Expression patterns and prognostic role of transketolase-like 1 in muscle-invasive bladder cancer

Purpose

The pentose phosphate pathway (PPP) has been shown to play an important role in the metabolism of cancer cells. The transketolase-like 1 gene (TKTL1) encodes an enzyme representing an essential component of this pathway. Its expression has been demonstrated to correlate with stage and outcome in various tumors. The aim of the present study was to assess expression patterns and the prognostic role of TKTL1 in muscle-invasive bladder cancer (MIBC).

Patients and methods

The expression of TKTL1 was assessed in a tissue microarray consisting of histopathologically benign and malign tissue of 112 patients who underwent radical cystectomy due to MIBC. Cytoplasmatic and nuclear expression were assessed by immunohistochemistry and compared separately with clinicopathologic parameters and outcome.

Results

Cytoplasmatic expression of TKTL1 was exclusively present in tumor tissue. In contrast, the proportion of nuclei positive for TKTL1 was higher in histopathologically benign tissue compared with malign tissue. No correlation was observed between cytoplasmatic or nuclear TKTL1 expression and tumor stage, grade or the presence of metastases. Patients with lymph node involvement showed a decreased frequency of cytoplasmatic expression compared with node-negative patients (p = 0.01). However, no further correlation was observed between the expression of TKTL1 and clinical outcome of patients.

Conclusions

The present study shows that the cytoplasmatic expression of TKTL1 is specific for MIBC tissue compared with histopathologically benign urothelium. This specific expression is present in a subgroup of MIBC potentially identifying patients with activated PPP suitable for a targeted inhibition of sugar metabolism. In contrast to other malignancies, TKTL1 shows no prognostic significance in MIBC.

     

Supraclavicular osteocutaneous free flap: Clinical application and surgical details for the reconstruction of composite defects of the nose

The supraclavicular fasciocutaneous flap is a well‐recognized flap in head and neck reconstruction. In this report, we describe for the first time a variation of this flap, the osteocutaneous supraclavicular (SOC) free flap, which was used to reconstruct a composite nasal defect. The defect arose after resection of a recurrent squamous cell carcinoma and involved dorsal nasal skin, cartilage, and the entire nasal bone. A 6 cm × 4 cm size flap including skin, subcutaneous tissue, and a vascularized cortico‐periosteal segment of the clavicle was raised based on the transverse cervical artery. The flap survived with no complications. A satisfactory aesthetic outcome was achieved following two revision procedures. We believe that the incorporation of bone to the supraclavicular flap may expand its applications in reconstruction of composite nasal and facial defects. © 2015 Wiley Periodicals, Inc. Microsurgery 35:328–332, 2015.