Little research has been done on the follow-up of patients in the active phase of treatment in primary care. This study aimed to build up a corpus of authentic clinical situations and carry out an inductive analysis of the data. Research in two stages: case study and qualitative analysis of verbatims. The authors conducted individual interviews using an interview guide. The questions targeted their experiences, focusing on their relationship with their general practitioner. Six themes were identified. The announcement of the diagnosis was a key moment. Patients emphasised their general practitioner's responsiveness and coordination, and stressed his involvement. They consulted him regularly during the active phase of treatment, and asked for information. They felt confident. The need to facilitate access to the general practitioner was noted, particularly in the event of a real or perceived emergency. The increase in the prevalence and incidence of cancer means that general practitioners need to be heavily involved. The authorities are advocating a strengthening of the general practitioner's "pivotal role", without clearly defining it. A perceived lack of skills may be an obstacle to general practitioner involvement. Training in cancer during the 3rd cycle of general medical studies is inadequate. By compiling and analysing a corpus of cases, it would be possible to redefine the training objectives and list the skills required to manage cancer patients.