Within a multifactorial etiology of cancers and a bio-psycho-social approach of patients, considering, among the risk factors, those related to personality in a preventive view, the authors investigate, by an epidemiologic methodology, for a correlation between break-down phenomena and the development of a cancer. The study was carried out at the Salah Azaïez Institute in 1992 and included 707 patients aged from 15 to 82 years, 44% presenting a malignant tumour. For a retrospective evaluation of break-down semiology, the study is based on DSM-III criteria of break-down diagnostic. Search for a clinic/psychic diagnostic relation reveals the difficulty of coexistence between break-down signs and the development of a cancer. That difficulty increases in case of an organised break-down.