Effect of radiotherapy after breast-conserving surgery for ductal carcinoma in situ: 20 years follow-up in the randomized SweDCIS Trial.

PURPOSE: Four randomized studies show that adjuvant radiotherapy (RT) lowers the risk of subsequent ipsilateral breast events (IBEs) after breast-conserving surgery (BCS) for ductal carcinoma in situ (DCIS) by approximately 50% after 10 to 15 years. We present 20 years of follow-up data for the SweDCIS trial. PATIENTS AND METHODS: Between 1987 and 1999 1,046 women were randomly assigned to RT or not after BCS for primary DCIS. Results up to 2005 have been published, and we now add another 7 years of follow-up. All breast cancer events and causes of death were registered. RESULTS: There were 129 in situ and 129 invasive IBEs. Absolute risk reduction in the RT arm was 12.0% at 20 years (95% CI, 6.5 to 17.7), with a relative risk reduction of 37.5%. Absolute reduction was 10.0% (95% CI, 6.0 to 14.0) for in situ and 2.0% (95% CI, -3.0 to 7.0) for invasive IBEs. There was a nonstatistically significantly increased number of contralateral events in the RT arm (67 v 48 events; hazard ratio, 1.38; 95% CI, 0.95 to 2.00). Breast cancer-specific death and overall survival were not influenced. Younger women experienced a relatively higher risk of invasive IBE and lower effect of RT. The hazard over time looked different for in situ and invasive IBEs. CONCLUSION: Use of adjuvant RT is supported by 20-year follow-up. Modest protection against invasive recurrences and a possible increase in contralateral cancers still call for a need to find groups of patients for whom RT could be avoided or mastectomy with breast reconstruction is indicated.

Absolute risk reductions for local recurrence after postoperative radiotherapy after sector resection for ductal carcinoma in situ of the breast.

PURPOSE: Evaluate the effects of radiotherapy after sector resection for ductal carcinoma in situ of the breast (DCIS) in patient groups as defined by age, size of the lesion, focality, completeness of excision and mode of detection. PATIENTS AND METHODS: A total of 1,067 women in Sweden were randomly assigned to either postoperative radiotherapy (RT) or control from 1987 to 1999, and 1,046 were followed for a mean of 8 years. The main outcome was new ipsilateral breast cancer events and distant metastasis-free survival analyzed according to intention to treat. RESULTS: There were 64 ipsilateral events in the RT arm and 141 in the control group corresponding to a risk reduction of 16.0 percentage points at 10 years (95% CI, 10.3% to 21.6%) and a relative risk of 0.40 (95% CI, 0.30 to 0.54). There was no statistically significant difference in distant metastasis-free survival. There was an effect modification by age, yielding a low effect of RT in women younger than 50, but substantial protection in women older than 60 years. The age effect was not confounded by focality, lesion size, completeness of excision, or detection mode. There was no group as defined by our stratification variables that had a low risk without radiotherapy. CONCLUSION: Our results indicate that younger women have a low protective effect of conventional RT after sector resection. Older women benefit substantially. We caution that the age effect was seen in a subgroup analysis. Further search with conventional clinical variables for a low risk group that does not need RT does not seem fruitful.

SweDCIS: Radiotherapy after sector resection for ductal carcinoma in situ of the breast. Results of a randomised trial in a population offered mammography screening.

We studied the effect of postoperative radiotherapy (RT) after breast sector resection for ductal carcinoma in situ (DCIS). The study protocol stipulated radical surgery but microscopically clear margins were not mandatory. We randomised 1,046 operated women to postoperative RT or control between 1987 and 1999. The primary endpoint was ipsilateral local recurrence. Secondary endpoints were contralateral breast cancer, distant metastasis and death. After a median follow-up of 5.2 years (range 0.1-13.8) there were 44 recurrences in the RT group corresponding to a cumulative incidence of 0.07 (95% confidence interval (CI) 0.05-0.10). In the control group there were 117 recurrences giving a cumulative incidence of 0.22 (95% CI 0.18-0.26) giving an overall hazard ratio of 0.33 (95% CI 0.24-0.47, p < 0.0001). Twenty two percent of the patients had microscopically unknown or involved margins. We found no evidence for different effects of RT on the relative risk of invasive or in situ recurrence. Secondary endpoints did not differ. Women undergoing sector resection for DCIS under conditions of population based screening mammography benefit from postoperative RT to the breast. Seven patients needed RT-treatment to prevent one recurrence.

Increased copy number at 3p14 in breast cancer.

