Evaluation of HER-2 neu oncoprotein expression as a prognostic indicator of local recurrence in conservatively treated breast cancer: a case-control study

Radiosensitization of HER2-positive esophageal cancer cells by pyrotinib

Radiation therapy is a widely used treatment for esophageal cancer. However, radiation resistance might result in a poor prognosis. Overexpression of HER2 has been related to adaptive radiation resistance. Pyrotinib is a HER2 inhibitor that shows an anti-tumor effect in breast cancer. The present study aims to explore the influence of pyrotinib combined with radiotherapy on HER2-positive esophageal cancer cells and explore the underlying mechanism. We screened two cell lines (TE-1 and KYSE30) that highly express HER2 from several human esophageal cancer cell lines. Cells were treated with pyrotinib or/and radiation. Cell proliferation, cell cycle distribution, and cell migration were measured. The protein levels involved in cell cycle and DNA repair were measured by Western blot. Results showed that pyrotinib inhibited HER2 activation and exerted an anti-proliferative effect in TE-1 and KYSE30 cells. Furthermore, it enhanced the anti-proliferative effect of radiation in these two cell lines. These effects might be via inhibiting HER2 phosphorylation, inducing G0/G1 arrest, and reducing EMT and DNA repair. Our results indicated that pyrotinib sensitivitied HER2 positive esophageal cancer cells to radiation treatment through various mechanisms. These findings may provide a new therapeutic strategy for treating HER2 positive esophageal cancer.

Molecular Subtypes and Local-Regional Control of Breast Cancer

In the era of personalized medicine, there has been significant progress regarding the molecular analysis of breast cancer subtypes. Research efforts have focused on how classification of subtypes could provide information on prognosis and influence treatment planning. Although much is known about the impact of different molecular subtypes on disease-specific survival, more recent studies have investigated the role of the different molecular subtypes on local-regional recurrence. This is an area of active study, and in recent years there has been significant progress. This article describes outcomes among disease subtypes to aid in optimal surgical decision-making to improve local-regional control.

How could breast cancer molecular features contribute to locoregional treatment decision making?

Systemic treatments are tailored to breast cancer (BC) heterogeneity, which is not yet taken into account for radiotherapy (RT) personalization. The primary objective of this review is to summarize existing data suggesting BC subtypes and genetic assays are prognostic and predictive biomarkers useful for RT decision-making and to provide implications for their incorporation into future translational and clinical research. The evidence suggesting that BC subtypes also exhibit distinct "locoregional recurrence (LRR)" patterns is retrospective but consistent and validated in over fifteen studies. The HER-2 positive and triple negative subtypes are the most susceptible to locoregional failure. The high risk of the HER-2 positive subtype can be reversed with trastuzumab administration. Very little is known on the subtypes' intrinsic radiosensitivity properties. Genetic assays have assessed retrospectively signatures' prognostic and predictive value in patients' cohorts (several coming from prospective studies) for LRR risk and radiotherapy (RT) benefit. Further confirmation is needed before their introduction into clinical routine. Evidence on the use of molecular biomarkers for adjuvant RT tailoring is emerging but needs validation and introduction into prospective studies. The plethora of modern RT options (partial breast irradiation, hypofractionation), as well as recent evidence pointing towards more extensive radiotherapy, demand introduction of biological features into clinical trials to improve therapeutic decisions. Open questions, such as tailoring of irradiation after neo-adjuvant chemotherapy in complete responders and the understanding of the interplay between local control, systemic recurrence and survival given modern systemic treatments, need to be addressed under the prism of biology within this heterogeneous disease. Intrinsic radiobiological properties within this heterogeneity need to be highlighted in order to further improve outcomes.

Breast cancer adaptive resistance: HER2 and cancer stem cell repopulation in a heterogeneous tumor society

Purpose

The lethal effects of cancer are associated with the enhanced tumor aggressiveness in recurrent and metastatic lesions that show resistant phenotype to anti-cancer therapy, a major barrier to improving overall survival of cancer patients. The presence of heterogeneous populations of cancer cells within a specific tumor including the tumor-initiating cells or so-called cancer stem cells (CSCs) has linked the acquired resistance (AR, or adaptive resistance). Herein, we discuss the CSC-mediated tumor repopulation in AR of breast cancer in this review.

Methods

We emphasize a dynamic feature of gene induction in tumor cells that undergo long-term treatment, and describe a specific HER2-NF-κB-HER2 pro-survival pathway that can be initiated in breast CSCs upon radiation therapy.

Results

Elucidation of HER2-induced pro-survival networks, specifically the force driving tumor repopulation due to radioresistant CSCs during anticancer therapies, will have a significant impact on the generation of new diagnostic and therapeutic targets to control of recurrent and metastatic breast tumors.

Polymalic acid nanobioconjugate for simultaneous immunostimulation and inhibition of tumor growth in HER2/neu-positive breast cancer

Breast cancer remains the second leading cause of cancer death among women in the United States. Breast cancer prognosis is particularly poor in case of tumors overexpressing the oncoprotein HER2/neu. A new nanobioconjugate of the Polycefin(TM) family of anti-cancer drugs based on biodegradable and non-toxic polymalic acid (PMLA) was engineered for a multi-pronged attack on HER2/neu-positive breast cancer cells. An antibody-cytokine fusion protein consisting of the immunostimulatory cytokine interleukin-2 (IL-2) genetically fused to an antibody specific for human HER2/neu [anti-HER2/neu IgG3-(IL-2)] was covalently attached to the PMLA backbone to target HER2/neu expressing tumors and ensure the delivery of IL-2 to the tumor microenvironment. Antisense oligonucleotides (AON) were conjugated to the nanodrug to inhibit the expression of vascular tumor protein laminin-411 in order to block tumor angiogenesis. It is shown that the nanobioconjugate was capable of specifically binding human HER2/neu and retained the biological activity of IL-2. We also showed the uptake of the nanobioconjugate into HER2/neu-positive breast cancer cells and enhanced tumor targeting in vivo. The nanobioconjugate exhibited marked anti-tumor activity manifested by significantly longer animal survival and significantly increased anti-HER2/neu immune response in immunocompetent mice bearing D2F2/E2 murine mammary tumors that express human HER2/neu. The combination of laminin-411 AON and antibody-cytokine fusion protein on a single polymeric platform results in a new nanobioconjugate that can act against cancer cells through inhibition of tumor growth and angiogenesis and the orchestration of an immune response against the tumor. The present Polycefin(TM) variant may be a promising agent for treating HER2/neu expressing tumors and demonstrates the versatility of the Polycefin(TM) nanobioconjugate platform.

"The Infinite Maze" of breast cancer, signaling pathways and radioresistance

The parallel growth in our understanding of tumor biology and genetics might be the key to understanding local recurrence after optimal treatment is applied. Data suggest that genetic alterations and breast cancer molecular subtypes have an effect on radiotherapy efficacy and that the HER2, EGFR/PI3K/Akt signaling pathways play a pivotal role in modulation of post-irradiation survival. These pathways have been found to be involved in radiosensitivity and/or radioresistance, tumor cell proliferation, and hypoxia. Therefore, affecting the functional activity of key players combined with radiotherapy might be the future of breast irradiation.

