Nab-paclitaxel weekly versus dose-dense solvent-based paclitaxel followed by dose-dense epirubicin plus cyclophosphamide in high-risk HR+/HER2- early breast cancer: results from the neoadjuvant part of the WSG-ADAPT-HR+/HER2- trial.

BACKGROUND: In high-risk hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer (EBC), nanoparticle albumin-bound (nab)-paclitaxel showed promising efficacy versus solvent-based (sb)-paclitaxel in neoadjuvant trials; however, optimal patient and therapy selection remains a topic of ongoing research. Here, we investigate the potential of Oncotype DX® recurrence score (RS) and endocrine therapy (ET) response (low post-endocrine Ki67) for therapy selection. PATIENTS AND METHODS: Within the WSG-ADAPT trial (NCT01779206), high-risk HR+/HER2- EBC patients were randomized to (neo)adjuvant 4× sb-paclitaxel 175 mg/m2 q2w or 8× nab-paclitaxel 125 mg/m2 q1w, followed by 4× epirubicin + cyclophosphamide (90 mg + 600 mg) q2w; inclusion criteria: (i) cN0-1, RS 12-25, and post-ET Ki67 >10%; (ii) cN0-1 with RS >25. Patients with cN2-3 or (G3, baseline Ki67 ≥40%, and tumor size >1 cm) were allowed to be included without RS and/or ET response testing. Associations of key factors with pathological complete response (pCR) (primary) and survival (secondary) endpoints were analyzed using statistical mediation and moderation models. RESULTS: Eight hundred and sixty-four patients received neoadjuvant nab-paclitaxel (n= 437) or sb-paclitaxel (n = 427); nab-paclitaxel was superior for pCR (20.8% versus 12.9%, P = 0.002). pCR was higher for RS >25 versus RS ≤25 (16.0% versus 8.4%, P = 0.021) and for ET non-response versus ET response (15.1% versus 6.0%, P = 0.027); no factors were predictive for the relative efficacy of nab-paclitaxel versus sb-paclitaxel. Patients with pCR had longer distant disease-free survival [dDFS; hazard ratio 0.42, 95% confidence interval (CI) 0.20-0.91, P = 0.024]. Despite favorable prognostic association of RS >25 versus RS ≤25 with pCR (odds ratio 3.11, 95% CI 1.71-5.63, P ≤ 0.001), higher RS was unfavorably associated with dDFS (hazard ratio 1.03, 95% CI 1.01-1.05, P = 0.010). CONCLUSIONS: In high-risk HR+/HER2- EBC, neoadjuvant nab-paclitaxel q1w appears superior to sb-paclitaxel q2w regarding pCR. Combining RS and ET response assessment appears to select patients with highest pCR rates. The disadvantage of higher RS for dDFS is reduced in patients with pCR. These are the first results from a large neoadjuvant randomized trial supporting the use of RS to help select patients for neoadjuvant chemotherapy in high-risk HR+/HER2- EBC.

Co-expression of transcription factor AP-2beta (TFAP2B) and GATA3 in human mammary epithelial cells with intense, apicobasal immunoreactivity for CK8/18.

AP-2ß is a new mammary epithelial differentiation marker and its expression is preferentially retained and enhanced in lobular carcinoma in situ and invasive lobular breast cancer. In normal breast epithelium AP-2ß is expressed in a scattered subpopulation of luminal cells. So far, these cells have not been further characterized. Co-expression of AP-2ß protein and luminal epithelium markers (GATA3, CK8/18), hormone receptors [estrogen receptor (ER), androgen receptor (AR)] and candidate stem cells markers (CK5/14, CD44) were assessed by double-immunofluorescence staining in normal mammary gland epithelium. The subpopulation of AP-2ß-positive mammary epithelial cells showed an almost complete, superimposable co-expression with GATA3 and a peculiar intense, ring-like appearing immunoreactivity for CK8/18. Confocal immunofluorescence microscopy revealed an apicobasal staining for CK8/18 in AP-2ß-positive cells, which was not seen in in AP-2ß-negative cells. Furthermore, AP-2ß-positive displayed a partial co-expression with ER and AR, but lacked expression of candidate stem cell markers CK5/14 and CD44. In summary, AP-2ß is a new luminal mammary epithelial differentiation marker, which is expressed in the GATA3-positive subpopulation of luminal epithelial cells. These AP-2ß-positive/GATA3-positive cells also show a peculiar CK8/18-expression which may indicate a previously unknown functionally specialized mammary epithelial cell population.