INTRODUCTION: The present study was conducted to investigate if chromosome band 3p14 is of any pathogenic significance in the malignant process of breast cancer. Genetic studies have implicated a tumour suppressor gene on chromosome arm 3p and we have proposed LRIG1 at 3p14 as a candidate tumour suppressor. The LRIG1 gene encodes an integral membrane protein that counteracts signalling by receptor tyrosine kinases belonging to the ERBB family. LRIG1 mRNA and protein are expressed in many tissues, including breast tissue. METHODS: In the present report we analysed the LRIG1 gene by fluorescence in situ hybridisation (FISH), LRIG1 mRNA by quantitative RT-PCR, and LRIG1 protein by western blot analysis. Two tumour series were analysed; one series consisted of 19 tumour samples collected between 1987 and 1995 and the other series consisted of 9 tumour samples with corresponding non-neoplastic breast tissues collected consecutively. RESULTS: The LRIG1 gene showed increased copy number in 11 out of 28 tumours (39%) and only one tumour showed a deletion at this locus. Increased LRIG1 copy number was associated with increased levels of LRIG1 mRNA (two of three tumours) and protein (four of four tumours) in the tumours compared to matched non-neoplastic breast tissue, as assessed by RT-PCR and western blot analysis. CONCLUSION: The molecular function of LRIG1 as a negative regulator of ERBB receptors questions the biological significance of increased LRIG1 copy number in breast cancer. We propose that a common, but hitherto unrecognised, breast cancer linked gene is located within an amplicon containing the LRIG1 locus at 3p14.3.

ERK phosphorylation is linked to VEGFR2 expression and Ets-2 phosphorylation in breast cancer and is associated with tamoxifen treatment resistance and small tumours with good prognosis.

Extracellular signal-regulated kinase (ERK)1/2 signalling mediates communication between growth factor receptors and the cell nucleus and has been linked to several key events in the transformation process such as proliferation and invasion. We therefore sought to delineate the degree of phosphorylated ERK1/2 in breast cancer and potential links to upstream receptors such as VEGFR2, ErbB2, downstream targets, such as Ets-2, as well as clinico-pathological parameters, clinical outcome and response to tamoxifen. ERK1/2 phosphorylation was assessed by immunohistochemistry using a phospho-specific ERK1/2 antibody in three breast cancer cohorts including a total of 886 tumours arranged in tissue arrays. Cohort I consisted of 114 patients, cohort II of 248 postmenopausal patients randomized to either 2 years of tamoxifen or no adjuvant treatment and cohort III of 524 patients. Surprisingly, ERK1/2 phosphorylation correlated inversely with tumour size. Phosphorylated ERK1/2 was further associated with the presence of VEGFR2 (cohorts II and III) and the degree of phosphorylated Ets-2, indicating in vivo, a signalling cascade from VEGFR2 via ERK1/2 to Ets-2 phosphorylation. Interestingly, ERK1/2 phosphorylation correlated with better survival in untreated patients independently of lymph-node status and tumour size indicating that ERK1/2 signalling might be associated with a less aggressive phenotype. Finally, patients with oestrogen receptor positive and ERK1/2 phosphorylated tumours also had an impaired tamoxifen response.

Tumor-specific VEGF-A and VEGFR2 in postmenopausal breast cancer patients with long-term follow-up. Implication of a link between VEGF pathway and tamoxifen response.

Vascular endothelial growth factor (VEGF-A) is considered a prognostic indicator for clinical outcome in breast cancer. Conflicting results nevertheless exist and there is a need for larger studies including untreated patients in order to clarify the importance of tumor-specific VEGF-A regarding prognosis as well as potential links to predictive treatment information. VEGF-A and its receptor, vascular endothelial growth receptor 2 (VEGFR2), were therefore analyzed by immunohistochemistry in postmenopausal breast cancers enrolled in a clinical trial where patients were randomized to adjuvant tamoxifen treatment (n = 124) for 2 years or no treatment (n = 127) with a median follow-up of 18 years. The tumors were arranged in a tumor tissue microarray system enabling parallel analysis of the angiogenic factors and hormone receptor status. Tumor-specific expression of VEGFR2 correlated strongly with expression of VEGF-A and progesterone receptor (PR) negativity, whereas VEGF-A was not associated with hormone receptor status. Among patients with estrogen receptor (ER) positive (fraction > 10%) tumors, there was a statistically significant tamoxifen response in VEGF-A negative tumors at both 10-year and 18-year disease-free survival (DFS), contrasting to VEGF-A positive tumors who had no beneficial effect of tamoxifen. A treatment-interaction variable indicated a marked difference in tamoxifen response depending on VEGFA-status in terms of DFS at 10 and 18 years of follow-up, p = 0.046 and p = 0.039, respectively. VEGFR2 status did not yield significant predicitve information for tamoxifen response in patients with ER fraction > 10%, whereas in patients with ER fraction > 90% both VEGF-A and VEGFR2 status were associated with tamoxifen treatment effect.

