Value of the 21-gene expression assay in predicting locoregional recurrence rates in estrogen receptor-positive breast cancer: a systematic review and network meta-analysis

Risk of locoregional recurrence after breast cancer surgery by molecular subtype-a systematic review and network meta-analysis

BACKGROUND

The prevention of locoregional recurrence (LRR) is crucial in breast cancer, as it translates directly into reduced breast cancer-related death. Breast cancer is subclassified into distinct intrinsic biological subtypes with varying clinical outcomes.

AIMS

To perform a systematic review and network meta-analysis (NMA) to determine the rate of LRR by breast cancer molecular subtype.

METHODS

A NMA was performed as per PRISMA-NMA guidelines. Molecular subtypes were classified by St Gallen expert consensus statement (2013). Analysis was performed using R and Shiny.

RESULTS

Five studies were included including 6731 patients whose molecular subtypes were available. Overall, 47.3% (3182/6731) were Luminal A (LABC: estrogen receptor (ER) + /human epidermal growth factor receptor-2 (HER2) - /progesterone receptor (PR) + or Ki-67 < 20%), 25.5% (1719/6731) were Luminal B (LBBC: ER + /HER2 - /PR - or Ki-67 ≥ 20%), 11.2% (753/6731) were Luminal B-HER2 + (LBBC-HER2: ER + /HER2 +), 6.9% (466/6731) were HER2 + (HER2 ER - /HER2 +), and finally 9.1% (611/6731) were triple-negative breast cancer (TNBC: ER - /HER2 -). The median follow-up was 74.0 months and the overall LRR rate was 4.0% (271/6731). The LRR was 1.7% for LABC (55/3182), 5.1% for LBBC (88/1719), 6.0% for LBBC-HER2 (45/753), 6.0% for HER2 (28/466), and 7.9% for TNBC (48/611). At NMA, patients with TNBC (odds ratio (OR) 3.73, 95% confidence interval (CI) 1.80-7.74), HER2 (OR 3.24, 95% CI 1.50-6.99), LBBC-HER2 (OR 2.38, 95% CI 1.09-5.20), and LBBC (OR 2.20, 95% CI 1.07-4.50) were significantly more likely to develop LRR compared to LABC.

CONCLUSION

TNBC and HER2 subtypes are associated with the highest risk of LRR. Multidisciplinary team discussions should consider these findings to optimize locoregional control following breast cancer surgery.

21-gene recurrence score in predicting the outcome of postoperative radiotherapy in T1-2N1 luminal breast cancer after breast-conserving surgery

BACKGROUND

In those with one to three positive lymph nodes (N1) breast cancer (BC), the 21-gene recurrence score (RS) classification can be referred for decision-making on adjuvant chemotherapy. This study aimed to investigate the effect of RS in predicting the survival benefit of postoperative radiotherapy (PORT) in T1-2N1 BC with estrogen receptor-positive and human epidermal growth factor receptor 2-negative disease after breast-conserving surgery (BCS).

METHODS

We included patients with BC and available RS data from the Surveillance, Epidemiology, and End Results Oncotype DX database. The chi-square test, Kaplan-Meier method, propensity score matching (PSM) as well as multivariable Cox proportional hazard analyses were used for statistical analyses.

RESULTS

We included 6509 patients in the analysis. Of these patients, 5302 (85.5%) were treated with BCS + PORT, and 207 (15.5%) had BCS alone. There were 1419 (21.8%), 4319 (66.4%), and 771 (11.8%) patients being low-, intermediate-, and high-risk RS, respectively. After PSM, PORT was significantly associated with a 5-year overall survival (OS) advantage (95.1% vs. 90.5%, P < 0.001) compared to those without PORT, which similar breast cancer-specific survival (BCSS) was found between the treatment arms (P = 0.126). The sensitivity analyses showed that PORT was not associated with a better BCSS (P = 0.472) and OS (P = 0.650) than those without PORT in the low-risk RS cohort. However, PORT was associated with a better BCSS (P = 0.031) and OS (P < 0.001) compared to those without PORT in the intermediate/high-risk RS cohorts.

CONCLUSIONS

Our study highlights the possible role of the RS in predicting the outcome of PORT in T1-2N1 luminal BC patients undergoing BCS.

Biomarkers in Breast Cancer: An Old Story with a New End

Breast cancer is the second most frequent cancer in the world. It is a heterogeneous disease and the leading cause of cancer mortality in women. Advances in molecular technologies allowed for the identification of new and more specifics biomarkers for breast cancer diagnosis, prognosis, and risk prediction, enabling personalized treatments, improving therapy, and preventing overtreatment, undertreatment, and incorrect treatment. Several breast cancer biomarkers have been identified and, along with traditional biomarkers, they can assist physicians throughout treatment plan and increase therapy success. Despite the need of more data to improve specificity and determine the real clinical utility of some biomarkers, others are already established and can be used as a guide to make treatment decisions. In this review, we summarize the available traditional, novel, and potential biomarkers while also including gene expression profiles, breast cancer single-cell and polyploid giant cancer cells. We hope to help physicians understand tumor specific characteristics and support decision-making in patient-personalized clinical management, consequently improving treatment outcome.

Caveolin-1 genotypes as predictor for locoregional recurrence and contralateral disease in breast cancer

PURPOSE

Caveolin-1 (CAV1) has been implicated in breast cancer oncogenesis and metastasis and may be a potential prognosticator, especially for non-distant events. CAV1 functions as a master regulator of membrane transport and cell signaling. Several CAV1 SNPs have been linked to multiple cancers, but the prognostic impact of CAV1 SNPs in breast cancer remains unclear. Here, we investigated CAV1 polymorphisms in relation to clinical outcomes in breast cancer.