[Ectopia of mammary tissue]. / Ektopien des Mammagewebes.

Ectopic breast tissue may represent the complete breast (accessory breast), glandular tissue without areola or nipple (aberrant breast tissue), or exclusively the nipple (polythelia). Localization is along the embryonic milk ridge extending from the axilla to the vulva. Only rarely, is ectopic tissue found outside of the milk ridge. Most frequently affected are the axilla, the breast itself, and its close neighbourhood. Ectopic breast tissue may rarely give rise to tumours such as fibroadenoma or carcinoma.

De-escalation strategies in HER2-positive early breast cancer (EBC): final analysis of the WSG-ADAPT HER2+/HR- phase II trial: efficacy, safety, and predictive markers for 12 weeks of neoadjuvant dual blockade with trastuzumab and pertuzumab ± weekly paclitaxel.

BACKGROUND: Response rates in HER2-overexpressing EBC treated with neoadjuvant chemotherapy and trastuzumab (T) have been improved by addition of pertuzumab (P). The prospective, phase II, neoadjuvant WSG-ADAPT HER2+/HR- trial assessed whether patients with strong early response to dual blockade alone might achieve pathological complete response (pCR) comparable to that of patients receiving dual blockade and chemotherapy. PATIENTS AND METHODS: Female patients with HER2+/HR- EBC (M0) were randomized (5:2) to 12 weeks of T + P ± weekly paclitaxel (pac) at 80 mg/m2. Early response was defined as proliferation decrease ≥30% of Ki-67 (versus baseline) or low cellularity (<500 invasive tumor cells) in the 3-week biopsy. The trial was designed to test non-inferiority for pCR in early responding patients of the T + P arm versus all chemotherapy-treated patients. RESULTS: From February 2014 to December 2015, 160 patients were screened, 92 were randomized to T + P and 42 to T + P+pac. Baseline characteristics were well balanced (median age 54 versus 51.5 years, cT2 51.1 versus 52.4%, cN0 54.3 versus 61.9%); 91.3% of patients completed T + P per protocol and 92.9% T + P+pac. The pCR rate in the T + P+pac arm was 90.5%, compared with 36.3% in the T + P arm as a whole. In the T + P arm, 24/92 were classified as non-responders, and their pCR rate was only 8.3% compared with 44.7% in responders (38/92) and 42.9% in patients with unclassified early response (30/92). No new safety signals were observed in the study population. CONCLUSION: Addition of taxane monotherapy to dual HER2 blockade in a 12-week neoadjuvant setting substantially increases pCR rates in HER2+/HR- EBC compared with dual blockade alone, even within early responders to dual blockade. Early non-response under dual blockade strongly predicts failure to achieve pCR.

[Histological grading of breast cancer]. / Histologisches Grading beim Mammakarzinom.

From a historical perspective, histological grading was the earliest cell-based method for assessing tumor biology and the prognosis of breast cancer. This review article provides detailed and practical instructions for grading of breast cancer in routine diagnostics. Furthermore, the increasing relevance of precise histological grading in the era of molecular pathology is discussed.

[Differential diagnosis of spindle cell tumors of the breast from biopsy material]. / Stanzbioptische Differenzialdiagnose von Spindelzelltumoren der Mamma.

