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Andreas Berger

Publications and source records attributed to Andreas Berger.

10 recordsLinked to original sources
PubMed2005

Circulating tumor-specific DNA: a marker for monitoring efficacy of adjuvant therapy in cancer patients.

Adjuvant systemic therapy (a strategy that targets potential disseminated tumor cells after complete removal of the tumor) has clearly improved survival of patients with cancer. To date, no tool is available to monitor efficacy of these therapies, unless distant metastases arise, a situation that unavoidably leads to death. We analyzed RASSF1A DNA methylation in pretherapeutic sera and serum samples collected 1 year after surgery from 148 patients with breast cancer who were receiving adjuvant tamoxifen; 19.6% and 22.3% of patients with breast cancer showed RASSF1A DNA methylation in their pretherapeutic and 1-year-after serum samples, respectively. RASSF1A methylation 1 year after primary surgery (and during adjuvant tamoxifen therapy) was an independent predictor of poor outcome, with a relative risk (95% confidence interval) for relapse of 5.1 (1.3-19.8) and for death of 6.9 (1.9-25.9). Measurement of serum DNA methylation allows adjuvant systemic treatment to be monitored for efficacy: disappearance of RASSF1A DNA methylation in serum throughout treatment with tamoxifen indicates a response, whereas persistence or new appearance means resistance to adjuvant tamoxifen treatment. It remains to be seen whether modifications made in adjuvant therapeutic strategies based on detection of circulating nucleic acids will improve survival as well as quality of life.

Adult↗
PubMed2005

Screening for prostate cancer: updated experience from the Tyrol study.

OBJECTIVES: The aim of this study was to monitor the impact of prostate cancer screening in a natural experiment by comparing prostate cancer mortality in Tyrol, Austria, where prostate-specific antigen (PSA) testing was made available at no charge, with the rest of Austria, where this screening was not introduced. METHODS: In 1993, PSA testing was made freely available to men aged 40 to 79 years old living in the Federal State of Tyrol, Austria. In the first 10 years of this study, at least 70% of all men in this age range had PSA tests done at least once. Initially, only total PSA was measured, but free PSA measurement was added in 1995, and complexed PSA was added in 2001. Digital rectal examination (DRE) was not part of the screening examination. RESULTS: Significant migration to lower clinical as well as pathological prostate cancer stages has been observed in patients undergoing radical prostatectomy since the introduction of this screening program. A reduction in mortality rates from prostate cancer in Austria occurred from 1993 onward, with a much greater reduction in Tyrol; mortality remained fairly constant between 1993 and 1995 and subsequently fell. From 1993 to 2000 (the most recent data), there was a significantly greater decrease in the rate of prostate cancer mortality in Tyrol compared to the rest of Austria (P value = 0.006). Based on age-specific death rates for men aged 40 to 79, the difference between the number of expected and observed deaths from prostate cancer in Tyrol was 22 in 1998 (a 42% decrease), 18 in 1999 (a 33% decrease) and 25 in 2000 (a 44% decrease). CONCLUSIONS: These findings are consistent with the hypothesis that a policy of making PSA testing freely available, and wide acceptance by men in the population, is associated with a reduction in prostate cancer mortality in an area in which urology services and radiotherapy are available freely to all patients. It is our opinion that most of this decline in mortality is likely to be due to aggressive downstaging and successful treatment and that any contribution from detecting and treating early cancers will only become apparent in the years to come.

Adult↗
PubMed2004

Screening for prostate cancer: updated experience from the Tyrol study.

The aim of the Tyrol study was to monitor the impact of screening in a natural experiment by comparing prostate cancer mortality in Tyrol, where prostate-specific antigen (PSA) testing was introduced at no charge, with the rest of Austria, where it was not strictly organized and not free of charge. In 1993, PSA testing was made freely available to men between the ages of 45 and 75 years in the Federal State of Tyrol, Austria. At least 70% of all of the men in this age range have been tested at least once during the first 10 years of the study. Initially, only total PSA was measured, but free PSA measurement was added in 1995. Since 2001, complexed PSA also has been measured. Digital rectal examination was not part of the screening examination. Significant migration to lower clinical and pathological stages has been observed since the introduction of this screening program. These findings are consistent with the hypothesis that the policy of making PSA testing freely available, and the wide acceptance by men in the population, is associated with a reduction in prostate cancer mortality in an area in which urology services and radiotherapy are available freely to all patients. It is our opinion that most of this decline is likely a result of aggressive downstaging and successful treatment and that any contribution from detecting and treating early cancers will become apparent in the years to come.

Aged↗
PubMed2004

Radical retropubic prostatectomy in men younger than 45 years diagnosed during early prostate cancer detection program.

