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Dive into the research topics where Walter Jonat is active.

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Featured researches published by Walter Jonat.


Journal of Clinical Oncology | 2006

Recommendations From an International Expert Panel on the Use of Neoadjuvant (Primary) Systemic Treatment of Operable Breast Cancer: An Update

Manfred Kaufmann; Gabriel N. Hortobagyi; Aron Goldhirsch; Suzy Scholl; Andreas Makris; Pinuccia Valagussa; Jens-Uwe Blohmer; Wolfgang Eiermann; Raimund Jackesz; Walter Jonat; Annette Lebeau; Sibylle Loibl; W.R. Miller; Sigfried Seeber; Vladimir Semiglazov; Roy E. Smith; Rainer Souchon; Vered Stearns; Michael Untch; Gunter von Minckwitz

Neoadjuvant (primary systemic) treatment is the standard treatment for locally advanced breast cancer and a standard option for primary operable disease. Because of new treatments and new understandings of breast cancer, however, recommendations published in 2003 regarding neoadjuvant treatment for operable disease required updating. Therefore, a second international panel of representatives of a number of breast cancer clinical research groups was convened in September 2004 to update these recommendations. As part of this effort, data published to date were reviewed critically and indications for neoadjuvant treatment were newly defined.


Journal of Clinical Oncology | 2009

Phase II Randomized Study of Neoadjuvant Everolimus Plus Letrozole Compared With Placebo Plus Letrozole in Patients With Estrogen Receptor-Positive Breast Cancer

José Baselga; Vladimir Semiglazov; Peter van Dam; Alexey Manikhas; Meritxell Bellet; Jose I. Mayordomo; Mario Campone; E. Kubista; Richard Greil; G V Bianchi; Jutta Steinseifer; Betty Molloy; Erika Tokaji; Humphrey Gardner; Penny Phillips; Michael Stumm; Heidi Lane; J. Michael Dixon; Walter Jonat; Hope S. Rugo

PURPOSE Cross-talk between the estrogen receptor (ER) and the phosphoinositide-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathways is a mechanism of resistance to endocrine therapy, and blockade of both pathways enhances antitumor activity in preclinical models. This study explored whether sensitivity to letrozole was enhanced with the oral mTOR inhibitor, everolimus (RAD001). PATIENTS AND METHODS Two hundred seventy postmenopausal women with operable ER-positive breast cancer were randomly assigned to receive 4 months of neoadjuvant treatment with letrozole (2.5 mg/day) and either everolimus (10 mg/day) or placebo. The primary end point was clinical response by palpation. Mandatory biopsies were obtained at baseline and after 2 weeks of treatment (ie, day 15). Samples were assessed for PI3K mutation status (PIK3CA) and for pharmacodynamic changes of Ki67, phospho-S6, cyclin D1, and progesterone receptor (PgR) by immunohistochemistry. RESULTS Response rate by clinical palpation in the everolimus arm was higher than that with letrozole alone (ie, placebo; 68.1% v 59.1%), which was statistically significant at the preplanned, one-sided, alpha = 0.1 level (P = .062). Marked reductions in progesterone receptor and cyclin D1 expression occurred in both treatment arms, and dramatic downregulation of phospho-S6 occurred only in the everolimus arm. An antiproliferative response, as defined by a reduction in Ki67 expression to natural logarithm of percentage positive Ki67 of less than 1 at day 15, occurred in 52 (57%) of 91 patients in the everolimus arm and in 25 (30%) of 82 patients in the placebo arm (P < .01). The safety profile was consistent with historical results of everolimus monotherapy; grades 3 to 4 adverse events occurred in 22.6% of patients who received everolimus and in 3.8% of patients who received placebo. CONCLUSION Everolimus significantly increased letrozole efficacy in neoadjuvant therapy of patients with ER-positive breast cancer.


Journal of Clinical Oncology | 2002

Goserelin versus cyclophosphamide, methotrexate, and fluorouracil as adjuvant therapy in premenopausal patients with node-positive breast cancer: The Zoladex Early Breast Cancer Research Association Study

Walter Jonat; M. Kaufmann; Willi Sauerbrei; R.W. Blamey; Jack Cuzick; M. Namer; Ignac Fogelman; J.C.J.M. de Haes; A. De Matteis; Alan L Stewart; Wolfgang Eiermann; I. Szakolczai; Michael Palmer; Martin Schumacher; Matthias Geberth; B. Lisboa

