The clinical management of cancer in senior adult patients is based on the results of clinical trials which were performed in adults, generally younger adult patients. It is therefore difficult to assess the feasibility of such treatments, mainly chemotherapy, in older patients. The evaluation of health status is an important step in the decision making of cancer treatment in senior adults. In non Hodgkin lymphomas, the standard treatment remains chemotherapy with Rituximab. Specific protocols and treatment adaptation have been proposed in very old seniors. Surgery is a very efficient treatment in breast cancer, colorectal cancer and sometimes in non small cell lung cancer. Radiotherapy is important in the curative management of prostate cancer and in the multidisciplinary treatment of breast, colorectal and lung cancers. Chemotherapy is generally feasible in senior adults. However, Cisplatin is often too much toxic. Chemotherapy has a palliative impact in the treatment of metastatic prostate and breast cancers. It would be discussed in some high-risk groups of patients with breast and colorectal cancers. New targeted drugs are active in breast, colorectal cancers and in non Hodgkin lymphomas. Indications of treatment tailored on health status evaluation are discussed in the manuscript.