Adjuvant T-DM1 versus trastuzumab in patients with residual invasive disease after neoadjuvant therapy for HER2-positive breast cancer: subgroup analyses from KATHERINE.

BACKGROUND: In the KATHERINE study (NCT01772472), patients with residual invasive early breast cancer (EBC) after neoadjuvant chemotherapy (NACT) plus human epidermal growth factor receptor 2 (HER2)-targeted therapy had a 50% reduction in risk of recurrence or death with adjuvant trastuzumab emtansine (T-DM1) versus trastuzumab. Here, we present additional exploratory safety and efficacy analyses. PATIENTS AND METHODS: KATHERINE enrolled HER2-positive EBC patients with residual invasive disease in the breast/axilla at surgery after NACT containing a taxane (± anthracycline, ± platinum) and trastuzumab (± pertuzumab). Patients were randomized to adjuvant T-DM1 (n = 743) or trastuzumab (n = 743) for 14 cycles. The primary endpoint was invasive disease-free survival (IDFS). RESULTS: The incidence of peripheral neuropathy (PN) was similar regardless of neoadjuvant taxane type. Irrespective of treatment arm, baseline PN was associated with longer PN duration (median, 105-109 days longer) and lower resolution rate (∼65% versus ∼82%). Prior platinum therapy was associated with more grade 3-4 thrombocytopenia in the T-DM1 arm (13.5% versus 3.8%), but there was no grade ≥3 hemorrhage in these patients. Risk of recurrence or death was decreased with T-DM1 versus trastuzumab in patients who received anthracycline-based NACT [hazard ratio (HR) = 0.51; 95% confidence interval (CI): 0.38-0.67], non-anthracycline-based NACT (HR = 0.43; 95% CI: 0.22-0.82), presented with cT1, cN0 tumors (0 versus 6 IDFS events), or had particularly high-risk tumors (HRs ranged from 0.43 to 0.72). The central nervous system (CNS) was more often the site of first recurrence in the T-DM1 arm (5.9% versus 4.3%), but T-DM1 was not associated with a difference in overall risk of CNS recurrence. CONCLUSIONS: T-DM1 provides clinical benefit across patient subgroups, including small tumors and particularly high-risk tumors and does not increase the overall risk of CNS recurrence. NACT type had a minimal impact on safety.

A randomised phase II study investigating durvalumab in addition to an anthracycline taxane-based neoadjuvant therapy in early triple-negative breast cancer: clinical results and biomarker analysis of GeparNuevo study.

BACKGROUND: Combining immune-checkpoint inhibitors with chemotherapy yielded an increased response rates in patients with metastatic triple-negative breast cancer (TNBC). Therefore, we evaluated the addition of durvalumab to standard neoadjuvant chemotherapy (NACT) in primary TNBC. PATIENTS AND METHODS: GeparNuevo is a randomised phase II double-blind placebo-controlled study randomising patients with TNBC to durvalumab or placebo given every 4 weeks in addition to nab-paclitaxel followed by standard EC. In the window-phase durvalumab/placebo alone was given 2 weeks before start of nab-paclitaxel. Randomisation was stratified by stromal tumour-infiltrating lymphocyte (sTILs). Patients with primary cT1b-cT4a-d disease, centrally confirmed TNBC and sTILs were included. Primary objective was pathological complete response (pCR) (ypT0 ypN0). RESULTS: A total of 174 patients were randomised, 117 participated in the window-phase. Median age was 49.5 years (range 23-76); 47 patients (27%) were younger than 40 years; 113 (65%) had stage ≥IIA disease, 25 (14%) high sTILs, 138 of 158 (87%) were PD-L1-positive. pCR rate with durvalumab was 53.4% (95% CI 42.5% to 61.4%) versus placebo 44.2% (95% CI 33.5% to 55.3%; unadjusted continuity corrected χ2P = 0.287), corresponding to OR = 1.45 (95% CI 0.80-2.63, unadjusted Wald P = 0.224). Durvalumab effect was seen only in the window cohort (pCR 61.0% versus 41.4%, OR = 2.22, 95% CI 1.06-4.64, P = 0.035; interaction P = 0.048). In both arms, significantly increased pCR (P < 0.01) were observed with higher sTILs. There was a trend for increased pCR rates in PD-L1-positive tumours, which was significant for PD-L1-tumour cell in durvalumab (P = 0.045) and for PD-L1-immune cell in placebo arm (P = 0.040). The most common immune-related adverse events were thyroid dysfunction any grade in 47%. CONCLUSIONS: Our results suggest that the addition of durvalumab to anthracycline-/taxane-based NACT increases pCR rate particularly in patients treated with durvalumab alone before start of chemotherapy. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT02685059.