Molecular class as a predictor of locoregional and distant recurrence in the neoadjuvant setting for breast cancer

BACKGROUND

The molecular subtype by hormone receptor status predicts recurrence in the adjuvant setting. Here, we report recurrence patterns by molecular subtype following neoadjuvant chemotherapy (NACT) to identify subgroups prone to recurrence.

MATERIALS AND METHODS

We retrospectively analyzed 331 patients receiving NACT plus lumpectomy and whole breast radiation therapy (RT) (n = 155), or mastectomy with (n = 122) or without (n = 50) adjuvant RT. Tumors were classified by immunohistochemical (IHC) surrogate markers into luminal A (strong ER+/PR+; HER2-), luminal B (weak-to-moderate ER+/PR+; HER2-), HER2 (HER2+), and triple-negative/basal subtypes.

RESULTS

The median follow-up was 43 months (range 10-104). The 5-year disease-free survival (DFS) was 71.4, 70.1, 70.4, and 62.1% for luminal A, luminal B, HER2, and basal subtypes, respectively. The 5-year distant recurrence rates were 25.8, 28.7, 28.7, and 35.2%. The 5-year locoregional recurrence rates were 3.8, 1.6, 1.3, and 4.2%. Molecular class (p = 0.003) and pathologic complete response (pCR; p = 0.004) predicted distant recurrence, DFS, and overall survival (OS). Only the omission of adjuvant RT following mastectomy (p = 0.006) predicted locoregional recurrence.

CONCLUSIONS

IHC subclassification and pCR predict distant failure, DFS, and OS in the neoadjuvant setting. While not predictive of locoregional recurrence, the total number of events were small. More work is needed to define if molecular class can predict patients at risk for locoregional recurrence.

Estrogen/progesterone receptor negativity and HER2 positivity predict locoregional recurrence in patients with T1a,bN0 breast cancer

PURPOSE

Data have suggested that the molecular features of breast cancer are important determinants of outcome; however, few studies have correlated these features with locoregional recurrence (LRR). In the present study, we evaluated estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) as predictors of LRR in patients with lymph node-negative disease and tumors < or = 1cm, because these patients often do not receive adjuvant chemotherapy or trastuzumab.

METHODS AND MATERIALS

The data from 911 patients with stage T1a,bN0 breast cancer who had received definitive treatment at our institution between 1997 and 2002 were retrospectively reviewed. We prospectively analyzed ER/PR/HER2 expression from the archival tissue blocks of 756 patients. These 756 patients represented the cohort for the present study.

RESULTS

With a median follow-up of 6.0 years, the 5- and 8-year Kaplan-Meier LRR rate was 1.6% and 5.9%, respectively, with no difference noted in those who underwent breast conservation therapy vs. mastectomy (p=.347). The 8-year LRR rates were greater in the patients with ER-negative (10.6% vs. 4.2%, p=.016), PR-negative (9.0% vs. 4.2%, p=.009), or HER2-positive (17.5% vs. 3.9%, p=0.009) tumors. On multivariate analysis, ER-negative and PR-negative disease (hazard ratio, 2.37; p=.046) and HER2-positive disease (hazard ratio, 3.13, p=.016) independently predicted for LRR.

CONCLUSION

Patients with ER/PR-negative or HER2-positive T1a,bN0 breast cancer had a greater risk of LRR. Therapeutic strategies, such as the use of chemotherapy and/or anti-HER2 therapies, should be considered for future clinical trials for these patients.

Radiosensitization of chemotherapy-refractory, locally advanced or locally recurrent breast cancer with trastuzumab: a phase II trial

PURPOSE

Trastuzumab (Herceptin), an anti-human epidermal growth factor receptor 2 (HER2) antibody, has been shown to be an effective radiosensitizer in preclinical studies. The present Phase II trial evaluated trastuzumab plus radiotherapy in patients with HER2-positive, chemotherapy-refractory, locally advanced or locoregionally recurrent breast cancer.

METHODS AND MATERIALS

Eligible patients had measurable disease, normal cardiac function, and biopsy-confirmed residual HER2-positive disease. Patients received weekly trastuzumab (2 mg/kg intravenously), concurrent with radiotherapy (50 Gy) to the breast and regional lymph nodes for 5 weeks. If feasible, surgery followed radiotherapy. The primary endpoint was safety, and the secondary endpoint was efficacy (pathologic response and interval to symptomatic local progression).

RESULTS

Of the 19 patients enrolled, 7 were ineligible and received radiotherapy alone and 12 received therapy per protocol. Of these 12 patients, 11 had a Stage T4 diagnosis. Grade 3 toxicities included skin (n = 2) and lymphopenia (n = 1). One patient experienced delayed wound healing after surgery. No patients developed symptomatic cardiac dysfunction. Of the 7 patients who had undergone mastectomy, 3 (43%) had a substantial pathologic response (complete response or microscopic residual disease), significantly more than a comparison cohort (2 of 38 or 5%, p = .02). The median interval to symptomatic local progression was not reached. The median overall survival was 39 months.

CONCLUSION

This is the first prospective trial providing evidence for a radiosensitizing effect of trastuzumab in breast cancer. The combination of trastuzumab and radiotherapy was well tolerated.

The HER-2 receptor and breast cancer: ten years of targeted anti-HER-2 therapy and personalized medicine

The human epidermal growth factor receptor (HER-2) oncogene encodes a transmembrane tyrosine kinase receptor that has evolved as a major classifier of invasive breast cancer and target of therapy for the disease. The validation of the general prognostic significance of HER-2 gene amplification and protein overexpression in the absence of anti-HER-2 targeted therapy is discussed in a study of 107 published studies involving 39,730 patients, which produced an overall HER-2-positive rate of 22.2% and a mean relative risk for overall survival (OS) of 2.74. The issue of HER-2 status in primary versus metastatic breast cancer is considered along with a section on the features of metastatic HER-2-positive disease. The major marketed slide-based HER-2 testing approaches, immunohistochemistry, fluorescence in situ hybridization, and chromogenic in situ hybridization, are presented and contrasted in detail against the background of the published American Society of Clinical Oncology-College of American Pathologists guidelines for HER-2 testing. Testing issues, such as the impact of chromosome 17 polysomy and local versus central HER-2 testing, are also discussed. Emerging novel HER-2 testing techniques, including mRNA-based testing by real-time polymerase chain reaction and DNA microarray methods, HER-2 receptor dimerization, phosphorylated HER-2 receptors, and HER-2 status in circulating tumor cells, are also considered. A series of biomarkers potentially associated with resistance to trastuzumab is discussed with emphasis on the phosphatase and tensin homologue deleted on chromosome ten/Akt and insulin-like growth factor receptor pathways. The efficacy results for the more recently approved small molecule HER-1/HER-2 kinase inhibitor lapatinib are also presented along with a more limited review of markers of resistance for this agent. Additional topics in this section include combinations of both anti-HER-2 targeted therapies together as well as with novel agents including bevacizumab, everolimus, and tenespimycin. A series of novel HER-2-targeting agents is also presented, including pertuzumab, ertumaxomab, HER-2 vaccines, and recently discovered tyrosine kinase inhibitors. Biomarkers predictive of HER-2 targeted therapy toxicity are included, and the review concludes with a consideration of HER-2 status in the prediction of response to non-HER-2 targeted treatments including hormonal therapy, anthracyclines, and taxanes.

