Evaluation of risk stratification using gene expression assays in patients with breast cancer receiving neoadjuvant chemotherapy

Association of Neighborhood-Level Household Income With 21-Gene Recurrence Score and Survival Among Patients With Estrogen Receptor-Positive Breast Cancer

IMPORTANCE

While low income has been associated with a higher incidence of triple-negative breast cancer, its association with 21-gene recurrence score (RS) among patients with estrogen receptor (ER)-positive breast cancer remains unclear.

OBJECTIVE

To evaluate the association of household income with RS and overall survival (OS) among patients with ER-positive breast cancer.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the National Cancer Database. Eligible participants included women diagnosed between 2010 and 2018 with ER-positive, pT1-3N0-1aM0 breast cancer who received surgery followed by adjuvant endocrine therapy with or without chemotherapy. Data analysis was performed from July 2022 to September 2022.

EXPOSURES

Low vs high neighborhood-level household income levels defined as below vs above the median household income of $50 353 based on each patient's zip code.

MAIN OUTCOMES AND MEASURES

RS (a score ranged from 0 to 100 based on gene expression signatures indicating the risk of distant metastasis, with RS of 25 or below indicating non-high risk and RS above 25 indicating high risk) and OS.

RESULTS

Among 119 478 women (median [IQR] age, 60 [52-67] years; 4737 [4.0%] Asian and Pacific Islander, 9226 [7.7%] Black, 7245 [6.1%] Hispanic, 98 270 [82.2%] non-Hispanic White), 82 198 (68.8%) and 37 280 (31.2%) patients had high and low income, respectively. Logistic multivariable analysis (MVA) showed that, compared with high income, low income was associated with higher RS (adjusted odds ratio [aOR], 1.11; 95% CI, 1.06-1.16). Cox MVA showed that low income was also associated with worse OS (adjusted hazards ratio [aHR], 1.18; 95% CI, 1.11-1.25). Interaction term analysis showed a statistically significant interaction between income levels and RS (interaction P < .001). On subgroup analysis, significant findings were noted among those with RS below 26 (aHR, 1.21; 95% CI, 1.13-1.29), while there was no significant OS difference between income levels among others with RS of 26 or higher (aHR, 1.08; 95% CI, 0.96-1.22).

CONCLUSIONS AND RELEVANCE

Our study suggested that low household income was independently associated with higher 21-gene recurrence scores and significantly worse survival outcomes among those with scores below 26, but not 26 or higher. Further studies are warranted to investigate the association between socioeconomic determinants of health and intrinsic tumor biology among patients with breast cancer.

Tailoring neoadjuvant treatment of HR-positive/HER2-negative breast cancers: Which role for gene expression assays?

Neoadjuvant chemotherapy (NACT) for breast cancer (BC) increases surgical and conservative surgery chances. However, a significant proportion of patients will not be eligible for conservative surgery following NACT because of large tumor size and/or low chemosensitivity, especially for hormone receptor (HR)-positive/ human epidermal growth factor receptor 2 (HER2)-negative tumors, for which pathological complete response rates are lower than for other BC subtypes. On the other hand, for luminal BC neoadjuvant endocrine therapy could represent a valid alternative. Several gene expression assays have been introduced into clinical practice in last decades, in order to define prognosis more accurately than clinico-pathological features alone and to predict the benefit of adjuvant treatments. A series of studies have demonstrated the feasibility of using core needle biopsy for gene expression risk testing, finding a high concordance rate in the risk result between biopsy sample and surgical samples. Based on these premises, recent efforts have focused on the utility of gene expression signatures to guide therapeutic decisions even in the neoadjuvant setting. Several prospective and retrospective studies have investigated the correlation between gene expression risk score from core needle biopsy before neoadjuvant therapy and the likelihood of 1) clinical and pathological response to neoadjuvant chemotherapy and endocrine therapy, 2) conservative surgery after neoadjuvant chemotherapy and endocrine therapy, and 3) survival following neoadjuvant chemotherapy and endocrine therapy. The purpose of this review is to provide an overview of the potential clinical utility of the main commercially available gene expression panels (Oncotype DX, MammaPrint, EndoPredict, Prosigna/PAM50 and Breast Cancer Index) in the neoadjuvant setting, in order to better inform decision making for luminal BC beyond the exclusive contribution of clinico-pathological features.

Escalating de-escalation in breast cancer treatment

Efforts have continually been made to de-escalate treatment for breast cancer, with the goal of balancing oncologic outcomes with complications and patient quality of life. In the early 2000s, two landmark studies firmly established that conservative treatment approaches for breast cancer can be safe and effective. More recently, neoadjuvant chemotherapy has gained momentum as a potential standard of care for breast cancer. An important question has thus arisen: Can neoadjuvant approaches themselves be de-escalated to further minimize adverse treatment effects while maintaining oncological outcomes? In this editorial, we look at the available evidence and assess current trends in treatment de-escalation for women with breast cancer.