Disease Characteristics and Patterns of Failure by Histologic Type for Patients Treated With Definitive Radiation for Cervical Cancer.

Abstract

PURPOSE/OBJECTIVE(S)\nTo assess differences in disease characteristics at the time of diagnosis and patterns of failure by histologic subtype following definitive therapy for cervical cancer.\n\n\nMATERIALS/METHODS\nPatients with cervical cancer who received definitive radiation between 2004 and 2017 at a single institution were identified. Concurrent chemotherapy was given at the discretion of the treating gynecologic oncologist with consideration of performance status and medical comorbidities. Details regarding disease characteristics, treatment parameters, and patient outcomes were collected. Patients were staged according to the 2009 FIGO staging criteria; and, details regarding the presence of clinically positive pelvic or para-aortic lymph nodes were included (currently, considered FIGO IIICI and IIIC2). Patients were divided between squamous (SCC) and non-squamous histologies (non-SCC) for outcome and disease characteristic analysis. Kaplan-Meier (KM) method was used to estimate progression free survival (PFS), distant metastasis free survival (DMFS), and overall survival (OS). A Cox proportional hazards model was utilized to identify if histologic type was associated with patient outcomes.\n\n\nRESULTS\n266 patients who received definitive radiation were identified with a median follow up of 34 months. 94% of patients received cisplatin based concurrent chemotherapy. 216 (81%) had squamous cell carcinoma, 36 (14%) had adenocarcinoma, 13 (5%) had adenosquamous carcinoma, and one patient had had a neuroendocrine small cell tumor. Patients with SCC were more likely than those with non-SCC to have involved lymph nodes (50% vs 36%, P\u202f=\u202f0.047) and have FIGO Stage II-IVA disease (57% vs 42%, P\u202f=\u202f0.016). The KM estimated 5-year PFS (57% vs 64%), DMFS (61% vs 71%), and OS (65% vs 71%) were not significantly different between those with SCC and non-SCC. On multivariable analysis, histologic distinction of SCC or non-SCC was not associated with PFS, DMFS, or OS. Increasing FIGO stage was associated with worse PFS (HR 1.2 per stage increase, 95% CI 1.1-1.3, P\u202f=\u202f0.001), DMFS (HR 1.2 per stage increase, 95% CI 1.1-1.3, P\u202f=\u202f0.001), and OS (HR 1.2 per stage increase, 95% CI 1.1-1.4, P < 0.0001). The presence of clinically positive para-aortic lymph nodes was also associated with worse PFS (HR 4.3 compared to no nodes, 95% CI 2.5-7.4, P < 0.0001), DMFS (HR 4.8 compared to no nodes, 95% CI 2.7-8.6, P < 0.0001), OS (HR 4.0 compared to no nodes, 95% CI 2.1-7.4, P < 0.0001) CONCLUSION: In a large single institution database, patients with non-SCC cervical cancer were more likely to present with earlier stage disease (FIGO Stage I) and were less likely to have clinically positive lymph nodes. However, despite the earlier presentation of these non-SCC patients, there was no difference in PFS, DMFS, or OS between the groups. Consideration of additional treatments, including variations in systemic therapy, dose escalation, or surgery, should be evaluated for non-SCC histology cervical cancer patients to improve outcomes in the future.\n\n\nAUTHOR DISCLOSURE\nD.F. Cousins: None. J. Sanders: None. D.A. Muller: None. K.A. Ward: None. E. Asare: None. B. Libby: None. T.N. Showalter: Research Grant; Varian Medical Systems. board member and committee chair in ABS; American Brachytherapy Society. K. Romano: None.