Survival analysis of carboplatin added to an anthracycline/taxane-based neoadjuvant chemotherapy and HRD score as predictor of response-final results from GeparSixto.

Background: In the neoadjuvant GeparSixto study, adding carboplatin to taxane- and anthracycline-based chemotherapy improved pathological complete response (pCR) rates in patients with triple-negative breast cancer (TNBC). Here, we present survival data and the potential prognostic and predictive role of homologous recombination deficiency (HRD). Patients and methods: Patients were randomized to paclitaxel plus nonpegylated liposomal doxorubicin (Myocet®) (PM) or PM plus carboplatin (PMCb). The secondary study end points disease-free survival (DFS) and overall survival (OS) were analyzed. Median follow-up was 47.3 months. HRD was among the exploratory analyses in GeparSixto and was successfully measured in formalin-fixed, paraffin-embedded tumor samples of 193/315 (61.3%) participants with TNBC. Homologous recombination (HR) deficiency was defined as HRD score ≥42 and/or presence of tumor BRCA mutations (tmBRCA). Results: A significantly better DFS (hazard ratio 0.56, 95% CI 0.34-0.93; P = 0.022) was observed in patients with TNBC when treated with PMCb. The improvement of OS with PMCb was not statistically significant. Additional carboplatin did not improve DFS or OS in patients with HER2-positive tumors. HR deficiency was detected in 136 (70.5%) of 193 triple-negative tumors, of which 82 (60.3%) showed high HRD score without tmBRCA. HR deficiency independently predicted pCR (ypT0 ypN0) [odds ratio (OR) 2.60, 95% CI 1.26-5.37, P = 0.008]. Adding carboplatin to PM significantly increased the pCR rate from 33.9% to 63.5% in HR deficient tumors (P = 0.001), but only marginally in HR nondeficient tumors (from 20.0% to 29.6%, P = 0.540; test for interaction P = 0.327). pCR rates with carboplatin were also higher (63.2%) than without carboplatin (31.7%; OR 3.69, 1.46-9.37, P = 0.005) in patients with high HRD score but no tmBRCA. DFS rates were improved with addition of carboplatin, both in HR nondeficient (hazard ratio 0.44, 0.17-1.17, P = 0.086) and HR deficient tumors (hazard ratio 0.49, 0.23-1.04, P = 0.059). Conclusions: The addition of carboplatin to neoadjuvant PM improved DFS significantly in TNBC. Long-term survival analyses support the neoadjuvant use of carboplatin in TNBC. HR deficiency in TNBC and HRD score in non-tmBRCA TNBC are predictors of response. HRD does not predict for carboplatin benefit.

Ten-year results of intense dose-dense chemotherapy show superior survival compared with a conventional schedule in high-risk primary breast cancer: final results of AGO phase III iddEPC trial.

Background: Primary breast cancer (BC) patients with extensive axillary lymph-node involvement have a limited prognosis. The Arbeitsgemeinschaft fuer Gynaekologische Onkologie (AGO) trial compared intense dose-dense (idd) adjuvant chemotherapy with conventionally scheduled chemotherapy in high-risk BC patients. Here we report the final, 10-year follow-up analysis. Patients and methods: Enrolment took place between December 1998 and April 2003. A total of 1284 patients with 4 or more involved axillary lymph nodes were randomly assigned to receive 3 courses each of idd sequential epirubicin, paclitaxel and cyclophosphamide (iddEPC) q2w or standard epirubicin/cyclophosphamide followed by paclitaxel (EC â†’ P) q3w. Event-free survival (EFS) was the primary end point. Results: A total of 658 patients were assigned to receive iddEPC and 626 patients were assigned to receive EC â†’ P. The median duration of follow-up was 122 months. EFS was 47% (95% CI 43% to 52%) in the standard group and 56% (95% CI 52% to 60%) in the iddEPC group [hazard ratio (HR) 0.74, 95% CI 0.63-0.87; log-rank P = 0.00014, one-sided]. This benefit was independent of menopausal, hormone receptor or HER2 status. Ten-year overall survival (OS) was 59% (95% CI 55% to 63%) for patients in the standard group and 69% (95% CI 65% to 73%) for patients in the iddEPC group (HR = 0.72, 95% CI 0.60-0.87; log-rank P = 0.0007, two-sided). Nine versus two cases of secondary myeloid leukemia/myelodysplastic syndrome were observed in the iddEPC and the EC â†’ P arm, respectively. Conclusion: The previously reported OS benefit of iddEPC in comparison to conventionally dosed EC â†’ P has been further increased and achieved an absolute difference of 10% after 10 years of follow-up.

