Treatment Trends and Outcomes for Patients With Lymph Node-Positive Cancer of the Penis

Abstract

Importance: Penile cancer is an uncommon disease with minimal level I evidence to guide therapy. The National Comprehensive Cancer Network (NCCN) guidelines advocate a lymph node dissection (LND) or radiotherapy with consideration of perioperative chemotherapy for all patients with lymph node-positive (LN+) penile cancer without metastasis.

Objectives: To determine temporal trends in use of chemotherapy for patients with LN+ penile cancer without metastasis and to evaluate outcomes between those who did or did not receive LND, chemotherapy, and radiotherapy.

Design, setting, and participants: The US National Cancer Database (NCDB) was queried for all 1123 patients with LN+, squamous cell carcinoma of the penis without metastasis from January 1, 2004, through December 31, 2014. Temporal trends were assessed using Cochran-Armitage tests. Multivariable logistic models were used to examine the association between treatments, clinicopathologic variables, and receipt of chemotherapy. Kaplan-Meier analyses with log-rank tests and multivariable Cox regressions were used to analyze overall survival. Data were analyzed between January 2017 and September 2017.

Main outcomes and measures: Use of chemotherapy over time. Survival outcomes by receipt or nonreceipt of LND, radiotherapy, and chemotherapy.

Results: Of 1123 patients identified, most were white (924 [82.3%]) vs African American (141 [12.6%]) or of other or unknown race (58 [5.2%]). The age of most patients (727 [64.7%]) was between 50 and 75 years, and 750 patients (66.8%) underwent an LND. From 2004 to 2014, the use of systemic therapy significantly increased (26 of 68 patients, 38.2% vs 65 of 136, 47.8%; P < .001). However, only 177 of 335 patients with N3 disease (52.8%) received chemotherapy (N1: 106 of 338, 31.4%; N2: 178 of 450, 39.6%). Following adjustment, older patients (>76 years: OR, 0.28; 95% CI, 0.15-0.50; P < .001) were less likely to receive chemotherapy. Patients who received radiotherapy (OR, 4.38; 95% CI, 3.10-6.18; P < .001) and those patients with N2 (OR, 1.62; 95% CI, 1.16-2.27; P = .005) or N3 (OR, 2.32; 95% CI, 1.67-3.22; P < .001) cancer were more likely to receive chemotherapy. On multivariable analysis, LND (HR, 0.64; 95% CI, 0.52-0.78; P < .001) was associated with better overall survival, while neither chemotherapy (HR, 1.01; 95% CI, 0.80-1.26; P = .95) nor radiotherapy (HR, 0.85; 95% CI, 0.70-1.04; P = .11) was associated with overall survival.

Conclusions and relevance: In hospitals reporting to the NCDB, only 66.8% of patients with LN+ penile cancer received an LND. While chemotherapy use has increased since 2004, rates remain low (52.8% for patients with N3 cancer). Receipt of LND, but not chemotherapy or radiotherapy, is associated with overall survival. This may reflect the aggressive natural history of penile cancer as well as the inherent analysis limitation of a relatively small sample size. These data highlight opportunities to improve adherence to guideline-recommended care.

Figure 1.. Study Cohort Eligibility

T indicates tumor; N0, no regional lymph node involvement; and M1, distant metastasis.

Figure 2.. Kaplan-Meier Curves of Overall Survival

A, Survival by receipt of lymph node dissection (LND) in all 1123 patients. B, Survival among 373 patients who did not receive LND. C, Survival among 750 patients who received LND. D, Survival by receipt of LND, chemotherapy (CT), and radiotherapy (XRT) in all 1123 patients. CT+ indicates received CT; CT−, no CT; LND+, received LND; LND−, no LND; mOS, median overall survival; XRT+, received XRT; and XRT−, no XRT.