NF-kappaB-mediated HER2 overexpression in radiation-adaptive resistance

The molecular mechanisms governing acquired tumor resistance during radiotherapy remain to be elucidated. In breast cancer patients, overexpression of HER2 (human epidermal growth factor receptor 2) is correlated with aggressive tumor growth and increased recurrence. In the present study, we demonstrate that HER2 expression can be induced by radiation in breast cancer cells with a low basal level of HER2. Furthermore, HER2-postive tumors occur at a much higher frequency in recurrent invasive breast cancer (59%) compared to the primary tumors (41%). Interestingly, NF-kappaB is required for radiation-induced HER2 transactivation. HER2 was found to be co-activated with basal and radiation-induced NF-kappaB activity in radioresistant but not radiosensitive breast cancer cell lines after long-term radiation exposure, indicating that NF-kappaB-mediated HER2 overexpression is involved in radiation-induced repopulation in heterogeneous tumors. Finally, we found that inhibition of HER2 resensitizes the resistant cell lines to radiation. Since HER2 is shown to activate NF-kappaB, our data suggest a loop-like HER2-NF-kappaB-HER2 pathway in radiation-induced adaptive resistance in breast cancer cells.

Bcl-2 expression predicts local relapse for early-stage breast cancer receiving conserving surgery and radiotherapy

BACKGROUND

This study was undertaken to evaluate the prognostic significance of Bcl-2, a apoptosis-related protein, in patients with early stage breast cancer treated with breast conservation treatment (BCT).

METHODS

After obtaining IRB approval, 504 patients with early stage breast cancer treated with BCT were entered in this study. The paraffin specimens were constructed into tissue micro-arrays with two-fold redundancy, processed and stained for Bcl-2 antibody. Bcl-2 expression was correlated with other clinicopathological parameters and clinical outcomes.

RESULTS

Bcl-2 expression was identified in 116 cases (28%). Bcl-2 expression was positively correlated with both estrogen receptor and progesterone receptor status (P < 0.0001, respectively). Bcl-2 expression was associated with ipsilateral breast tumor recurrence (P = 0.0322, by log-rank test). Multivariate analysis using Cox proportional hazard model showed that Bcl-2 expression still retained significance as an independent prognostic factor for breast recurrence (P = 0.0348).

CONCLUSIONS

Bcl-2 expression is highly associated with an increased risk of local recurrence in patients with early stage breast cancer. Immunohistochemical staining of the primary tumor for Bcl-2 might be useful to select optimal treatment options for these patients.

NF-kappa B-mediated adaptive resistance to ionizing radiation

Ionizing radiation (IR) began to be a powerful medical modality soon after Wilhelm Röntgen's discovery of X-rays in 1895. Today, more than 50% of cancer patients receive radiotherapy at some time during the course of their disease. Recent technical developments have significantly increased the precision of dose delivery to the target tumor, making radiotherapy more efficient in cancer treatment. However, tumor cells have been shown to acquire a radioresistance that has been linked to increased recurrence and failure in many patients. The exact mechanisms by which tumor cells develop an adaptive resistance to therapeutic fractional irradiation are unknown, although low-dose IR has been well defined for radioadaptive protection of normal cells. This review will address the radioadaptive response, emphasizing recent studies of molecular-level reactions. A prosurvival signaling network initiated by the transcription factor NF-kappa B, DNA-damage sensor ATM, oncoprotein HER-2, cell cyclin elements (cyclin B1), and mitochondrial functions in radioadaptive resistance is discussed. Further elucidation of the key elements in this prosurvival network may generate novel targets for resensitizing the radioresistant tumor cells.

HER-2/neu status and response to CMF: retrospective study in a series of operable breast cancer treated with primary CMF chemotherapy

PURPOSE

Primary chemotherapy brings the opportunity for an early and accurate assessment of response and offers an ideal model to search for new predictors of response. HER-2/neu is one of the most studied genes for this purpose.

PATIENTS AND METHODS

Her-2/neu was tested in a non-randomized series of 300 patients with operable breast carcinomas treated with primary CMF. Response was assessed by mammography. Disease-free survival (DFS) and overall survival (OS) were calculated after a mean follow-up of 116 months. Statistical analysis was performed to study the association between HER-2/neu status and response to CMF.

RESULTS

Overexpression/amplification was found in 23.66% cases. Univariate analysis showed that response was similar in HER-2/neu positive and negative tumors (51.38 vs. 47.36%, P = 0.6). Triple negative tumors (ER, PR and HER-2/neu negative) presented the highest response rate (64.9%). By multivariate analysis, response was significantly correlated to higher nuclear grade and negative estrogen receptor status (P = 0.02 and 0.007, respectively). Patients with HER-2/neu positive tumors presented shorter survival rates (P = 0.06). Patients with response to CMF showed a better survival over non-responders independent of Her-2/neu status. Patients with the combination of response to CMF and Her-2/neu negative tumors presented the best outcome. On the other hand, the association of no response to CMF and positive Her-2/neu score was statistically related to poor DFS and OS.

CONCLUSIONS

CMF indication is independent of Her-2/neu status.

The Impact of HER-2 Status on Local Recurrence in Women with Stage I?II Breast Cancer Treated with Breast-Conserving Therapy

This study was undertaken to determine whether overexpression of the oncogene HER-2 is associated with an increase in local recurrence in women with early stage breast cancer treated with breast-conserving therapy (BCT). A retrospective review of the medical records of all women treated with stage I-II invasive breast cancer from 1991 through 2001 was performed. Of 596 eligible patients treated in that time period, immunohistochemical testing for HER-2 expression was performed in 352 patients (59%): 266 patients (76%) were HER-2 negative and 86 patients (24%) were HER-2 positive. Median follow-up was 5.4 years. The patient characteristics for the two groups were compared for age, pathologic T and N stage, number of positive nodes, estrogen receptor (ER) and progesterone receptor (PR) status, radiation treatment, and use of hormonal therapy or chemotherapy. There were no significant differences in any of these parameters between the two groups (all p > or = 0.10). Local recurrence at 5 years was 2% in the HER-2-negative group and 0% in the HER-2-positive group (p = 0.15). There was no difference in local recurrence after BCT between HER-2-positive and negative breast cancers at 5 years. Therefore HER-2 overexpression does not appear to be a contraindication to BCT.

Radiobiology of Breast Cancer

Advances in molecular and cellular biology are transforming our understanding of breast cancer and promise the same for radiotherapy over the next few years. At the clinical level, the molecular basis of fractionation dependency and other tumour and normal tissue responses are likely to become clearer. More importantly, they will become useful in the clinic, where molecular characterisation of the patient and tumour will start to determine therapeutic options. Although many of the fundamental processes are only amenable to study in laboratory systems, the power of array-based technologies makes it possibly to address highly relevant questions in the clinic, using functional imaging and/or tissue biopsies. To help clinical oncologists exploit these opportunities in translational research, some aspects of the molecular and cellular basis of radiotherapy are described below in their relation to breast cancer.

