Clinical and analytical validation of Ki-67 in 9069 patients from IBCSG VIII + IX, BIG1-98 and GeparTrio trial: systematic modulation of interobserver variance in a comprehensive in silico ring trial.

PURPOSE: Ki-67 has been clinically validated for risk assessment in breast cancer, but the analytical validation and cutpoint-definition remain a challenge. Intraclass correlation coefficients (ICCs) are a statistical parameter for Ki-67 interobserver performance. However, the maximum degree of variance among pathologists allowed for meaningful biomarker results has not been defined. METHODS: Different amounts of variance were added to central pathology Ki-67 data (n = 9069) from three cohorts (IBCSGVIII + IX, BIG1-98, GeparTrio) by simulation of 4500 evaluations for each cohort, which were grouped by ICCs, ranging from excellent (ICC = 0.9) to poor concordance (ICC = 0.1). Endpoints were disease-free survival (DFS) and pathological complete response (pCR, GeparTrio). RESULTS: Ki-67 was a significant continuous prognostic marker for DFS over a wide range of cutpoints between 8% and 30% in all three cohorts. In our modelling approach, Ki-67 was a stable prognostic marker despite increased interpathologist variance. Even for a poor ICC of 0.5, one or more significant Ki-67 cutoffs were detected in 86.8% (GeparTrio), 92.4% (IBCSGVIII + IX) and 100% of analyses (BIG1-98). Similarly, in GeparTrio, even with an extremely low ICC of 0.2, 99.6% of analyses were significant for pCR. CONCLUSIONS: Our study shows that Ki-67 is a continuous marker which is extremely robust to pathologist variation. Even if only 50% of variance is attributable to true Ki-67-based proliferation (ICC = 0.5), this information is sufficient to obtain statistically significant differences in clinical cohorts. This stable performance explains the observation that many Ki-67 studies achieve significant results despite relevant interobserver variance and points to a high clinical validity of this biomarker. For clinical decisions based on analysis of individual patient data, ongoing efforts to further reduce interobserver variability, including ring trials and standardized guidelines as well as image analysis approaches, should be continued.

Tumour-infiltrating lymphocytes and prognosis in different subtypes of breast cancer: a pooled analysis of 3771 patients treated with neoadjuvant therapy.

BACKGROUND: Tumour-infiltrating lymphocytes (TILs) are predictive for response to neoadjuvant chemotherapy in triple-negative breast cancer (TNBC) and HER2-positive breast cancer, but their role in luminal breast cancer and the effect of TILs on prognosis in all subtypes is less clear. Here, we assessed the relevance of TILs for chemotherapy response and prognosis in patients with TNBC, HER2-positive breast cancer, and luminal-HER2-negative breast cancer. METHODS: Patients with primary breast cancer who were treated with neoadjuvant combination chemotherapy were included from six randomised trials done by the German Breast Cancer Group. Pretherapeutic core biopsies from 3771 patients included in these studies were assessed for the number of stromal TILs by standardised methods according to the guidelines of the International TIL working group. TILs were analysed both as a continuous parameter and in three predefined groups of low (0-10% immune cells in stromal tissue within the tumour), intermediate (11-59%), and high TILs (≥60%). We used these data in univariable and multivariable statistical models to assess the association between TIL concentration and pathological complete response in all patients, and between the amount of TILs and disease-free survival and overall survival in 2560 patients from five of the six clinical trial cohorts. FINDINGS: In the luminal-HER2-negative breast cancer subtype, a pathological complete response (pCR) was achieved in 45 (6%) of 759 patients with low TILs, 48 (11%) of 435 with intermediate TILs, and 49 (28%) of 172 with high TILs. In the HER2-positive subtype, pCR was observed in 194 (32%) of 605 patients with low TILs, 198 (39%) of 512 with intermediate TILs, and 127 (48%) of 262 with high TILs. Finally, in the TNBC subtype, pCR was achieved in 80 (31%) of 260 patients with low TILs, 117 (31%) of 373 with intermediate TILs, and 136 (50%) of 273 with high TILs (p<0·0001 for each subtype, χ2 test for trend). In the univariable analysis, a 10% increase in TILs was associated with longer disease-free survival in TNBC (hazard ratio [HR] 0·93 [95% CI 0·87-0·98], p=0·011) and HER2-positive breast cancer (0·94 [0·89-0·99], p=0·017), but not in luminal-HER2-negative tumours (1·02 [0·96-1·09], p=0·46). The increase in TILs was also associated with longer overall survival in TNBC (0·92 [0·86-0·99], p=0·032), but had no association in HER2-positive breast cancer (0·94 [0·86-1·02], p=0·11), and was associated with shorter overall survival in luminal-HER2-negative tumours (1·10 [1·02-1·19], p=0·011). INTERPRETATION: Increased TIL concentration predicted response to neoadjuvant chemotherapy in all molecular subtypes assessed, and was also associated with a survival benefit in HER2-positive breast cancer and TNBC. By contrast, increased TILs were an adverse prognostic factor for survival in luminal-HER2-negative breast cancer, suggesting a different biology of the immunological infiltrate in this subtype. Our data support the hypothesis that breast cancer is immunogenic and might be targetable by immune-modulating therapies. In light of the results in luminal breast cancer, further research investigating the interaction of the immune system with different types of endocrine therapy is warranted. FUNDING: Deutsche Krebshilfe and European Commission.

