Phase III randomized multicenter study on the effects of adjuvant CMF in patients with node-negative, rapidly proliferating breast cancer: twelve-year results and retrospective subgroup analysis

Spotlight on Ki67 as a prognostic marker in early breast cancer: all that glitters may not be gold

Kang and colleagues evaluated on a case series of 1848 breast cancer (BC) patients operated for a first primary ER positive HER2 negative BC if Ki67 expression is a significant prognostic factor only when PgR expression is low. The authors concluded that Ki67 with 10% cut off value is a prognostic factor only under low PgR expression level in early BC. We would like to underline, that as already stated in our previous papers, we believe that proliferation is important to define the decision-making of adjuvant therapies in early BC. The issue on Ki67 detection is the poor reproducibility due to different antibody clones, platforms and scoring methods. Not less important is that different Ki67 cut off values have been used by San Gallen guidelines and changed overtime. Then, despite the interesting results, we believe it would be better to use Ki67 biomarker in according to the standard Ki67 cut off according to San Gallen guidelines. Nowadays, standardization and optimization of Ki67 is still an urgent need.

The impact of progesterone receptor expression on prognosis of patients with rapidly proliferating, hormone receptor-positive early breast cancer: a post hoc analysis of the IBIS 3 trial

Background

In the Italian Breast Cancer Intergroup Studies (IBIS) 3 phase III trial, we compared cyclophosphamide, methotrexate, 5-fluorouracil (CMF) alone to sequential epirubicin/CMF regimens in patients with rapidly proliferating early breast cancer (RPEBC). We performed a post hoc analysis in the subgroup of patients with hormone-receptor-positive RPEBC on the prognostic role of progesterone receptor (PgR) status.

Methods

RPEBC was defined by thymidine labeling index (TLI) >3% or grade 3 or S-phase >10% or Ki67 >20%. We analyzed 466 patients with hormone-receptor-positive RPEBC receiving sequential epirubicin/CMF regimens followed by tamoxifen, and for whom the status of ER and PgR was available.

Results

Considering both cut-off values of 10% and 20%, PgR expression was significantly associated with age, menopausal status, and ER expression; HER2 status was associated with PgR status only at a cutoff value of 20% PgR. Upon univariate analysis, tumor size, nodal status, and PgR were significantly associated with disease-free survival (DFS) and overall survival (OS), while age class and local treatment type were associated only with DFS. Patients with PgR <20% showed lower 5- and 10-year DFS [hazard ratio (HR) = 1.48; 95%CI: 1.01-2.18; p = 0.044] and OS (HR = 1.85; 95%CI: 1.08-3.19, p = 0.025) rates compared with patients with PgR ⩾20%. Upon multivariate analysis, only tumor size, nodal status, and PgR were independent prognostic factors.

Conclusions

Our results highlight the independent prognostic relevance of PgR expression in patients with hormone-receptor-positive RPEBC treated with adjuvant chemotherapy and endocrine therapy, where the definition of prognostic subgroups is still a major need.

Effectiveness of an Adjuvant Chemotherapy Regimen for Early-Stage Breast Cancer: A Systematic Review and Network Meta-analysis

IMPORTANCE

Different adjuvant chemotherapy regimens are available for early-stage breast cancer. Because conventional meta-analysis does not allow comparing all regimens, we performed a network meta-analysis to identify the most effective adjuvant chemotherapy regimen.

OBJECTIVE

To find the most effective adjuvant therapy regimen for early-stage breast cancer.

DATA SOURCES

We searched MEDLINE, Embase, and the Cochrane Library for articles published before June 2015; the American Society of Clinical Oncology annual meeting abstracts from January 1983 through December 2014; and the American Association for Cancer Research annual meeting abstracts from January 1916 through December 2014. Additionally, we manually searched bibliographies for related references.

STUDY SELECTION

We included randomized clinical trials of adjuvant treatments for early-stage breast cancer that compared 2 or more of the following: no adjuvant chemotherapy; sequential anthracycline-cyclophosphamide and taxane (AC-T); concurrent anthracycline-cyclophosphamide and taxane (ACT); anthracycline-cyclophosphamide without taxane (AC); docetaxel and cyclophosphamide (TC); cyclophosphamide, methotrexate, and fluorouracil (CMF); and platinum-containing regimens.

DATA EXTRACTION AND SYNTHESIS

We followed the PRISMA guidelines. Two investigators independently selected the articles and extracted information. Disagreements were resolved by discussion with another author. Quality was assessed by Cochrane risk-of-bias method. Data were pooled using random-effects models.

MAIN OUTCOMES AND MEASURES

We used network meta-analysis to test the most effective adjuvant therapy regimen in terms of overall survival (OS) by comparing regimens listed in the National Comprehensive Cancer Network guidelines and platinum-containing regimens.

