The 21-Gene Recurrence Score Assay Improved Multidisciplinary Treatment Compliance in Hormone Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Patients: An Analysis of 2,323 Patients.

PURPOSE

The 21-gene recurrence score (RS) can guide adjuvant chemotherapy decisions in the multidisciplinary treatment (MDT) of patients with early breast cancer. This study aimed to evaluate the influence of the 21-gene RS assay on patient' compliance with MDT and its association with disease outcomes.

METHODS

Patients diagnosed with pN0-1, hormone receptor-positive, human epidermal growth factor receptor-2-negative breast cancer between January 2013 and June 2019 were enrolled. A logistic regression model was used to identify parameters associated with treatment adherence. Prognostic indicators were evaluated using the Cox proportional hazard models.

RESULTS

After the assay, patients were less likely to violate the treatment plan (14.9% vs. 23.1%, < 0.001), and higher compliance rates were observed for chemotherapy ( = 0.042), radiotherapy ( = 0.012), and endocrine therapy ( < 0.001). Multivariable analysis demonstrated that the 21-gene RS assay (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.09-1.88; = 0.009) was independently associated with MDT compliance. Moreover, compliance with MDT was independently associated with better disease-free survival (hazard ratio, 0.43; 95% CI, 0.29-0.64; < 0.001), regardless of the 21-gene RS assay (interaction = 0.842).

CONCLUSION

The 21-gene RS assay improved the MDT compliance rate in patients with early breast cancer. Adherence to MDT is associated with a better prognosis.