Hans Peterse

Netherlands Cancer Institute, Amsterdamo, North Holland, Netherlands

Are you Hans Peterse?

Claim your profile

Publications (51)434.34 Total impact

  • Source
  • [Show abstract] [Hide abstract]
    ABSTRACT: The Dutch MRI Screening Study on early detection of hereditary breast cancer started in 1999. We evaluated the long-term results including separate analyses of BRCA1 and BRCA2 mutation carriers and first results on survival. Women with higher than 15% cumulative lifetime risk (CLTR) of breast cancer were screened with biannual clinical breast examination and annual mammography and magnetic resonance imaging (MRI). Participants were divided into subgroups: carriers of a gene mutation (50% to 85% CLTR) and two familial groups with high (30% to 50% CLTR) or moderate risk (15% to 30% CLTR). Our update contains 2,157 eligible women including 599 mutation carriers (median follow-up of 4.9 years from entry) with 97 primary breast cancers detected (median follow-up of 5.0 years from diagnosis). MRI sensitivity was superior to that of mammography for invasive cancer (77.4% v 35.5%; P<.00005), but not for ductal carcinoma in situ. Results in the BRCA1 group were worse compared to the BRCA2, the high-, and the moderate-risk groups, respectively, for mammography sensitivity (25.0% v 61.5%, 45.5%, 46.7%), tumor size at diagnosis≤1 cm (21.4% v 61.5%, 40.9%, 63.6%), proportion of DCIS (6.5% v 18.8%, 14.8%, 31.3%) and interval cancers (32.3% v 6.3%, 3.7%, 6.3%), and age at diagnosis younger than 30 years (9.7% v 0%). Cumulative distant metastasis-free and overall survival at 6 years in all 42 BRCA1/2 mutation carriers with invasive breast cancer were 83.9% (95% CI, 64.1% to 93.3%) and 92.7% (95% CI, 79.0% to 97.6%), respectively, and 100% in the familial groups (n=43). Screening results were somewhat worse in BRCA1 mutation carriers, but 6-year survival was high in all risk groups.
    Journal of Clinical Oncology 11/2010; 28(36):5265-73. DOI:10.1200/JCO.2009.27.2294 · 18.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The clinical, pathologic, and molecular features of pleomorphic lobular carcinoma in situ (PLCIS) and the relationship of PLCIS to classic LCIS (CLCIS) are poorly defined. In this study, we analyzed 31 cases of PLCIS (13 apocrine and 18 nonapocrine subtypes) and compared the clinical, pathologic, immunophenotypic, and genetic characteristics of these cases with those of 24 cases of CLCIS. Biomarker expression was examined using immunostaining for E-cadherin, gross cystic disease fluid protein-15, estrogen, progesterone, androgen receptor, human epidermal growth factor receptor2, CK5/6, and Ki67. Array-based comparative genomic hybridization to assess the genomic alterations was performed using microdissected formalin-fixed paraffin-embedded samples. Patients with PLCIS presented with mammographic abnormalities. Histologically, the tumor cells were dyshesive and showed pleomorphic nuclei, and there was often associated necrosis and microcalcifications. All lesions were E-cadherin negative. Compared with CLCIS, PLCIS showed significantly higher Ki67 index, lower estrogen receptor and progesterone receptor expression, and higher incidence of HER2 gene amplification. The majority of PLCIS and CLCIS demonstrated loss of 16q and gain of 1q. Apocrine PLCIS had significantly more genomic alterations than CLCIS and nonapocrine PLCIS. Although lack of E-cadherin expression and the 16q loss and 1q gain-array-based comparative genomic hybridization pattern support a relationship to CLCIS, PLCIS has clinical, mammographic, histologic, immunophenotypic, and genetic features that distinguish it from CLCIS. The histologic features, biomarker profile, and genomic instability observed in PLCIS suggest a more aggressive phenotype than CLCIS. However, clinical follow-up studies will be required to define the natural history and most appropriate management of these lesions.
