Timing of Pregnancy and Survival in Women With Breast Cancer

To the Editor Iqbal et al 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. 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. 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.

http://ift.tt/2xdOqud