HER2 amplification in recurrent breast cancer following breast-conserving therapy correlates with distant metastasis and poor survival

The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer groups following breast-conserving treatment. Retrospective analyses of a group of 36 invasive early breast cancer (IBC) patients who developed a local recurrence as a first event and of a random control group of 69 IBC patients were made. HER2 status was assessed by the HercepTest and fluorescence in situ hybridization. The Kaplan-Meier proportional log-rank test was used to study the impact of the biological factors on the metastasis-free interval (MFI) and the overall survival (OS). The Cox proportional hazards model, using stepwise selection was performed to identify the independent predictors of poor outcome. The median time of follow-up was 156 months (range: 22-230) for the nonrecurrent group of patients and 119 months (range: 36-228) for the recurrent group. No significant differences between either group were observed in terms of either patient or tumor characteristics, or of HER2 expression. However, a higher proportion of HER2 amplified cases were found in the recurrent group, in contrast to a higher proportion of hormonal receptor positive cases in the nonrecurrent group. After univariate and multivariate analyses, HER2 amplification was found to be an independent predictive factor for distant metastasis (HR = 10.75; p = 0.00008) and for survival (HR = 4.22; p = 0.004). In conclusion, HER2 amplification constitutes an independent poor prognostic factor for the MFI and OS in patients with recurrent breast cancer. The clinical implications are discussed.

Estrogen Receptor ?? in Breast Cancer: Associations Between ER??, Hormonal Receptors, and Other Prognostic Biomarkers

The estrogen receptor (ER)-beta isoform has been recently identified to be distinct from ERalpha isoform and regulates separate sets of genes, and can exert opposite signaling functions depending on the ligand and response elements. Previous studies of ERbeta have been at the mRNA level and few by immunohistochemistry, and the results are inconsistent. In this study the authors compared expression of ERbeta with those of other prognostic biomarkers by immunohistochemistry on tissue microarray slides, and with morphologic parameters on 147 cases of primary breast cancer. Immunoreactivity of more than 10% of cancer cells was considered to be positive. Associations between categoric variables were analyzed using the chi test, and a P value less than 0.05 was considered to be significant. ERbeta was expressed in benign epithelium and stromal cells, and breast cancer cells in 59% of different histologic types of breast cancer. ERbeta was coexpressed with ERalpha in 45% of cases. There was a statistically significant association between expression of ERbeta and Her-2/neu (P<0.000), cathepsin D (P<0.02), p53 (P<0.03), and PS2 (P<0.002). Ki-67 was almost exclusively expressed in ERbeta-positive cells. No statistically significant association was seen between ERbeta expression and histologic grade, DNA ploidy, or S-phase.

HER-2 gene amplification correlates with higher levels of angiogenesis and lower levels of hypoxia in primary breast tumors

PURPOSE

This study investigated the connection among HER-2 gene amplification, HER-2 protein expression, and markers of tumor angiogenesis and oxygenation in patients with operable, invasive breast tumors.

EXPERIMENTAL DESIGN

From 1988 to 1995, 425 patients with metastatic breast cancer were enrolled in a study of high-dose chemotherapy with autologous transplant. Primary tumor blocks were obtained and evaluated using immunohistochemistry (IHC) staining of vessels with von Willebrand factor antibody. Mean microvessel densities (MVD) were determined by counting von Willebrand factor stained cells in three separate "vascular hot spots" using image analysis. Tumor samples were also stained for HER-2 by IHC, HER-2 gene amplification by fluorescence in situ hybridization, carbonic anhydrase 9 by IHC, and vascular endothelial growth factor (VEGF) by IHC. Plasma from 36 patients with primary tumor samples had VEGF (R&D Systems, MN) and d-dimer (American Diagnostica, Greenwich, CT) levels determined.

RESULTS

There was a significant positive correlation between HER-2 gene amplification and both maximum and average MVD (Spearman coefficient = 0.51 and 0.50; P = 0.03 and 0.05, respectively). There was an inverse correlation with HER-2 gene amplification and expression of the tumor hypoxia marker CA-9 (chi(2) P = 0.02). The level of HER-2 gene amplification correlated with plasma d-dimer levels (Spearman coefficient = 0.43; P = 0.021). Interestingly, tumors with HER-2 by IHC had decreased amounts of VEGF staining (chi(2) = 5.81; P = 0.01). There was no correlation between HER-2 by IHC and MVD or d-dimer. Of all of the variables examined, only average (P = 0.0016) and maximum MVD (P = 0.0128) predicted disease-free survival (Cox univariate model).

CONCLUSIONS

HER-2-amplified breast cancers have increased amounts of angiogenesis, decreased amounts of hypoxia, and increased markers of fibrin degradation. These findings have prognostic, predictive, and therapeutic implications in breast cancer treatment.

Her2/neu-positive disease does not increase risk of locoregional recurrence for patients treated with neoadjuvant doxorubicin-based chemotherapy, mastectomy, and radiotherapy

PURPOSE

Preclinical data suggest that overexpression of Her2/neu confers cellular radioresistance. We retrospectively studied whether Her2/neu-positive disease was associated with locoregional recurrence (LRR) after postmastectomy radiotherapy (RT) for breast cancer.

METHODS AND MATERIALS

Data from 337 patients treated in four institutional prospective clinical trials neoadjuvant doxorubicin-based chemotherapy, mastectomy, and RT were reviewed. The trials were conducted between 1989 and 2000. Of the 337 patients, 108 (32%) had tumors that were tested for Her2/neu, with positivity defined by 3+ immunohistochemistry staining or gene amplification detected by fluorescence in situ hybridization. RT was delivered to the chest wall and draining lymphatics (median dose, 50 Gy) followed by a chest wall boost (median dose, 10 Gy).

RESULTS

Thirty-two patients had Her2/neu-positive disease and 76 patients had Her2/neu-negative disease. The Her2/neu-positive tumors were associated with a greater rate of estrogen receptor-negative disease (p = 0.03), the presence of supraclavicular disease at diagnosis (p = 0.027), and a greater number of positive lymph nodes after chemotherapy (p = 0.026). Despite these adverse features, the actuarial overall LRR rate was roughly equivalent for the patients with Her2/neu-positive tumors vs. those with Her2/neu-negative tumors (5-year rate 17.5% vs. 13.9%, respectively; 10-year rate 17.5% vs. 18.9%, respectively; p = 0.757). On Cox regression analysis of LRR adjusted for N stage and estrogen receptor status, the hazard ratio for Her2/neu positivity was 0.89 (95% confidence interval, 0.31-2.59; p = 0.83).

CONCLUSION

Her2/neu overexpression does not appear to predispose to LRR after neoadjuvant doxorubicin-based chemotherapy, mastectomy, and RT.

