MicroRNA expression as risk biomarker of breast cancer metastasis: a pilot retrospective case-cohort study.

BACKGROUND: MicroRNAs (miRNAs) are small, non-coding RNA molecules involved in post-transcriptional gene regulation and have recently been shown to play a role in cancer metastasis. In solid tumors, especially breast cancer, alterations in miRNA expression contribute to cancer pathogenesis, including metastasis. Considering the emerging role of miRNAs in metastasis, the identification of predictive markers is necessary to further the understanding of stage-specific breast cancer development. This is a retrospective analysis that aimed to identify molecular biomarkers related to distant breast cancer metastasis development. METHODS: A retrospective case cohort study was performed in 64 breast cancer patients treated during the period from 1998-2001. The case group (n = 29) consisted of patients with a poor prognosis who presented with breast cancer recurrence or metastasis during follow up. The control group (n = 35) consisted of patients with a good prognosis who did not develop breast cancer recurrence or metastasis. These patient groups were stratified according to TNM clinical stage (CS) I, II and III, and the main clinical features of the patients were homogeneous. MicroRNA profiling was performed and biomarkers related to metastatic were identified independent of clinical stage. Finally, a hazard risk analysis of these biomarkers was performed to evaluate their relation to metastatic potential. RESULTS: MiRNA expression profiling identified several miRNAs that were both specific and shared across all clinical stages (p ≤ 0.05). Among these, we identified miRNAs previously associated with cell motility (let-7 family) and distant metastasis (hsa-miR-21). In addition, hsa-miR-494 and hsa-miR-21 were deregulated in metastatic cases of CSI and CSII. Furthermore, metastatic miRNAs shared across all clinical stages did not present high sensitivity and specificity when compared to specific-CS miRNAs. Between them, hsa-miR-183 was the most significative of CSII, which miRNAs combination for CSII (hsa-miR-494, hsa-miR-183 and hsa-miR-21) was significant and were a more effective risk marker compared to the single miRNAs. CONCLUSIONS: Women with metastatic breast cancer, especially CSII, presented up-regulated levels of miR-183, miR-494 and miR-21, which were associated with a poor prognosis. These miRNAs therefore represent new risk biomarkers of breast cancer metastasis and may be useful for future targeted therapies.

The Accuracy of p16/Ki-67 and HPV Test in the Detection of CIN2/3 in Women Diagnosed with ASC-US or LSIL.

The objective of this study was to compare the accuracies of double staining for p16/Ki-67 and the molecular test for high-risk HPV (hr-HPV) to identify high-grade cervical intraepithelial neoplasia (CIN2/CIN3) in women with cervical cytology of atypical squamous cells of undetermined significance (ASC-US) and low-grade squamous intraepithelial lesion (LSIL). Data were collected from 201 women who underwent cervical cytology screening in the Barretos Cancer Hospital and their results were categorized as ASC-US (n=96) or LSIL (n=105). All patients underwent colposcopy with or without cervical biopsy for diagnosis of CIN2/CIN3. The hr-HPV test (Cobas 4800 test) and immunocytochemistry were performed to detect biomarkers p16/Ki-67 (CINtec PLUS test). Two samples (1 ASC-US/1 LSIL) were excluded from the analysis due to inconclusive results of the histologic examination. There were 8 cases of CIN2/CIN3 among 95 women with ASC-US (8.4%), and 23 cases of CIN2/CIN3 among 104 women with LSIL (22.1%). In the group of women with ASC-US, the sensitivity and specificity in diagnosing CIN2/CIN3 were 87.5% and 79.5% for the HPV test and 62.5% and 93.1% for p16/Ki-67. Among women with LSIL, the sensitivity and specificity in the diagnosis of CIN2/CIN3 were 87% and 34.7% for the HPV test and 69.6% and 75.3% for immunocytochemistry. Superior performance was observed for p16/Ki-67 double staining, especially among women under 30 for whom the test had an area under the ROC curve of 0.762 (p<0.001). Both p16/Ki-67 double staining and the hr-HPV DNA test had similar performance in predicting high-grade cervical intraepithelial neoplasia among women with ASC-US. The best performance was observed in women aged >30 years. In younger women (≤30 years) with LSIL, p16/Ki-67 had greater accuracy in identifying precursor lesions. Among women >30 years diagnosed with LSIL, the two methods showed similar performance.