Expression of Cyclin D1 protein in residual tumor after neoadjuvant chemotherapy for breast cancer.

PURPOSE: Hormone receptor (HR)-positive breast cancer (BC) shows a poor response to neoadjuvant chemotherapy (NACT). New treatment targets like the Cyclin D1-CDK4/CDK6 complex are promising adjuvant/post-neoadjuvant therapeutic strategies. Evaluating Cyclin D1 overexpression in residual tumor could recognize those patients that benefit most from such post-neoadjuvant treatment. In this study, we determined Cyclin D1 expression in residual BC after NACT. Secondary aims were to correlate Cyclin D1 expression levels with clinicopathological parameters and to assess its prognostic value after NACT. METHODS: We retrospectively assessed the nuclear expression of Cyclin D1 on tissue microarrays with residual tumor from 284 patients treated in the neoadjuvant GeparTrio (n = 186) and GeparQuattro (n = 98) trials. Evaluation was performed with a standardized immunoreactive score (IRS) after selecting a cut-off value. RESULTS: A high expression level (IRS ≥ 6) of Cyclin D1 was found in 37.3% of the assessed specimens. An increased Cyclin D1 expression was observed in HR-positive tumors, compared to HR-negative tumors (p = 0.02). Low Cyclin D1 levels correlated with clinical tumor stage 1-3 (p = 0.03). Among patients with HR-positive/Her2-negative tumors and high Cyclin D1 expression, a better disease-free survival (DFS) was graphically suggested, but not significant (p = 0.21). CONCLUSION: Our study demonstrates a measurable nuclear expression of Cyclin D1 in post-neoadjuvant residual tumor tissue of HR-positive BC. Cyclin D1 expression was not prognostic for DFS after NACT. Our results and defined cut-off suggest that the marker can be used to stratify tumors according to protein expression levels. Based on this, a prospective evaluation is currently performed in the ongoing Penelope-B trial.

BRCA1-like profile is not significantly associated with survival benefit of non-myeloablative intensified chemotherapy in the GAIN randomized controlled trial.

PURPOSE: The BRCA1-like profile identifies tumors with a defect in homologous recombination due to inactivation of BRCA1. This profile has been shown to predict which stage III breast cancer patients benefit from myeloablative, DNA double-strand-break-inducing chemotherapy. We tested the predictive potential of the BRCA1-like profile for adjuvant non-myeloablative, intensified dose-dense chemotherapy in the GAIN trial. METHODS: Lymph node positive breast cancer patients were randomized to 3 × 3 dose-dense cycles of intensified epirubicin, paclitaxel, and cyclophosphamide (ETC) or 4 cycles concurrent epirubicin and cyclophosphamide followed by 10 cycles of weekly paclitaxel combined with 4 cycles capecitabine (EC-TX). Only triple negative breast cancer patients (TNBC) for whom tissue was available were included in these planned analyses. BRCA1-like or non-BRCA1-like copy number profiles were derived from low coverage sequencing data. RESULTS: 119 out of 163 TNBC patients (73%) had a BRCA1-like profile. After median follow-up of 83 months, disease free survival (DFS) was not significantly different between BRCA1-like and non-BRCA1-like patients [adjusted hazard ratio (adj.HR) 1.02; 95% confidence interval (CI) 0.55-1.86], neither was overall survival (OS; adj.HR 1.26; 95% CI 0.58-2.71). When split by BRCA1-like status, DFS and OS were not significantly different between treatments. However, EC-TX seemed to result in a trend to an improvement in DFS in patients with a BRCA1-like tumor, while the reverse accounted for ETC treatment in patients with a non-BRCA1-like tumor (p for interaction = 0.094). CONCLUSIONS: The BRCA1-like profile is not associated with survival benefit for a non-myeloablative, intensified regimen in this study population. Considering the limited cohort size, capecitabine might have additional benefit for TNBC patients.