Clinical relevance and concordance of HER2 status in local and central testing-an analysis of 1581 HER2-positive breast carcinomas over 12 years.

Human epidermal growth factor receptor 2 (HER2) is a central predictive biomarker in breast cancer. Inaccurate HER2 results in different laboratories could be as high as 20%. However, this statement is based on data generated more than 13 years ago and may not reflect the standards of modern diagnostic pathology. We compared central and local HER2 testing in a total of 1581 HER2-positive tumors from five clinical trials. We evaluated the clinical relevance for pathological complete response (pCR) and disease-free survival in a subgroup of 677 tumors, which received an anti-HER2 therapy. Over the period of 12 years, the discordance rate for HER2 decreased from 52.4 (GeparTrio) to 8.4% (GeparSepto). Discordance rates were significantly higher in hormone receptor (HR)-positive tumors (26.6%), compared to HR-negative tumors (16.3%, P<0.0001), which could be explained by a different distribution of HER2 mRNA levels in HR-positive and HR-negative tumors. pCR rates were significantly lower in discordant tumors (13.7%) compared to concordant tumors (32.2%, GeparQuattro and GeparQuinto, P<0.001). In survival analysis, tumors with discordant HER2 testing had a reduced overall survival (OS) in the HR-negative group (P=0.019) and a trend for improved OS in the HR-positive group (P=0.125). The performance of local HER2 testing was considerably improved over time and has reached a 92% concordance, which shows that quality initiatives in diagnostic pathology are working. Tumors with discordant HER2 testing had a reduced therapy response and different survival rates.

In vivo effects of bupivacaine and gadobutrol on the intervertebral disc following discoblock and discography: a histological analysis.

OBJECTIVES: The aim of the present study was to histologically compare chondrotoxicity in surgically harvested intervertebral discs (IVDs) of patients following discoblock, discography, or no preoperative intervention. METHODS: Thirty patients (IVD degeneration Modic ≥ 2°, Pfirrmann 3° or 4°) at L4/5 or L5/S1 who were planned for anterior lumbar interbody fusion were randomly assigned to three groups (open MRI: group DG - discography with gadobutrol; group DB - discoblock with bupivacaine at 4 weeks prior to surgery; group C - no intervention). The intervertebral discs were histologically evaluated and compared using ANOVA and Bonferroni tests for cell count, apoptosis, and proliferation. RESULTS: A reduced cell count (groups DG vs. DB vs. C: 14.9 ± 7.1, 9.2 ± 3.8, and 16.6 ± 5.2 cells/mm2, respectively; p ANOVA = 0.016), increased apoptosis (groups DG vs. DB vs. C: 34.9 ± 10.2, 47.4 ± 16.3, 32.6 ± 12.2 %, respectively; p ANOVA = 0.039) and increased cell proliferation (post hoc pDB vs. DG or C p < 0.001; for 3-7 cell monoclonal cell nests: groups DG vs. DB vs. C: 2.4 ± 1, 3.9 ± 1, 2.2 ± 1.1, respectively; p interventionx nest size = 0.006) were found in the IVDs of patients in group DB. CONCLUSIONS: This in vivo study suggests that chondrotoxic effects occur in IVD cells after the intradiscal injection of bupivacaine but not after gadobutrol administration. KEY POINTS: • Local bupivacaine administration to intervertebral discs leads to cell toxicity and proliferation. • Gadobutrol demonstrated no significant effect on cell count, apoptosis, or cell proliferation. • In vivo cytotoxicity was demonstrated histologically in humans for the first time. • Addition/administration of bupivacaine during discographies must be judged critically.

