(P 473) GROIN PAINS: APPROACHES AND OUTCOMES FOR INGUINOFEMORAL SOFT TISSUE SARCOMAS

Objective: Soft tissue sarcomas (STS) involving the groin and inguinal canal present diagnostic and therapeutic challenges. These can be diagnosed after incidental or incomplete resection resulting in delays to definitive care. Furthermore, sarcomas arising in or invading structures in the inguinofemoral region are more likely to require complex vascular resections and abdominopelvic reconstructions, outcomes of which are significantly impacted by perioperative therapy. This cohort study from a high-volume center aims to characterize the modes of diagnosis, diagnostic and therapeutic considerations, and outcomes for inguinofemoral sarcomas.

Methods: A single institution retrospective cohort study was conducted at a high-volume sarcoma center. Patients treated for STS involving the groin or inguinal canal from 2004 to 2022 were included. Data on patient demographics, family history, presenting symptoms, diagnostic approaches, treatment received, perioperative complications, and oncologic outcomes were collected. Actual wound complication rates compared to those predicted by a lower extremity sarcoma nomogram were reviewed. Descriptive statistics are presented as frequencies and measures of central tendency. Univariate and multivariate regression analyses were conducted to identify variables associated with complications and recurrence.

Results: Forty patients aged 25-96 years were included in our study. Median age at diagnosis was 56.6 years. Histologies are summarized in Figure 1. 100% of biopsies were reviewed by a sarcoma pathologist. The most common presenting symptoms were pain (46.2%) and palpable mass (59%); two were diagnosed incidentally after inguinal hernia surgery. 7.5% were recurrences from a previous or remote operation. Site of origin is summarized in Figure 2.

More than half of patients had a family history of cancer and 22.7% had >1 first-degree relative with a cancer diagnosis. Subjects had been treated at our institution prior to routine institutional germline genetic testing for sarcoma patients. However, three patients underwent genetic testing and two were found to have pathologic germline mutations (MSH3 and NF2).

75% of patients were treated with radiation (76.7% neoadjuvant) and 35% of patients were treated with chemotherapy (38.5% neoadjuvant). All resectable patients underwent surgery. Nine required vascular resection, 8 required orchiectomy, and 15 underwent an inguinal ligament, abdominal wall, or pelvic floor reconstruction. Thirty-day complication rate was 36.4% and 90-day complication rate was 39.4%. Anticipated risk of post-operative wound complications from validated nomogram data for lower extremity sarcoma (Bedi et al. 2020) ranged from 9-41% depending on patient data. The observed wound complication rate in our cohort was 24.2%. None of neoadjuvant radiation, chemotherapy, vascular resection, or abdominopelvic reconstruction were associated with postoperative complications on univariate or multivariate analysis.

Median duration of follow-up was 46 months (IQR 17-96), during which time 17.5% of patients developed a local recurrence (LR). Median time to LR was 5 months (IQR 2-18). Distant recurrence (DR) rate was 33% and median time to DR was 18 months (IQR 3-30). 20% of patients in the cohort died after presentation with metastatic disease or DR.

Conclusion: Inguinofemoral sarcomas present several challenges related to timely diagnosis and referral, perioperative therapy, complex surgical decision-making, and translation of these factors into oncologic outcomes. This study provides a granular foundation and direction for future studies, including an upcoming collaborative TARPSWG initiative, that will address unique facets of diagnosis, provider education, perioperative care, and optimizing of outcomes for this population.