Combining Clinical and Pathologic Staging Variables Has Prognostic Value in Predicting Local-regional Recurrence
Jose Vila1, Mediget Teshome, Susan L Tucker
1*Department of Breast Surgical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX †Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX ‡Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX §Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX ¶Health Services Research, The University of Texas MD Anderson Cancer Center, Houston, TX.
Objective:
The current study was undertaken to determine if the CPS+EG score could stratify patients with respect to local-regional recurrence (LRR).
Background:
We previously defined and validated a novel breast cancer staging system incorporating the American Joint Committee on Cancer clinical stage (CS), final pathologic stage (PS), estrogen receptor status (E), and nuclear grade (G) (CPS+EG score). The score is associated with disease-specific survival outcomes in patients treated with neoadjuvant chemotherapy.
Methods:
Patients receiving neoadjuvant chemotherapy between 1997 and 2005 were identified and clinicopathologic data were used to determine the CPS+EG score. Type of local therapy, breast-conserving therapy, mastectomy alone, or mastectomy followed by postmastectomy radiation therapy was recorded. Multivariate analysis, including CPS+EG score and local therapy, was performed to evaluate for association with LRR.
Results:
Of 1697 patients, breast conserving therapy was performed in 656 (39%), mastectomy in 297 (17%) and mastectomy + postmastectomy radiation therapy in 744 (44%). At a median follow-up of 49 months, the crude incidence of LRR was 6.5%. Freedom from LRR at 5 years ranged from 86% to 97% by clinical stage, 86% to 97% by pathologic stage, and 71% to 99% by CPS+EG score. On multivariate analysis, CPS+EG score and surgery type were independently associated with LRR, with increased risk among patients with CPS+EG scores of 3 or greater (HR 1.94, 95% CI 1.04-3.63) or mastectomy alone (HR 2.14, 95% CI 1.26-3.63).
Conclusions:
The CPS+EG staging system better stratifies patients with respect to LRR after neoadjuvant chemotherapy than presenting clinical stage or final pathologic stage. For CPS+EG scores ≥3, use of postmastectomy radiation therapy decreases the likelihood of LRR after mastectomy.