Expression and signaling activity of Wnt-5a/discoidin domain receptor-1 and Syk plays distinct but decisive roles in breast cancer patient survival.

PURPOSE: The loss of Wnt-5a, a G-protein-coupled receptor ligand, or Syk, an intracellular kinase, has in separate studies been associated with poor prognosis of breast cancer patients. Both proteins are involved in cell adhesion, a key event in epithelial cancer metastasis. Here, we have investigated whether Syk is part of the Wnt-5a/discoidin domain receptor-1 (DDR1) signaling pathway and if a signaling interaction of these proteins is important for breast cancer-specific survival. EXPERIMENTAL DESIGN: The signaling interactions between Wnt-5a/DDR1 and Syk were addressed in mammary cell lines. Their mRNA and protein levels and the respective clinical correlates were investigated in 94 cases of primary breast cancer. RESULTS: The expression of Wnt-5a and Syk correlated in four of five tumor cell lines. However, despite a constitutive association between Syk and the Wnt-5a-dependent adhesion receptor DDR1, we found no evidence of a Wnt-5a/DDR1-mediated activation of Syk. Instead, beta(1) integrins initiate the adhesion-induced activation of Syk. In tumors from breast cancer patients, the protein expression of Wnt-5a and Syk were differently regulated at the translational and transcriptional level, respectively. Analysis of breast cancer-specific survival revealed that the presence of Wnt-5a and Syk in primary tumors has good predictive value for a favorable outcome. Intriguingly, a simultaneous loss of both proteins did not reduce survival more than loss of either. CONCLUSIONS: Despite the difference in regulation of Wnt-5a and Syk protein expression and their lack of signaling interaction, our clinical data indicate that a favorable prognosis in breast cancer requires the expression and signaling activity of both.

Spectrum of cytokeratin-positive cells in the bone marrows of colorectal carcinoma patients.

BACKGROUND: Bone marrow micrometastases (BMM) is considered to be of interest as a prognostic marker in solid tumors. The use of density-gradient separated bone marrow (BM) aspirates does not allow proper morphological characterization of the cells. An alternative approach, using routinely processed clots of BM aspirates, is presented. MATERIALS AND METHODS: BM clots from 56 colorectal carcinoma patients were stained for cytokeratin (CK), p53 and Ki67 by double immunohistochemistry. Cytokeratin-positive (CK+) cells were immunohistochemically divided into three groups, viz. Group A (CK+ probably malignant epithelial cells), Group B (CK+ morphologically non-epithelial cells) and Group C (CK+ contaminating cells). RESULTS: Thirty-three patients (59%) had CK+ cells, of which 19 (58%) had Group A cells and 14 (42%) had Group B cells. Fourteen of the 56 patients had reactive BM, eight of these had Group A cells and 3 had Group B cells. Group B cells and Group C cells did not express p53. Group A cells were noted in 35% of patients with carcinomas of Dukes' stage C and in 41% of patients with metastatic disease. CONCLUSION: Double immunohistochemical staining of routinely processed BM clot, for p53 and Ki67 along with CK allows the sub-classification of CK+ cells.

Regional cyclin D1 overexpression or hypoxia correlate inversely with heterogeneous oestrogen receptor-alpha expression in human breast cancer.

The oestrogen receptor-alpha (ER alpha) differs in expression and regulation in breast cancer and, by studying the co-factor cyclin D1 as well as changes in the microenvironment, we here delineate two conditions that potentially cause regional down-regulation of the receptor. Heterogeneously expressed ER alpha was observed in 24 out of 134 of the studied breast cancer samples. In 6 out of 24 of the heterogeneous tumours, there was a clear inverse association between cyclin D1 protein/gene amplification and presence of ER alpha. In a subset of 120 tumours, analysed by Western blotting and ELISA, we further showed disparity in differentiation grade and proliferation between tumours with varied cyclin D1/ER alpha content. In another fraction (9 out of 24) of the heterogeneous tumours, there was an inverse association between the ER alpha and Hypoxia-Inducible Factor-1 alpha (HIF-1 alpha) suggesting that ER alpha was down-regulated during hypoxic conditions. These results were verified by culturing ER alpha breast cancer cell lines under hypoxic conditions showing a prominent down-regulation of the ER alpha. The two factors linked to ER alpha down-regulation can also be used to design new treatment approaches interfering with key proteins in these ER alpha regulatory pathways, thereby hopefully increasing the effect of anti-hormonal treatment.