RESULTS

We identified 24 trials. The TC and platinum-containing regimens had OS benefit similar to that of sequential AC-T (TC hazard ratio [HR], 0.93; 95% CI, 0.62-1.40; and platinum HR, 0.93; 95% CI, 0.66-1.31). Patients treated with CMF or AC had significantly worse OS than those treated with sequential AC-T (CMF HR, 1.56; 95% CI, 1.32-1.85; and AC HR, 1.22; 95% CI, 1.10-1.37). Platinum-containing regimens tended to be more toxic than sequential AC-T. The toxicity of TC was similar to or less than that of sequential AC-T. Meta-regression analysis showed that hormone receptor status did not impact the HRs for OS for any regimen.

CONCLUSIONS AND RELEVANCE

Sequential AC-T is likely to be the most effective adjuvant therapy regimen for early-stage breast cancer regardless of hormone receptor status.

Adjuvant chemotherapy for early female breast cancer: a systematic review of the evidence for the 2014 Cancer Care Ontario systemic therapy guideline

BACKGROUND

The Program in Evidence-Based Care (pebc) of Cancer Care Ontario recently created an evidence-based consensus guideline on the systemic treatment of early breast cancer. The evidence for the guideline was compiled using a systematic review to answer the question "What is the optimal systemic therapy for patients with early-stage, operable breast cancer, when patient and disease factors are considered?" The question was addressed in three parts: cytotoxic chemotherapy, endocrine treatment, and human epidermal growth factor receptor 2 (her2)-directed therapy.

METHODS

For the systematic review, the medline and embase databases were searched for the period January 2008 to May 2014. The Standards and Guidelines Evidence directory of cancer guidelines and the Web sites of major oncology guideline organizations were also searched. The basic search terms were "breast cancer" and "systemic therapy" (chemotherapy, endocrine therapy, targeted agents, ovarian suppression), and results were limited to randomized controlled trials (rcts), guidelines, systematic reviews, and meta-analyses.

RESULTS

Several hundred documents that met the inclusion criteria were retrieved. The Early Breast Cancer Trialists' Collaborative Group meta-analyses encompassed many of the rcts found. Several additional studies that met the inclusion criteria were retained, as were other guidelines and systematic reviews. Chemotherapy was reviewed mainly in three classes: anti-metabolite-based regimens (for example, cyclophosphamide-methotrexate-5-fluorouracil), anthracyclines, and taxane-based regimens. In general, single-agent chemotherapy is not recommended for the adjuvant treatment of breast cancer in any patient population. Anthracycline-taxane-based polychemotherapy regimens are, overall, considered superior to earlier-generation regimens and have the most significant impact on patient survival outcomes. Regimens with varying anthracycline and taxane doses and schedules are options; in general, paclitaxel given every 3 weeks is inferior. Evidence does not support the use of bevacizumab in the adjuvant setting; other systemic therapy agents such as metformin and vaccines remain investigatory. Adjuvant bisphosphonates for menopausal women will be discussed in later work.

CONCLUSIONS

The results of this systematic review constitute a comprehensive compilation of the high-level evidence that is the basis for the 2014 pebc guideline on systemic therapy for early breast cancer. Use of cytotoxic chemotherapy is presented here; the results addressing endocrine therapy and her2-targeted treatment, and the final clinical practice recommendations, are published separately in this supplement.

The combination of Ki67, histological grade and estrogen receptor status identifies a low-risk group among 1,854 chemo-naïve women with N0/N1 primary breast cancer

Background

The aim was to confirm a previously defined prognostic index, combining a proliferation marker, histological grade, and estrogen receptor (ER) in different subsets of primary N0/N1 chemo-naïve breast cancer patients.

Methods/design

In the present study, including 1,854 patients, Ki67 was used in the index (KiGE), since it is the generally accepted proliferation marker in clinical routine. The low KiGE-group was defined as histological grade 1 patients and grade 2 patients which were ER-positive and had low Ki67 expression. All other patients made up the high KiGE-group. The KiGE-index separated patients into two groups with different prognosis. In multivariate analysis, KiGE was significantly associated with disease-free survival, when adjusted for age at diagnosis, tumor size and adjuvant endocrine treatment (hazard ratio: 3.5, 95% confidence interval: 2.6–4.7, P<0.0001).

Discussion

We have confirmed a prognostic index based on a proliferation marker (Ki67), histological grade, and ER for identification of a low-risk group of patients with N0/N1 primary breast cancer. For this low-risk group constituting 57% of the patients, with a five-year distant disease-free survival of 92%, adjuvant chemotherapy will have limited effect and may be avoided.