Article révisé par les pairs
Résumé : Patients with breast cancer undergoing systemic therapies can have mixed response to treatment, with some lesions reducing their dimensions or also, in some cases, disappearing, and others progressing. Of note, breast cancer is an example of tumor heterogeneity, and this reflects the ability of the tumor to adapt to changing conditions and to overcome constraints to growth and dissemination. Hence, a mixed response to treatment may indicate that some clones have become resistant to the treatment and are triggering a disease progression. Nevertheless, a differential diagnosis should always be implemented when new lesions are detected, to rule out potential different etiologies. Too often subjects who received a prior diagnosis of cancer may face stigma of “cancer patients” although they have been successfully cured and have no evidence of residual disease. The systematic implementation of a sensible, appropriate differential diagnosis can help reduce the time to diagnosis and to treatment, with positive impact in patients’ outcomes and quality of life. Our case report describes the incidental finding of lung lesions in a woman treated for early breast cancer and highlights the importance of differential diagnosis in the specific subset of subjects who received a prior diagnosis of cancer.