Cancer risk increases with age, cancer-related stress is common and devastating to mental health of patients, yet little work has explored age differences in cancer-related stress. This study investigated sources of stress related to cancer diagnosis and treatment and its association with age and emotional health. Though not an a priori aim of the study, adaptive strategies mentioned within discussions of stress-which we classify as spontaneous emotion regulation (ER) - were also investigated. Participants (N = 147, aged 27-88) recruited from the VA (98% male) with oral-digestive cancers participated in semi-structured interviews regarding sources of stress 6-months post-diagnosis (T1) and treatment-related stress at 12-months post-diagnosis (T2). Patients also reported their emotional distress at T2 via the PROMIS-29. Inductive content analysis was used to classify sources of stress and ER into semantic themes and relative frequencies. The greatest source of stress at diagnosis was psychological; physical symptoms were the greatest source of stress at treatment. Older adults less frequently reported psychological uncertainty, social stress, and situational stress, whereas age groups reported similar rates of physical stress. When describing stress, older adults more often made spontaneous references to emotion regulation (ER). Across age groups, those who reported stress without ER in qualitative comments had higher emotional distress on the PROMIS-29 than those reporting stress with ER or no stress. ER may be key to psychological adjustment to cancer, especially in later-life. implications for assessment of stress at pivotal visits and mental health referral are discussed.