Targeted therapy in breast cancer: the HER-2/neu gene and protein

The HER-2/neu oncogene, a member of the epidermal growth factor receptor or erb gene family, encodes a transmembrane tyrosine kinase receptor that has been linked to prognosis and response to therapy with the anti-HER-2-humanized monoclonal antibody, trastuzumab (Herceptin, Genentech, South San Francisco, CA) in patients with advanced metastatic breast cancer. HER-2/neu status has also been tested for its ability to predict the response of breast cancer to other therapies including hormonal therapies, topoisomerase inhibitors, and anthracyclines. This review includes an analysis of 80 published studies encompassing more than 25,000 patients designed to consider the relative advantages and disadvantages of the various methods of measuring HER-2/neu in clinical breast cancer specimens. Southern blotting, PCR amplification detection, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is reviewed along with the current studies designed to test whether HER-2/neu status can predict the response to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review will also evaluate the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.

Molecular markers for prognosis after isolated postmastectomy chest wall recurrence

BACKGROUND

Local chest wall recurrence after mastectomy occurs in 10-20% of patients with operable breast carcinoma. The objective of the current study was to assess the prognostic value of molecular markers at the time of local recurrence and to compare these markers with clinical variables.

METHODS

Between 1975 and 1999, the authors treated 113 patients at their institution for postmastectomy chest wall recurrences with full-course external beam radiotherapy. Patients who presented primarily with lymph node recurrences or with simultaneous distant metastasis were excluded. Follow-up from the time of chest wall recurrence was 10.13 years. All clinical and pathologic data from the original diagnosis and from the time of chest wall recurrence were entered into a computerized database. Paraffin-embedded tumor specimens from the chest wall recurrences were available for 43 patients and were constructed into tissue microarrays for immunohistochemical staining of estrogen receptor, progesterone receptor (PR), p53, HER-2/neu, and cyclin D.

RESULTS

Overall survival after chest wall recurrence for the entire cohort was 46% at 5 years and 28% at 10 years. The distant metastasis-free survival rate was 49% at 5 years and 40% at 10 years. Local-regional control of disease was achieved in 79% of patients at 10 years. In multivariate analysis, significant factors for distant metastasis after local recurrence were time to recurrence (< 2 years from the original diagnosis to chest wall recurrence) and PR status (distant metastasis-free survival rate: 84% [PR-positive] vs. 38% [PR-negative]; P = 0.007). The only significant factor for local-regional disease progression was HER-2/neu status. Patients with positive HER-2/neu status had a local-regional progression-free rate of 59%, compared with 92% for patients with negative HER-2/neu status.

CONCLUSIONS

The prognosis for patients after local-regional recurrence of breast carcinoma is relatively poor. Longer time to local recurrence and positive PR status were associated with favorable distant metastasis-free rates and long-term survival. Positive HER-2/neu status was associated with poorer local-regional control of disease. Implications for systemic therapy and further studies are discussed.

HER2/neu reduces the apoptotic effects of N-(4-hydroxyphenyl)retinamide (4-HPR) in breast cancer cells by decreasing nitric oxide production

The retinoid N-(4-hydroxyphenyl)retinamide (4-HPR also known as fenretinide) is a potent inducer of apoptosis in breast cancer cells. We observed a 4.5-fold reduction in 4-HPR-mediated apoptosis in MCF-7 breast cancer cells transfected with HER2/neu (MCF-7/HER2) as compared with the parental MCF-7 (MCF-7/WT) cells. Blocking HER2/neu with trastuzumab (Herceptin) led to a six-fold increase in 4-HPR-induced apoptosis in HER2/neu-overexpressing cells. These data indicate that HER2/neu reduces the sensitivity of breast cancer cells to 4-HPR. We showed previously that nitric oxide (NO) is essential for 4-HPR to induce apoptosis in breast cancer cells. The inhibitory effects of the 4-HPR and trastuzumab combination correlated with the amount of NO produced in HER2/neu-overexpressing cells. When a NO synthase (NOS) inhibitor was used to block NO production, decreased apoptosis by the 4-HPR and trastuzumab combination was observed. Furthermore, 4-HPR-mediated NOSII expression was lower in MCF-7/HER2 than MCF-7/WT cells, but was increased by trastuzumab in HER2/neu-overexpressing cells. Here we report the novel findings that HER2/neu reduces the ability of 4-HPR to induce apoptosis in breast cancer cells, and that one mechanism by which HER2/neu increases the resistance of breast cancer cells to 4-HPR is by decreasing NOSII-mediated NO production.

Molecular markers in clinical radiation oncology

Radiation therapy plays a critical role in the management of a majority of patients diagnosed with cancer. Identification of factors that help predict which patients are at risk for relapse within the irradiated field remains an active area of investigation. Although conventional clinical and pathologic factors have been helpful in identifying risk and guiding clinical decision-making for both local and systemic management, there is clearly a need to identify additional prognostic markers, which can aid in refining our treatment strategies and improving outcomes. A substantial amount of research efforts have been devoted to identifying molecular markers for prognostic and therapeutic strategies. The recent emergence of a powerful armamentarium of molecular tools has resulted in rapid expansion of our fund of knowledge and understanding of the molecular biology underlying tumor behavior and response. While a majority of these efforts have been focused on risk factors for metastatic disease and survival, there is a rapidly growing body of literature focused on molecular factors associated with radiation resistance and locoregional failure. In this review, we summarize recent advances and the available literature evaluating molecular markers as they relate to radiation sensitivity of solid tumors. Literature regarding the potential application of expression of genes related to apoptosis, angiogenesis, cell cycle, DNA repair and growth factors will be reviewed. Some of the basic biology and laboratory evidence demonstrating how the marker relates to radiation response and available correlative clinical studies employing these markers as prognostic tools are presented. The majority of molecular markers that have potential clinical significance with respect to radiation sensitivity and local control will be highlighted.

Combined-modality treatment of solid tumors using radiotherapy and molecular targeted agents

PURPOSE

Molecular targeted agents have been combined with radiotherapy (RT) in recent clinical trials in an effort to optimize the therapeutic index of RT. The appeal of this strategy lies in their potential target specificity and clinically acceptable toxicity.

DESIGN

This article integrates the salient, published research findings into the underlying molecular mechanisms, preclinical efficacy, and clinical applicability of combining RT with molecular targeted agents. These agents include inhibitors of intracellular signal transduction molecules, modulators of apoptosis, inhibitors of cell cycle checkpoints control, antiangiogenic agents, and cyclo-oxygenase-2 inhibitors.

RESULTS

Molecular targeted agents can have direct effects on the cytoprotective and cytotoxic pathways implicated in the cellular response to ionizing radiation (IR). These pathways involve cellular proliferation, DNA repair, cell cycle progression, nuclear transcription, tumor angiogenesis, and prostanoid-associated inflammation. These pathways can also converge to alter RT-induced apoptosis, terminal growth arrest, and reproductive cell death. Pharmacologic modulation of these pathways may potentially enhance tumor response to RT though inhibition of tumor repopulation, improvement of tumor oxygenation, redistribution during the cell cycle, and alteration of intrinsic tumor radiosensitivity.