METHODS

A cohort of 1017 breast cancer patients (inclusion 2002-2012, Sweden) were genotyped using Oncoarray by Ilumina. Patients were followed for up to 15 years. Five out of six CAV1 SNPs (rs10256914, rs959173, rs3807989, rs3815412, and rs8713) passed quality control and were used for haplotype construction. CAV1 genotypes and haplotypes in relation to clinical outcomes were assessed with Cox regression and adjusted for potential confounders (age, tumor characteristics, and adjuvant treatments).

RESULTS

Only one SNP was associated with lymph node status, no other SNPs or haplotypes were associated with tumor characteristics. The CAV1 rs3815412 CC genotype (5.8% of patients) was associated with increased risk of contralateral breast cancer, adjusted hazard ratio (HR_adj) 4.26 (95% CI 1.86-9.73). Moreover, the TTACA haplotype (13% of patients) conferred an increased risk for locoregional recurrence HR_adj 2.24 (95% CI 1.24-4.04). No other genotypes or haplotypes were associated with clinical outcome.

CONCLUSION

CAV1 polymorphisms were associated with increased risk for locoregional recurrence and contralateral breast cancer. These findings may identify patients that could derive benefit from more tailored treatment to prevent non-distant events, if confirmed.

Evaluating the Necessity for Routine Sentinel Lymph Node Biopsy in Postmenopausal Patients Being Treated for Clinically Node Negative Breast Cancer the Era of RxPONDER

INTRODUCTION

Traditionally, sentinel lymph node biopsy (SLNB) was performed to inform adjuvant chemotherapy prescription and prognosis in breast cancer. Following RxPONDER, the OncotypeDX Recurrence Score (RS) guides adjuvant chemotherapy prescription for all postmenopausal patients with estrogen receptor positive, human epidermal growth factor receptor-2 negative (ER+/HER2-) breast cancer with 0 to 3 positive lymph nodes (0-3 + LN).

AIMS

To establish the oncological safety of omitting SLNB in postmenopausal patients with ER+/HER2- breast cancer indicated to undergo SLNB and to evaluate the primary determinants of chemotherapy prescription for these patients.

PATIENTS AND METHODS

A retrospective cohort study was undertaken. Cox regression and Kaplan-Meier analyses were performed. Data analytics was performed using SPSS v26.0.

RESULTS

Five hundred and seventy five consecutive patients were included (mean age: 66.5 years, range: 45-96). The median follow-up was 97.2 months (range: 3.0-181.6). Of the 575 patients, just 12 patients had positive SLNB (SLNB+) (2.1%). Using Kaplan-Meier analyses, SLNB+ failed to impact recurrence (P = .766) or mortality (P = .310). However, using Cox regression analyses, SLNB+ independently predicted poorer disease-free survival (hazard ratio: 1.001, 95% confidence interval (95% CI): 1.000-1.001, P = .029). Logistic regression analysis identified RS as the sole predictor of chemotherapy prescription (odds ratio: 1.171, 95% CI: 1.097-1.250, P < .001).

CONCLUSION

Omitting SLNB may be safe and justifiable in postmenopausal patients with ER+/HER2- breast cancer with clinically negative axillae. Following RxPONDER, RS is the most important guide of chemotherapy use in these patients and SLNB may be less important than previously perceived. Prospective, randomized clinical trials are required to fully establish the oncological safety of omitting SLNB in this setting.

Favorable locoregional control in clinically node-negative hormone-receptor positive breast cancer with low 21-gene recurrence scores: a single-institution study with 10-year follow-up

BACKGROUND

Recent studies have shown a lower likelihood of locoregional recurrences in patients with a low 21-gene recurrence score (RS). In this single-institution study, we investigated whether there are any associations between different cutoff values of 21-gene RS, histopathological factors, and outcome in patients with long-term follow-up.

METHODS

The study included 61 patients who had early-stage (I-II) clinically node-negative hormone receptor-positive and HER2-negative breast cancer and were tested with the 21-gene RS assay between February 2010 and February 2013. Demographic, clinicopathological, treatment, and outcome characteristics were analyzed.

RESULTS

The median age was 48 years (range, 29-72 years). Patients with high histologic grade (HG), Ki-67 ≥ 25%, or Ki-67 ≥ 30% were more likely to have intermediate/high RS (≥ 18). Based on the 21-gene RS assay, only 19 patients (31%) received adjuvant chemotherapy. At a median follow-up of 112 months, 3 patients developed locoregional recurrences (4.9%), which were treated with endocrine therapy alone. Among patients treated with endocrine treatment alone (n = 42), the following clinicopathological characteristics were not found to be significantly associated with 10-year locoregional recurrence free survival (LRRFS): age < 40 years, age < 50 years, high histological or nuclear grade, high Ki-67-scores (≥ 15%, ≥ 20%, ≥ 25%, ≥ 30%), presence of lymphovascular invasion, luminal-A type, multifocality, lymph node positivity, tumor size more than 2 cm, RS ≥ 18, and RS > 11. However, patients with RS ≥ 16 had significantly poorer 10-year LRRFS compared to those with RS < 16 (75% vs. 100%, respectively; p = 0.039).

CONCLUSIONS

The results suggest that patients with clinically node-negative disease and RS ≥ 16 are more likely to benefit from adjuvant chemotherapies. However, those with RS < 16 have an excellent outcome and local control in long-term follow-up with endocrine treatment alone.