Glutamate enrichment as new diagnostic opportunity in breast cancer.

Exogenous glutamine is an important source of energy and molecular building blocks for many tumors. There is a renewed interest in therapeutically targeting glutamine metabolism due to the recent discovery of two novel glutaminase inhibitors. To quantify the dysregulation of the glutamate-glutamine equilibrium in breast cancer, metabolomics analysis of 270 clinical breast cancer samples and 97 normal breast samples was carried out using gas chromatography combined with time-of-flight mass spectrometry. Positive correlation between glutamate and glutamine in normal breast tissues switched to negative correlation between glutamate and glutamine in breast cancer tissues. Compared with the ratio of glutamate to glutamine in normal tissues, we found 56% of the ER+ tumor tissues and 88% of the ER- tumor tissues glutamate-enriched. The glutamate-to-glutamine ratio (GGR) significantly correlated with ER status (p = 8.0E-09) and with tumor grade (p = 3.3E-05). Higher levels of GGR were associated with prolonged overall survival in univariate analysis (HR = 0.77, p = 0.027) and in multivariate analysis (HR = 0.73, p = 0.038). GGR levels were reflected in an unsupervised clustering of metabolomics profiles. In a supervised analysis of metabolomics data and of genome-wide expression data, replacement of GGR by metabolite surrogate markers was feasible, while replacement of GGR by RNA markers had a limited accuracy. Functional analysis of the gene expression data showed negative correlation between glutamate enrichment and activation of peroxisome proliferator-activated receptor (PPAR) pathway. Our findings may have important implications for patient stratification related to utilization of glutaminase inhibitors.

Bioactive coating of zirconia toughened alumina ceramic implants improves cancellous osseointegration.

Bioactive coatings have the potential to improve the bony integration of mechanically loaded orthopedic ceramic implants. Using the concept of mimicking the natural bone surface, four different coatings of varying thickness on a zirconia toughened alumina (ZTA) ceramic implant were investigated regarding their osseointegration in a drill-hole model in sheep. The hypothesis that a bioactive coating of ZTA ceramics would facilitate cancellous bone integration was investigated. The bioactive coatings consisted of either a layer of covalently bound multi phosphonate molecules (chemical modification = CM), a nano hydoxyapatite coating (HA), or two different bioactive glass (BG) coatings in micrometer thickness, forming a hydroxyl-carbonate apatite layer on the implant surface in vivo (dip-coated 45S5 = DipBG; sol-gel 70S30C = SGBG). Coated surfaces were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. After 12 weeks, osseointegration was evaluated via mechanical push-out testing and histology. HA enhanced the maximum push-out force (HA: mean 3573.85 ± 1119.91 N; SGBG: mean 1691.57 ± 986.76 N; p = 0.046), adhesive shear strength (HA: mean 9.82 ± 2.89 MPA; SGBG: mean 4.57 ± 2.65 MPA; p = 0.025), and energy release rate (HA: mean 3821.95 ± 1474.13 J/mm2; SGBG: mean 1558.47 ± 923.47 J/mm2; p = 0.032) compared to SGBG. The implant-bone interfacial stiffness increased by CM compared to SGBG coating (CM: mean 6258.06 ± 603.80 N/mm; SGBG: mean 3565.57 ± 1705.31 n/mm; p = 0.038). Reduced mechanical osseointegration of SGBG coated implants could be explained histologically by a foreign body reaction surrounding the implants.

Tumor-Infiltrating Lymphocytes: A Predictive and Prognostic Biomarker in Neoadjuvant-Treated HER2-Positive Breast Cancer.

