To date there is no agreement on the usefulness of physical symptoms to express a mood disorder diagnosis in psychoncology. The aim of this study was to evaluate the relevance of somatic, affective and cognitive clusters in mood disorders in oncological comorbidity. 151 consecutive in-patients of the Surgical Oncology Unit of S. Giovanni Battista Hospital (Turin, Italy) were evaluated for depression using the HADS and the MADRS. In addition, behavioural, somatic and cognitive clusters of the MADRS were analysed, comparing depressed and non-depressed patients, subdivided according to the HADS-D scores. Since the HADS does not consider the somatic symptoms of depression this comparison allowed us to evaluate the relevance of the three different clusters for depressive symptoms. According to the HADS, 57.4% of patients scored above the cut-off (≥ 8) for depression and 47,3% scored above the cut-off (≥ 8) for anxiety. As for the MADRS, 44% of patients scored between 0-9, indicating the absence of depression, 43.7% were found to have mild/moderate depressive symptoms and 12.3% showed severe mood depression. Comparison between patients above and below the cut-off of HADS-D showed significant differences in all the three clusters (p < 0.01). In addition, more relevant differences were observed in the affective and somatic clusters than in the cognitive cluster. Results of the present study suggest the importance of somatic symptoms in the perception and expression of psychological suffering in cancer patients.