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Nils M Diaz

Publications and source records attributed to Nils M Diaz.

8 recordsLinked to original sources
PubMed2006

Mapping geographic zones of cancer risk with epigenetic biomarkers in normal breast tissue.

PURPOSE: Genetic alterations were previously identified in normal epithelia adjacent to invasive cancers. The aim of this study was to determine DNA methylation in histologically normal tissues from multiple geographic zones adjacent to primary breast tumors. EXPERIMENTAL DESIGN: First, methylation status of a 4-kb region of RASSF1A promoter was interrogated using oligonucleotide-based microarray in 144 samples (primary tumors, 47; adjacent normals, 69; reduction mammoplasty tissues, 28). Second, allelic imbalance (AI)/loss of heterozygosity (LOH) surrounding RASSF1A promoter were analyzed in 30 samples (tumors, 8; adjacent normals, 22). Third, global methylation screening of 49 samples (tumors, 12; adjacent normals, 25; reduction mammoplasty, 12) was done by differential methylation hybridization. Real-time quantitative methylation-specific PCR was used to validate the microarray findings. RESULTS: DNA methylation in the core RASSF1A promoter was low in reduction mammoplasty tissues (P=0.0001) when compared with primary tumors. The adjacent normals had an intermediate level of methylation. The regions surrounding the core were highly methylated in all sample types. Microsatellite markers showed AI/LOH in tumors and some of the adjacent normals. Concurrent AI/LOH and DNA methylation in RASSF1A promoter occurred in two of six tumors. Global methylation screening uncovered genes more methylated in adjacent normals than in reduction mammoplasty tissues. The methylation status of four genes was confirmed by quantitative methylation-specific PCR. CONCLUSIONS: Our findings suggest a field of methylation changes extending as far as 4 cm from primary tumors. These frequent alterations may explain why normal tissues are at risk for local recurrence and are useful in disease prognostication.

Allelic Imbalance↗
PubMed2005

Breast epithelial cells in dermal angiolymphatic spaces: a manifestation of benign mechanical transport.

Evidence suggesting that breast epithelial cells may reach axillary lymph nodes by benign mechanical transport (BMT), rather than metastatic means, has been recently reported. We report a case of a patient with ductal carcinoma in situ of the breast, who had displaced epithelial elements in the mastectomy specimen, dermal angiolymphatic spaces, and a sentinel lymph node. We attribute the epithelial aggregates in the dermal angiolymphatic spaces and a single cell in the sentinel lymph node to BMT, based on the clinicopathological findings of the case. We, therefore, suggest that the effects of BMT be considered in the differential diagnosis of epithelial aggregates in dermal angiolymphatic spaces in the appropriate clinicopathological setting.

Adult↗
PubMed2005

Modes of benign mechanical transport of breast epithelial cells to axillary lymph nodes.

The status of axillary lymph nodes is a key prognostic indicator available for the management of patients with breast cancer. Sentinel lymph node (SLN) evaluation as a predictor of lymph node status has led to increased use of ancillary methods, principally immunohistochemistry, to increase the sensitivity of the SLN biopsy. So-called "occult" micrometastases detected by such methods have led to speculation that some may have reached the SLNs by benign mechanical transport (BMT) rather than a metastatic process. We review evidence suggesting two potential modes of BMT: lymphatic transport of epithelial cells displaced by biopsy of the primary breast tumor and by breast massage-assisted SLN localization. The biopsy techniques under most scrutiny include fine needle aspiration and large-gauge core biopsy. The evidence implicating breast massage prior to SLN biopsy as a mode of BMT has been supported by statistical analysis; however, no method of distinguishing massage-associated cells in SLNs from true occult micrometastases is available. The significance of small epithelial clusters in SLNs is currently unknown. Thus, deviation from current biopsy and SLN-localizing practices is unwarranted.

Axilla↗
PubMed2004

Benign mechanical transport of breast epithelial cells to sentinel lymph nodes.

The evaluation of sentinel lymph nodes (SLNs) for the presence of malignant epithelial cells is essential to the staging of breast cancer patients. Recently, increased attention has focused on the possibility that epithelial cells may reach SLNs by benign mechanical means, rather than by metastasis. The purpose of this study was to test the hypothesis that pre-SLN biopsy breast massage, which we currently use to facilitate the localization of SLNs, might represent a mode of benign mechanical transport. We studied 56 patients with invasive and/or in situ ductal carcinoma and axillary SLNs with only epithelial cells and/or cell clusters (< or =0.2 mm in diameter and not associated with features of established metastases) detected predominantly in subcapsular sinuses of SLNs on hematoxylin and eosin- and/or anti-cytokeratin-stained sections. No patient had an SLN involved by either micro- or macro-metastatic carcinoma. Epithelial cells and cell clusters, < or =0.2 mm in size and without features of established metastases, occurred more frequently in the SLNs of patients who underwent pre-SLN biopsy breast massage (P < 0.001, chi2 test). The latter finding supports the hypothesis that pre-SLN biopsy breast massage is a mode of benign mechanical transport of epithelial cells to SLNs.

