[Rich66]

Target Now, molecular profiling:
http://www.carislifesciences.com/oncology-target-now

Target Now helps patients and their treating physicians create a cancer treatment plan based on the tumor tested. By comparing the tumor's information with data from published clinical studies by thousands of the world's leading cancer researchers, Caris can help determine which treatments are likely to be most effective and, just as important, which treatments are likely to be ineffective.
The Target Now test is performed after a cancer diagnosis has been established and the patient has exhausted standard of care therapies or if questions in therapeutic management exists. Using tumor samples obtained from a biopsy, the tumor is examined to identify biomarkers that may have an influence on therapy. Using this information, Target Now provides valuable information on the drugs that will be more likely to produce a positive response. Target Now can be used with any solid cancer such as lung cancer, breast cancer, and prostate cancer.

What does my doctor need from me to perform the test?
Target Now is performed on tissue that is obtained during the surgical removal or biopsy of your tumor. Even if your doctor doesn’t order Target Now testing at this time, the hospital where your biopsy was performed will typically store some of your tissue as standard procedure. Now or in the future, your doctor can request that Target Now testing be run and coordinate with the hospital to have your sample sent to us.

Is Target Now reimbursed?
The Target Now is typically reimbursed by Medicare and other third party payers. Other than co-payments or deductibles required by the patient's plan, there are normally no out-of-pocket costs for the patient

RESEARCH:
Prediction of breast cancer sensitivity to neoadjuvant chemotherapy based on status of DNA damage repair proteins

Breast Cancer Research 2010, 12:R17 doi:10.1186/bcr2486
Hideki Asakawa (hiddie_vr4@hotmail.com)
Hirotaka Koizumi (koizumi@marianna-u.ac.jp)
Ayaka Koike (a2koike@marianna-u.ac.jp)
Makiko Takahashi (takamaki@marianna-u.ac.jp)
Wenwen Wu (wuwenwen@marianna-u.ac.jp)
Hirotaka Iwase (hiwase@kumamoto-u.ac.jp)
Mamoru Fukuda (m2fukuda@marianna-u.ac.jp)
Tomohiko Ohta (to@marianna-u.ac.jp)
ISSN 1465-5411
Article type Research article
Submission date 18 September 2009
Acceptance date 5 March 2010
Publication date 5 March 2010
Article URL http://breast-cancer-research.com/content/12/2/R17
http://breast-cancer-research.com/co...df/bcr2486.pdf

Abstract
Introduction: Various agents used in breast cancer chemotherapy provoke DNA double-strand breaks (DSBs). DSB repair competence determines the sensitivity of cells to these agents whereby aberrations in the repair machinery leads to apoptosis. Proteins required for this pathway can be detected as nuclear foci at sites of DNA damage when the pathway is intact. Here we investigate whether focus formation of repair proteins can predict chemosensitivity of breast cancer.

Methods: Core needle biopsy specimens were obtained from sixty cases of primary breast cancer before and 18-24 hours after the first cycle of neoadjuvant epirubicin plus cyclophosphamide (EC) treatment. Nuclear focus formation of DNA damage repair proteins was immunohistochemically analyzed and compared with tumor response to chemotherapy.

Results: EC treatment induced nuclear foci of H2AX, conjugated ubiquitin, and Rad51 in a substantial amount of cases. In contrast, BRCA1 foci were observed
before treatment in the majority of the cases and only decreased after EC in
thirteen cases. The presence of BRCA1-, H2AX-, or Rad51-foci before treatment
or the presence of Rad51-foci after treatment was inversely correlated with tumor response to chemotherapy. DNA damage response (DDR) competence was further evaluated by considering all four repair indicators together. A high DDR score significantly correlated with low tumor response to EC and EC + docetaxel whereas other clinicopathological factors analyzed did not.

Conclusions: High performing DDR focus formation resulted in tumor resistance to DNA damage-inducing chemotherapy. Our results suggested an importance of evaluation of DDR competence to predict breast cancer chemosensitivity, and merits further studying into its usefulness in exclusion of non-responder patients.