PURPOSE Current adjuvant therapies have improved survival for premenopausal patients with breast cancer but may have short-term toxic effects and long-term effects associated with premature menopause. PATIENTS AND METHODS The Zoladex Early Breast Cancer Research Association study assessed the efficacy and tolerability of goserelin (3.6 mg every 28 days for 2 years; n = 817) versus cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy (six 28-day cycles; n = 823) for adjuvant treatment in premenopausal patients with node-positive breast cancer. RESULTS Analysis was performed when 684 events had been achieved, and the median follow-up was 6 years. A significant interaction between treatment and estrogen receptor (ER) status was found (P =.0016). In ER-positive patients (approximately 74%), goserelin was equivalent to CMF for disease-free survival (DFS) (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.84 to 1.20). In ER-negative patients, goserelin was inferior to CMF for DFS (HR, 1.76; 95% CI, 1.27 to 2.44). Amenorrhea occurred in more than 95% of goserelin patients by 6 months versus 58.6% of CMF patients. Menses returned in most goserelin patients after therapy stopped, whereas amenorrhea was generally permanent in CMF patients (22.6% v 76.9% amenorrheic at 3 years). Chemotherapy-related side effects such as nausea/vomiting, alopecia, and infection were higher with CMF than with goserelin during CMF treatment. Side effects related to estrogen suppression were initially higher with goserelin, but when goserelin treatment stopped, reduced to a level below that observed in the CMF group. CONCLUSION Goserelin offers an effective, well-tolerated alternative to CMF in premenopausal patients with ER-positive and node-positive early breast cancer.


Journal of Clinical Oncology | 2007

Improved Overall Survival in Postmenopausal Women With Early Breast Cancer After Anastrozole Initiated After Treatment With Tamoxifen Compared With Continued Tamoxifen: The ARNO 95 Study

M. Kaufmann; Walter Jonat; J. Hilfrich; Holger Eidtmann; Günther Gademann; Ivan Zuna; Gunter von Minckwitz

PURPOSE In postmenopausal women with estrogen receptor-positive early breast cancer, surgery is usually followed by a 5-year course of tamoxifen. This report presents results of a prospective, open-label, randomized study, designed to evaluate the benefits of switching to anastrozole after 2 years of tamoxifen treatment, compared with continuing on tamoxifen for 5 years. PATIENTS AND METHODS After receiving tamoxifen treatment for 2 years, eligible patients (n = 979) were randomly assigned to switch to anastrozole (1 mg/d) or continue tamoxifen (20 or 30 mg/d) for an additional 3 years. Patients were monitored every 6 months during years 1 to 3 and annually thereafter. The primary efficacy variable was disease-free survival, including local or distant recurrence, new contralateral breast cancer, or death. Secondary variables were overall survival and assessment of safety. RESULTS Switching to anastrozole resulted in a significant reduction in the risk of disease recurrence (hazard ratio [HR], 0.66; 95% CI, 0.44 to 1.00; P = .049), and improved overall survival (HR, 0.53; 95% CI, 0.28 to 0.99; P = .045) compared with continuing on tamoxifen. Fewer patients who switched to anastrozole reported serious adverse events (22.7% v 30.8%) compared with those who continued on tamoxifen, mainly due to more patients in the tamoxifen group with endometrial events. The overall safety profile for anastrozole was consistent with previous reports and no new safety issues were identified. CONCLUSION Postmenopausal women who have taken tamoxifen for 2 years as adjuvant therapy are less likely to experience a recurrence of breast cancer and have improved overall survival if they switch to anastrozole compared with continuing to receive tamoxifen.


Lancet Oncology | 2006

Effectiveness of switching from adjuvant tamoxifen to anastrozole in postmenopausal women with hormone-sensitive early-stage breast cancer: a meta-analysis

Walter Jonat; Michael Gnant; Francesco Boccardo; Manfred Kaufmann; Alessandra Rubagotti; Ivan Zuna; Mike Greenwood; Raimund Jakesz

BACKGROUND For more than 20 years, tamoxifen has been the mainstay of adjuvant endocrine therapy for women with hormone-sensitive early-stage breast cancer. However, not only does tamoxifen have potential side-effects such as an increased risk of endometrial cancer and thromboembolic events, but patients can also develop resistance to the drug. We aimed to investigate whether switching treatment of postmenopausal women with such breast cancer to anastrozole after 2-3 years of tamoxifen would be more effective than continuing on tamoxifen for a total of 5 years. METHODS We did a meta-analysis of three clinical trials--the Austrian Breast and Colorectal Cancer Study Group (ABCSG 8), Arimidex-Nolvadex (ARNO 95), and the Italian Tamoxifen Anastrozole (ITA) studies--in which postmenopausal women with histologically confirmed, hormone-sensitive early-stage breast cancer were randomised to 1 mg/day anastrozole (n=2009) after 2-3 years of tamoxifen treatment or to continued 20 or 30 mg/day tamoxifen (n=1997). We analysed the data with a stratified Cox proportional hazards model with the covariates of age, tumour size, nodal status, grade, surgery, and chemotherapy. FINDINGS Patients who switched to anastrozole had fewer disease recurrences (92 vs 159) and deaths (66 vs 90) than did those who remained on tamoxifen, resulting in significant improvements in disease-free survival (hazard ratio 0.59 [95% CI 0.48-0.74]; p<0.0001), event-free survival (0.55 [0.42-0.71]; p<0.0001), distant recurrence-free survival (0.61 [0.45-0.83]; p=0.002), and overall survival (0.71 [0.52-0.98]; p=0.04). INTERPRETATION Our results show that the clinical benefits in terms of event-free survival seen in individual trials for those patients who switched to anastrozole translate into a benefit in overall survival. These findings confirm that clinicians should consider switching postmenopausal women who have taken adjuvant tamoxifen for 2-3 years to anastrozole.


