- The sample size was small (112) so it is difficult to estimate the overall benefit of the drug on a large number of TNBC patients.
- The study design and participant eligibility changed during the study.
- While only of few of the participants responded to the drug (15 out of 112 or 10% of participants) these results are important for the few who did respond. There was no randomized control group (patients who did received standard care) in this study.
- While the authors are optimistic that their results suggest that atezolizumaboptimistic may increase overall survival in patients who respond, the small study size and the lack of response for most (90%) participants makes it hard to justify the claim that these results provide evidence that immunotherapy may play a significant role in the treatment of breast cancer generally.
- TNBC is more common in young breast cancer patients so this study is particularly applicable to young patients.