Dysarthria and dysphagia in patients with mitochondrial diseases.

BACKGROUND: Information about dysarthria and dysphagia in mitochondrial diseases (MD) is scarce. However, this knowledge is needed to identify speech and swallowing problems early, to monitor the disease course, and to develop and offer optimal treatment and support. This study therefore aims to examine the prevalence and severity of dysarthria and dysphagia in patients with MD and its relation to clinical phenotype and disease severity. Secondary aim is to determine clinically relevant outcome measures for natural history studies and clinical trials. METHODS: This retrospective cross-sectional medical record study includes adults (age ≥ 18 years) diagnosed with genetically confirmed MD who participated in a multidisciplinary admission within the Radboud center for mitochondrial medicine between January 2015 and April 2023. Dysarthria and dysphagia were examined by administering the Radboud dysarthria assessment, swallowing speed, dysphagia limit, test of mastication and swallowing solids (TOMASS), and 6-min mastication test (6MMT). The disease severity was assessed using the Newcastle mitochondrial disease scale for adults (NMDAS). RESULTS: The study included 224 patients with MD with a median age of 42 years of whom 37.5% were male. The pooled prevalence of dysarthria was 33.8% and of dysphagia 35%. Patients with MD showed a negative deviation from the norm on swallowing speed, TOMASS (total time) and the 6MMT. Furthermore, a significant moderate relation was found between the presence of dysarthria and the clinical phenotypes. There was a statistically significant difference in total time on the TOMASS between the clinical phenotypes. Finally, disease severity showed a significant moderate relation with the severity of dysarthria and a significant weak relation with the severity of dysphagia. CONCLUSION: Dysarthria and dysphagia occur in about one-third of patients with MD. It is important for treating physicians to pay attention to this subject because of the influence of both disorders on social participation and wellbeing. Referral to a speech and language therapist should therefore be considered, especially in patients with a more severe clinical phenotype. The swallowing speed, TOMASS and 6MMT are the most clinically relevant tests to administer.

Micro-metastases in axillary lymph nodes: an increasing classification and treatment dilemma in breast cancer due to the introduction of the sentinel lymph node procedure.

BACKGROUND: Sentinel lymph node (SN) biopsy will increasingly replace axillary lymph node dissection (ALND) for staging in breast cancer. For daily practice, examination of the SN by serial sectioning (SS) and/or immunohistochemistry (IHC) is being promoted. Use of these techniques may result into stage migration due to the increased detection of micro-metastases. The consequence may be overshooting of patients with adjuvant therapy, as the prognostic relevance of (small) micro-metastases and isolated tumor cells is unclear. METHODS: The prognostic impact of micro-metastases is determined by reviewing ALND studies with a follow up of at least 5 years, including more than 100 patients, before the SN era. Furthermore, studies in which conventionally haematoxylin-eosin (H&E) negative SNs are investigated for occult metastases by SS and/or IHC are reviewed. RESULTS: In only one of eight studies, occult metastases were an independent risk factor for reduced survival. The outcome is dependent on the size of the nodal metastasis. IHC and SS as used in the SN procedure indeed induce a shift from pNO to pN1a (according to TNM). CONCLUSION: By the thorough pathologic examination of the SN, isolated tumor cells and micro-metastases are more frequently detected. We propose to classify small micro-metastases (<0.5 mm) in a separate pN1a(min) category (min for minimal) to prevent stage migration. As the prognostic relevance of isolated tumor cells and (small) micrometastases has not been proven, the value of adjuvant therapy can be questioned for patients with otherwise good prognostic factors.