Selective sentinel lymph node biopsy after neoadjuvant chemotherapy in breast cancer: results of the GEICAM 2005-07 study.

INTRODUCTION: A controversial aspect of breast cancer management is the use of sentinel lymph node biopsy (SLNB) in patients requiring neoadjuvant chemotherapy (NCT). This paper discusses the detection rate (DT) and false negatives (FN) of SLNB after NCT to investigate the influence of initial nodal disease and the protocols applied. METHODS: Prospective observational multicenter study in women with breast cancer, treated with NCT and SLNB post-NCT with subsequent lymphadenectomy. DT and FN rates were calculated, both overall and depending on the initial nodal status or the use of diagnostic protocols pre-SLNB. RESULTS: No differences in DT between initial node-negative cases and positive cases were found (89.8 vs. 84.4%, P=.437). Significant differences were found (94.1 vs. 56.5%, P=0,002) in the negative predictive value, which was lower when there was initial lymph node positivity, and a higher rate of FN, not significant (18.2 vs. 43.5%, P=.252) in the same cases. The axillary study before SLNB and after the NCT, significantly decreased the rate of FN in patients with initial involvement (55.6 vs 12.5, P=0,009). CONCLUSIONS: NCT means less DT and a higher rate of FN in subsequent SLNB, especially if there is initial nodal involvement. The use of protocols in axillary evaluation after administering the NCT and before BSGC, decreases the FN rate in these patients.

CDH22 hypermethylation is an independent prognostic biomarker in breast cancer.

BACKGROUND: Cadherin-like protein 22 (CDH22) is a transmembrane glycoprotein involved in cell-cell adhesion and metastasis. Its role in cancer is controversial because it has been described as being upregulated in colorectal cancer, whereas it is downregulated in metastatic melanoma. However, its status in breast cancer (BC) is unknown. The purpose of our study was to determine the molecular status and clinical value of CDH22 in BC. RESULTS: We observed by immunohistochemistry that the level of CDH22 expression was lower in BC tissues than in their matched adjacent-to-tumour and non-neoplastic tissues from reduction mammoplasties. Since epigenetic alteration is one of the main causes of gene silencing, we analysed the hypermethylation of 3 CpG sites in the CDH22 promoter by pyrosequencing in a series of 142 infiltrating duct BC cases. CDH22 was found to be hypermethylated in tumoral tissues relative to non-neoplastic mammary tissues. Importantly, this epigenetic alteration was already present in adjacent-to-tumour tissues, although to a lesser extent than in tumoral samples. Furthermore, CDH22 gene regulation was dynamically modulated in vitro by epigenetic drugs. Interestingly, CDH22 hypermethylation in all 3 CpG sites simultaneously, but not expression, was significantly associated with shorter progression-free survival (p = 0.015) and overall survival (p = 0.021) in our patient series. Importantly, CDH22 hypermethylation was an independent factor that predicts poor progression-free survival regardless of age and stage (p = 0.006). CONCLUSIONS: Our results are the first evidence that CDH22 is hypermethylated in BC and that this alteration is an independent prognostic factor in BC. Thus, CDH22 hypermethylation could be a potential biomarker of poor prognosis in BC.

CHL1 hypermethylation as a potential biomarker of poor prognosis in breast cancer.

The CHL1 gene encodes a cell-adhesion molecule proposed as being a putative tumour-suppressor gene in breast cancer (BC). However, neither the underlying molecular mechanisms nor the clinical value of CHL1 downregulation in BC has been explored. The methylation status of three CpG sites in the CHL1 promoter was analysed by pyrosequencing in neoplastic biopsies from 142 patients with invasive BC and compared with that of non-neoplastic tissues. We found higher CHL1 methylation levels in breast tumours than in non-neoplastic tissues, either from mammoplasties or adjacent-to-tumour, which correlated with lower levels of protein expression in tumours measured by immunohistochemistry. A panel of five BC cell lines was treated with two epigenetic drugs, and restoration of CHL1 expression was observed, indicating in vitro dynamic epigenetic regulation. CHL1 was silenced by shRNA in immortalized but non-neoplastic mammary cells, and enhanced cell proliferation and migration, but not invasion, were found by real-time cell analysis. The prognostic value of CHL1 hypermethylation was assessed by the log-rank test and fitted in a Cox regression model. Importantly, CHL1 hypermethylation was very significantly associated with shorter progression-free survival in our BC patient series, independent of age and stage (p = 0.001). In conclusion, our results indicate that CHL1 is downregulated by hypermethylation and that this epigenetic alteration is an independent prognostic factor in BC.

Differential involvement of RASSF2 hypermethylation in breast cancer subtypes and their prognosis.