Introduction
Recent advances in chemotherapy have significantly improved the prognosis of breast cancer patients. However, prediction of tumor sensitivity to chemotherapy
has not reached a high level of confidence, whereas determining sensitivity to hormone therapy or trastuzumab is relatively more established. Estrogen and
progesterone receptors (ER and PR) and HER2/ErbB2 are practical benchmarks
to exclude non-responding patients, and tailoring treatment based on gene status significantly optimizes the response rate of hormone therapy and trastuzumab, respectively. Prediction of chemosensitivity with equivalent accuracy is currently anticipated to further improve breast cancer prognosis.
Anthracycline-based regimen, such as epirubicin plus cyclophosphamide (EC), and taxanes represent the major chemotherapeutic agents used in the breast cancer field[1, 2]. Of these, anthracycline-based chemotherapy induces DNA double-strand breaks (DSBs)[3, 4], the most cytotoxic DNA lesion, that leads cells into apoptosis especially when relevant repair pathways (represented by homologous recombination (HR) repair) are perturbed[5]. It is important to note that DNA damage repair competence varies among individual breast tumors and closely correlates with chemosensitivity. For example, secondary mutations of BRCA1 or 2 (essential factors in the HR pathway) caused by chemotherapy using cisplatin or poly(ADP-ribose) polymerase (PARP) inhibitor in BRCA1/2-mutated cancers restore the wild-type reading frame and, therefore, the tumor acquires resistance to these drugs [6-8].
These facts indicate that chemosensitivity of BRCA-associated cancers could be
strongly affected by DNA damage repair capability. Based on this evidence it has
been suggested that HR competence could be a potential biomarker for chemosensitivity [9]. Rad51, a protein that plays a direct role in HR, especially
reflects the HR-competence of cells. Therefore, knowing its status is likely
valuable when assessing HR-competence in tumor cells in order to instruct therapeutic decisions [9].
The HR pathway for DSB repair is executed by sequential recruitment of repair proteins to chromatin around DNA lesions. Accumulation of the proteins is regulated by complex mechanisms that utilize phosphorylation and ubiquitination
modifications mediated by kinases, including ATM, and at least three ubiquitin
E3 ligases, RNF8, RNF168, Rad18, and BRCA1 [10-17]. The Mre11-Rad50-Nbs1 complex first recognizes DSBs and recruits ATM. ATM then phosphorylates the histone variant H2AX (H2AX) [18, 19] that triggers accumulation of the downstream E3 ligases RNF8 [11-13, 20] and RNF168 [14,15]. Lysine 63 (K63)–linked polyubiquitin chains built at the sites of DNA damage by these E3 ligases next recruits the BRCA1-Abraxas-RAP80 complex through the RAP80 component, a protein that contains UIM (ubiquitin interacting motif) domains [21-23]. BRCA1 is then essential to recruit repair effector proteins, including Rad51, that perform HR through sister chromatid exchange [24, 25].
Depletion of any one of these proteins results in HR deficiency accompanied by
loss of Rad51 focus formation, causing cells to become hypersensitive to
DSB-inducing agents.
In this study we attempt to clarify the value of HR-competence for prediction of breast cancer chemosensitivity. One contention is that nuclear focus formation of repair proteins in baseline breast cancer tissues is a response to spontaneous DNA damage during cell proliferation and, in turn, may represent a marker of HR-competence of cells to exogenous DNA damage. Therefore, it may predict tumor response to DNA damage-inducing chemotherapy such as EC. Also, the focus formation after chemotherapy could provide us additional information regarding the DNA damage response capacity. To verify in vivo whether focus formation of repair proteins actually occurs in response to DNA damage-inducing chemotherapy and whether it correlates with tumor fates after chemotherapy, we analyzed foci in core needle biopsy specimens from breast cancer before and after neoadjuvant EC treatment.
Materials and methods
Patients and tumors: Sixty patients with primary breast cancer (2 cm or larger) who
consecutively underwent neoadjuvant chemotherapy with epirubicin plus cyclophosphamide (EC) followed by docetaxel (DOC) at the Division of Breast
and Endocrine Surgery, St. Marianna University School of Medicine, Japan, were enrolled in the present study from August 2005 to July 2007. Tumor specimens were obtained by core needle biopsy prior to starting therapy and 18 to 24 hours after the first cycle of EC treatment.