Oncogene | 2005

Molecular and prognostic distinction between serous ovarian carcinomas of varying grade and malignant potential

Ivo Meinhold-Heerlein; Dirk O. Bauerschlag; Felix Hilpert; Petre Dimitrov; Lisa M. Sapinoso; Marzenna Orlowska-Volk; Thomas Bauknecht; Tjoung-Won Park; Walter Jonat; Anja Jacobsen; Jalid Sehouli; Jutta Lüttges; Maryla Krajewski; Stan Krajewski; John C. Reed; Norbert Arnold; Garret M. Hampton

Profiles of gene transcription have begun to delineate the molecular basis of ovarian cancer, including distinctions between carcinomas of differing histology, tumor progression and patient outcome. However, the similarities and differences among the most commonly diagnosed noninvasive borderline (low malignant potential, LMP) lesions and invasive serous carcinomas of varying grade (G1, G2 and G3) have not yet been explored. Here, we used oligonucleotide arrays to profile the expression of 12 500 genes in a series of 57 predominantly stage III serous ovarian adenocarcinomas from 52 patients, eight with borderline tumors and 44 with adenocarcinomas of varying grade. Unsupervised and supervised analyses showed that LMP lesions were distinct from high-grade serous adenocarcinomas, as might be expected; however, well-differentiated (G1) invasive adenocarcinomas showed a strikingly similar profile to LMP tumors as compared to cancers with moderate (G2) or poor (G3) cellular differentiation, which were also highly similar. Comparative genomic hybridization of an independent cohort of five LMP and 63 invasive carcinomas of varying grade demonstrated LMP and G1 were again similar, exhibiting significantly less chromosomal aberration than G2/G3 carcinomas. A majority of LMP and G1 tumors were characterized by high levels of p21/WAF1, with concomitant expression of cell growth suppressors, gadd34 and BTG-2. In contrast, G2/G3 cancers were characterized by the expression of genes associated with the cell cycle and by STAT-1-, STAT-3/JAK-1/2-induced gene expression. The distinction between the LMP-G1 and G2–G3 groups of tumors was highly correlated to patient outcome (χ2 for equivalence of death rates=7.681189; P=0.0056, log-rank test). Our results are consistent with the recent demonstration of a poor differentiation molecular ‘meta-signature’ in human cancer, and underscore a number of cell-cycle- and STAT-associated targets that may prove useful as points of therapeutic intervention for those patients with aggressive disease.


European Journal of Cancer | 2003

Survival analyses from the ZEBRA study: goserelin (Zoladex™) versus CMF in premenopausal women with node-positive breast cancer

M. Kaufmann; Walter Jonat; R.W. Blamey; Jack Cuzick; M. Namer; Ignac Fogelman; J.C.J.M. de Haes; Martin Schumacher; Willi Sauerbrei

The Zoladex Early Breast Cancer Research Association (ZEBRA) trial compared the efficacy and tolerability of goserelin (Zoladex) with cyclophosphamide, methotrexate and 5-fluorouracil (CMF) chemotherapy in pre-/perimenopausal women with node-positive early breast cancer. The results of disease-free survival (DFS) analyses have already been published. Here we present an update including data on overall survival (OS) from the ZEBRA trial at a median follow-up of 7.3 years. In patients with oestrogen receptor (ER)-positive tumours, non-inferiority of goserelin versus CMF for OS was shown; goserelin was again shown to be equivalent to CMF for DFS. This updated analysis has demonstrated that the two treatments are also equivalent for distant disease-free survival (DDFS). In patients with ER-negative disease, goserelin was inferior to CMF for DFS, DDFS and OS. This follow-up analysis confirms the previously reported outcomes from the ZEBRA trial and demonstrates that goserelin offers an effective alternative to CMF chemotherapy for adjuvant therapy of premenopausal patients with ER-positive, node-positive early breast cancer.


