To the Editor Iqbal et al¹ reported no survival difference in pregnant compared with nonpregnant women with a breast cancer diagnosis in a recent JAMA Oncology article. The 5-year actuarial survival rate was 97% for women who had pregnancy 6 months or more after diagnosis of breast cancer vs 88% for women with no pregnancy, with age-adjusted hazard ratio of 0.22.¹ According to eTable 6 in their study, 53% of the analyzed patients are labeled with unknown tumor size. Moreover, 55% of the patients’ lymph node status was unknown. Such a degree of missing data can affect the authors’ conclusion given the survival relationship with both tumor size and nodal status.² Despite correlation between tumor size and nodal involvement, the prognostic value of the 2 factors is independent. On the other hand, unknown receptor status may affect the results.

致编辑Iqbal 等人^{1在最近的}JAMA Oncology文章中报告说，与诊断为乳腺癌的非孕妇相比，孕妇的生存率没有差异。在诊断乳腺癌后怀孕 6 个月或更长时间的女性的 5 年精算生存率为 97%，而未怀孕女性的 5 年精算生存率为 88%，年龄调整后的风险比为 0.22。¹根据他们研究中的 eTable 6，53% 的分析患者被标记为肿瘤大小未知。此外，55% 的患者淋巴结状态未知。考虑到与肿瘤大小和淋巴结状态的生存关系，这种程度的缺失数据会影响作者的结论。²尽管肿瘤大小和淋巴结受累之间存在相关性，但这两个因素的预后价值是独立的。另一方面，未知的受体状态可能会影响结果。