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Jean-Marc Guinebretière

Publications and source records attributed to Jean-Marc Guinebretière.

7 recordsLinked to original sources
PubMed2006

Epstein-Barr virus (EBV) genome and expression in breast cancer tissue: effect of EBV infection of breast cancer cells on resistance to paclitaxel (Taxol).

The Epstein-Barr virus (EBV) has been detected in subsets of breast cancers. In order to elaborate on these observations, we quantified by real-time PCR (Q-PCR) the EBV genome in biopsy specimens of breast cancer tissue as well as in tumor cells isolated by microdissection. Our findings show that EBV genomes can be detected by Q-PCR in about half of tumor specimens, usually in low copy numbers. However, we also found that the viral load is highly variable from tumor to tumor. Moreover, EBV genomes are heterogeneously distributed in morphologically identical tumor cells, with some clusters of isolated tumor cells containing relatively high genome numbers while other tumor cells isolated from the same specimen may be negative for EBV DNA. Using reverse transcription-PCR, we detected EBV gene transcripts: EBNA-1 in almost all of the EBV-positive tumors and RNA of the EBV oncoprotein LMP-1 in a smaller subset of the tissues analyzed. Moreover, BARF-1 RNA was detected in half of the cases studied. Furthermore, we observed that in vitro EBV infection of breast carcinoma cells confers resistance to paclitaxel (taxol) and provokes overexpression of a multidrug resistance gene (MDR1). Consequently, even if a small number of breast cancer cells are EBV infected, the impact of EBV infection on the efficiency of anticancer treatment might be of importance.

Adenocarcinoma↗
PubMed2005

Radiation dose and risk of soft tissue and bone sarcoma after breast cancer treatment.

BACKGROUND: To quantify the risk of soft tissue and bone sarcomas after breast cancer according to the doses and technical modalities of irradiation. METHODS: We followed a cohort of 6597 breast-cancer patients for 8.3 years on average. The number of soft tissue and bone sarcomas was compared to the expected number based on the incidence rates in the general French population. We also estimated the risk of sarcoma according to the radiation dose received at site of the sarcoma in a nested case control study of 14 breast-cancer patients who subsequently developed a sarcoma and 98 controls matched for age at diagnosis of breast cancer, period of initial treatment and length of follow-up. RESULTS: In the cohort-study, 12 women who had initially received radiotherapy treatment developed a bone or soft tissue sarcoma during the follow-up period. The expected number of cases during this period was 1.7 (SIR = 7.0, 95% CI: 3.7-11.7) and the mean annual excess incidence during the same period was 21 per 100,000 person-years. The 15-year cumulative incidence of sarcoma was 0.28% (95% CI: 0.10-0.45%). In the case-control study, all the 14 cases had received at least 11.8 Gray at the site of the sarcoma, which was always located in the irradiated field or in the upper ipsilateral extremity of the arm. A dose-effect relationship was observed (p < 0.001). The best fit was obtained for a quadratic dose-response relationship, without a negative exponential term for cell killing at high doses. The risk of sarcoma was 30.6 higher for doses of more than 44 Gray than for doses of less than 15 Gray. CONCLUSIONS: High doses of radiation strongly increase the risk of bone and soft tissue sarcoma.

Adult↗
PubMed2004

Specifications and implementation of a new exchange format to support computerized consensus in pathology.

In the pathology domain, consensus sessions around multi-headed microscopes enhance reproducibility and can reduce inter- and intra-observer variability. Computerized tools and Web technology could facilitate the organization of consensus sessions and assist pathologists to agree on features that are relevant to diagnosis. In the context of the IDEM project, whose aim is to achieve a computerized platform to allow pathologists to derive consensual diagnostic during Internet-based collaborative sessions, we propose a new extension of the existing TELESLIDE format. This new extended format enables the storage and the exchange of multi-experts descriptions that will be processed by the IDEM consensus engine to produce consensual descriptions. We describe this new format and its implementation in the IDEM teleconsensus platform.

Consensus↗
PubMed2003

[Biopsy of breast microcalcifications using an 11-Gauge vacuum-assisted device: roles and challenges for the pathologist].

Stereotactic 11-Gauge vacuum-assisted biopsy provides a valuable tool in the diagnosis of mammographically detected breast microcalcifications. However, this new diagnostic technology presents some limitations and requires a close collaboration between radiologists, pathologists and physicians. The aim of this work is to propose a practical approach in the management of large core biopsies and to summarize the different difficulties faced by the pathologist in the management and histological interpretation of specimens issuing from this device.

Biopsy, Needle↗
PubMed2003

[Diagnostic immunohistochemistry of breast epithelial lesions].

Routine H&E sections are sufficient for diagnosis of the vast majority of breast lesions. Development of mammography mass screening and widespread use of preoperative needle biopsy diagnosis have led to diagnostic difficulties for pathologists. The samples are smaller and more and more preinvasive lesions are seen. It is mainly in those situations that immunohistochemistry (IHC) can efficiently back up histopathology. This review details the main applications of diagnostic IHC in breast pathology. The advantages of IHC in various clinical situations are discussed diagnosis of benign breast lesions mimicking malignancy, distinction between simple type ductal hyperplasia and atypical hyperplasia or ductal in situ carcinoma, confirmation of malignancy, distinction between lobular and ductal carcinoma, identification of specific histological subtypes, and, diagnosis of intra and extra mammary metastases.

Biomarkers, Tumor↗
PubMed2002

Prognostic factors for death after an isolated local recurrence in patients with early-stage breast carcinoma.

BACKGROUND: The authors analyzed the outcome of patients with early-stage breast carcinoma after an isolated local recurrence, taking into account initial tumor characteristics and the type of initial treatment and local salvage treatment. METHODS: One hundred five patients were studied who presented with a breast tumor measuring <or= 25 mm and who subsequently developed an isolated local recurrence (breast or chest wall) as the first tumor event. A second series included 335 patients who developed distant metastases as the first event. Cox models that took into account potential prognostic factors were used to estimate the risk of death. First, survival rates were compared after an isolated local recurrence and after a diagnosis of distant metastases; and, second, effects of initial treatments and local or systemic treatments of local recurrences were analyzed. RESULTS: The 10-year survival rate was 56% (95% confidence interval, 45-65%) after an isolated local recurrence compared with 9% (95% confidence interval, 7-13%) after distant metastasis as the first event. Three independent prognostic factors for the risk of death after local recurrence were identified: histologic tumor grade, patient age at the time of diagnosis with the primary tumor, and disease free interval until recurrence. The type of initial treatment and local salvage treatment did not influence the risk of death. Systemic treatments of local recurrence had different effects according to the patient's menopausal status. In premenopausal patients, ovarian suppression and chemotherapy significantly decreased the risk of death. In postmenopausal women, systemic treatments did not affect the risk of death. CONCLUSIONS: Isolated local recurrences in patients with early-stage breast carcinoma carry a moderately good prognosis. The outcome of patients is not affected by the type of initial treatment or local salvage treatment. After a local recurrence, ovarian suppression or chemotherapy had a beneficial effect in premenopausal patients.

Adult↗