NTRK-Fusions – A new kid on the block

The neurotrophic tyrosine receptor kinases (NTRK) play an important role in the development and function of the nervous system. Fusions involving NTRK and a wide range of genes that act as fusion partners are oncogenic and activate well-known signal transduction pathways like the MAPK-ERK pathway. NTRK fusions occur in many very different tumor entities in children and youth as well as in adults. There are a few tumors like secretory breast cancer and congenital fibrosarcoma for which NTRK fusions are pathognomonic. At the same time there a large number of tumors in which NTRK fusions occur in very rare frequency (e.g., lung cancer). TRK inhibitors offer now the possibility to use NTRK fusion as antitumorigenic targets in a tumor agnostic fashion regardless of the basic histology. It is the task of modern pathology to identify such targetable fusions in a highly effective and efficient manner.     

Effect of tumor size on recurrence-free survival of upper tract urothelial carcinoma following surgical resection

ObjectiveTo identify predictors of recurrence-free survival (RFS) based on the clinicopathological features of patients with upper tract urothelial carcinoma (UTUC) who have undergone radical nephroureterectomy (RNU) with bladder cuff resection.Materials and methodsWe retrospectively reviewed the records of patients from October 1998 to July 2012 at our tertiary institution and identified 120 patients with sufficient data who underwent RNU for UTUC. We recorded various clinical and histopathological parameters as potential predictors of outcome. Recurrence was defined as any occurrence of urothelial carcinoma after RNU either intravesically, local/regionally, or at distant sites. Univariate, multivariate, and RFS analyses were conducted using the Cox regression and Kaplan-Meier methods.ResultsThe median age of our cohort was 71 years (interquartile range: 64–78). Median RNU-specimen tumor size was 3.0 cm (interquartile range: 2.0–5.0 cm). Fifty-four patients (45%) had a tumor<3.0 cm and 66 (55%) had a tumor≥3.0 cm. Eighty patients (66.7%) had organ-confined UTUC (≤pT2) and 40 (33.3%) had non–organ-confined UTUC (≥pT3). Sixty-five patients (54.2%) experienced at least 1 recurrence. Forty-three patients (35.8%) had at least 1 episode of intravesical recurrence and 28 (23.3%) had distant recurrence. A multivariate analysis revealed non–organ-confined disease (hazard ratio [HR] = 3.62, P<0.001), tumor diameter≥3 cm (HR = 1.97, P = 0.011), and male gender (HR = 1.81, P = 0.047) to be significant independent predictors of disease recurrence. The 5-year RFS rate was 46.9% and 25.8% for patients with tumor size<3 and≥3 cm, respectively.ConclusionsFollowing RNU, the incidence of recurrence remains high among patients with UTUC. In our cohort of patients, tumor diameter≥3.0 cm, non–organ-confined UTUC, and male gender constitute important risk factors for poor RFS outcomes following RNU. These patients require diligent postoperative surveillance and may potentially benefit from perioperative systemic therapy.