CONCLUSION

Combining RT and molecular targeted agents is a rational approach in the treatment of solid tumors. Translation of this approach from promising preclinical data to clinical trials is actively underway.

The Her-2/neu gene and protein in breast cancer 2003: biomarker and target of therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. In this review, the association of HER-2/neu gene and protein abnormalities with prognosis and response to therapy with trastuzumab and to other therapies in breast cancer is presented. By considering a series of 80 published studies encompassing more than 25,000 patients, the relative advantages and disadvantages of Southern blotting, polymerase chain reaction amplification, and fluorescence in situ hybridization assays designed to detect HER-2/neu gene amplification are compared with HER-2/neu protein overexpression assays performed by immunohistochemical techniques applied to frozen and paraffin-embedded tissues and enzyme immunoassays performed on tumor cytosols. The significance of HER-2/neu overexpression in ductal carcinoma in situ and the HER-2/neu status in uncommon female breast conditions and male breast cancer are also considered. The role of HER-2/neu testing for the prediction of response to trastuzumab therapy in breast cancer is presented as well as its potential impact on responses to standard and newer hormonal therapies, cytotoxic chemotherapy, and radiation. The review also evaluates the status of serum-based testing for circulating HER-2/neu receptor protein and its ability to predict disease outcome and therapy response.

Epidermal growth factor family receptors and inhibitors: radiation response modulators

Growing evidence suggests that epidermal growth factor family receptors (HERs) play a significant role in radiation response. EGFR expression levels and activation by ligand correlate with radioresistance, and exogenous HER2 expression alters radiation response. Preclinical studies of anti-EGFR anti-HER2 antibodies, and kinase inhibitors that inhibit EGFR, both EGFR and HER2, or all 4 family members show potential for clinical radiosensitization. Early-phase clinical trials of the anti-EGFR antibody, C225, prove the combination of C225 and radiotherapy to be well tolerated and promising. A phase 3 randomized trial in head and neck cancer is underway, and clinical investigation of other HER inhibitors is in progress. The mechanisms(s) of radiation response modulation by HERs appear complex and diverse. Signal transduction initiated by receptor activation promotes survival and proliferation after ionizing radiation, and HER inhibitors affect cellular responses to ionizing radiation (IR) in diverse ways, including inducing apoptosis, cell cycle arrest, and impeding DNA repair. HER signaling and inhibition also affect tumor-stroma interactions, particularly angiogenesis and endothelial survival after IR. Further investigation of the radiation response modulation by EGFR family members and their inhibitors will lead to optimization of this promising therapeutic approach.

Molecular and genetic markers in the local-regional management of breast cancer

The clinical application of molecular markers in the diagnosis, staging, and management of breast cancer continues to expand. Although the use of molecular markers in local-regional disease does not approach the level of their application in the systemic management of breast cancer, a growing body of rature supports the potential for molecular and genetic factors in clinical decision making regarding the local-regional management of breast cancer. As with conventional clinical and histopathologic factors, data regarding molecular and genetic factors as they relate to local-regional relapse may be conflicting and are subject to the usual limitations of predominantly retrospective studies. There are, however, some consistent data suggesting associations between local-regional control of disease and several molecular markers, including hormone receptor status, HER2/neu, p53, proliferative markers, and others. Interpretation of these data and how to use this information in clinical practice remains challenging. The available rature regarding the use of genetic and molecular markers in the local-regional management of breast cancer is summarized in this review.

Molecular targets as therapeutic strategies in the management of breast cancer

Therapy directed against specific biologic targets has long been used in the treatment of breast cancer; the estrogen receptor is a validated prognostic and therapeutic target, and antiestrogen therapy has been used effectively for decades. Recently, scientific progress and increased comprehension of mechanisms of breast cancer pathogenesis have led to the proliferation of both potential molecular targets and new therapeutic agents. The success of traztuzumab (Herceptin, Genentech, South San Francisco, CA), an anti-HER2 antibody, has spurred the development of other biologically directed therapeutics. In this overview, I discuss three targets relevant to breast cancer (the epidermal growth factor receptor family, angiogenesis, and NF-kappa B), and therapeutic approaches directed against these targets are discussed.

Protein overexpression and gene amplification of c-erbB-2 in breast carcinomas: a comparative study of immunohistochemistry and fluorescence in situ hybridization of formalin-fixed, paraffin-embedded tissues

We evaluated 173 consecutive breast carcinomas for c-erbB-2 using a combination of immunohistochemistry (IHC) with a commercial polyclonal antibody (Nitirei) and dual-color fluorescence in situ hybridization (FISH) using the c-erbB-2-specific probe and the chromosome 17 centromere-specific probe from Vysis (Downers Grove, IL) and compared the results with the histologic characteristics of intraductal spread, cancer invasion, and intratumoral heterogeneity. With correction for chromosome 17 copy number, c-erbB-2 amplification was observed in 26 tumors (13.5%): high-level amplification in 23 tumors, and low-level amplification in 3. The gene amplification was positively correlated with c-erbB-2 protein overexpression, defined as 2+ or 3+ immunostaining, on a case-by-case basis (P < .000001). All 3+ immunostaining tumors (19 tumors) showed high-level amplification, although gene amplification was found in only 5 of 27 2+ immunostaining tumors. Although the rates of overexpression and gene amplification did not differ in ductal carcinomas in situ and invasive carcinomas (P = .46 and .53, respectively), they were significantly higher in invasive carcinomas with intraductal spreading (P < .0001). Intratumoral heterogeneity of c-erbB-2 amplification was found in only 1 case; however, in 17 invasive carcinomas, intraductal components expressed c-erbB-2 more intensely than invasive components. We conclude that in breast carcinomas, c-erbB-2 overexpression occurs mostly in tumors with high-level gene amplification, and such overexpression appears to endow carcinoma cells with the capacity for intraductal spreading. The best method for detecting breast carcinomas with c-erbB-2 aberrations using archival tissues is to screen cases by IHC; however, follow-up FISH assays are indispensable for excluding false-positive results.

[Radiotherapy of the breast and chest wall: treatment volume]

The radiotherapy of the breast or the chest wall is a complex technique. The definition of the gross tumour volume and the clinical target volume depends on clinical, anatomical and histological criteria. The volumes are located by physical examination, mammography, echography and tomodensitometry. The implantation of surgical clips in the lumpectomy cavity is useful for the boost field. The planning target volume takes into consideration movements of tissues during respiration and variations in beam geometry characteristics. The organs at risk (heart, lung) must be considered systematically. Technical contrivances are necessary to modify and homogenize dose distribution. Conformational irradiation allows an individually design treatment planning. Intensity-modulated radiotherapy technique is a future advantageous technique still under evaluation.