Breast Neoplasms↗
PubMed2003

The clinical relevance of positive sentinel nodes only versus positive nonsentinel lymph nodes in breast cancer patients.

BACKGROUND: The purpose of this study was to determine the difference in clinical outcomes for patients with histologically positive sentinel lymph nodes (SLN+) compared with patients with histologically positive nonsentinel second echelon lymph nodes (NSLN+). METHODS: Eight hundred thirteen node positive patients from a prospectively accrued database of 3200 patients who underwent sentinel node mapping were evaluated. In all, 506 of the 813 patients (62%) were SLN+ only and 307 of the 813 patients (38%) were SLN+ plus at least one NSLN+. Patients' overall survival and disease-free survival were obtained and statistical analyses performed comparing the two groups. RESULTS: As the number of NSLN+ increased, there was a significant difference in disease-free survival (P = 0.001) and overall survival (P = 0.003) between those patients who had 0 to 4 NSLN+ and those who had 5 or more NSLN+. The SLN+ only patients did not show significant differences with respect to survival, based on the number of SLN+ (overall survival, disease-free survival; P = 0.742). CONCLUSIONS: The survival (overall survival, disease-free survival) for patients with 3 or more SLN+ was not statistically different than for patients with 1 or 2 SLN+ (P = 0.742). However, an alteration of biologic behavior was observed when multiple NSLN+ contain metastatic breast cancer. Involvement of 5 or more NSLN+ portends a significantly (P = 0.001) worse prognosis, regardless of the number of SLN+.

Breast Neoplasms↗
PubMed2003

Effect of lymphatic mapping on diagnosis and treatment of patients with T1a, T1b favorable breast cancer.

OBJECTIVE: To investigate the incidence of nodal metastasis in a consecutive series of patients treated at the authors' institution with highly selective criteria, and to determine the impact that lymphatic mapping and sentinel node biopsy have on the detection of nodal metastases in this carefully selected patient population. METHODS: Study patients were selected from the 7,750 breast cancer patients entered into the authors' database from April 1989 to August 2001, based on the following criteria: nonpalpable, T1a and T1b, non-high nuclear grade tumors, without lymphovascular invasion. RESULTS: Of the 7,750 patients in the database 1,327 (17%) were found to have T1a and T1b lesions. Three hundred eighty-nine patients were confirmed to meet all four selection criteria. This represents 5% (389/7,750) of the authors' breast cancer patients and 29.3% (389/1,327) of the authors' T1a/T1b tumors. One hundred sixty patients were diagnosed before routine use of lymphatic mapping, and only one patient had a positive axillary lymph node. Two hundred twenty-nine patients underwent lymphatic mapping and sentinel lymph node biopsy, and 10 had a positive axillary lymph node. The difference in proportions of nodal positivity between the mapped and unmapped patients was significant. CONCLUSIONS: This study clearly demonstrates the ability of lymphatic mapping and a more detailed examination of the sentinel node to increase the accuracy of axillary staging. It has been argued that this highly selected group of breast cancer patients possessing retrospectively identified "favorable" characteristics does not require axillary staging. This select population represents only 5% of breast cancer patients in this series, and the authors do not believe they can be accurately identified preoperatively. Therefore, the authors strongly argue for evaluation of the axillary nodal status by lymphatic mapping.

Breast Neoplasms↗
PubMed2002

Completion axillary lymph node dissection minimizes the likelihood of false negatives for patients with invasive breast carcinoma and cytokeratin positive only sentinel lymph nodes.

OBJECTIVE: To document the incidence of metastatic disease in complete axillary lymph node dissections (CALND) of patients with invasive carcinoma after a sentinel lymph node (SLN) biopsy, positive only by immunohistochemical staining for cytokeratin (CK-IHC). METHODS: Sections of all SLNs, negative by routine histology, were immunostained and examined for cytokeratin positive cells. Sections of lymph nodes from CALND specimens were interpreted using routine hematoxylin and eosin (H&E) staining. RESULTS: A total of 409 patients (29.6%) had metastatic disease in at least one sentinel lymph node on H&E examination. Of 971 H&E negative patients, 78 (8.0%) were positive only by CK-IHC. Sixty-two of the CK-IHC positive only patients underwent CALND. Nine of these 62 patients (14.5%) had metastases identified in the CALND specimen. CONCLUSIONS: Because 14.5% of patients with invasive breast cancer and SLNs positive only by CK-IHC were found to have H&E positive lymph nodes on CALND, we conclude first, that CK-IHC should be used to evaluate SLNs, and second, that CALND should be considered when SLNs are positive by CK-IHC only. This approach will result in an absolute reduction of the false negative rate (absolute false negative rate reduced by 2.6% in our series).

Adenocarcinoma↗