    The American journal of surgical pathology 09/2009; 33(11):1683-94. DOI:10.1097/PAS.0b013e3181b18a89 · 4.59 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study aimed to quantify the incidence and extension of microscopic disease around primary breast tumors in patients undergoing breast-conserving therapy (BCT), focusing on a potential application to reduce radiotherapy boost volumes. An extensive pathology tumor-distribution study was performed using 38 wide local excision specimens of BCT patients. Specimen orientation was recorded and microscopic findings reconstructed to assess the incidence of microscopic disease around the macroscopic tumor. A model of disease spread was built, showing probability of disease extension outside a treated volume (P(out,vol)). The model was applied in 10 new BCT patients. Taking asymmetry of tumor excision into account, new asymmetric margins for the clinical target volume of the boost (CTV(boost)) were evaluated that minimize the volume without increasing P(out,TTV) (TTV being total treated volume: V(surgery) + CTV(boost)). Potential reductions in CTV(boost) and TTV were evaluated. Microscopic disease beyond the tumor boundary occurred isotropically at distances > 1 cm (intended surgical margin) and > 1.5 cm (intended TTV margin) in 53% and 36% of the excision specimens, respectively. In the 10 prospective patients, the average P(out,TTV) was, however, only 16% due to larger surgical margins than intended in some directions. Asymmetric CTV(boost) margins reduced the CTV(boost) and TTV by 27% (20 cc) and 12% (21 cc) on average, without compromising tumor coverage. Microscopic disease extension may occur beyond the current CTV(boost) in approximately one sixth of patients. An asymmetric CTV(boost) that corrects for asymmetry of the surgical excision has the potential to reduce boost volumes while maintaining tumor coverage.
    International journal of radiation oncology, biology, physics 05/2009; 74(3):898-905. DOI:10.1016/j.ijrobp.2009.01.026 · 4.18 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Currently, the local treatment of most patients with early invasive breast cancer consists of breast-conserving therapy (BCT). We have previously reported on the risk factors for ipsilateral breast relapse (IBR) in 1,026 patients treated with BCT after a median follow-up of 5.5 years. In the present study, we evaluated the IBR incidence and the risk factors for IBR after prolonged follow-up. We updated the disease outcome for all 1,026 patients using the clinical information collected from the medical registration of The Netherlands Cancer Institute and performed step-wise proportional hazard Cox regression analysis to identify the risk factors associated with an increased risk of IBR after BCT at long-term follow-up. After a median follow-up of 13.3 years, 114 patients had developed an IBR as the first event. The IBR rate was 9.3% and 13.8%, respectively, at 10 and 15 years. Also, the increase in IBR was continuous without reaching a plateau, even after 15 years. Univariate analysis showed that involved surgical resection margins, young age, vascular invasion, and the presence and quantity of an in situ component are risk factors for IBR. Multivariate analysis showed that tumor-positive surgical resection margins (hazard ratio, 2.9; 95% confidence interval, 1.7-5.2, p = 0.0002) or the presence of vascular invasion (hazard ratio, 2.0; 95% confidence interval, 1.2-3.2, p = 0.004) is the major independent risk factor for IBR. The data from long-term follow-up showed a constant increase in IBR among patients treated by BCT, even after 15 years, without reaching a plateau. Involved surgical resection margins and vascular invasion were the most important risk factors for IBR.
    International Journal of Radiation OncologyBiologyPhysics 08/2008; 71(4):1014-21. DOI:10.1016/j.ijrobp.2007.11.029 · 4.18 Impact Factor
  • EJC Supplements 04/2008; 6(7):132-133. DOI:10.1016/S1359-6349(08)70601-3 · 9.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: In the MRISC study, women with an inherited risk for breast cancer were screened by a 6-month clinical breast examination (CBE) and yearly MRI and mammography. We found that the MRISC screening scheme could facilitate early breast cancer diagnosis and that MRI was a more sensitive screening method than mammography, but less specific. In the current study we investigated the contribution of MRI in the early detection of breast cancer in relation to tumor characteristics. From November 1999 to October 2003, 1909 women were included and 50 breast cancers were detected, of which 45 were evaluable and included in the current study. We compared the characteristics of tumors detected by MRI-only with those of all other (non-palpable) screen-detected tumors. Further, we compared the sensitivity of mammography and MRI within subgroups according to different tumor characteristics. Twenty-two (49%) of the 45 breast cancers were detected by MRI and not visible at mammography, of which 20 (44%) were also not palpable (MRI-only detected tumors). MRI-only detected tumors were more often node-negative than other screen-detected cancers (94 vs. 59%; P=0.02) and tended to be more often <or=1 cm (58 vs. 31%; P=0.11). MRI was more sensitive than mammography for a wide spectrum of invasive tumor characteristics i.e., size, nodal status, histology, grade and ER status. Half of the breast cancers detected in this study were visible by MRI only and these tumors were smaller and significantly more often node-negative than other screen-detected tumors, suggesting that MRI makes an important contribution to the early detection of hereditary breast cancer.
