Introduction. Loneliness is a subjective and distressing experience associated with adverse physical and mental health outcomes. In oncology, loneliness has been identified as a psychosocial risk factor that negatively influences quality of life, coping, and survival. However, there are no culturally adapted and validated instruments in Spanish to assess cancer-related loneliness.


Purpose. This study aimed to translate and cross-culturally adapt the Cancer Loneliness Scale (CLS) for use among Colombian cancer patients.


Method. Authorization for the use of the instrument was obtained from the original authors. The process followed the European Organisation for Research and Treatment of Cancer (EORTC) translation guidelines to ensure semantic, cultural, and conceptual equivalence. The procedure included forward translation by two independent translators, reconciliation, back translation, expert committee review, and a pilot test with 20 Colombian cancer patients receiving care at the Instituto Nacional de Cancerología. Participants evaluated clarity, comprehensibility, and acceptability of items.


Results. Minor discrepancies emerged during translation, particularly regarding the adverb how often. After consensus, the phrase "qué tan a menudo" was selected as the most accurate option. The reconciled version preserved semantic equivalence with the original. In the pilot test, patients found the items clear and non-offensive, with only minor suggestions that did not warrant changes. As a result, a culturally adapted Spanish version of the CLS was obtained without modifications after pilot testing.


Conclusions. The Spanish version of the Cancer Loneliness Scale is linguistically and culturally appropriate for Colombian cancer patients. This adaptation provides the foundation for subsequent psychometric validation, supporting the measurement of cancer-related loneliness in Spanish-speaking populations.