Her4 mediates ligand-dependent antiproliferative and differentiation responses in human breast cancer cells

The function of the epidermal growth factor receptor (EGFR) family member HER4 remains unclear because its activating ligand, heregulin, results in either proliferation or differentiation. This variable response may stem from the range of signals generated by HER4 homodimers versus heterodimeric complexes with other EGFR family members. The ratio of homo- and heterodimeric complexes may be influenced both by a cell's EGFR family member expression profile and by the ligand or even ligand isoform used. To define the role of HER4 in mediating antiproliferative and differentiation responses, human breast cancer cell lines were screened for responses to heregulin. Only cells that expressed HER4 exhibited heregulin-dependent antiproliferative responses. In-depth studies of one line, SUM44, demonstrated that the antiproliferative and differentiation responses correlated with HER4 activation and were abolished by stable expression of a kinase-inactive HER4. HB-EGF, a HER4-specific ligand in this EGFR-negative cell line, also induced an antiproliferative response. Moreover, introduction and stable expression of HER4 in HER4-negative SUM102 cells resulted in the acquisition of a heregulin-dependent antiproliferative response, associated with increases in markers of differentiation. The role of HER2 in these heregulin-dependent responses was examined through elimination of cell surface HER2 signaling by stable expression of a single-chain anti-HER2 antibody that sequestered HER2 in the endoplasmic reticulum. In the cell lines with either endogenously (SUM44) or exogenously (SUM102) expressed HER4, elimination of HER2 did not alter HER4-dependent decreases in cell growth. These results suggest that HER4 is both necessary and sufficient to trigger an antiproliferative response in human breast cancer cells.

When is a tumor marker ready for prime time? A case study of c-erbB-2 as a predictive factor in breast cancer

PURPOSE

c-erbB-2 (HER-2, c-neu) might play a role as a predictive factor in breast cancer. However, the clinical utility of the marker in this disease is still not established. We conducted a critical analysis of the literature, in which we reviewed the factors that contribute to the lack of acceptance of c-erbB-2 for clinical use and attempted to determine the predictive role of c-erbB-2 for response to specific therapies.

METHODS

We conducted a MEDLINE literature search using the keywords c-erbB-2, HER2, neu, and breast cancer, reviewed the references included in each publication, and reviewed abstracts that have been reported in the 1997-2000 proceedings to the American Association of Cancer Research and American Society for Clinical Oncology annual meetings.

RESULTS

The preclinical and clinical data reported to date suggest that amplification or overexpression of c-erbB-2 is a weak to moderate negative pure prognostic factor. c-erbB-2 seems to be a weak to moderate negative predictive factor for response to endocrine therapy. The marker is also a moderate negative predictive factor for response to alkylating agents and a moderate positive predictive factor for response to anthracyclines. The data regarding response to taxanes or radiotherapy are not sufficient to make recommendations regarding treatment decision making. Finally, c-erbB-2 is a strong predictive factor for response to trastuzumab.

CONCLUSION

We conclude that, in the adjuvant setting, c-erbB-2 status should not be used to determine whether a woman should receive adjuvant systemic therapy (weak prognostic factor). In addition, c-erbB-2 status should not be used to determine whether a patient should receive endocrine therapy. When adjuvant chemotherapy is recommended, anthracycline-based therapy should be the preferred regimen for c-erbB-2-positive patients. However, when anthracyclines are contraindicated, alkylating agent-based therapy should not be withheld. To determine the true predictive role and strength of the marker for response to each therapy, prospective randomized clinical trials or formal meta-analyses are required.

Locoregionally recurrent breast cancer: incidence, risk factors and survival

Locoregional recurrence (LRR) after therapy for early breast cancer is common. Patients with LRR can suffer both local consequences and symptoms of metastatic disease, as LRR is an independent predictor of subsequent distant metastases. Much of the available data on LRR is derived from small, single institution, retrospective studies, so marked differences in the incidence rates for LRR, it's risk factors and subsequent systemic recurrence are reported. The purpose of this review was to try and collate this data in a format that would be useful for both clinicians and their patients.

True recurrence vs. new primary ipsilateral breast tumor relapse: an analysis of clinical and pathologic differences and their implications in natural history, prognoses, and therapeutic management

PURPOSE

The purpose of this study was to classify all ipsilateral breast tumor relapses (IBTR) in patients treated with conservative surgery and radiation therapy (CS+RT) as either new primary tumors (NP) or true local recurrences (TR) and to assess the prognostic and therapeutic implications of this classification.

METHODS AND MATERIALS

Of the 1152 patients who have been treated at Yale-New Haven Hospital before 1990, 136 patients have experienced IBTR as their primary site of failure. These relapses were classified as either NP or TR. Specifically, patients were classified as NP if the recurrence was distinctly different from the primary tumor with respect to the histologic subtype, the recurrence location was in a different location, or if the flow cytometry changed from aneuploid to diploid. This information was determined by a detailed review of each patient's hospital and/or radiotherapy record, mammograms, and pathologic reports.

RESULTS

As of 2/99, with a mean follow-up of 14. 2 years, the overall ipsilateral breast relapse-free rate for all 1152 patients was 86% at 10 years. Using the classification scheme outlined above, 60 patient relapses were classified as TR, 70 were classified as NP and 6 were unable to be classified. NP patients had a longer mean time to breast relapse than TR patients (7.3 years vs. 3.7 years, p < 0.0001) and were significantly younger than TR patients (48.9 years vs. 54.5 years, p < 0.01). Patients developed both TR and NP at similar rates until approximately 8 years, when TR rates stabilized but NP rates continued to rise. By 15 years following original diagnosis, the TR rate was 6.8% compared to 13.1% for NP. Of the patients who had been previously tested for BRCA1/2 mutations, 17% (8/52) had deleterious mutations. It is noteworthy that all patients with deleterious mutations had new primary IBTR, while patients without deleterious mutations had both TR and NP (p = 0.06). Ploidy was evenly distributed between TR and NP but NP had a significantly lower S phase fraction (NP 13.1 vs. TR 22.0, p < 0.05). The overall survival following breast relapse was 64% at 10 years and 49% at 15 years. With a mean follow-up of 10.4 years following breast relapse, patients with NP had better 10-year overall survival (TR 55% vs. NP 75%, p < 0.0001), distant disease-free survival (TR 41% vs. NP 85%, p < 0.0001), and cause-specific survival (TR 55% vs. NP 90%, p < 0.0001).

CONCLUSION

It appears that a significant portion of patients who experience ipsilateral breast tumor relapse following conservative surgery and radiation therapy have new primary tumors as opposed to true local recurrences. True recurrence and new primary tumor ipsilateral breast tumor relapses have different natural histories, different prognoses, and, in turn, different implications for therapeutic management.

Cyclin D1 expression and early breast cancer recurrence following lumpectomy and radiation

PURPOSE

The purpose of this study was to determine the prognostic significance of cyclin D1 (cycD1) levels in ipsilateral breast tumor recurrence (IBTR) following lumpectomy and radiation therapy.

METHODS AND MATERIALS

A total of 98 patients (49 patients with IBTR and 49 matched cases without IBTR) selected from our conservatively treated breast cancer population served as the patient population for the current study. All patients were treated with lumpectomy followed by radiation therapy to the intact breast to a total median dose of 64 Gy. The patients were followed in our clinic with a median follow-up of 13 years. Immunohistochemical analysis of cycD1 in these 98 early-stage breast cancer patients was performed using a polyclonal antibody generated against the human cycD1 protein. All clinical, pathologic, and molecular variables were entered into a computerized data base for statistical analysis.

