Subclinical myopathy in early stage colorectal cancer

Skeletal muscle biopsies harvested from asymptomatic patients affected with early stage colorectal cancer present centralized and central myonuclei, a feature that may be indicative of tumor associated muscle disorders, potentially leading to cachexia.. Biopsy of the rectus abdominis muscle were harvested during elective laparoscopic tumor resection, before any chemotherapeutic treatment., thus excluding the most trivial ethiologic hypothesis. On the other hands, anestetics and other medications could induce a mild myopathy that we may exclude on the basis of morphometric analyses, ATPase histochemichemistry, and immunohistochemical studies using antibodies directed to N-CAM and to MHC-emb, two sound makers of muscle denervation and damage-induced muscle regeneration. Here we present immunohistochemical evidence of no infiltration of the muscle tissue with inflammatory cells, thus excluding also the trivial explanation of a trauma-inducted myopathy during laparoscopy. Factors and mechanisms of this early cancer-associated mild myopathy are yet unknown. Follow-up of patients will grant the clinical relevance of these surprising observations and their predictive value of an incoming severe muscle wasting syndrome.