Department of Clinical Oncology and Hematology, The Jikei University School of Medicine, 3-25-8, Nishi-shimbashi, Minato-ku, Tokyo, 105-8461, Japan.
Breast Cancer. 2012 Jul;19(3):218-37. doi: 10.1007/s12282-012-0347-0. Epub 2012 Apr 25.
Metastatic breast cancer (MBC) is generally incurable. However, 10-20-year relapse-free survival of MBC is approximately 2%, implying that at least a small subset of MBC patients achieve prolonged survival. We therefore analyzed long-term outcome in a particular subset, i.e., oligometastatic breast cancer (OMBC).
Data of OMBC subjects (N = 75) treated in our institution from April 1980 to March 2010 were retrospectively analyzed. OMBC was identified as: one or 2 organs involved with metastatic lesions (excluding the primary lesion resectable by surgery), fewer than 5 lesions per metastasized organ, and lesion diameter less than 5 cm. Patients were generally treated with systemic chemotherapy first, and those who achieved complete response (CR) or partial response (PR) were further treated, if applicable, with local therapy (surgical or radiation therapy) to maintain CR or to induce no evidence of clinical disease (NED), with additional systemic therapy.
Median follow-up duration was 103 (6-329) months. Single or 2 organs were involved in, respectively, 44 (59%) and 31 (41%) cases with metastatic lesions, 48% of which were visceral. In cases where effects of systemic therapy, possibly in combination with other treatments, were evaluated (N = 68), CR or PR was achieved in 33 (48.5%) or 32 (47.1%), respectively, with overall response rate (ORR: CR + PR) of 95.6% (N = 65). In cases receiving multidisciplinary treatment (N = 75), CR or NED (CR/NED), or PR was induced in 48 (64.0%) or 23 (30.7%) cases, respectively, with ORR (CR/NED + PR) of 94.7% (N = 71). CR rates (60.5%) with systemic therapy and CR/NED rates (79.5%) with multidisciplinary treatment were significantly better in subjects with a single involved organ than in those with two involved organs (P = 0.047 and 0.002, systemic only or multidisciplinary treatments, respectively). Medians estimated by Kaplan-Meier method were: overall survival (OS) of 185.0 months and relapse-free interval (RFI) of 48.0 months. Estimated outcomes were: OS rates (OSR) of 59.2% at 10 years and 34.1% at 20 years, and relapse-free rates (RFR) of 27.4% at 10 years and 20 years. No disease progression was observed after 101.0 months as RFR. Cases with single organ involvement (N = 44) showed significantly better outcomes (OSR of 73% at 10 years and 52% at 20 years, RFR of 42% at 10 years and 20 years). Those who received local therapies (N = 35) also showed better prognosis: OSR of 82% at 10 years and 53% at 20 years, RFR of 38% at 10 years and 20 years. Three cases (4%) survived for their lifetime without relapse after achieving CR or NED, our definition of clinical cure. Multivariate analysis revealed factors favoring better prognosis as: none for OS, and single organ involvement with metastasis, administration of local treatment, and shorter disease-free interval (DFI) (P = 0.030, 0.039, and 0.042, respectively) for RFR. Outcomes in OMBC in literature were OSR of 35-73% at 10 years and 26-52% at 20 years, and RFR of 27-42% at 10 years and 26-42% at 20 years.
The present analyses clearly indicate that OMBC is a distinct subgroup with long-term prognosis superior to MBC, with reasonable provability for clinical cure. Further prospective studies to better characterize OMBC are warranted to improve prognosis in MBC.
转移性乳腺癌（MBC）通常无法治愈。然而，MBC 的 10-20 年无复发生存率约为 2%，这意味着至少有一小部分 MBC 患者实现了长期生存。因此，我们分析了一个特定的亚组，即寡转移性乳腺癌（OMBC）的长期结果。
我们回顾性分析了 1980 年 4 月至 2010 年 3 月期间在我院治疗的 75 例 OMBC 患者的数据。OMBC 的定义为：一个或两个器官受累，转移性病变数少于 5 个，每个转移器官的病变直径小于 5cm。一般先给予全身化疗，对获得完全缓解（CR）或部分缓解（PR）的患者，如果适用，给予局部治疗（手术或放疗）以维持 CR 或诱导无临床疾病证据（NED），同时进行额外的全身治疗。
中位随访时间为 103（6-329）个月。44 例（59%）和 31 例（41%）患者的转移病变累及单个或 2 个器官，其中 48%为内脏转移。在评估可能联合其他治疗的全身治疗效果的情况下（N=68），33 例（48.5%）和 32 例（47.1%）分别达到 CR 或 PR，总缓解率（CR+PR）为 95.6%（N=65）。在接受多学科治疗的情况下（N=75），48 例（64.0%）和 23 例（30.7%）分别诱导 CR/NED 或 PR，总缓解率（CR/NED+PR）为 94.7%（N=71）。在单一器官受累的患者中，CR 率（60.5%）和全身治疗后的 CR/NED 率（79.5%）明显高于受累器官为两个的患者（P=0.047 和 0.002，分别为全身治疗和多学科治疗）。通过 Kaplan-Meier 法估计的中位数为：总生存期（OS）为 185.0 个月，无复发生存期（RFI）为 48.0 个月。估计的结果为：10 年和 20 年的 OS 率（OSR）分别为 59.2%和 34.1%，10 年和 20 年的无复发生存率（RFR）分别为 27.4%和 20.0%。RFR 为 101.0 个月后未观察到疾病进展。单一器官受累的患者（N=44）的结局明显更好（10 年 OSR 为 73%，20 年 OSR 为 52%，10 年和 20 年的 RFR 分别为 42%和 20%）。接受局部治疗的患者（N=35）也显示出更好的预后：10 年和 20 年的 OSR 分别为 82%和 53%，10 年和 20 年的 RFR 分别为 38%和 20%。3 例（4%）患者在达到 CR 或 NED 后终生无复发，这是我们对临床治愈的定义。多变量分析显示，有利于更好预后的因素为：OS 无任何因素，转移病变单一器官受累、局部治疗和较短的无疾病间期（DFI）（P=0.030、0.039 和 0.042），RFR 更好。文献中 OMBC 的结果为 10 年 OSR 为 35-73%，20 年 OSR 为 26-52%，10 年 RFR 为 27-42%，20 年 RFR 为 26-42%。
本分析清楚地表明，OMBC 是一个具有长期预后优于 MBC 的独特亚组，具有合理的临床治愈可能性。需要进一步的前瞻性研究来更好地描述 OMBC，以改善 MBC 的预后。