    Breast Cancer Research and Treatment 06/2007; 102(3):357-63. DOI:10.1007/s10549-006-9341-6 · 4.20 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Breast cancer is a heterogeneous group of tumors, and can be subdivided on the basis of histopathological features, genetic alterations and gene-expression profiles. One well-defined subtype of breast cancer is characterized by a lack of HER2 gene amplification and estrogen and progesterone receptor expression ('triple-negative tumors'). We examined the histopathological and gene-expression profile of triple-negative tumors to define subgroups with specific characteristics, including risk of developing distant metastases. 97 triple-negative tumors were selected from the fresh-frozen tissue bank of the Netherlands Cancer Institute, and gene-expression profiles were generated using 35K oligonucleotide microarrays. In addition, histopathological and immunohistochemical characterization was performed, and the findings were associated to clinical features. All triple-negative tumors were classified as basal-like tumors on the basis of their overall gene-expression profile. Hierarchical cluster analysis revealed five distinct subgroups of triple-negative breast cancers. Multivariable analysis showed that a large amount of lymphocytic infiltrate (HR = 0.30, 95% CI 0.09-0.96) and absence of central fibrosis in the tumors (HR = 0.14, 95% CI 0.03-0.62) were associated with distant metastasis-free survival. Triple-negative tumors are synonymous with basal-like tumors, and can be identified by immunohistochemistry. Based on gene-expression profiling, basal-like tumors are still heterogeneous and can be subdivided into at least five distinct subgroups. The development of distant metastasis in basal-like tumors is associated with the presence of central fibrosis and a small amount of lymphocytic infiltrate.
    Breast cancer research: BCR 02/2007; 9(5):R65. DOI:10.1186/bcr1771 · 5.88 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Several risk factors for local recurrence of breast cancer after breast-conserving therapy (BCT) have been identified. The identification of additional risk factors would be very useful in guiding optimal therapy and also in improving understanding of the mechanisms underlying local recurrence. We used cDNA microarray analysis to identify gene expression profiles associated with local recurrence. Using 18K cDNA microarrays, gene expression profiles were obtained from 50 patients who underwent BCT. Of these 50 patients, 19 developed a local recurrence; the remaining 31 patients were selected as controls as they were free of local recurrence at least 11 years after treatment. For 9 of 19 patients, the local recurrence was also available for gene expression profiling. Unsupervised and supervised methods of classification were used to separate patients in groups corresponding to disease outcome and to study the overall gene expression pattern of primary tumors and their recurrences. Hierarchical clustering of patients did not show any grouping reflecting local recurrence status. Supervised analysis revealed no significant set of genes that was able to distinguish recurring tumors from nonrecurring tumors. Paired-data analysis of primary tumors and local recurrences showed a remarkable similarity in gene expression profile between primary tumors and their recurrences. No significant differences in gene expression between primary breast cancer tumors in patients with or without local recurrence after BCT were identified. Furthermore, analyses of primary tumors and local recurrences show a preservation of the overall gene expression pattern in the local recurrence, even after radiotherapy.
    Clinical Cancer Research 11/2006; 12(19):5705-12. DOI:10.1158/1078-0432.CCR-06-0805 · 8.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Lobular carcinoma in situ was first described over 60 years ago. Despite the long history, it continues to pose significant difficulties in screening, diagnosis, management and treatment. This is partly due its multi-focal and bilateral presentation, an incomplete understanding of its biology and natural history and perpetuation of misconceptions gathered over the last decades. In this review, the working group on behalf of EUSOMA has attempted to summarise the current thinking and management of this interesting lesion.
    European Journal of Cancer 10/2006; 42(14):2205-11. DOI:10.1016/j.ejca.2006.03.019 · 4.82 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cytokeratin immunohistochemistry (IHC) reveals a higher rate of occult lymph node metastases among lobular carcinomas than among ductal breast cancers. IHC is widely used but is seldom recommended for the evaluation of sentinel lymph nodes in breast cancer patients. Objective: To assess the value of cytokeratin IHC for the detection of metastases in sentinel lymph nodes of patients with invasive lobular carcinoma. The value of IHC, the types of metastasis found by this method, and the involvement of non-sentinel lymph nodes were analysed in a multi-institutional cohort of 449 patients with lobular breast carcinoma, staged by sentinel lymph node biopsy and routine assessment of the sentinel lymph nodes by IHC when multilevel haematoxylin and eosin staining revealed no metastasis. 189 patients (42%) had some type of sentinel node involvement, the frequency of this increasing with increasing tumour size. IHC was needed for identification of 65 of these cases: 17 of 19 isolated tumour cells, 40 of 64 micrometastases, and 8 of 106 larger metastases were detected by this means. Non-sentinel-node involvement was noted in 66 of 161 cases undergoing axillary dissection. Although isolated tumour cells were not associated with further lymph node involvement, sentinel node positivity detected by IHC was associated with further nodal metastases in 12 of 50 cases (0.24), a proportion that is higher than previously reported for breast cancer in general. IHC is recommended for the evaluation of sentinel nodes from patients with lobular breast carcinoma, as the micrometastases or larger metastases demonstrated by this method are often associated with a further metastatic nodal load.
