: The study was conducted in anaesthetized and intravenously inoculated pigs, and was based on bacteriological examination of blood and testing of blood for IL-6 and C-reactive protein. Following killing of the animals and necropsy bacteriological and histological examinations of different organs were performed 4, 5 or 6 h after inoculation. RESULTS: Clearance of bacteria from the blood was completed within the first 2 h in some of the pigs and the highest bacterial load was recorded in the lungs as compared to the spleen, liver and bones. This probably was a consequence of both the intravenous route of inoculation and the presence of pulmonary intravascular macrophages. Inoculation of bacteria induced formation of acute microabscesses in the lungs, spleen and liver, but not in the kidneys or bones. No generalized inflammatory response was recorded, i.e. IL-6 was not detected in the blood and C-reactive protein did not increase, probably because of the short time course of the study. CONCLUSION: This study demonstrates the successful induction of acute pyemia (microabscesses), and forms a basis for future experiments that should include inoculation with strains of S. aureus isolated from man and an extension of the timeframe aiming at inducing sepsis, severe sepsis and septic shock.