Abstract 151P
Background
Mesothelioma in tunica vaginalis testis (MTVT) is extremely rare and less than 300 cases have been reported worldwide, the vast majority being case reports. We present characteristics and treatment outcome in a consecutive cohort from a national treatment program in Denmark (population 5.8 million).
Methods
The oncological treatment of MTVT is centralized to one national center due to the rarity of this disease, and diagnosis is verified by the Dept of Pathology at the center. Patients (pts) are followed for totally five years, then through the Centralized Person Register in Denmark until death. No pts are lost to follow-up. Previously we reported results on fewer pts, while this is an enlarged cohort with updated results on treatment, recurrence, and survival.
Results
This cohort is constituted of 10 consecutive pts diagnosed 2016 through 2023, with updates on January 2024. Annual incidence was 1.4 pts out of 5.8 million Inhabitants, i.e. 0.02 cases/100,000. Median age was 73 years (range 26-86 years), and 6 pts (60%) had had previous cancers [male breast cancer, neuroendocrine large intestine, prostate, squamous cell skin, and basocellular skin (2 cases), respectively]. Only 20% reported prior asbestos exposure. Nine pts had epithelioid subtype while one had biphasic with 40% sarcomatoid component. Ki67 index ranged from 5% to 60%. All received primary scrotal surgery with only three having R0 resection (no microscopic residual disease). Repeated surgery was possible in three cases, resulting in R0 resection, while radiotherapy with curative intention was used in two cases. One pt had advanced disease. Seven received adjuvant chemotherapy (platinum + pemetrexed). Four (40%) had disease recurrence, and two (20%) have died. Median PFS is 23 months (range 3+ - 75+ months), and median OS 47 months. Genomic evaluation is ongoing.
Conclusions
MTVT is extremely rare with an incidence of 0.02 cases/100,000. 70% of pts did not achieve initial R0 resection, but use of re-surgery, radiotherapy with curative intent, and adjuvant chemotherapy led to median OS of 47 months. Thus, prognosis may be somewhat better than for pleural and peritoneal mesothelioma. The rarity of MTVT argues for centralization of treatment.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
J.B. Sørensen.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.