German Adjuvant Intergroup Node-positive Study (GAIN): a phase III trial comparing two dose-dense regimens (iddEPC versus ddEC-PwX) in high-risk early breast cancer patients.

BACKGROUND: Dose-dense (dd) regimens are one of the preferred options for the adjuvant treatment of breast cancer patients with intermediate to high risk. The German Adjuvant Intergroup Node-positive trial aimed at optimizing intense dd (idd) strategies by evaluating drug combinations and the addition of capecitabine. PATIENTS AND METHODS: Women (aged 18 years and biologically <65 years) with histologically involved axillary lymph nodes were randomly assigned to receive three courses each of epirubicin (E) 150 mg/m2, paclitaxel (P) 225 mg/m2 and cyclophosphamide (C) 2500 mg/m2 (reduced to 2000 mg/m2 after recruitment of 1200 patients) q2w intravenously (i.v.) (iddEPC-regimen) or ddEC (E 112.5 mg/m2 + C 600 mg/m2, i.v. q2w for 4 cycles) followed by paclitaxel weekly (Pw 67.5 mg/m2 i.v. q8d for 10 weeks) plus capecitabine (X 2000 mg/m2 p.o. days 1-14, q22 for 4 cycles) (ddEC-PwX-regimen). Further randomization assigned patients to ibandronate for 2 years versus observation and to pegfilgrastim day 2 versus 4. RESULTS: From June 2004 to August 2008, 2994 patients were randomized to either iddEPC (N = 1498), or ddEC-PwX (N = 1496) and started treatment. Median age was 50 years; pN1 (37.8%), pN2 (35.3%); pN3 (26.9%); 46.4% were G3 tumors; 76.9% hormone receptor-positive and 22% HER2-positive. After a median follow-up of 74 months, 645 events and 383 deaths were recorded. Hematological adverse events grades 3-4 were more common with iddEPC (P < 0.001), nonhematological with ddEC-PwX (P = 0.04), even if the toxicity profile of the two regimens was different. At 5 years, estimated disease-free survival rates for ddEC-PwX and iddEPC were 81.7% [95% confidence interval (CI) 79.5-83.6] versus 80.2% (95% CI 78.0-82.2). Hazard ratio (HR)=0.95 (95% CI 0.81-1.11, log-rank P = 0.49). Five-year overall survival rates were 89.4% for ddEC-PwX (95% CI 87.7-91.0) and 89.0% for iddEPC (95% CI 87.2-90.6), HR = 0.85 (95% CI 0.69-1.04, log-rank P = 0.10). CONCLUSION: Adding capecitabine to ddEC-Pw did not improve outcome in comparison to iddEPC but increased toxicity and should not be recommended for further use.

Dual HER2-blockade with pertuzumab and trastuzumab in HER2-positive early breast cancer: a subanalysis of data from the randomized phase III GeparSepto trial.

Background: The neoadjuvant phase III GeparSepto study showed that substituting nab-paclitaxel for standard solvent-based paclitaxel significantly improved the pathologic complete response (pCR) rate achieved with a sequential neoadjuvant chemotherapy regimen of paclitaxel, epirubicin, and cyclophosphamide for high-risk primary breast cancer. Recent trials demonstrated that in HER2+ breast cancer pCR can be increased by using pertuzumab in addition to trastuzumab and chemotherapy. The present analysis focuses on efficacy and safety data from the subset of patients with HER2+ tumors from the GeparSepto trial (n = 396) in comparison to the HER2- cohort. Patients and methods: Patients with histologically confirmed breast cancer (n = 1206) received four cycles of weekly paclitaxel [either solvent-based (Pac) or nab-paclitaxel (nab-Pac), according to randomization] followed by 4 cycles of epirubicin 90 mg/m2 plus cyclophosphamide 600 mg/m2 q3w, with concurrent trastuzumab and pertuzumab q3w for those with HER2+ tumors. The primary endpoint was pCR defined as ypT0 ypN0. Results: Higher rates of pCR were achieved in HER2+ than in HER2- tumors (57.8% versus 22.0%, P < 0.0001), with the highest rate in the HER2+/HR- cohort (71.0%; 66.7% Pac, 74.6% nab-Pac). In HER2+/HR+ tumors, the pCR rate was 52.9% (49.7% Pac, 56.4% nab-Pac). Grade ≥3 toxic effects were significantly more common in HER2+ than in HER2- patients, with grade 3-4 diarrhea in 7.6% versus 0.9% (P < 0.001) and febrile neutropenia in 6.3% versus 3.3% (P = 0.023) of patients. Left ventricular ejection fraction decreases from baseline were uncommon, with 2.0% versus 0.4% of patients showing decreases to <50% along with a ≥10% decrease from baseline. Conclusion: In HER2+ early breast cancer, a dual HER2-targeted combination of pertuzumab and trastuzumab, together with taxane-epirubicin-cyclophosphamide neoadjuvant chemotherapy, achieved high rates of pCR.

