Use and Impact of the 21-Gene Recurrence Score in Relation to the Clinical Risk of Developing Metastases in Early Breast Cancer Patients in the Netherlands

Comparing Genetic Risk and Clinical Risk Classification in Luminal-like Breast Cancer Patients Using a 23-Gene Classifier

Background: A 23-gene classifier has been developed based on gene expression profiles of Taiwanese luminal-like breast cancer. We aim to stratify risk of relapse and identify patients who may benefit from adjuvant chemotherapy based on genetic model among distinct clinical risk groups. Methods: There were 248 luminal (hormone receptor-positive and human epidermal growth factor receptor II-negative) breast cancer patients with 23-gene classifier results. Using the modified Adjuvant! Online definition, clinical high/low-risk groups were tabulated with the genetic model. The primary endpoint was a recurrence-free interval (RFI) at 5 years. Results: There was a significant difference between the high/low-risk groups defined by the 23-gene classifier for the 5-year prognosis of recurrence (16 recurrences in high-risk and 3 recurrences in low-risk; log-rank test: p < 0.0001). Among the clinically high-risk group, the 5-year RFI of high risk defined by the 23-gene classifier was significantly higher than that of the low-risk group (15 recurrences in high-risk and 2 recurrences in low-risk; log-rank test: p < 0.0001). Conclusion: This study showed that 23-gene classifier can be used to stratify clinically high-risk patients into distinct survival patterns based on genomic risks and displays the potentiality to guide adjuvant chemotherapy. The 23-gene classifier can provide a better estimation of breast cancer prognosis which can help physicians make a better treatment decision.

Rate and predictors of nodal pathological complete response following neoadjuvant endocrine treatment in clinically biopsy-proven node-positive breast cancer patients

BACKGROUND

Data on effectiveness and optimal use of neoadjuvant endocrine therapy (NET) in clinically biopsy-proven node-positive breast cancer is lacking. This study examined the incidence of axillary pathological complete response (pCR) on NET in clinically biopsy-proven node-positive breast cancer patients. Secondary, patient and tumour characteristics, as well as the optimal duration of NET in relation to the occurrence of axillary pCR were investigated.

MATERIAL AND METHODS

Patients diagnosed with primary hormone receptor positive, HER2 negative breast cancer between 2014 and 2019, with at least one positive axillary lymph node (pathologically proven), treated with NET were selected from the Netherlands Cancer Registry. The incidence of axillary pCR in combination with patient, tumour and treatment characteristics was analysed.

RESULTS

In a population of 561 patients, an axillary pCR of 7.3% on NET was observed. Median length of treatment was 8.1 months in the patients without vs. 8.8 months in those with axillary pCR, with no statistically significant difference. A p-value <0.30 was found for age, histologic type, clinical tumour status, hormone receptor status and the type of NET in univariable analysis. After multivariable logistic regression analyses, none of these variables were independently associated with the likelihood of an axillary pCR.

CONCLUSION

The rate of axillary pCR after NET in HR + HER2-clinically biopsy-proven node-positive breast cancer patients is low. Factors independently associated with the likelihood of an axillary pCR could not be identified. More research is warranted regarding optimizing the duration of NET and the prognostic value of residual disease in the axilla after NET.

Personalised medicine and the decision to withhold chemotherapy in early breast cancer with intermediate risk of recurrence - a systematic review and meta-analysis

PURPOSE

To assess the evidence for decision making, at the health care and the patient levels, regarding the use of gene expression assays to inform chemotherapy decisions in breast cancer patients with intermediate clinical risk of recurrence.

METHODS

Systematic literature searches were performed (January 2002-April 2020) in Medline, Embase, PubMed, Cochrane Library, PsycINFO and HTA databases.

INCLUSION CRITERIA

patients (P) were individuals with post-surgical breast cancer at intermediate clinical risk of recurrence; intervention (I)/comparison (C) was (i) use of, versus no use of, a gene expression assay and (ii) withholding versus providing chemotherapy; outcomes (O) were overall survival (OS), health-related quality of life (HRQL), and recurrence. Randomised controlled trials (RCTs) and non-RCTs were included. Random-effects meta-analyses were performed where possible.

RESULTS

Three inconclusive non-RCTs, respectively, compared OS and recurrence with and without a gene expression assay. No studies investigated HRQL. Regarding the comparison withholding versus providing chemotherapy based on a gene expression assay, one RCT and four non-RCTs evaluated OS. In the RCT, 93.9% (I) versus 93.8% (C) were alive at 9 years. Three RCTs and seven non-RCTs evaluated recurrence. Three RCTs could be pooled regarding distant recurrence; 4.29% versus 3.88% had such an event (risk ratio: 1.12 (95% confidence interval: 0.90 to 1.39).

CONCLUSION

Regarding the use of gene expression assays in breast cancer, evidence on patient effects, informing patient-level chemotherapy decision making, is available. However, evidence for prioritisation at the overall health care level, i.e. use of, versus no use of, such assays, is largely lacking.

Comparison of 21-gene assay and St.Gallen International Expert Consensus in the treatment decision for patients with early invasive breast cancers

This study aimed to evaluate the impacts of 21-gene recurrence score (RS) and St. Gallen International Expert Consensus on treatment decision and prognosis of patients with invasive breast cancer. We retrospectively analyzed the therapy protocol and outcome of 134 cases based on age, body mass index (BMI), menopause, pathological types, tumor-node-metastasis (TNM) stages, percentage of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor 2 (HER2), Ki-67, molecular subtype, and tumor biomarkers. RS was calculated based on 21-gene assay following traditional (old RS cutoff) and updated (new RS cutoff) National Comprehensive Cancer Network (NCCN) guideline. In addition, we also compared treatment protocol of NCCN guidelines with St. Gallen International Expert Consensus. The results showed that BMI, PR, Ki-67, and molecular subtype are critical for the evaluation of risk factors. Based on the new cutoff, low, middle, and high RS were 18%, 66%, and 16%, respectively. In contrast, based on the old cutoff, low, middle, and high RS were 60%, 29%, and 11%, respectively. The agreement rate of NCCN guidelines and St. Gallen International Expert Consensus for adjuvant treatment was 50. However, there is minimal agreement (0.151, 0.071) in kappa coefficient of old and new cutoff. This study revealed that the combination of NCCN guidelines and St. Gallen International Expert Consensus might improve the benefits of adjuvant treatment in patients with early invasive breast cancer.