Novel Use of Circulating Tumor DNA to Identify Muscle-invasive and Non-organ-confined Upper Tract Urothelial Carcinoma.

BACKGROUND: Optimal patient selection for neoadjuvant chemotherapy prior to surgical extirpation is limited by the inaccuracy of contemporary clinical staging methods in high-risk upper tract urothelial carcinoma (UTUC). OBJECTIVE: To investigate whether the detection of plasma circulating tumor DNA (ctDNA) can predict muscle-invasive (MI) and non-organ-confined (NOC) UTUC. DESIGN, SETTING, AND PARTICIPANTS: Plasma cell-free DNA was prospectively collected from chemotherapy-naïve, high-risk UTUC patients undergoing surgical extirpation and sequenced using a 152-gene panel and low-pass whole-genome sequencing. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: To test for concordance, whole-exome sequencing was performed on matching tumor samples. The performance of ctDNA for predicting MI/NOC UTUC was summarized using the area under a receiver-operating curve, and a variant count threshold for predicting MI/NOC disease was determined by maximizing Youden's J statistic. Kaplan-Meier methods estimated survival, and Mantel-Cox log-rank testing assessed the association between preoperative ctDNA positivity and clinical outcomes. RESULTS AND LIMITATIONS: Of 30 patients enrolled prospectively, 14 were found to have MI/NOC UTUC. At least one ctDNA variant was detected from 21/30 (70%) patients, with 52% concordance with matching tumor samples. Detection of at least two panel-based molecular alterations yielded 71% sensitivity at 94% specificity to predict MI/NOC UTUC. Imposing this threshold in combination with a plasma copy number burden score of >6.5 increased sensitivity to 79% at 94% specificity. Furthermore, the presence of ctDNA was strongly prognostic for progression-free survival (PFS; 1-yr PFS 69% vs 100%, p < 0.001) and cancer-specific survival (CSS; 1-yr CSS 56% vs 100%, p = 0.016). CONCLUSIONS: The detection of plasma ctDNA prior to extirpative surgery was highly predictive of MI/NOC UTUC and strongly prognostic of PFS and CSS. Preoperative ctDNA demonstrates promise as a biomarker for selecting patients to undergo neoadjuvant chemotherapy prior to nephroureterectomy. PATIENT SUMMARY: Here, we show that DNA from upper tract urothelial tumors can be detected in the blood prior to surgical removal of the kidney or ureter. This circulating tumor DNA can be used to predict that upper tract urothelial carcinoma is invasive into the muscular lining of the urinary tract and may help identify those patients who could benefit from chemotherapy prior to surgery.

Impact of radiation therapy on perineal urethrostomy for penile cancer.

OBJECTIVE: A lack of demonstrated clinical benefit precludes radiotherapy (RT) from being recommended for pN1/pN2 penile cancer (PeCa) lesions; but it may be recommended in case of extranodal (pN3) disease or for positive resection margins. Perineal urethrostomy (PU) is a technique of urinary diversion in patients with PeCa requiring total or subtotal penectomy as primary therapy. Prior studies suggest PU failure rates of up to 30%, without specific mention of the potential role of RT. When RT is delivered for PeCa it is usually to the pre-pubic fat, groin and lateral pelvis, and not to the region of the PU. Here we describe the role of perioperative RT in a large, multi-institutional registry of PU for PeCa. METHODS: In our cohort, 299 patients from seven international, high-volume centers in Belgium, Brazil, China, Netherlands, United Kingdom and the United States underwent PU as urinary diversion for PeCa between 2000 and 2020. Demographic and clinicopathologic characteristics were reviewed. RESULTS: Median patient age was 67 years and median follow-up was 19 months. Seven patients (2.3%) received pre-operative RT; six of them with chemotherapy. 37 received RT post-operatively, 21 (57%) with chemotherapy. Stenosis of the PU occurred in 35 (12%) of the total population. The majority of these patients (74%) required surgical revision at a median of 6.1 months post-operatively. RT delivery was neither significantly related to PU stenosis (p = 0.16) or to subsequent revision (p = 0.75). CONCLUSION: Receipt of RT was not significantly associated with increased stenosis risk in PeCa patients who underwent PU.