Clinicopathological and prognostic characteristics of acral metastases in patients with malignant disease: A retrospective study

OBJECTIVE: This study aimed to investigate the clinical, pathological, and prognostic characteristics of acral metastases in patients with malignant disease and to determine the impact of different types of acral metastasis treatment on patient survival. METHODS: In this retrospective study, 64 acral metastatic lesions in 46 patients (17 women, 29 men; mean age, 61.5 years; age range, 35-82 years) who were evaluated by the Bone and Soft Tissue Tumors Council of our institute from 2015 to 2019 were included. The patients' primary tumor site, tumor type, localization of acral metastases, main symptom, duration from the diagnosis of the primary tumor to the diagnosis of acral metastasis, duration from the diagnosis of acral metastasis to death, and survival data were analyzed. The diagnosis of acral metastasis was confirmed by histopathological evaluation in 38 patients and clinical and radiological assessment of the lesions in 8 patients. The treatment type for each acral metastasis was individualized by the institutional Bone and Soft Tissue Tumors Council and categorized into 3 groups: excisional surgery (amputations and resections), palliative surgery (prophylactic fixation, intralesional curettage, and bone cement augmentation), and non-surgical treatment (chemotherapy, radiotherapy, and hormone therapy). RESULTS: A total of 16 acral metastases (25%) were identified in the upper extremity and 48 (75%) in the lower extremity. The most common primary tumor site was the lungs (32.6%), and the most common tumor type was adenocarcinoma (43.2%). The most frequent symptom and the primary reason for admission was pain (58.7%). The mean duration between the diagnosis of primary tumor and the diagnosis of acral metastasis was 19.1 (range, 0-124) months. No significant correlation was determined between the primary tumor types and duration from the diagnosis of primary tumor to the diagnosis of acral metastasis (p=0.278). Acral metastases were treated by excisional surgery in 15 (32.6%) patients, palliative surgery combined with non-surgical treatment in 10 (21.7%) patients, and only non-surgical treatment modalities in 21 (45.7%) patients. No significant correlation existed between the treatment types and patient survival (p=0.058). At the final follow-up, 30 (65.2%) patients were dead owing to the disease. The mean overall survival of the entire study group was 24.9 (range, 3-55) months. The mean duration between the diagnosis of acral metastasis and death was 7.6 (range, 3-24) months in patients who were dead owing to the disease (p=0.012). CONCLUSION: When the diagnosis of acral metastasis is established, it should be borne in mind that the most common primary tumor site and type are most likely the lungs and adenocarcinoma, respectively. The treatment type for acral metastasis may have no significant impact on patient survival, but the extensiveness of the disease may be a critical factor for survival. LEVEL OF EVIDENCE: Level IV, Prognostic study.