RESULTS

Low levels of immunohistochemically detected cycD1 protein correlated with IBTR (p = 0.001), but there was no association between cycD1 protein levels and metastatic disease, axillary lymph node involvement, distant disease-free survival (DDFS), and overall survival (OS). Subgroup analysis revealed that for early breast tumor relapses (within 4 years of initial breast tumor diagnosis), low levels of cycD1 were associated with IBTR (p = 0.004), but cycD1 expression was not prognostic for IBTR from breast cancer patients with late relapses (p = NS).

CONCLUSION

These studies provide in vivo evidence for the prognostic and biologic significance of cycD1 expression in determining response to radiation therapy in breast cancer patients.

Prognostic and predictive implications of HER2 status for breast cancer patients

Women diagnosed with breast cancer face many emotional and psychological challenges, which are often related to how they perceive their chances of survival. A number of factors are known to be indicators of breast cancer prognosis, including tumour type, size and grade, and lymph node status. These factors can be used alone or in combination to make management decisions based on a broad assessment of tumour aggression. However, identifying an independent marker of prognosis has proved more difficult. The human epidermal growth factor receptor-2 (HER2) is amplified/overexpressed in 25-30% of breast tumours. This event has been shown to be associated with poor prognosis in breast cancer patients. Initial observations indicated that median survival duration is reduced by at least 50% in patients who overexpress HER2 compared with those who do not overexpress the receptor. This finding has been supported by many subsequent studies and data are accumulating to indicate that the relationship holds for both node-negative and node-positive patients. This could be particularly important for identifying the 30% of node-negative patients who will progress despite therapy. HER2 status may also be able to predict the outcome of therapy. It appears likely that HER2 overexpression predicts for resistance to tamoxifen and other hormonal therapies. It is also possible that HER2-overexpressing patients may respond better to dose-intense anthracycline therapy and worse to cyclophosphamide/methotrexate/5-fluorouracil than non-overexpressing patients. Explaining these associations to patients may empower them to deal with the psychological effects of a diagnosis of breast cancer while providing hope for the future.

BRCA1/BRCA2 germline mutations in locally recurrent breast cancer patients after lumpectomy and radiation therapy: implications for breast-conserving management in patients with BRCA1/BRCA2 mutations

PURPOSE

Breast cancer patients treated conservatively with lumpectomy and radiation therapy (LRT) have an estimated lifetime risk of local relapse (ipsilateral breast tumor recurrence [IBTR]) of 10% to 15%. For breast cancer patients carrying BRCA1 or BRCA2 (BRCA1/2) mutations, the outcome of treatment with LRT with respect to IBTR has not been determined. In this study, we estimate the frequency of BRCA1/2 mutations in a study of breast cancer patients with IBTR treated with LRT.

PATIENTS AND METHODS

Between 1973 and 1994, there were 52 breast cancer patients treated with LRT who developed an IBTR within the prior irradiated breast and who were willing to participate in the current study. From our database, we also identified 52 control breast cancer patients treated with LRT without IBTR. The control patients were individually matched to the index cases with respect to multiple clinical and pathologic parameters. Lymphocyte DNA specimens from all 52 locally recurrent patients and 15 of the matched control patients under age 40 were used as templates for polymerase chain reaction amplification and dye-primer sequencing of exons 2 to 24 of BRCA1, exons 2 to 27 of BRCA2, and flanking intron sequences.

RESULTS

After LRT, eight (15%) of 52 breast cancer patients had IBTR with deleterious BRCA1/2 mutations. By age, there were six (40%) of 15 patients with IBTR under age 40 with BRCA1/2 mutations, one (9.0%) of 11 between ages 40 and 49, and one (3.8%) of 26 older than age 49. In comparison to the six (40%) of 15 of patients under age 40 with IBTR found to have BRCA1/2 mutations, only one (6.6%) of 15 matched control patients without IBTR and had a BRCA1/2 mutation (P =.03). The median time to IBTR for patients with BRCA1/2 mutations was 7.8 years compared with 4.7 years for patients without BRCA1/2 mutations (P =.03). By clinical and histologic criteria, these relapses represented second primary tumors developing in the conservatively treated breast. All patients with BRCA1/2 mutations and IBTR underwent successful surgical salvage mastectomy at the time of IBTR and remain alive without evidence of local or systemic progression of disease.

CONCLUSION

In this study, we found an elevated frequency of deleterious BRCA1/2 mutations in breast cancer patients treated with LRT who developed late IBTR. The relatively long time to IBTR, as well as the histologic and clinical criteria, suggests that these recurrent cancers actually represent new primary breast cancers. Early onset breast cancer patients experiencing IBTR have a disproportionately high frequency of deleterious BRCA1/2 mutations. This information may be helpful in guiding management in BRCA1 or BRCA2 patients considering breast-conserving therapy.

Risk factors for local recurrence after breast-conserving therapy for invasive carcinomas: a case-control study of histological factors and alterations in oncogene expression

PURPOSE

Many studies have focused on histological risk factors for local recurrence (LR) after breast-conserving therapy (BCT). In addition to histological factors, we studied alterations in the expression of various proteins in relation to LR using a case-control approach.

METHODS AND MATERIALS

Ninety-nine LR occurred in a patient cohort of 1,481 tumors treated with BCT. These patients were randomly matched, each with two controls. Matching was performed for age group (< or = 50 and > 50 years), pN stage, and follow-up time. Histology slides were reviewed. Immunohistochemical staining was performed for the following proteins: bcl-2, CD31, cyclin D1, E-cadherin, EGF receptor, ER, PR, Ki-67, c-erbB2/neu, and p53. Statistical analyses were performed using conditional logistic regression.

RESULTS

Sixty-six cases and 139 controls with invasive carcinoma remained for analysis. The following variables were significant risk factors for LR: young age (p = 0.006), high nuclear grade (p = 0.04), high mitotic count (p = 0.03), extensive DCIS around the tumor (p = 0.02) but not within the tumor, poorly differentiated type of DCIS (p = 0.03), > 20% ki-67 positive cells (p = 0.006), and PR negativity (p = 0.03). When the analysis was performed for patients < or = and > 50 years, these risk factors were found in the older patients, but not in the younger patients.

CONCLUSION

High mitotic count and Ki-67 positivity are risk factors for LR. EDCIS surrounding the invasive tumor is a risk factor for LR, especially when of poorly differentiated type. Age is an important risk factor for LR independent of other risk factors, including alterations in oncogene expression.

The HER-2/neu oncogene: prognostic factor, predictive factor and target for therapy

The HER-2/neu oncogene encodes a transmembrane tyrosine kinase receptor with extensive homology to the epidermal growth factor receptor. HER-2/neu has been widely studied in breast cancer. The potential value of HER-2/neu status for the prediction of disease outcome and response to therapy in breast cancer is presented in the light of a series of recently published studies showing a range of impact on the outcome of patients treated with hormonal, cytotoxic and radiation therapies. This review includes the application of serum-based HER-2/neu testing and the use of antibody-based therapies directed against the HER-2/neu protein and their potential to become a new modality for breast cancer treatment.