Higher rate of severe toxicities in obese patients receiving dose-dense (dd) chemotherapy according to unadjusted body surface area: results of the prospectively randomized GAIN study.

BACKGROUND: In routine clinical practice, chemotherapy doses are frequently capped at a body surface area (BSA) of 2.0 m2 or adjusted to an ideal weight for obese patients due to safety reasons. MATERIALS AND METHODS: Between August 2004 and July 2008, a total of 3023 patients were enrolled in the GAIN study, a randomized phase III adjuvant trial, comparing two types of dose-dense (dd) regimen [epirubicin, docetaxel and cyclophosphamide (iddETC) versus epirubicin and cyclophosphamide (EC) followed by docetaxel (T) plus capecitabine (X)]. We retrospectively evaluated a total of 555 patients with a BMI of ≥30 for safety and outcome. RESULTS: Eighteen percent of all patients were obese: 31% of those received chemotherapy according to an unadjusted BSA. For the remaining patients, BSA was adjusted to ideal weight or was capped at 2.0 m2. A total of 15% of obese patients receiving full (unadjusted) dose of chemotherapy versus 6% of obese patients with an adjusted BSA experienced febrile neutropenia (P = 0.003) and 9% versus 3% high-grade thrombopenia (P = 0.002). Overall, 17% versus 10% had a thromboembolic event (P = 0.017), which was high grade in 13% versus 6%, respectively (P = 0.019), and 3% versus 0.3% high-grade hot flushes (P = 0.013). Dizziness (5% versus 11%; P = 0.016), diarrhea (19% versus 27%; P = 0.033) and an increase in serum creatinine (7% versus 14%; P = 0.019) were higher in the adjusted group. However, no differences in disease-free survival (DFS) and overall survival (OS) were observed between non-obese patients, obese patients receiving full-dose chemotherapy or according to an adjusted BSA [5-year DFS 81% (confidence interval 79% to 83%) versus 82% (75% to 87%) versus 81% (76% to 84%); P = 0.761; 5-year OS 90% (88% to 91%) versus 86% (80% to 91%) versus 88% (84% to 91%); P = 0.143]. CONCLUSION: Obese patients receiving dd chemotherapy according to their real BSA have a higher risk of developing severe toxicities without influencing survival. Therefore, a dose adjustment of intense dd chemotherapy should be carried out to avoid life-threatening complications.

Final results of the TANIA randomised phase III trial of bevacizumab after progression on first-line bevacizumab therapy for HER2-negative locally recurrent/metastatic breast cancer.

