**2. Evolving landscape of cancer therapy**

#### **2.1 Effect of the progress in cancer therapy on communicating prognosis**

Oncologists in training 40 years ago very easily saw the natural history of most adult cancers during the 2 or 3 years of their fellowship program. There were very few effective treatments for the most common advanced stage cancers. In that period, discussing prognosis with patients who had advanced cancer caused emotional distress in oncologists and their patients and this was a significant barrier to effective conversation about prognosis. Contrast that with what the current trainee faces in this era of targeted and immunotherapy: 50 or more new drugs for cancer treatment have been approved in both 2020 and 2021 [9, 10] and a significant decrease is now evident in cancer mortality [11] contributing to an increased lifespan [12]. Therefore, advanced cancers now are not always rapidly fatal and decision-making regarding treatment forces even the expert hematology and medical oncology physicians to pause before rendering prognostic opinions. The pause is not only to assess the impact of performance status and co-morbidities on prognosis, but also to: 1) ponder and choose from a bewildering array of treatment choices; 2) to consider the likelihood of rapid response and degree of complete remissions possible in the "exceptional responders;" 3) to consider the quality of life of patients who may have to learn to live with their cancer on maintenance therapy; and 4) to consider if the patient they face now will one day be monitored for treatment-free remissions. All these points deeply influence how we should think about discussing prognosis in patients with advanced cancer.
