Triple-negative breast cancer outcomes: Does AJCC 8th
staging improve chemotherapy decision-making
by Chen-Lu Lian, Guan-Qiao Li, Ping Zhou, Jun Wang, Zhen-Yu
He, San-Gang Wu
The Breast: VOLUME 59, P117-123, OCTOBER
01, 2021
Purpose
To investigate the effect of the 8th American Joint
Committee on Cancer (AJCC) pathological prognostic staging on chemotherapy
decision-making for triple-negative breast cancer (TNBC) patients with T1-2N0M0
disease.
Methods
Patients diagnosed with T1-2N0M0 TNBC were retrieved from
the Surveillance, Epidemiology, and End Results program. Statistical methods
including Kaplan-Meier survival curve, receiver operating characteristics
curve, and Cox proportional hazard model.
Results
We identified 12,156 patients, including 9371 (77.1%)
patients who received chemotherapy. Overall, 57.4% of patients
(n = 6975) were upstaged after being reassigned by the 8th AJCC
staging. However, the 8th staging of AJCC did not have a greater prognostic
value compared to the 7th staging (P = 0.064). The receipt of
chemotherapy significantly improved the breast cancer-specific survival for
stage T1c and T2 tumors (P < 0.001), but not for stage T1a
(P = 0.188) and T1b (P = 0.376) tumors. Using AJCC 8th
staging, chemotherapy benefit was only found in stage IIA patients
(P = 0.002), but not for stage IA (P = 0.653) and IB
(P = 0.492) patients. There were 9564 patients with stage T1c and T2
diseases and 4979 patients with 8th AJCC stage IIA disease. Therefore,
approximately half of patients (47.9%, n = 4585) may be safe to omit
chemotherapy using the AJCC 8th staging compared to the current chemotherapy
recommendation for T1-2N0M0 TNBC.
Conclusion
The 8th AJCC staging system did not demonstrate the superior
discriminatory ability of prognostic stratification than the 7th AJCC staging
system in T1-2N0M0 TNBC. However, this new AJCC staging could more accurately
predict the chemotherapy benefit, thereby enabling more patients to avoid
unnecessary chemotherapy.
