SYMPTOMS AND CANCER SPECIfiC PREDICTORS OF LOCAL RECURRENCE IN BRAIN METASTASES

Abstract AIMS Local control is often used as the primary outcome measure in brain metastases (BM) studies including the major RCTs on radiotherapy and surgery that guide practice but how relevant is this to patients? We examined the symptoms associated with local recurrence (LR) in BM and what the cancer specific predictive factors were for the most common primaries – lung, breast and melanoma. METHODS Retrospective database of 556 cases at a single institution in the UK with comprehensive demographic and clin- ical data from hospital records. RESULTS 138/556 patients were identified with LR following surgery. The 12-month local control rate was 79% for breast cancer, 76% for lung cancer and 68% for malignant melanoma. Information on symptoms was obtained for 81 patients at LR: 12% had PS0, 53% PS1, 19% PS 2 and 16% PS3. The most common symptoms of LR were headache, seizures and new motor deficit but 35% reported no new symptoms with no difference amongst patients with differing primary cancers. For 209 lung cancer patients, 58 experienced LR and having oligometastatic brain disease rather than a single BM was the only factor significantly associated with LR (HR 2.5, 95% CI 1.1 - 5.7, p=0.02). For 53/124 breast cancer patients no significant factors for LR were identified but HER2+ cases tended to better local control than TN. For 26 / 74 malignant melanoma cases a KPS>70 was associated with a lower risk of LR (HR 0.17, 95% CI 0.04 - 0.68, p=0.012). CONCLUSION Many patients with BM are either not symptomatic or mildly symptomatic of LR in the brain. Predictors of local control differ between different BM from different primary cancers. Quality of life or combined endpoints such as deterioration free survival may be more appropriate outcomes for trials of focal therapies in BM and primary cancer is a confounder.