Human Mutation | 1999

A highly sensitive, fast, and economical technique for mutation analysis in hereditary breast and ovarian cancers

Norbert Arnold; Eva Gross; Ulrike Schwarz-Boeger; Jacobus Pfisterer; Walter Jonat; Marion Kiechle

Mutation analysis of complex genes without hotspots for sequence variations, such as BRCA1, is time‐consuming and expensive. Of all currently available methods, direct sequencing has the highest sensitivity, but also the highest costs. Other techniques, such as SSCP, DGGE, and PTT, are more economical but, depending on the experience of the investigator, have at best a sensitivity of 90%. We investigated in a prospective study the feasibility and accuracy of the DHPLC technique. We present the application of the DHPLC protocol for BRCA1 mutation detection on a HPLC device from Bio‐Tek Kontron Instruments (Neufahrn, Germany). DNA from 46 women with hereditary breast and ovarian cancer undergoing genetic testing for BRCA1 mutations were tested. Of 1,518 amplicons analyzed by DHPLC, corresponding to 33 fragments spanning the entire BRCA1 gene, 626 were also directly sequenced. The comparison demonstrated that DHPLC detected all alterations found by direct sequencing. No false‐positive signals were seen in cases of homozygous sequences. Further, no false‐negative results were ever obtained in women with mutations or polymorphisms, or both. In cases of known genetic variations, the nature of the alterations could be predicted by DHPLC. We also compared different separation matrices. Up to about 500 injections, no significant differences in sensitivity could be observed between poly(styrene divinylbenzene) and end‐capped silica based columns. However, after more than 500 injections, the resolution of hetero‐ from homoduplex deteriorated rapidly on silica columns. Hum Mutat 14:333–339, 1999.


The Journal of Pathology | 2001

Decline in the expression of the serine proteinase inhibitor maspin is associated with tumour progression in ductal carcinomas of the breast

Nicolai Maass; Martin Teffner; Frank Rösel; Reza Pawaresch; Walter Jonat; Koichi Nagasaki; Pierre Rudolph

Maspin is an inhibitor of serine proteinases with tumour suppressor activity. Its expression appears to be reduced in advanced stages of breast cancer. A large series of archival breast tissue specimens has been examined, including normal glands (n=7), fibrocystic change (n=22), ductal carcinoma in situ (DCIS, n=12), infiltrating carcinomas (n=128) and their lymph node metastases (n=65), using a specific monoclonal antibody. Myoepithelium invariably showed strong maspin expression. In epithelial cells, the strongest expression was found in normal breast and fibrocystic change. A significant stepwise decrease in maspin expression (p<0.0001) occurred in the sequence DCIS – invasive cancer – lymph node metastasis. However, a subset of infiltrating carcinomas showed strong maspin expression, significantly associated with a lower rate of lymph node metastasis at the time of diagnosis (p<0.01). This was independent of tumour size and grade. The in vivo observations presented here are in keeping with data obtained in prior in vitro experiments. Maspin emerges as an indicator of tumour progression and metastatic potential, and might be exploited to predict breast cancer prognosis. According to in vitro data, its tumour suppressor activity is likely to involve both the modulation of cell motility/invasiveness and the inhibition of angiogenesis. Copyright


Clinical Biochemistry | 2001

Down regulation of the tumor suppressor gene maspin in breast carcinoma is associated with a higher risk of distant metastasis

Nicolai Maass; Takashi Hojo; Frank Rösel; Tadashi Ikeda; Walter Jonat; Koichi Nagasaki

BACKGROUND Maspin (mammary serpin) is a relatively novel serine protease inhibitor with tumor suppressing function in breast cancer. Maspin expression was found in normal breast epithelial cells, but was decreased during tumor progression. Only a few systematic analyses of this phenomenon have been undertaken so far. In this study we developed specific nested reverse transcription polymerase chain reaction (RT-PCR) conditions for the detection of maspin expression in human breast carcinoma and assessed maspins association with the clinical behavior of primary breast cancers. METHODS Tumor specimens obtained from 45 primary breast cancer patients were analyzed for maspin expression by a nested RT-PCR assay. Recurrence free survival was evaluated and correlated to maspin expression. RESULTS The maspin transcript was detected in 29 (64%) breast cancer specimens whereas no expression was found in 16 (36%) cancer specimens. This expression was unrelated to any of the established prognostic factors. However, 6 out of 8 patients who developed distant metastasis (lymph nodes, lung, liver, bone, pleura) within 3 yr after their initial diagnosis showed no maspin expression of the primary breast cancer (p < 0.05). CONCLUSIONS The lack of maspin expression in breast cancer seems to be associated with a short disease free survival and supports maspins function as an indicator of tumor aggressiveness and metastatic potential. Nested RT-PCR is a sensitive method to determine maspin expression in human breast cancer tissue.

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Matthias W. Beckmann

University of Erlangen-Nuremberg

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M. Kaufmann

German Cancer Research Center

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