BACKGROUND: The randomised phase III TANIA trial demonstrated that continuing bevacizumab with second-line chemotherapy for locally recurrent/metastatic breast cancer (LR/mBC) after progression on first-line bevacizumab-containing therapy significantly improved progression-free survival (PFS) compared with chemotherapy alone [hazard ratio (HR) = 0.75, 95% confidence interval (CI) 0.61-0.93]. We report final results from the TANIA trial, including overall survival (OS) and health-related quality of life (HRQoL). PATIENTS AND METHODS: Patients with HER2-negative LR/mBC that had progressed on or after first-line bevacizumab plus chemotherapy were randomised to receive standard second-line chemotherapy either alone or with bevacizumab. At second progression, patients initially randomised to bevacizumab continued bevacizumab with their third-line chemotherapy, but those randomised to chemotherapy alone were not allowed to cross over to receive third-line bevacizumab. The primary end point was second-line PFS; secondary end points included third-line PFS, combined second- and third-line PFS, OS, HRQoL and safety. RESULTS: Of the 494 patients randomised, 483 received second-line therapy; 234 patients (47% of the randomised population) continued to third-line study treatment. The median duration of follow-up at the final analysis was 32.1 months in the chemotherapy-alone arm and 30.9 months in the bevacizumab plus chemotherapy arm. There was no statistically significant difference between treatment arms in third-line PFS (HR = 0.79, 95% CI 0.59-1.06), combined second- and third-line PFS (HR = 0.85, 95% CI 0.68-1.05) or OS (HR = 0.96, 95% CI 0.76-1.21). Third-line safety results showed increased incidences of proteinuria and hypertension with bevacizumab, consistent with safety results for the second-line treatment phase. No differences in HRQoL were detected. CONCLUSIONS: In this trial, continuing bevacizumab beyond first and second progression of LR/mBC improved second-line PFS, but no improvement in longer term efficacy was observed. The second-line PFS benefit appears to be achieved without detrimentally affecting quality of life. CLINICALTRIALSGOV: NCT01250379.

Zoledronate for patients with invasive residual disease after anthracyclines-taxane-based chemotherapy for early breast cancer - The Phase III NeoAdjuvant Trial Add-oN (NaTaN) study (GBG 36/ABCSG 29).

BACKGROUND: Patients with invasive residual disease after neoadjuvant chemotherapy (NACT) are considered to have chemo-resistant breast cancer. Bisphosphonates are an established treatment for bone metastases and are of potential benefit as adjuvant treatment in early breast cancer. PATIENTS AND METHODS: Patients who had invasive tumour residuals (ypT1-4 and/or ypN+) after a minimum of four cycles of anthracycline-taxane-containing NACT were eligible for the NeoAdjuvant Trial Add-oN study. Patients were randomised within 3 years after surgery to receive zoledronate 4 mg i.v. for 5 years versus observation. Zoledronate was given every 4 weeks for the first 6 months, every 3 months for the following 2 years, and every 6 months for the last 2.5 years. Primary objective was disease-free survival. RESULTS: After a median time of 54.7 months no difference in disease-free survival was observed between the zoledronate and observation groups (hazard ratio [HR] 0.960, 95% confidence interval [CI] 0.709-1.30, log rank P=0.789). Various subgroups were examined without identifying a treatment effect of zoledronate. Patients over 55 years of age showed a HR of 0.832 in favour of zoledronate, but the result was not significant (P=0.480). A similar result was obtained for overall survival with a HR of 1.19 (95% CI 0.79-1.79; log rank P=0.408). Zoledronate was well tolerated and no new toxicity signal was identified. CONCLUSION: Postneoadjuvant treatment with zoledronate does not improve outcome in patients without pathological complete response after neoadjuvant anthracycline-taxane-based chemotherapy for early breast cancer.

PIK3CA mutations are associated with reduced pathological complete response rates in primary HER2-positive breast cancer: pooled analysis of 967 patients from five prospective trials investigating lapatinib and trastuzumab.

BACKGROUND: The predictive value of PIK3CA mutations in HER2 positive (HER2+) breast cancer treated with neoadjuvant anti-HER2 and chemotherapy has been reported, but the power for subgroup analyses was lacking. PATIENTS AND METHODS: We combined individual patient data from five clinical trials evaluating PIK3CA mutations and associations with pathological complete response (pCR), disease-free survival (DFS) and overall survival (OS). Patients received either trastuzumab (T), lapatinib (L) or the combination T/L in addition to a taxane-based chemotherapy. PIK3CA was genotyped in tumour biopsies taken before therapy. RESULTS: A total of 967 patients were included in this analysis; the median follow-up is 47 months. Overall, the pCR rate was significantly lower in the PIK3CA mutant compared with the wild-type group (16.2% versus 29.6%; P < 0.001). Within the hormone-receptor positive (HR+) subgroup, the PIK3CA mutant group had a pCR rate of only 7.6% compared with 24.2% in the wild-type group (P < 0.001). In contrast, in the HER2+/HR- group, there was no difference in pCR (27.2% versus 36.4%; P = 0.125) according to PIK3CA mutation status (interaction test P = 0.036). According to treatment arm, the pCR rate for mutant versus wild-type was 20.3% versus 27.1% for T (P = 0.343), 11.3% versus 16.9% for L (P = 0.369) and 16.7% versus 39.1% for T/L (P < 0.001). In the HR+ T/L group, the pCR rate was 5.5% versus 33.9% (interaction between HR and PIK3CA genotype P = 0.008). DFS and OS were not significantly different by mutation status, though the incidence rate of events was low. However, HR+/PIK3CA mutant patients seemed to have significantly worse DFS {hazard ratio (HR) 1.56 [95% confidence interval (CI) 1.00-2.45], P = 0.050; Pinteraction = 0.021}. T/L tended to improve DFS compared with T in the wild-type cohort, especially in the HR- group [HR 0.72, 95% CI (0.41-1.25), P = 0.242]. CONCLUSION: Overall PIK3CA mutant/HER2+ tumours had significantly lower pCR rates compared with wild-type tumours, however mainly confined to the HR+/PIK3CA mutant population. No definite conclusions can be drawn regarding survival.

