(UroToday.com) Penile cancer is a rare genitourinary malignancy, affecting less than 1 in 100,000 patients in Western industrialized countries. Platinum chemotherapy is the mainstay of treatment for metastatic penile cancer (disease that has spread outside the pelvis), but unfortunately, disease control is poor, and overall survival in the metastatic setting is typically less than 1 year. Given the rarity of this disease, data regarding patient treatment patterns and outcomes is lacking. In this presentation, Dr. Liu presented treatment, toxicity, and outcomes data from 1200 penile cancer patients referred to a large quarternary academic center in the UK, including 101 patients with metastatic penile carcinoma, 59 of whom received chemotherapy.
The 59 patients with metastatic disease were broken down by whether their disease with metachronous (happened after initial diagnosis) or synchronous (same time as initial diagnosis). The median age was 61 in the metachronous group and 52 in the synchronous group. Most patients with metachronous disease had received surgery for primary treatment (98%), with 30% also having undergone inguinal lymph node dissection and 40% having received adjuvant chemoradiotherapy. The most common histology across all groups was keratinizing-squamous, and tumors were most commonly grade 3 at diagnosis. The most common metastatic site was lymph nodes followed by lungs.
Treatment responses in the 59 patients who received chemotherapy are shown below. The clinical benefit rate for first-line therapy was 45.7%, and the clinical benefit rate dropped substantially for subsequent lines of treatment. Chemotherapy as first-line therapy was associated with longer median survival (7.2 months) versus best supportive care (2 months). Patients with a fewer number of metastatic lesions lived longer (11.9 months median survival for 1 metastatic lesion verses 9.7 and 5.3 months for 2 or 3 met sites), and patients who did not develop metastatic disease within 1 year of adjuvant chemoradiotherapy lived longer (median OS 9.8 months versus 5.6 months).
The most common chemotherapy regimen was cisplatin and capecitabine (33 patients), with less than 5 patients receiving each of other chemotherapy regimens such as TIP, TPF, cisplatin-ifosfamide, etc. Grade ¾ toxicities for each regimen are shown below.
In summary, this presentation represents a summary of patient clinical characteristics, treatment, and response from a quarternary-care referral hospital for metastatic penile cancer. Patients who were able to receive first line chemotherapy had a longer survival over patients who received best supportive care, though the clinical benefit from subsequent lines of chemotherapy was much lower. Improved treatment regimens and cooperative research efforts will be essential for improving patient outcomes in this rare malignancy.
Presented by: Wing Kin Liu, PhD, St. George’s University Hospitals NHS Foundation Trust London, United Kingdom
Written by: Alok Tewari, MD, PhD, Medical Oncologist at the Dana-Farber Cancer Institute, at the European Society for Medical Oncology Virtual Congress, ESMO Virtual Congress 2020 #ESMO20, 18 Sept - 21 Sept 2020