Spindle cell proliferations are a rare but diagnostically challenging finding in breast biopsy material. The spectrum of possible diagnoses ranges from benign lesions, such as hamartomas, myofibroblastomas and biphasic tumors, such as adenomyoepitheliomas to malignant lesions, such as metaplastic carcinomas, phyllodes tumors and genuine sarcomas. A correct diagnosis from the preoperative biopsy material helps prevent inappropriate therapy and overtreatment or undertreatment. In this review five morphological patterns of spindle cell tumors of the breast and the most important representatives in this group are discussed.

[Determination of proliferation in breast cancer by immunohistochemical detection of Ki-67]. / Proliferationsbestimmung beim Mammakarzinom durch den immunhistochemischen Nachweis von Ki-67.

Gene expression profiling has demonstrated the prognostic relevance of genes associated with proliferation in breast cancer. The immunohistochemical marker Ki-67 enables routine assessment of proliferation activity in pathology. In a number of retrospective but only few prospective studies the prognostic relevance of Ki-67 in breast cancer could be shown. Although there is no standardized approach with regard to which area of a histological section and how many cells should be counted in a quantitative or semiquantitative fashion as well as to the threshold, Ki-67 is broadly applied in breast pathology. This can be explained by the good reproducibility of the degree of proliferation assessed by Ki-67, at least in the low and high ranges, the possibility to substantiate grading and better practicability in core biopsies in comparison to mitotic counting. In neoadjuvant therapy of hormone receptor positive breast cancer, Ki-67 can probably predict the efficacy of pure hormone receptor blockade without chemotherapy.

[Beyond staging, typing and grading. New challenges in breast cancer pathology]. / Jenseits von Staging, Typing und Grading. Herausforderungen und Perspektiven für die Tumorpathologie der Mamma.

Tumor biological parameters for the prediction and prognosis of invasive breast cancer are gaining in importance compared to traditional pathological categories. The immunohistochemically determined steroid hormone receptor status is not only the decisive factor influencing whether endocrine therapy (which is indicated in cases of even slight expression) is given or not, but also whether chemotherapy is considered. The Her2 status is of similar importance and needs to be analysed in every case of invasive carcinoma, whereby reproducibility, which requires greater efforts than with steroid hormone receptors, has to be assured. Probably only a small portion of breast cancers will benefit from chemotherapy. Since traditional pathological categories are not sufficient for the identification of this subgroup, there has been an intense search for alternative prognostic parameters, whereby gene expression profiling has emerged as the most promising tool. Despite minimal concordance with regard to single genes, the various profiles available converge in the identification of the proliferative signature as the prognostically most relevant. Whether histopathological grading and immunohistochemical determination of the growth fraction with Ki-67 or genetic profiling will be more reliable in the identification of the aggressive subtype has yet to be clarified in clinical studies which encompass central pathological review.

Epigenetic inactivation of microRNA gene hsa-mir-9-1 in human breast cancer.

MicroRNAs (miRNAs) represent a new class of small non-coding RNAs regulating gene expression by inducing RNA degradation or interfering with translation. Aberrant miRNA expression has been described for several human malignancies and tumour suppressor functions have been ascribed to this new class of small regulatory RNAs. Accordingly, inactivation due to deletion or mutation has been found in human malignancies. Here, we describe the role of aberrant hypermethylation as an additional mechanism for miRNA gene inactivation in human breast cancer. Aberrant hypermethylation was shown for mir-9-1, mir-124a3, mir-148, mir-152, and mir-663 in 34-86% of cases in a series of 71 primary human breast cancer specimens. For comprehensive methylation analysis, combined bisulphite restriction analysis, bisulphite sequencing, and Pyrosequencing were employed. miRNA gene hypermethylation correlated strongly with methylation of known tumour suppressor genes (p = 0.003). After treatment of various breast cancer cell lines with the demethylating agent 5-aza-2'-deoxycytidine, reduction of mir-9-1 gene methylation and concomitant reactivation of expression could be observed. For the mir-9-1 gene, which is already hypermethylated in pre-invasive intraductal lesions, a good correlation between quantitative methylation level and reduction of expression could be demonstrated in a subset of primary human breast cancer specimen (r = 0.8). In conclusion, this study demonstrates that various microRNA genes are also affected by epigenetic inactivation due to aberrant hypermethylation and that this is an early and frequent event in breast cancer development.

