Ki-67 assessment in early breast cancer: SAKK28/12 validation study on the IBCSG VIII and IBCSG IX cohort.

The assessment of Ki-67 in early-stage breast cancer has become an important diagnostic tool in planning adjuvant therapy, particularly for the administration of additional chemotherapy to hormone-responsive patients. An accurate determination of the Ki-67 index is of the utmost importance; however, the reproducibility is currently unsatisfactory. In this study, we addressed the predictive/prognostic value of Ki-67 index assessed by using the most reproducible methods, which were identified in the pilot phase. Paraffin blocks obtained from patients with moderately differentiated, estrogen receptor (ER)-positive early-stage breast cancer in Switzerland, who were originally randomized to the treatment arms with and without chemotherapy in the IBCSG VIII-IX trials, were retrieved. Of these 344 randomized patients, we identified 158 patients (82 treated with and 76 treated without chemotherapy) for whom sufficient tumour tissue was available. The presence of Ki-67 was assessed visually by counting 2000 cells at the periphery (A) and estimating the number of positive cells in five different peripheral regions (C), which was determined to be the most reproducible method identified the pilot phase. The prognostic and predictive value was assessed by calculating the breast cancer-free interval (BCFI) and overall survival (OS) rate. Ki-67 was considered a numerical and categorical variable when different cut-off values were used (10%, 14%, 20% and 30%). An mRNA-based subtyping by using the MammaTyper kit with the application of a 20% Ki-67 immunohistochemistry (IHC) cut-off equivalent was also performed. 158 of 344 randomized patients could be included in the Ki-67 analysis. The mean Ki-67 values obtained by using the two methods differed (A: 21.32% and C: 16.07%). Ki-67 assessed by using method A with a cut-off of 10% was a predictive marker for OS, as the hazard ratio (>10% vs. <=10%) in patients with chemotherapy was 0.48 with a 95% confidence interval of [0.19-1.19]. Further, the HR of patients treated without chemotherapy was 3.72 with a 95% confidence interval of [1.16-11.96] (pinteraction=0.007). Higher Ki-67 index was not associated with outcome and using the 10% Ki-67 cut-off there was an opposite association for patients with and without chemotherapy. Ki-67 assessments with IHC significantly correlated with MammaTyper results (p=0.002). The exact counting method (A) performed via a light-microscope revealed the predictive value of Ki-67 assessment with a 10% cut-off value. Further analyses employing image analyses and/or mRNA-based-assessments in larger populations are warranted.

A Cost-Effectiveness Analysis of Nivolumab versus Docetaxel for Advanced Nonsquamous NSCLC Including PD-L1 Testing.

INTRODUCTION: Nivolumab (NIV) was recently approved in several countries for patients with pretreated advanced NSCLC. NIV is not cost-effective compared with docetaxel (DOC) for the treatment of squamous NSCLC. However, its cost-effectiveness for nonsquamous NSCLC and the consequences of programmed death ligand 1 (PD-L1) testing are unknown. METHODS: This literature-based health economic study used CheckMate-057 trial data to model the incremental cost-effectiveness ratio (ICER) of NIV versus DOC in the Swiss health care setting. The effect of PD-L1 positivity for patient selection was assessed. RESULTS: In the base case model, NIV (mean cost CHF66,208; mean effect 0.69 quality-adjusted life-years [QALYs]) compared with DOC (mean cost CHF37,618; mean effect 0.53 QALYs) resulted in an ICER of CHF177,478/QALY gained. Treating only patients with PD-L1-positive tumors (threshold ≥10%) with NIV compared with treating all patients with DOC produced a base case ICER of CHF124,891/QALY gained. Reduced drug price, dose, or treatment duration decreased the ICER partly below a willingness-to-pay threshold of CHF100,000/QALY. Health state utilities strongly influenced cost-effectiveness. CONCLUSIONS: Compared with DOC, NIV is not cost-effective for the treatment of nonsquamous NSCLC at current prices in the Swiss health care setting. Price reduction or PD-L1 testing and selection of patients for NIV on the basis of test positivity improves cost-effectiveness compared with DOC.

