P-69 Anal squamous cell carcinoma (ASCC) outcomes in clinical practice: From localized to metastatic setting

Abstract

Anal cancer is an infrequent neoplasm, usually diagnosed at localized stages. A multidisciplinary approach involving chemoradiotherapy (CRT) and surgery is necessary. Real-world data in both locally advanced and metastatic setting is needed to support therapeutic decisions. Patients with ASCC diagnosis between 2004 and 2022 in three tertiary care centers in Spain were reviewed. Demographic, clinical, pathological, and therapeutic variables were collected. Comparative analyses have been performed by Chi-squared tests. Survival estimates have been calculated by Kaplan-Meier method and comparations have been made using Cox proportional hazards model. 111 patients were included (45.9% males, median age 61y, 9.9% metastatic at initial diagnosis). Preferred treatment in localized stage was CRT (88.1%) with 5-fluorouracil and mytomicin-C (5FU-MMC) (55%) or 5FU-Cisplatin (33%). Response in patients treated with CRT was assessed by MRI at 3 and/or 6 months after CRT in 60.4% and 53.1% respectively. 19.6% of patients needed surgical intervention due to persistent or progressive disease after CRT. There were no significant differences between 5FU-MMC or 5FU-Cisplatin in terms of complete radiological response (45,28% vs. 51,61%; p = 0.58), need of surgical rescue (18,85% vs. 19,35%; p = 0.96), distant or localized relapse (30,18% vs. 25,80%; p = 0.67), median disease-free survival (DFS) (50,00 months vs. non reached (NR); p = 0.24) or overall survival (117,26 months vs. NR; p = 0.45). OS was significantly improved in patients who achieved a complete radiological response vs. patients who not (117,26 months vs. 29,01 months p 42,57% of all patients treated with curative intent relapsed locally (44.2%) or distant (55.8%), being regional nodes most common place of recurrence. The median OS of metastatic patients at diagnosis was 14,75 months. Considering all metastatic patients (de novo or relapsed), no significant differences in OS were found between patients who received treatment with curative intent (surgery, CRT) and patients only candidate to palliative chemotherapy 15,97 months vs. 13,11 months; p = 0.072). Median progression-free survival (PFS) of Carboplatin-Paclitaxel was 4,76 months. 62,85% of metastatic patients received a 2nd line of treatment. 48,57% of metastatic patients received immunotherapy. PD-(L)1 was only determined in 11,42% of metastatic patients. PFS of immunotherapy was 2,27 months. One patient receiving immunotherapy achieved a complete response and two patients achieved a PFS > 12 months. Other regimens used in latter lines included oxaliplatin (5,71%) and irinotecan-based (14,28%) regimens. Real world data in ASCC population reveals a complex scenario with significant heterogeneity in response to treatments and outcomes. Multidisciplinary collaboration is essential. Role of immunotherapy in ASCC patients in clinical practice is still unknown. More research is needed in the refractory setting after Carboplatin-Paclitaxel to increase OS.