We found that foci of BRCA1, H2AX and Rad51 prior to treatment and EC-induced foci of Rad51 correlated with tumor response when compared either with the mean tumor volume reduction or the tumor response rate. Upon incorporating these four factors into one DDR score, a significant correlation was observed with mean tumor volume reduction after EC, whereas no other factors correlated with the mean tumor volume reduction (Table 4, and Figure 3a). Although it was not statistically significant the similar correlation was also observed between DDR score and the tumor response rate (Table 3). These correlations became more significant after EC+DOC treatment (Table 3, 4, 5, and Figure 3b) and the DDR score was independent predictive factor of other factors including tumor subtype when evaluated with volume reduction using 50% of the PR/SD border (Table 6). Recent studies suggested that luminal tumors have low response rate to neoadjuvant chemotherapy, while basal-like and HER2+ tumors have higher response rates. For example it has been reported that clinical response rate (CR and PR) to anthracyclin-based chemotherapy of luminal A was 39% whereas that of basal-like, which has been implicated with BRCA1 dysfunction[44, 45], was 85%[46]. The response rates to EC treatment of luminal A (15/37 cases, 40.5%) and basal-like (4/6 cases, 66.7%) subtypes in the current study were not very different from the previous report. However, we could not find any correlation between subtype and DDR sore while DDR score independently predicted the chemosensitivity. The result may reflect the fact that luminal A tumors also include DNA damage-sensitive tumors with defective HR pathway that can be counted by the DDR score.
Supporting this it has been shown that tumors caused by BRCA2 deficiency mainly become luminal A tumor[45, 47, 48].
The reason why the correlation between the DDR score and tumor response after EC+DOC treatment became more significant than that after EC is not clear at present. Because DOC does not induce DNA double-strand breaks, the observed effect is not likely due to the sensitivity to DNA damage in those tumors. DOC might be more toxic for the cells with gross genomic aberration caused by the pretreatment with EC under the condition with less HR competent. Alternatively it is possible that time length after EC treatment enhanced the difference of the outcome.
Interestingly, DDR score group 4 consisted of cases with poor tumor responses to chemotherapy when evaluated for both mean tumor volume reduction (Figure 3) and tumor response rate (Table 3). This result may lead to the possibility of using DDR status in the clinic to predict and exclude non-responders to EC treatment. It is noteworthy to point out that the HR repair cascade for DSB contains many essential proteins other than that tested in this study. By including select subsets of proteins for analysis, it may be possible to identify non-responders in order to avoid unnecessary chemotherapy. Ideally in such cases, the levels of baseline foci present prior to treatment would provide enough information to determine appropriate treatment, preventing the need for additional core needle biopsy after chemotherapy.
Conclusions
In conclusion, our results suggest the importance of evaluating DDR competence to predict breast cancer chemosensitivity and warrant further investigation into its effectiveness as a way to exclude non-responding patients.

9/2010

24-hour Test Predicts Breast Cancer's Likely Response To Chemotherapy

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A new test has been developed which can predict whether a breast cancer patient will respond to chemotherapy [adriamycin]within 24-hours of starting treatment, thus sparing her unnecessary treatment and side effects, according to a study published in the medical journal Clinical Cancer Research...

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Abstract

Low RAD51 score was strongly predictive of pathological complete response to chemotherapy, with 33% low RAD51 score cancers achieving pathological complete response compared to 3% of other cancers (p=0.011).