C-erbB2, p27 and G1/S aberrations in human primary breast cancer.

BACKGROUND: C-erbB2 is overexpressed in approximately one-fourth of human breast cancers. In spite of numerous reports suggesting a connection of c-erbB2 overexpression with cell cycle regulation through p27, D cyclins and c-myc, the relationship between c-erbB2 and proliferation through de-regulation of the pRb pathway in primary breast cancer has not been fully clarified. MATERIALS AND METHODS: For this purpose we compared the expression of c-erbB2 in a total of 105 primary breast tumours with a variety of cell cycle proteins and clinical parameters. RESULTS: C-erbB2 was strongly correlated with down-regulation of p27 and overexpression of c-erbB2 was, as expected, associated with poor survival. However, there was no correlation with proliferation. There was, nevertheless, an association between c-erbB2 and proliferation in certain subtypes of breast cancer, as in oestrogen-receptor-positive tumours, tumours with high cyclin D1, and in tumours with an overall linear pRb pathway, i.e. tumours with a preserved linearity between cyclin D1, pRb phosphorylation and proliferation. CONCLUSION: Our results suggest that c-erbB2 may have alternative functions in different subtypes of breast cancer, and further stress that c-erbB2, in addition to promoting proliferation, also functions through other mechanisms in breast cancer.

Tumor specific VEGF-A and VEGFR2/KDR protein are co-expressed in breast cancer.

Angiogenesis is a prognostic indicator in primary breast cancer regulated by specific angiogenic factors and their receptors. Vascular endothelial growth factor-A (VEGF-A), so far considered the most important, acts through dimerization of the receptor VEGFR2/KDR within the receptor tyrosine kinase family of VEGF receptors. In order to study the interplay between VEGF-A and VEGFR2/KDR in breast cancer we evaluated their expression by immunohistochemistry in 102 breast cancers organized in a tumor tissue array system allowing semi-quantitative evaluation of cytoplasmatic staining intensity. In addition, VEGF-A165 was analyzed by an enzyme immuno assay (ELISA) in protein extracts prepared from frozen tissue from 98 of 102 tumors included in the array. Cytoplasmatic staining of VEGF of varying intensity was observed in all samples and correlated with the ELISA results of VEGF content (p = 0.007). Interestingly, VEGFR2/KDR expression correlated with VEGF expression using immunohistochemistry, indicating that VEGF and VEGFR2/KDR may be co-expressed in breast cancer. Furthermore, high levels of VEGF-A165 in the protein extracts was associated with impaired short time survival but not long term survival whereas immunohistochemically assessed VEGF and VEGFR2/KDR were not significantly associated with survival. In summary, immunohistochemically based analysis of VEGF using a tumor tissue array system seems to be a useful method for VEGF quantification in breast cancer here validated using an ELISA based method. The tumor tissue array system enables opportunities of simultaneous analysis of markers engaged in angiogenesis justifying further studies using larger series of tumors.

The cyclin D1 high and cyclin E high subgroups of breast cancer: separate pathways in tumorogenesis based on pattern of genetic aberrations and inactivation of the pRb node.

In an attempt to identify subtypes of breast cancer and pinpoint patterns of cell cycle regulatory defects associated with clinical behaviour, proliferation and other transformation associated events, a multitude of cell cycle regulatory proteins were analysed in a material of 113 primary breast cancers. Increased proliferation was observed in two different scenarios; (1) with high cyclin D1 and elevated retinoblastoma protein (pRb) phosphorylation, (cyclin D1(high) tumours) or (2) with high cyclin E protein but low cyclin D1 and lack of corresponding pRb phosphorylation (cyclin E(high) tumours) indicative of an interrupted pRb pathway. Characteristic for cyclin E(high) tumours were further defects in p53, p27 and bcl-2, while c-erbB2 overexpression and c-myc amplification was found in both cyclin D1(high) and E(high) tumours. Using transfected cell lines overexpressing cyclin E, cyclin E(high) and D1(high) tumours were mimicked and the cyclin D1(high) cell line normalized the cyclin E kinase activity by an induction and redirection of p21 and p27 to the cyclin E complex whereas cyclin E(high) cell lines obtained increased kinase activity without redirection of inhibitors. Based on differences in genetic aberrations as well as function of the pRb node we therefore propose a model in which cyclin D1(high) and cyclin E(high) tumours represent two alternative mechanisms to inactivate the pRb pathway and thereby achieve unrestrained growth in the tumorogenesis of breast cancer.