Progression-free survival as surrogate end point for overall survival in clinical trials of HER2-targeted agents in HER2-positive metastatic breast cancer.

BACKGROUND: The gold standard end point in randomized clinical trials in metastatic breast cancer (MBC) is overall survival (OS). Although therapeutics have been approved based on progression-free survival (PFS), its use as a primary end point is controversial. We aimed to assess to what extent PFS may be used as a surrogate for OS in randomized trials of anti-HER2 agents in HER2+ MBC. METHODS: Eligible trials accrued HER2+ MBC patients in 1992-2008. A correlation approach was used: at the individual level, to estimate the association between investigator-assessed PFS and OS using a bivariate model and at the trial level, to estimate the association between treatment effects on PFS and OS. Correlation values close to 1.0 would indicate strong surrogacy. RESULTS: We identified 2545 eligible patients in 13 randomized trials testing trastuzumab or lapatinib. We collected individual patient data from 1963 patients and retained 1839 patients from 9 trials for analysis (7 first-line trials). During follow-up, 1072 deaths and 1462 progression or deaths occurred. The median survival time was 22 months [95% confidence interval (CI) 21-23 months] and the median PFS was 5.7 months (95% CI 5.5-6.1 months). At the individual level, the Spearman correlation was equal to ρ = 0.67 (95% CI 0.66-0.67) corresponding to a squared correlation value of 0.45. At the trial level, the squared correlation between treatment effects (log hazard ratios) on PFS and OS was provided by R(2) = 0.51 (95% CI 0.22-0.81). CONCLUSIONS: In trials of HER2-targeted agents in HER2+ MBC, PFS moderately correlates with OS at the individual level and treatment effects on PFS correlate moderately with those on overall mortality, providing only modest support for considering PFS as a surrogate. PFS does not completely substitute for OS in this setting.

Primary Therapy of Patients with Early Breast Cancer: Evidence, Controversies, Consensus: Opinions of German Specialists to the 14th St. Gallen International Breast Cancer Conference 2015 (Vienna 2015).

For the first time, this year's St. Gallen International Consensus Conference on the treatment of patients with primary breast cancer, which takes place every two years, was held not in St. Gallen (Switzerland) but - for logistical reasons - in Vienna (Austria) under its usual name. The 2015 St. Gallen International Consensus Conference was the 14th of its kind. As the international panel of the St. Gallen conference consists of experts from different countries, the consensus mirrors an international cross-section of opinions. From a German perspective, it was considered useful to translate the results of the votes of the St. Gallen conference into practical suggestions, particularly in light of the recently updated treatment guideline of the Gynecologic Oncology Group (AGO-Mamma 2015) in Germany. A German group consisting of 14 breast cancer experts, three of whom are members of the international St. Gallen panel, has therefore provided comments on the results of this year's votes at the 2015 St. Gallen Consensus Conference and their impact on clinical care in Germany. The 14th St. Gallen conference once again focused on surgery of the breast and the axilla, radio-oncologic and systemic treatment options for primary breast cancer depending on tumor biology, and the clinical use of multigene assays. The conference also considered targeted therapies for older and for younger patients, including the diagnosis/treatment of breast cancer during and after pregnancy and the preservation of fertility.

Recommendations for standardized pathological characterization of residual disease for neoadjuvant clinical trials of breast cancer by the BIG-NABCG collaboration.