    Journal of Clinical Pathology 06/2006; 59(5):518-22. DOI:10.1136/jcp.2005.029991 · 2.55 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Histologic grade in breast cancer provides clinically important prognostic information. However, 30%-60% of tumors are classified as histologic grade 2. This grade is associated with an intermediate risk of recurrence and is thus not informative for clinical decision making. We examined whether histologic grade was associated with gene expression profiles of breast cancers and whether such profiles could be used to improve histologic grading. We analyzed microarray data from 189 invasive breast carcinomas and from three published gene expression datasets from breast carcinomas. We identified differentially expressed genes in a training set of 64 estrogen receptor (ER)-positive tumor samples by comparing expression profiles between histologic grade 3 tumors and histologic grade 1 tumors and used the expression of these genes to define the gene expression grade index. Data from 597 independent tumors were used to evaluate the association between relapse-free survival and the gene expression grade index in a Kaplan-Meier analysis. All statistical tests were two-sided. We identified 97 genes in our training set that were associated with histologic grade; most of these genes were involved in cell cycle regulation and proliferation. In validation datasets, the gene expression grade index was strongly associated with histologic grade 1 and 3 status; however, among histologic grade 2 tumors, the index spanned the values for histologic grade 1-3 tumors. Among patients with histologic grade 2 tumors, a high gene expression grade index was associated with a higher risk of recurrence than a low gene expression grade index (hazard ratio = 3.61, 95% confidence interval = 2.25 to 5.78; P < .001, log-rank test). Gene expression grade index appeared to reclassify patients with histologic grade 2 tumors into two groups with high versus low risks of recurrence. This approach may improve the accuracy of tumor grading and thus its prognostic value.
    CancerSpectrum Knowledge Environment 03/2006; 98(4):262-72. DOI:10.1093/jnci/djj052 · 15.16 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Imaging is often performed yearly for the surveillance of BRCA1/2 mutation carriers and women at high familial breast cancer risk. Growth of cancers in carriers may be faster as these tumours are predominantly high grade. Quantitative data on tumour growth rates in these 2 groups are lacking. Here, we have examined 80 high-risk women under surveillance for tumour size at diagnosis and preceding examinations at mammography and/or MRI. Tumour volume doubling time (DT) was assessed in 30 cancers in BRCA1/2 mutation carriers and 25 non-carriers. Impact of age and menopausal status were also evaluated. Mean DT of all invasive cancers was shorter in carriers (45 days CI: 26-73) than non-carriers (84 days CI: 58-131) (P = 0.048). Mean age at diagnosis was lower in carriers (40 years) than non-carriers (45 years) (P = 0.007). At multivariable analysis only age (P = 0.03), not risk-group (P = 0.26) nor menopause (P = 0.58) correlated significantly with DT. The mean growth rate slowed down to half in each successive 10 years-older group. In conclusion, age at detection indicated the growth rates of hereditary and familial breast cancers. It is recommended that the screening frequency should be adjusted according to a woman's age and a high-sensitive biannual test may be appropriate before the age of 40 years.
    European Journal of Cancer 08/2005; 41(11):1610-7. DOI:10.1016/j.ejca.2005.02.034 · 4.82 Impact Factor
  • Source
    Breast Cancer Research 05/2005; 7:1-1. DOI:10.1186/bcr1227 · 5.33 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The authors report a prospective study comparing magnetic resonance imaging (MRI) with mammography for screening in women having an estimated cumulative lifetime risk of breast cancer of at least 15% because of a familial or genetic predisposition. A clinical breast examination was done every 6 months and imaging studies (with independent readings) every 12 months. The study group included 1909 eligible women 25 to 70 years of age, 358 of whom were carriers of germline mutations. A BRCA1 mutation was by far the most common pathogenic mutation. A total of 51 tumors were found during a median follow up of 2.9 years. There were 44 invasive cancers, 6 ductal carcinomas in situ, and 1 lymphoma. An additional woman had a lobular carcinoma in situ. The overall detection rate for all breast cancers was 9.5 per 1000 woman-years at risk. Twenty-two of the 32 cancers found by magnetic resonance imaging (MRI) were not found on mammograms. Eight of 13 cancers missed by MRI were visible on mammograms. Sensitivity figures for all breast cancers were 18% for clinical breast examination, 40% for mammography, and 71% for MRI. Twenty-two of 41 cancers found by screening were detected at the first imaging screening. Specificity figures for invasive breast cancer were 98% for clinical beast examination, 95% for mammography, and 90% for MRI. The overall discriminating ability of MRI significantly exceeded that of mammography. Invasive cancers measuring 10 mm or less in diameter were significantly more frequent in women under surveillance than in control women. More than half of control women but only approximately one fifth of screened women had positive axillary lymph nodes and/or micrometastases. These findings indicate that MRI is more sensitive than mammography for detecting beast cancers in women at increased risk because of inherited susceptibility.
