PubMed Health⌕ Search

Biomedical subjects

Patrick A Treseler

Publications and source records attributed to Patrick A Treseler.

9 recordsLinked to original sources
PubMed2005

Clinical significance of occult metastatic melanoma in sentinel lymph nodes and other high-risk factors based on long-term follow-up.

Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow-up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease-free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.

Adult↗
PubMed2004

Id1 gene expression is up-regulated in hyperplastic and neoplastic thyroid tissue and regulates growth and differentiation in thyroid cancer cells.

The Id (inhibitor of DNA binding) proteins are a family of helix-loop-helix (HLH) proteins (Id1, Id2, Id3, and Id4) that lack the basic domain necessary for DNA binding. The Id1 protein enhances cell proliferation and inhibits cellular differentiation in a variety of cell types. We have previously demonstrated that the Id1 gene is up-regulated in papillary and medullary thyroid cancers. In this study we characterized the expression and distribution of the Id1 protein in normal, hyperplastic, and neoplastic human thyroid tissue. We also evaluated the effect of the Id1 gene on thyroid cancer cell growth and markers of thyroid cell differentiation. We used semiquantitative immunohistochemistry to characterize Id1 protein expression in normal, hyperplastic (multinodular goiter and Graves' disease), and neoplastic thyroid tissue from 103 patients. Normal thyroid tissue had the lowest level of Id1 protein expression (P < 0.0001). Anaplastic thyroid cancer had the highest level (vs. benign and malignant thyroid tissues, P < 0.01). Id1 protein expression was higher in malignant thyroid tissue than in hyperplastic thyroid tissue (P < 0.02). We found no significant association between the level of Id1 protein expression and patient age, sex, tumor-node-metastasis stage, tumor size, primary tumor vs. lymph node metastasis, primary tumor vs. recurrent tumors, and extent of tumor differentiation. Inhibiting Id1 mRNA expression in thyroid cancer cell lines using Id1 antisense oligonucleotides resulted in growth inhibition (P < 0.03) and decreased thyroglobulin and sodium-iodine symporter mRNA expression (P < 0.02). In conclusion, Id1 is overexpressed in hyperplastic and neoplastic thyroid tissue and directly regulates the growth of thyroid cancer cells of follicular cell origin, but is not a marker of aggressive phenotype in differentiated thyroid cancer.

Adult↗
PubMed2003

The helix-loop-helix protein, Id-1, is overexpressed and regulates growth in papillary thyroid cancer.

BACKGROUND: Members of the Id helix-loop-helix proteins are key regulators of cell growth and differentiation in a variety of cell types. They are also required for cell cycle progression and regulate tumor angiogenesis. Furthermore, deregulated expression of Id proteins has been observed in some human malignancies. Therefore we hypothesized that the Id-1 gene may play a role in papillary thyroid carcinogenesis. METHODS: Id-1 gene expression was characterized by Northern blot analysis and Id-1 immunohistochemistry in human thyroid tissue. Id-1 gene expression and regulation was evaluated in a human papillary thyroid cancer cell line, TPC-1, by Northern blot analysis. RESULTS: The Id-1 gene was significantly overexpressed in papillary thyroid cancer compared with normal thyroid tissue from the same patients (n = 18) by both Northern blot analysis and semiquantitative Id-1 immunohistochemistry (P <.001). Id-1 immunoreactivity was primarily localized to the cytoplasm of the thyroid follicular cells. In the TPC-1 cell line, stimulation by TSH and serum up-regulated Id-1 mRNA expression 1.5- and 4.0-fold, respectively. Activation of the mitogen intracellular protein kinase A and protein kinase C signaling pathways also up-regulated Id-1 mRNA expression. Inhibition of Id-1 mRNA expression with Id-1 antisense oligonucleotide inhibited growth compared with control Id-1 sense and random oligonucleotides (P <.05). CONCLUSIONS: The Id-1 gene is overexpressed in papillary thyroid cancer. Id-1 may play a role in the regulation of growth in papillary thyroid cancer.

Blotting, Northern↗
PubMed2003

c-Kit is not expressed in malignant mesothelioma.

Overexpression of KIT protein (CD117), the product of the c-kit gene, has been shown to have important prognostic and therapeutic implications for a number of malignant neoplasms. Previous studies have shown conflicting results regarding the expression of c-kit in malignant mesothelioma. To determine whether malignant mesothelioma expresses KIT, immunohistochemistry and RT-PCR were used to analyze archived tissue from 37 cases of mesothelioma. Although a subset of mesotheliomas demonstrated specific staining with the DAKO anti-KIT antibody, in each case staining was nuclear. We could not detect c-kit mRNA by a sensitive RT-PCR assay, even in cases with strong nuclear staining. Furthermore, a second anti-KIT antibody (Cell-Marque) only demonstrated staining in a single mesothelioma case and in none of the cases that demonstrated nuclear staining. We conclude that immunoreactivity for KIT in mesothelioma does not represent expression of the c-kit gene and may represent antibody cross-reaction with nuclear proteins. Our results raise doubt about previously reported expression of KIT in mesothelioma and consequently, the applicability of therapeutic agents that target the kinase activity of KIT.