OBJECTIVES: To evaluate the incidence and outcome of prostate cancer in men younger than 45 years of age treated with radical retropubic prostatectomy after screening in an early prostate cancer detection program. METHODS: Our study group comprised 19,302 men younger than 45 years old who participated in this program. The indications for prostate biopsy were a prostate-specific antigen (PSA) level of 1.25 ng/mL or greater and a percent-free PSA value of 18% or less. Patients with prostate cancer underwent nerve-sparing radical retropubic prostatectomy. Intraoperative and early postoperative complications, clinical and pathologic stage, Gleason score, and surgical margins were reviewed retrospectively. In addition, potency, continence, and biochemical recurrence were assessed at the last follow-up visit. RESULTS: Of the study population eligible for prostate biopsy (1027 patients), only 175 (17%) consented to undergo the procedure (mean PSA 3.8 ng/mL). Twenty-eight men were diagnosed with prostate cancer, corresponding to 0.14% of the screened population and 16% of the biopsied patients. Twenty-six patients agreed to undergo radical retropubic prostatectomy. Pathologic examination revealed organ-confined disease in 22 (84.6%) and extraprostatic extension in 4 (15.4%). Positive surgical margins were seen in 2 patients (7.7%). The Gleason score was 7 or greater in 11 (42.3%) and 6 or less in 15 patients (57.7%). During a mean follow-up period of 15.8 months (range 3 to 36), all patients were continent, and 13 of the 16 patients with a follow-up of 12 months or longer were potent. CONCLUSIONS: In a large screening population younger than 45 years old, 16% of biopsied patients were positive for prostate cancer. These tumors were clinically significant but of a low stage and therefore potentially curable by surgery.

Adenocarcinoma↗
PubMed2004

Evaluation of urinary extravasation and results after continence-preserving radical retropubic prostatectomy.

OBJECTIVE: To evaluate the feasibility of urinary catheter removal 10 days after a radical retropubic prostatectomy (RRP) by assessing the incidence of urinary extravasation and its effect on postoperative stricture and continence rates. PATIENTS AND METHODS: During a 4.5-year period, 619 patients undergoing RRP were evaluated. If no extravasation was detected on gravity cystography, the urinary catheter was removed 10 days after RRP. In patients with significant extravasation the catheter was left in place for 3 weeks. Overall stricture and continence rates were recorded in patients at 3, 6 and 12 months after surgery. RESULTS: There was extravasation during cystography in 29 patients (4.6%). At 3, 6 and 12 months, continence rates after catheter removal at 10 days were 74.9%, 87.9%, and 93.6%, respectively, while in the late-removal group they were 72.4%, 84.6% and 90.9%, respectively, with no significant difference between the groups. At 3 months the overall continence rate was 74.8% and at 12 months up to 93.5%. There was no difference in stricture rates between the groups, with an overall stricture rate of 0.7%. CONCLUSIONS: Catheter removal 10 days after RRP is feasible, giving excellent early and late continence rates, with low anastomotic stricture rates obtained using good surgical technique. Extravasation at 10 days was rare and with proper management did not influence the final results.

Adult↗
PubMed2003

Domain walls in antiferromagnetically coupled multilayer films.

We report experimentally observed magnetic domain-wall structures in antiferromagnetically coupled multilayer films with perpendicular anisotropy. Our studies reveal a first-order phase transition from domain walls with no net moment to domain walls with ferromagnetic cores. The transition originates from the competition between dipolar and exchange energies, which we tune by means of layer thickness. Although observed in a synthetic antiferromagnetic system, such domain-wall structures may be expected to occur in A-type antiferromagnets with anisotropic exchange coupling.

Journal Article↗
PubMed2003

Magnetic tuning of biquadratic exchange coupling in magnetic thin films.

The effective interlayer coupling between antiferromagnetically coupled hard and soft ferromagnetic thin films is investigated as a function of the magnetic bit length in the hard layer, which is controlled using a magnetic recording system. The interlayer coupling is explored by studying the magnetization reversal of the soft layer. As the bit length decreases, the coupling evolves from antiferromagnetic to biquadratic to uncoupled. These results are reproduced using a micromagnetic model and determine the applicability range of Slonczewski's fluctuation model of biquadratic coupling.

Journal Article↗
PubMed2003

A new phase diagram for layered antiferromagnetic films.

Magnetic multilayer films provide convenient model systems for studying the physics of antiferromagnetic films and surfaces. Here we report on the magnetic reversal and domain structure in antiferromagnetically coupled Co/Pt multilayers that are isomorphic to layered antiferromagnetic films with perpendicular magnetic anisotropy. We observe two distinct remanent states and reversal modes of the system. In mode 1 the magnetization in each layer reverses independently, producing an antiferromagnetic remanent state that shows full lateral correlation and vertical anticorrelation across the interlayers. In mode 2 the reversal in adjacent layers is locally synchronized with a remanent state that is vertically correlated but laterally anticorrelated in ferromagnetic stripe domains. Theoretical energy calculations of the two ground states identify a new phase boundary that is in good agreement with our experimental results.

Chemistry, Physical↗