Jatoi Ismail
Division of Surgical Oncology and Endocrine Surgery, University of Texas Health Science Center, San Antonio, TX 78229 USA.
Indian J Surg Oncol. 2014 Mar;5(1):5-9. doi: 10.1007/s13193-013-0274-3. Epub 2013 Nov 5.
There are no randomized trials comparing local therapy versus no therapy in patients with primary breast cancer, as such trials would be deemed unethical. Thus, the impact of local therapy on breast cancer mortality is poorly understood. However, an overview of clinical trials comparing various permutations in the local therapy of breast cancer suggests that inadequate local therapy increases the risk of local recurrences, and thereby increases breast cancer mortality. Yet, age-interactions are commonly reported in studies that have examined the etiology, prognosis, and treatment of breast cancer, and might be associated with the effect of local therapy as well. Moreover, the effect of local therapy on breast cancer mortality might be time-dependent. In cohorts of women with high-risk tumors (predominantly younger women) local therapy may adversely (but only transiently) perturb the natural history of breast cancer. In contrast, such an effect is not evident in cohorts of women with low-risk tumors (predominantly older women). For both groups of patients, local therapy appears to ultimately have a beneficial effect in reducing breast cancer mortality, but in patients with low-risk tumors the benefit is immediate, while in patients with high-risk tumors it is delayed. Evidence for such an age-interaction is derived from comparison of the breast cancer hazard curves in women with high-risk and low-risk tumors, and analysis of the mammography screening trials. Neo-adjuvant systemic therapy may eventually prove useful in modulating the effects of local therapy.
尚无随机试验比较原发性乳腺癌患者接受局部治疗与不接受治疗的情况，因为此类试验被认为不符合伦理道德。因此，局部治疗对乳腺癌死亡率的影响尚不清楚。然而，一项对比较乳腺癌局部治疗各种组合的临床试验的综述表明，局部治疗不足会增加局部复发的风险，从而增加乳腺癌死亡率。然而，在研究乳腺癌的病因、预后和治疗的研究中，年龄相互作用的情况普遍存在，并且可能也与局部治疗的效果有关。此外，局部治疗对乳腺癌死亡率的影响可能与时间有关。在高危肿瘤患者队列（主要是年轻女性）中，局部治疗可能会对乳腺癌的自然病程产生不利影响（但只是短暂的）。相比之下，在低危肿瘤患者队列（主要是老年女性）中，这种影响并不明显。对于这两组患者，局部治疗最终似乎都对降低乳腺癌死亡率有有益影响，但在低危肿瘤患者中，这种益处是即时的，而在高危肿瘤患者中则是延迟的。这种年龄相互作用的证据来自对高危和低危肿瘤女性乳腺癌风险曲线的比较以及对乳腺钼靶筛查试验的分析。新辅助全身治疗最终可能被证明有助于调节局部治疗的效果。
