Distribution, Chemotherapy Use, and Outcome of the 21-Gene Recurrence Score Between Chinese and White breast Cancer in the United States

This large retrospective study using the data from the Surveillance, Epidemiology, End Results found a similar distribution of 21-gene recurrence score, similar trends of chemotherapy regarding 21-gene recurrence score, and similar prognostic effect of the 21-gene recurrence score between those with Chinese and White American breast cancer. Purpose: To compare the distribution, chemotherapy-decision making, and prognosis of the 21-gene recurrence score (RS) between Chinese breast cancer (BC) in the United States and White American (WA) BC. Methods: We identified early-stage and estrogen receptor-positive BC patients diagnosed between 2004 and 2015. Multivariate logistic regression, Kaplan-Meier analysis, and multivariate Cox proportional hazards models were used for statistical analyses. Results: A total of 67,486 patients were identified, including 66,215 (98.1%) WA patients and 1271 (1.9%) Chinese patients. Regarding the RS, 38,894 (57.6%) had low RS, 23,882 (35.4%) had intermediate RS, and 4710 (7.0%) had high RS. A similar distribution of RS was found between WA and Chinese BC (P = .280). The race was not the predictor associated with high RS. Similar trends of chemotherapy use were found in Chinese and WA BC. In WA BC, there were 4 %, 31.5%, and 72.2% of patients receiving chemotherapy in low, intermediate, and high RS cohorts, respectively (P < .001). The proportion of chemotherapy use was 6.8%, 30.9%, and 74.0% in Chinese BC with low, intermediate, and high RS cohorts, respectively (P < 0.001). The multivariate prognostic analyses indicated that a higher RS was independently associated with an inferior breast cancer-specific survival. Similar trends were found among those with Chinese and WA BC. Conclusion: Our results demonstrate similar distribution, chemotherapy use, and outcome of the 21-gene RS between Chinese and WA BC in the United States. (C) 2021 The Authors. Published by Elsevier Inc.

Automated summary

This large retrospective study found similar distribution, chemotherapy use, and outcome of the 21-gene recurrence score between Chinese and White American breast cancer patients in the United States.