Multiple and synergistic deregulations of apoptosis-controlling genes in pancreatic carcinoma cells.

Inability to die by apoptosis is one of the reasons for the deregulated growth of tumour cells and the frequently observed failure of chemotherapy. In this study we thought to identify the common and functionally important characteristics responsible for the apoptosis resistance of pancreatic tumour cells. We analysed cell surface expression level of death receptors CD95 and TRAIL-R1-4 as well as the expression profile of sixteen apoptosis-relevant proteins in five pancreatic carcinoma cell lines Capan1, Colo357, PancTuI, Panc89 and Panc1. These data were evaluated in the context of sensitivity towards anti-CD95 and TRAIL-mediated apoptosis. Here we report that except for resistant Panc1 cells, which only marginally expressed CD95, all other cell lines showed comparable levels of CD95 and TRAIL receptors irrespectively of their apoptotic phenotype. Interestingly, we found that the elevated expression of FLIP, Bcl-x(L) and IAP in parallel with a downregulation of FADD and Bid was common for the resistant cell lines. Consequently, stable overexpression of XIAP, Bcl-x(L) or dominant negative FADD in sensitive cells significantly reduced the death receptor mediated apoptosis while the overexpression of Bid rendered the resistant cells sensitive.

Manumycin enhances the cytotoxic effect of paclitaxel on anaplastic thyroid carcinoma cells.

Despite the current multimodal approach to treatment of anaplastic thyroid cancer (ATC), the prognosis for patients with the disease is poor. New effective therapy for ATC is desperately needed. Thus, we investigated the effects of manumycin (a farnesyl:protein transferase inhibitor), alone and in combination with other drugs frequently used to treat ATC, in six human ATC cell lines: ARO, C643, DRO, Hth-74, KAT-4, and KAT-18. By means of a formazan dye-based spectrophotometric assay of cell viability and light microscopy, manumycin was shown to decrease the number of viable cells in all six of the cell lines though to a lesser degree in DRO and C643 cells than in ARO, Hth-74, KAT-4, and KAT-18 cells. In combination, manumycin enhanced the effect of paclitaxel in all six of the cell lines. The mechanism of cell death was investigated by measuring caspase-3 activity, immunoblotting with anti-poly-(ADP-ribose)polymerase (PARP) antibody and electrophoresis of DNA. After an 18-h incubation, manumycin plus paclitaxel caused enhanced activation of caspase-3 activity, cleavage of PARP into Mr 89,000 and 28,000 fragments, and internucleosomal fragmentation of DNA (all of which are characteristic of apoptotic cell death). In contrast, neither manumycin alone, paclitaxel alone, doxorubicin alone, nor doxorubicin plus manumycin produced significant specific cleavage of PARP and internucleosomal DNA fragmentation after 18 h of incubation. The in vivo effect and toxicity of combined manumycin and paclitaxel treatments were evaluated in a nude mouse xenograft model using ARO and KAT-4 cells. Drugs were injected i.p. on days 1 and 3 of a 7-day cycle for three cycles. Both manumycin (7.5 mg/kg/dose) and paclitaxel (20 mg/kg/dose) had significant inhibitory effects on tumor growth. Combined manumycin and paclitaxel treatments seemed as effective as manumycin against ARO cells and more effective than either manumycin or paclitaxel alone against KAT-4 cells. No significant morbidity or mortality was caused by the treatments. In conclusion, manumycin can inhibit the growth of ATC both in vitro and in vivo. Manumycin plus paclitaxel has enhanced cytotoxic effects and increased apoptotic cell death in ATC cells in vitro compared with either drug by itself. The combination of manumycin and paclitaxel is also effective in vivo with no significant toxicity observed. The lack of synergy observed in this in vivo experiment may be due to a ceiling effect, and further experimentation is warranted to ascertain the optimal way to combine these two agents for maximal therapeutic effects.