Truong Pauline T, Olivotto Ivo A, Speers Caroline H, Wai Elaine S, Berthelet Eric, Kader Hosam A
Breast Cancer Outcomes Unit, British Columbia Cancer Agency-Vancouver Island Centre and the University of British Columbia, Victoria, BC, Canada.
Int J Radiat Oncol Biol Phys. 2004 Mar 1;58(3):797-804. doi: 10.1016/S0360-3016(03)01626-2.
Postoperative radiotherapy is frequently employed among breast cancer patients with positive surgical margins after mastectomy but there is little evidence to support this practice. This study examined relapse and survival among women with node-negative breast cancer and positive surgical margins after mastectomy.
Among 2570 women diagnosed between 1989 and 1998 and referred to the British Columbia Cancer Agency with pathologic (p)T1-2, pN0 invasive breast cancer treated with mastectomy, 94 had positive surgical margins and formed the study cohort. Women with more established indications for postmastectomy radiotherapy (PMRT) including T3-4 tumors or node-positive disease were excluded. Demographic, tumor, and treatment factors; relapse patterns; and Kaplan-Meier 8-year locoregional relapse-free, breast cancer-specific, and overall survival rates were compared between women who were treated with (n = 41) and without (n = 53) PMRT.
Median follow-up time was 7.7 years. The distributions of age, histologic grade, lymphovascular invasion (LVI), estrogen receptor status, and number of axillary nodes removed were similar between the two treatment groups. Six local chest wall recurrences (6.4%), 4 regional recurrences (4.3%), and 11 distant recurrences (11.7%) were identified. Local relapse rates were 2.4% vs. 9.4% (p = 0.23), and regional relapse rates were 2.4% vs. 5.7% (p = 0.63), with and without PMRT, respectively. Trends for higher cumulative locoregional relapse (LRR) rates without PMRT were identified in the presence of age <==50 years (LRR 20% without vs. 0% with PMRT), T2 tumor size (19.2% vs. 6.9%), grade III disease (23.1% vs. 6.7%), and LVI (16.7% vs. 9.1%). Statistical significance was not demonstrated in these differences (p > 0.10), possibly because of the small number of events. In patients with age >50 years, T1 tumors, grade I/II disease, and absence of LVI, no locoregional relapse occurred even with positive margins. PMRT did not improve distant relapse, 8-year breast cancer-specific and overall survival rates.
This study suggests that not all patients with node-negative breast cancer with positive margins after mastectomy require radiotherapy. Locoregional failure rates approximating 20% were observed in women with positive margins plus at least one of the following factors: age <==50 years, T2 tumor size, grade III histology, or LVI. The absolute and relative improvements in locoregional control with radiotherapy in these situations support the judicious, but not routine, use of PMRT for positive margins after mastectomy in patients with node-negative breast cancer.
乳房切除术后手术切缘阳性的乳腺癌患者常接受术后放疗，但几乎没有证据支持这种做法。本研究调查了乳房切除术后淋巴结阴性且手术切缘阳性的女性的复发情况和生存率。
在1989年至1998年间被诊断为病理（p）T1-2、pN0浸润性乳腺癌并接受乳房切除术、转诊至不列颠哥伦比亚癌症机构的2570名女性中，94名手术切缘阳性，构成研究队列。排除有更明确的乳房切除术后放疗（PMRT）指征的女性，包括T3-4肿瘤或淋巴结阳性疾病。比较接受（n = 41）和未接受（n = 53）PMRT治疗的女性的人口统计学、肿瘤和治疗因素；复发模式；以及Kaplan-Meier 8年局部区域无复发生存率、乳腺癌特异性生存率和总生存率。
中位随访时间为7.7年。两个治疗组之间的年龄、组织学分级、淋巴管浸润（LVI）、雌激素受体状态和切除腋窝淋巴结数量的分布相似。共发现6例局部胸壁复发（6.4%）、4例区域复发（4.3%）和11例远处复发（11.7%）。接受和未接受PMRT的患者局部复发率分别为2.4%和9.4%（p = 0.23），区域复发率分别为2.4%和5.7%（p = 0.63）。在年龄<=50岁（未接受PMRT时局部区域复发率为20%，接受PMRT时为0%）、T2肿瘤大小（19.2%对6.9%）、III级疾病（23.1%对6.7%）和LVI（16.7%对9.1%）的情况下，发现未接受PMRT时局部区域复发（LRR）累积率有升高趋势。这些差异未显示出统计学意义（p > 0.10），可能是因为事件数量较少。在年龄>50岁、T1肿瘤、I/II级疾病且无LVI的患者中，即使切缘阳性也未发生局部区域复发。PMRT并未改善远处复发、8年乳腺癌特异性生存率和总生存率。
本研究表明，并非所有乳房切除术后淋巴结阴性且切缘阳性的患者都需要放疗。在切缘阳性且至少具备以下因素之一的女性中观察到局部区域失败率约为20%：年龄<=50岁、T2肿瘤大小、III级组织学或LVI。在这些情况下，放疗对局部区域控制的绝对和相对改善支持对乳房切除术后切缘阳性的淋巴结阴性乳腺癌患者谨慎但非常规地使用PMRT。