Breast cancer is a heterogeneous disease that can be subdivided into clinical, histopathological and molecular subtypes (luminal A-like, luminal B-like/HER2-negative, luminal B-like/HER2-positive, HER2-positive, and triple-negative). The study of new molecular factors is essential to obtain further insights into the mechanisms involved in the tumorigenesis of each tumor subtype. RASSF2 is a gene that is hypermethylated in breast cancer and whose clinical value has not been previously studied. The hypermethylation of RASSF1 and RASSF2 genes was analyzed in 198 breast tumors of different subtypes. The effect of the demethylating agent 5-aza-2'-deoxycytidine in the re-expression of these genes was examined in triple-negative (BT-549), HER2 (SK-BR-3), and luminal cells (T-47D). Different patterns of RASSF2 expression for distinct tumor subtypes were detected by immunohistochemistry. RASSF2 hypermethylation was much more frequent in luminal subtypes than in non-luminal tumors (p = 0.001). The re-expression of this gene by lentiviral transduction contributed to the differential cell proliferation and response to antineoplastic drugs observed in luminal compared with triple-negative cell lines. RASSF2 hypermethylation is associated with better prognosis in multivariate statistical analysis (P = 0.039). In conclusion, RASSF2 gene is differently methylated in luminal and non-luminal tumors and is a promising suppressor gene with clinical involvement in breast cancer.

Tumoral load quantification of positive sentinel lymph nodes in breast cancer to predict more than two involved nodes.

AIM: One-Step Nucleic Acid Amplification (OSNA) can detect isolated tumour loads in axillary lymph nodes of breast cancer patients. We investigated the predictability of the non-sentinel lymph node (SLN) metastatic involvement (MI) based on the OSNA SLN assessment in surgical invasive breast cancer. METHODS: We studied surgical breast invasive carcinoma patients, not taking neoadjuvant chemotherapy, having SLN positive by OSNA and having received axillary lymphadenectomy. Age, basic histopathological, immunohistochemical, SLN biopsy and lymphadenectomy data were compared between patients with or without MI of more than 2 non-SLN in both univariate and multivariate analyses. The discriminating capacity of the multivariate model was characterized by the ROC AUC. RESULTS: 726 patients from 23 centers in Spain aged 55.3 ± 12.2 years were analysed. The univariate analysis comparing patients with or without MI of more than 2 non-SLN detected statistically significant differences in primary tumour size, multifocality, presence of lymphovascular infiltration, positive proliferation index with ki67, immunophenotype and logTTL (Tumour Total Load). The multivariate logistic analyses (OR (95% CI)) confirmed multifocality (2.16 (1.13-4.13), p = 0.019), lymphovascular infiltration (4.36 (2.43-7.82), p < 0.001) and logTTL (1.22 (1.10-1.35), p < 0.001) as independent predictors, and exhibit an AUC (95% CI) of 0.78 (0.72-0.83) with an overall fit (Hosmer-Lemeshow test) of 0.359. A change in the slope of both sensitivity and specificity is observed at about 10,000 copies/µL, without relevant changes in the Negative Predictive Values. CONCLUSIONS: Using OSNA technique, the MI of more than 2 non-SLN can be reliably predicted.

[Training periods with experts improve results in colorectal laparoscopic surgery]. / Las estancias de formación con expertos mejoran los resultados en cirugía laparoscópica colorrectal.

OBJECTIVE: To analyse the effects of training in elective colorectal laparoscopic surgery with a minimum 6 months follow up to assess early and delayed complications, and comparing the first 40 cases in the 1st Period (P-1: 1996-2002) with the 100 cases in the 2nd Period (P-2: 2003-2008). One of the surgeons had two training courses between P-1 and P-2. MATERIAL AND METHODS: A total of 66 colorectal resections due to cancer were performed and 74 operations for benign disease. The cases of malignant diseases increased between P-1 and P-2 (P<0.001). (Odds-Ratio=0.16). RESULTS: There number of complex cases increased between P-1 and P-2 (Anterior resection-amputation, left hemicolectomy, total colectomy, rectopexy) vs. Others (Sigmoidectomy, right resections) (P<0.05), but the mean duration of the operations was reduced by 29 minutes P<0.01). There were 24% conversions, with no change in P-2 (P=0.85). Surgical mortality at 3 months (1.4%) showed no differences (P=0.49). The total complications rate (31%) was significantly lower in P-2 (P=0.001), because medical complications (P=0.05), the more serious surgical complications (with reintervention) (P=0.05) and wound infections (P=0.0001) were lower. There was no change in the other surgical complications (P=0.61). The overall mean stay was 7.8 days (3-36) (median=6 days), with no differences between P-1 and P-2 (P=0.165). Conversion significantly lengthened the mean hospital stay (P=0.015) (from 7.2+/-5 days to 10.1+/-7 days), but there was no increase in complications (P=0.31). CONCLUSION: Training in colorectal laparoscopy and training periods with experts improve results (duration, complications, more complex surgery). Conversions did not decrease with experience and the hospital stays lengthened, but they were not associated with more complications.