Neoadjuvant systemic therapy (NAST) provides the unique opportunity to assess response to treatment after months rather than years of follow-up. However, significant variability exists in methods of pathologic assessment of response to NAST, and thus its interpretation for subsequent clinical decisions. Our international multidisciplinary working group was convened by the Breast International Group-North American Breast Cancer Group (BIG-NABCG) collaboration and tasked to recommend practical methods for standardized evaluation of the post-NAST surgical breast cancer specimen for clinical trials that promote accurate and reliable designation of pathologic complete response (pCR) and meaningful characterization of residual disease. Recommendations include multidisciplinary communication; clinical marking of the tumor site (clips); and radiologic, photographic, or pictorial imaging of the sliced specimen, to map the tissue sections and reconcile macroscopic and microscopic findings. The information required to define pCR (ypT0/is ypN0 or ypT0 yp N0), residual ypT and ypN stage using the current AJCC/UICC system, and the Residual Cancer Burden system were recommended for quantification of residual disease in clinical trials.

Expression of secreted protein acidic and rich in cysteine (SPARC) in breast cancer and response to neoadjuvant chemotherapy.

BACKGROUND: Secreted protein acidic and rich in cysteine (SPARC) has been suggested as a new biomarker and therapeutic target in breast cancer, as well as other tumor types. PATIENTS AND METHODS: We evaluated the frequency of SPARC expression among different molecular breast cancer subtypes and its role for therapy response after neoadjuvant chemotherapy. In this study, pretherapeutic core biopsies of 667 patients from the neoadjuvant GeparTrio trial were evaluated for SPARC expression by immunohistochemistry using a standardized immunoreactive score (IRS). RESULTS: An increased SPARC expression (IRS ≥6) was observed in 26% of all tumors. In triple-negative tumors, SPARC expression was increased in 37% of tumors, compared with other molecular subtypes (23% HR+/HER2-, 29% HR+/HER2+ and 22% HR-/HER2+; P = 0.038). Increased SPARC expression was associated with an increased pathological complete response (pCR) rate of 27%, compared with 15% in tumors with low SPARC expression (P < 0.001). In the triple-negative subgroup, pCR rates were 47% in tumors with high SPARC expression, compared with 26% in tumors with low SPARC expression (P = 0.032). In multivariable analysis, SPARC was independently predictive in the overall population (P = 0.010) as well as the triple-negative subgroup (P = 0.036). CONCLUSIONS: SPARC is frequently expressed in breast cancer with triple-negative breast cancer revealing the highest expression rate. High SPARC expression of the primary tumor is associated with a higher chance of achieving a pathological complete remission after TAC or TAC-NX chemotherapy. As SPARC is an albumin-binding protein and might mediate intratumoral accumulation of albumin bound drugs, SPARC should be further evaluated as a predictive marker especially for response to albumin-bound drugs like nab-paclitaxel. CLINICAL TRIAL NUMBER: NCT00544765.

The AURORA initiative for metastatic breast cancer.

Metastatic breast cancer is one of the leading causes of cancer-related mortality among women in the Western world. To date most research efforts have focused on the molecular analysis of the primary tumour to dissect the genotypes of the disease. However, accumulating evidence supports a molecular evolution of breast cancer during its life cycle, with metastatic lesions acquiring new molecular aberrations. Recognising this critical gap of knowledge, the Breast International Group is launching AURORA, a large, multinational, collaborative metastatic breast cancer molecular screening programme. Approximately 1300 patients with metastatic breast cancer who have received no more than one line of systemic treatment for advanced disease will, after giving informed consent, donate archived primary tumour tissue, as well as will donate tissue collected prospectively from the biopsy of metastatic lesions and blood. Both tumour tissue types, together with a blood sample, will then be subjected to next generation sequencing for a panel of cancer-related genes. The patients will be treated at the discretion of their treating physicians per standard local practice, and they will be followed for clinical outcome for 10 years. Alternatively, depending on the molecular profiles found, patients will be directed to innovative clinical trials assessing molecularly targeted agents. Samples of outlier patients considered as 'exceptional responders' or as 'rapid progressors' based on the clinical follow-up will be subjected to deeper molecular characterisation in order to identify new prognostic and predictive biomarkers. AURORA, through its innovative design, will shed light onto some of the unknown areas of metastatic breast cancer, helping to improve the clinical outcome of breast cancer patients.