PURPOSE: We elucidated the value of tumor-infiltrating lymphocytes (TIL) as an independent predictor for pathologic complete response (pCR) rate and as a prognostic marker for disease-free survival (DFS) in patients with HER2-positive breast cancer in the neoadjuvant setting. EXPERIMENTAL DESIGN: We evaluated stromal TILs in 498 HER2-positive breast cancer samples of the neoadjuvant GeparQuattro (G4) and GeparQuinto (G5) trials. Levels of TILs were determined as a continuous parameter per 10% increase and as lymphocyte-predominant breast cancer (LPBC; ≥ 60% TILs), and correlated with pCR rate and DFS. RESULTS: In the complete cohort, HER2-positive LPBC cases had a significantly increased pCR rates compared with non-LPBC types. They were significant predictors for pCR in univariate (10% TILs: OR 1.12, P = 0.002; LPBC: OR 2.02, P = 0.002) and multivariate analyses (10% TILs: OR 1.1, P = 0.014; LPBC: OR 1.87, P = 0.009). This effect was also detectable in the trastuzumab-treated (10% TILs: OR 1.12, P = 0.018; LPBC: OR 2.08, P = 0.013) but not in the lapatinib-treated subgroup. We identified a low-risk (pCR/LPBC) and a high-risk group (no pCR/no LPBC) regarding DFS. In triple-positive breast cancer, TILs are of more prognostic relevance than pCR. CONCLUSIONS: We could demonstrate the predictive and prognostic impact of TILs in HER2-positive breast cancer in the neoadjuvant setting. In combination with pCR rate, TILs may help to stratify prognostic subgroups, thereby guiding future therapy decisions. Clin Cancer Res; 22(23); 5747-54. ©2016 AACR.

Tumor-infiltrating lymphocytes and response to neoadjuvant chemotherapy with or without carboplatin in human epidermal growth factor receptor 2-positive and triple-negative primary breast cancers.

PURPOSE: Modulation of immunologic interactions in cancer tissue is a promising therapeutic strategy. To investigate the immunogenicity of human epidermal growth factor receptor 2 (HER2) -positive and triple-negative (TN) breast cancers (BCs), we evaluated tumor-infiltrating lymphocytes (TILs) and immunologically relevant genes in the neoadjuvant GeparSixto trial. PATIENTS AND METHODS: GeparSixto investigated the effect of adding carboplatin (Cb) to an anthracycline-plus-taxane combination (PM) on pathologic complete response (pCR). A total of 580 tumors were evaluated before random assignment for stromal TILs and lymphocyte-predominant BC (LPBC). mRNA expression of immune-activating (CXCL9, CCL5, CD8A, CD80, CXCL13, IGKC, CD21) as well as immunosuppressive factors (IDO1, PD-1, PD-L1, CTLA4, FOXP3) was measured in 481 tumors. RESULTS: Increased levels of stromal TILs predicted pCR in univariable (P < .001) and multivariable analyses (P < .001). pCR rate was 59.9% in LPBC and 33.8% for non-LPBC (P < .001). pCR rates ≥ 75% were observed in patients with LPBC tumors treated with PMCb, with a significant test for interaction with therapy in the complete (P = .002) and HER2-positive (P = .006), but not the TNBC, cohorts. Hierarchic clustering of mRNA markers revealed three immune subtypes with different pCR rates (P < .001). All 12 immune mRNA markers were predictive for increased pCR. The highest odds ratios (ORs) were observed for PD-L1 (OR, 1.57; 95% CI, 1.34 to 1.86; P < .001) and CCL5 (OR, 1.41; 95% CI, 1.23 to 1.62; P < .001). CONCLUSION: Immunologic factors were highly significant predictors of therapy response in the GeparSixto trial, particularly in patients treated with Cb. After further standardization, they could be included in histopathologic assessment of BC.

Preanalytical variables and performance of diagnostic RNA-based gene expression analysis in breast cancer.

Prognostic multigene expression assays have become widely available to provide additional information to standard clinical parameters and to support clinicians in treatment decisions. In this study, we analyzed the impact of variations in tissue handling on the diagnostic EndoPredict test results. EndoPredict is a quantitative reverse transcription PCR assay conducted on RNA from formalin-fixed, paraffin-embedded (FFPE) tissue that predicts the likelihood of distant recurrence in patients with ER-positive/HER2-negative breast cancer. In this study, we performed a total of 138 EndoPredict assays to study the effects of preanalytical variables such as time to fixation, fixation time, tumor cell content, and section storage time on the EndoPredict test results. A time to fixation of up to 12 h and fixation of up to 5 days did not affect the results of the gene expression test. Paired samples of FFPE sections with tumor cell content ranging from 15 to 95 % and tumor-enriched samples showed a correlation coefficient of 0.97. Test results of tissue sections that have been stored for 12 months at +4 or +20 °C showed a correlation of 0.99 when compared to results of nonstored sections. In conclusion, preanalytical tissue handling is not a critical factor for diagnostic gene expression analysis with the EndoPredict assay. The test can therefore be easily integrated into the standard workflow of molecular pathology.