ERBB2 Mutations Characterize a Subgroup of Muscle-invasive Bladder Cancers with Excellent Response to Neoadjuvant Chemotherapy.
BACKGROUND In a retrospective study of Southwestern Oncology Group (SWOG)-S8710/INT-0080 (radical cystectomy [RC] alone vs 3 cycles of neoadjuvant chemotherapy [NC] with methotrexate, vinblastine, doxorubicin, and cisplatin before RC for bladder cancer), factors found to be associated with improved overall survival (OS) included pathologic complete response, defined as P0; treatment with NC; completion of RC with negative surgical margins; and >or=10 pelvic lymph nodes (LNs) removed. METHODS The authors used stratified Cox regression to retrospectively study the association of quality of pathologic response after RC with OS in the subset of S8710 patients who received NC and RC with negative surgical margins. RESULTS Of 154 patients who received NC, 68 (44.2%) were <P2 (P0, Pa, P1, or carcinoma in situ [CIS]) at RC, 46 (29.9%) were P0, and the remainder had P2+ disease or did not undergo RC. In 115 patients who had RC with negative surgical margins, compared with P0 patients, those with residual Pa, P1, or CIS appeared to have worse OS (P=.054); OS was significantly worse for patients with residual P2+ disease (P=.0006). LN-positive (LN+) disease was found to be associated with worse OS than LN-negative (LN-) disease (P=.0005). Patients with LN- disease (ie, those with <10 LNs removed) appeared to have inferior OS compared with those with 10+ LNs removed (P=.079). The combination of pre-NC clinical stage and post-RC pathologic stage was found to be predictive of OS (P<.0001). CONCLUSIONS NC and RC with negative surgical margins for bladder cancer followed by pathologic P0 and LN- disease were found to correlate with improved OS. A combination of baseline clinical stage and post-RC pathologic stage may better predict OS.