A randomized controlled trial comparing primary tumor resection plus systemic therapy with systemic therapy alone in metastatic breast cancer (PRIM-BC): Japan Clinical Oncology Group study JCOG1017.

• DOI: 10.1200/jco.2023.41.16_suppl.523
• Publication Date: 2023-06-04T14:02:11Z
• Authors: Tadahiko Shien; Fumikata Hara; Kenjiro Aogi; Yasuhiro Yanagita; Michiko Tsuneizumi; Naohito Yamamoto; Hiroshi Matsumoto; Akihiko Suto; Kenichi Watanabe; Michiko Harao; Chizuko Kanbayashi; Mitsuya Ito; Takayuki Kadoya; Keisei Anan; Shigeto Maeda; Keita Sasaki; Gakuto Ogawa; Haruhiko Fukuda; Hiroji Iwata
• Keywords: Systemic therapy; Clinical endpoint; Primary tumor; Progression-free survival

523 Background: The possibility of primary tumor resection (PTR) improving the survival de-novo Stage IV breast cancer (dn-StIV BC) patients has been evaluated by several prospective studies but remains controversial. We designed this phase 3 trial (JCOG1017) comparing with/without dissection after initial systemic therapy based on clinical subtype in dn-StIV BC patients. Methods: Dn-StIV were enrolled first registration. All received therapies according to subtypes. not showing refractory disease randomized alone (arm A) or PTR plus (Arm B). same was continued randomization as additional therapy, for long possible. endpoint overall (OS). Secondary endpoints included proportion without progression at metastatic sites months, local relapse-free (LRFS), resection-free survival, and incidence ulcer/local bleeding adverse events. median time (MST) with 20 average, a clinically relevant prolongation MST Arm B considered be 6.0 months longer (hazard ratio: 0.77). required number events 359, obtain statistical power 80% one-sided significance level 0.05. Thus, planned sample size 410 second registration, assuming an accrual period 7 years follow-up 4 years. Results: 570 between 11/5/2011 31/5/2018 Of these, 407 eligible either A (N = 205) 202). patient characteristics well balanced two arms. 70 221 deaths. difference OS statistically significant (HR 0.857, 90% CI 0.686-1.072, p 0.1283). 69 75 B. proportions Arms 81.5% 67.3%, respectively (p 0.0014). LRFS significantly than that (median vs 63 months: HR 0.415, 95% 0.327-0.527, < 0.0001). In B, incomplete had poorer outcomes those whom complete (94 vs. 61 1.971 (1.161-3.347) 0.0120). subgroup analysis, improved ER-positive tumors, pre-menopausal status single-organ metastasis. Conclusions: is recommended all can control acceptable select population because clear improvement control. Clinical information: UMIN000005586 .