    Obstetrical and Gynecological Survey 01/2005; 60(2):107-109. DOI:10.1097/01.ogx.0000151669.38495.2e · 2.36 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The value of regular surveillance for breast cancer in women with a genetic or familial predisposition to breast cancer is currently unproven. We compared the efficacy of magnetic resonance imaging (MRI) with that of mammography for screening in this group of high-risk women. Women who had a cumulative lifetime risk of breast cancer of 15 percent or more were screened every six months with a clinical breast examination and once a year by mammography and MRI, with independent readings. The characteristics of the cancers that were detected were compared with the characteristics of those in two different age-matched control groups. We screened 1909 eligible women, including 358 carriers of germ-line mutations. Within a median follow-up period of 2.9 years, 51 tumors (44 invasive cancers, 6 ductal carcinomas in situ, and 1 lymphoma) and 1 lobular carcinoma in situ were detected. The sensitivity of clinical breast examination, mammography, and MRI for detecting invasive breast cancer was 17.9 percent, 33.3 percent, and 79.5 percent, respectively, and the specificity was 98.1 percent, 95.0 percent, and 89.8 percent, respectively. The overall discriminating capacity of MRI was significantly better than that of mammography (P<0.05). The proportion of invasive tumors that were 10 mm or less in diameter was significantly greater in our surveillance group (43.2 percent) than in either control group (14.0 percent [P<0.001] and 12.5 percent [P=0.04], respectively). The combined incidence of positive axillary nodes and micrometastases in invasive cancers in our study was 21.4 percent, as compared with 52.4 percent (P<0.001) and 56.4 percent (P=0.001) in the two control groups. MRI appears to be more sensitive than mammography in detecting tumors in women with an inherited susceptibility to breast cancer.
    New England Journal of Medicine 07/2004; 351(5):427-37. DOI:10.1056/NEJMoa031759 · 54.42 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Disseminated breast tumour cells in sentinel lymph nodes (SNs) were evaluated by quantitative real-time PCR and the sensitivity of this assay was compared to the routine histological analysis. First, several candidate marker genes were tested for their specificity in axillary lymph nodes (ALN) of 50 breast cancer patients and 43 women without breast cancer. The marker gene panel selected, designed to detect the mRNA of CK19, p1B, EGP2 and SBEM, was subsequently applied to detect metastases in 70 SNs that were free of metastases as determined by standard histological evaluation. Remarkably, seven negative SNs showed increased marker gene expression, suggesting the presence of (micro) metastases. Four of these seven SNs positive by real-time PCR proved to contain tumour deposits after careful review of the slides or further sectioning of the paraffin-embedded material. In three PCR positive SNs, however, no tumour cells were found by haematoxylin and eosin staining (H&E) and immunohistologically analysis. The quantitative real-time PCR assay with multiple mRNA markers for the detection of disseminated breast cancer cells in SNs thus resulted in an upstaging of SNs containing metastastic disease of 10% compared to the routine histological analysis. The application of this technique may be of clinical relevance, as it is suggested that micrometastatic disease in SNs are associated with further nodal non-SN metastases in breast cancer.
    British Journal of Cancer 04/2004; 90(8):1531-7. DOI:10.1038/sj.bjc.6601659 · 4.82 Impact Factor
  • EJC Supplements 03/2004; 2(3):80-80. DOI:10.1016/S1359-6349(04)90685-4 · 9.39 Impact Factor
  • EJC Supplements 03/2004; 2(3):161-161. DOI:10.1016/S1359-6349(04)90962-7 · 9.39 Impact Factor
  • EJC Supplements 03/2004; 2(3):86-86. DOI:10.1016/S1359-6349(04)90710-0 · 9.39 Impact Factor