Biomarkers, Tumor↗
PubMed2003

Malignant mesothelioma does not demonstrate overexpression or gene amplification despite cytoplasmic immunohistochemical staining for c-Erb-B2.

BACKGROUND: Previous studies have shown conflicting results regarding the expression of c-Erb-B2 in malignant mesothelioma. Overexpression of the c-erb-B2 gene product in a subset of mesothelioma may have prognostic or therapeutic implications. OBJECTIVE: To determine whether malignant mesothelioma demonstrates c-Erb-B2 overexpression and, if so, whether such overexpression correlates with gene amplification. METHODS: Immunohistochemistry, reverse transcription-polymerase chain reaction, and fluorescent in situ hybridization were used to analyze archived tissue from 37 cases of malignant mesothelioma. RESULTS: Although immunohistochemical staining for c-Erb-B2 was detected in most mesotheliomas, the staining was cytoplasmic and was not consistent between the 2 different primary antibodies used. Moreover, even cases with strong cytoplasmic staining for c-Erb-B2 did not demonstrate increased messenger RNA levels or gene copy numbers compared to cases that demonstrated no staining. CONCLUSIONS: Cytoplasmic immunoreactivity for c-Erb-B2 in mesothelioma does not represent gene overexpression or amplification and may be an immunohistochemical artifact.

Antibodies, Monoclonal↗
PubMed2002

Genomic copy number analysis of non-small cell lung cancer using array comparative genomic hybridization: implications of the phosphatidylinositol 3-kinase pathway.

Genomic abnormalities at 348 loci encoding genes that may contribute to lung cancer transformation and progression were assessed using array comparative genomic hybridization in 21 squamous carcinomas (SqCas) and 16 adenocarcinomas (AdCas). Hierarchical clustering showed a clear pattern of gains and losses for the SqCas, whereas the pattern for AdCas was less distinct. Cross-validated classification using a K-nearest-neighbor assigned, on average, 32 of 37 samples to their proper histological subtype. The most noticeable differences between SqCas and AdCas were gain of chromosome 3q22-q26 and loss of chromosome 3p. These occurred almost exclusively in SqCas. The region of recurrent increase is approximately 30 Mb in extent, ranging from EVI1 to TFRC. PIK3CA, the alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is in this region. The PIK3CA copy number increase was validated using fluorescence in situ hybridization to lung cancer tissue microarrays. Activity of the downstream PI3K effector protein kinase B (PKB) was higher in SqCas than in AdCas and was correlated with PIK3CA copy number (r = 0.75), suggesting that these copy number increases contribute to activation of PI3K signaling in SqCas of the lung.

Adenocarcinoma↗
PubMedDate not supplied

Failure to harvest sentinel lymph nodes identified by preoperative lymphoscintigraphy in breast cancer patients.

Selective sentinel lymphadenectomy dissection has been demonstrated to have high predictive value for axillary staging in breast cancer patients. Preoperative lymphoscintigraphy can localize and facilitate the harvesting of sentinel lymph nodes (SNLs) with a high success rate. The failure rate of selective sentinel lymphadenectomy ranges between 2% and 8%. Details of the failures were seldom addressed. This study analyzes the causes of failure to harvest SLNs in spite of positive preoperative lymphoscintigraphy. From November 1997 through November 2000, 201 female patients with histologically confirmed and operable breast carcinoma underwent selective sentinel lymphadenectomy at the University of California, San Francisco (UCSF) Carol Franc Buck Breast Care Center. Among these patients, 183 (91%) received preoperative lymphoscintigraphy to identify axillary lymph nodes. The causes of failure to harvest the SLNs in this group of patients despite successful preoperative lymphoscintigraphy were analyzed. In our series, the failure rate of SLN identification was 7.0% (14/201). The failure rate for our first year was 11.1% (6/54), second year 9.1% (7/77), and third year 1.4% (1/70). The incidence of failure in spite of positive preoperative lymphoscintigraphy was 3.5% (6/170). The shine-through effect of the primary injection site and failure to visualize a blue lymph node were the main reasons for technical failure. Most of these cases occurred during our learning curve of the procedure. The possibility of failure to get the SLN should be explained to patients before surgery. Axillary lymph node dissection (ALND) should be done if selective SLN dissection is not successful.

Adult↗