Standardization for Ki-67 assessment in moderately differentiated breast cancer. A retrospective analysis of the SAKK 28/12 study.

BACKGROUND: Proliferative activity (Ki-67 Labelling Index) in breast cancer increasingly serves as an additional tool in the decision for or against adjuvant chemotherapy in midrange hormone receptor positive breast cancer. Ki-67 Index has been previously shown to suffer from high inter-observer variability especially in midrange (G2) breast carcinomas. In this study we conducted a systematic approach using different Ki-67 assessments on large tissue sections in order to identify the method with the highest reliability and the lowest variability. MATERIALS AND METHODS: Five breast pathologists retrospectively analyzed proliferative activity of 50 G2 invasive breast carcinomas using large tissue sections by assessing Ki-67 immunohistochemistry. Ki-67-assessments were done on light microscopy and on digital images following these methods: 1) assessing five regions, 2) assessing only darkly stained nuclei and 3) considering only condensed proliferative areas ('hotspots'). An individual review (the first described assessment from 2008) was also performed. The assessments on light microscopy were done by estimating. All measurements were performed three times. Inter-observer and intra-observer reliabilities were calculated using the approach proposed by Eliasziw et al. Clinical cutoffs (14% and 20%) were tested using Fleiss' Kappa. RESULTS: There was a good intra-observer reliability in 5 of 7 methods (ICC: 0.76-0.89). The two highest inter-observer reliability was fair to moderate (ICC: 0.71 and 0.74) in 2 methods (region-analysis and individual-review) on light microscopy. Fleiss'-kappa-values (14% cut-off) were the highest (moderate) using the original recommendation on light-microscope (Kappa 0.58). Fleiss' kappa values (20% cut-off) were the highest (Kappa 0.48 each) in analyzing hotspots on light-microscopy and digital-analysis. No methodologies using digital-analysis were superior to the methods on light microscope. CONCLUSION: Our results show that all methods on light-microscopy for Ki-67 assessment in large tissue sections resulted in a good intra-observer reliability. Region analysis and individual review (the original recommendation) on light-microscopy yielded the highest inter-observer reliability. These results show slight improvement to previously published data on poor-reproducibility and thus might be a practical-pragmatic way for routine assessment of Ki-67 Index in G2 breast carcinomas.

Using the EuroQol EQ-5D in Swiss cancer patients, which value set should be applied?

BACKGROUND: The European Quality of Life-5 Dimensions (EQ-5D) instrument combines questionnaire responses into a single utility estimate using country-specific value sets. Countries without a national value set are advised to select one based on geographic proximity. In the absence of a Swiss value set, we used foreign value sets to gain insights into their appropriateness for use with Swiss cancer patients. METHODS: EQ-5D health states and visual analogue scale (VAS) ratings were collected in one German and three Swiss oncology trials. Utilities were calculated based on the United Kingdom (UK), German (GE), French (FR) and European Union (EU) value sets. Resulting differences and Pearson partial correlation coefficients with corresponding VAS ratings were assessed. RESULTS: In total, 202 Swiss and 154 German patients undergoing cancer treatment completed at least two EQ-5D forms. The mean difference between GE-based and FR-, UK- or EU-based utilities was significantly larger than the differences between the latter. The absolute mean difference between utilities and VAS ratings was highest for GE-based utilities, for Swiss (0.170, 95 % confidence interval [CI] 0.146-0.194) and German patients (0.174, 95 % CI 0.145-0.202). The correlation between GE-based utilities and VAS ratings was the lowest (r = 0.36, 95 % CI 0.33-0.40); the highest was between FR-based utilities and VAS ratings (r = 0.43, 95 % CI 0.39-0.46). CONCLUSION: For Switzerland, utility calculations based on the German or French value set would be an obvious choice. Our results suggest that the German value set may not be the most appropriate for use with Swiss cancer patients. The French and EU value sets may be relevant alternatives and improve international comparability.