Validation and applicability of para-aortic lymph nodal contouring atlas in cervical cancer

Clinical Outcomes and Prognostic Factors in Stage III C Cervical Cancer Patients Treated with Radical Radiotherapy or Radiochemotherapy

Objective: Since the update of the 2018 International Federation of Gynecology and Obstetrics (FIGO) staging criteria, there have been few reports on the prognosis of stage III C cervical cancer. Moreover, some studies have drawn controversial conclusions, necessitating further verification. This study aims to evaluate the clinical outcomes and determine the prognostic factors for stage III C cervical cancer patients treated with radical radiotherapy or radiochemotherapy. Methods: The data of 117 stage III C cervical cancer patients (98 III C1 and 19 III C2) who underwent radical radiotherapy or radiochemotherapy were retrospectively analyzed. We evaluated 3-year overall survival (OS) and disease-free survival (DFS) using the Kaplan-Meier method. Prognostic factors were analyzed using the Log-rank test and Cox proportional hazard regression model. The risk of para-aortic lymph node metastasis (LNM) in all patients was assessed through Chi-squared test and logistic regression analysis. Results: For stage III C1 and III C2 patients, the 3-year OS rates were 77.6% and 63.2% (P = .042), and the 3-year DFS rates were 70.4% and 47.4% (P = .003), respectively. The pretreatment location of pelvic LNM, histological type, and FIGO stage was associated with OS (P = .033, .003, .042, respectively); the number of pelvic LNM and FIGO stage were associated with DFS (P = .015, .003, respectively). The histological type was an independent prognostic indicator for OS, and the numbers of pelvic LNM and FIGO stage were independent prognostic indicators for DFS. Furthermore, a pelvic LNM largest short-axis diameter ≥ 1.5 cm and the presence of common iliac LNM were identified as high-risk factors influencing para-aortic LNM in stage III C patients (P = .046, .006, respectively). Conclusions: The results of this study validated the 2018 FIGO staging criteria for stage III C cervical cancer patients undergoing concurrent chemoradiotherapy. These findings may enhance our understanding of the updated staging criteria and contribute to better management of patients in stage III C.

Optimal prophylactic para-aortic radiotherapy in locally advanced cervical cancer: anatomy-based versus margin-based delineation

OBJECTIVE

Precise delineation of the para-aortic nodal region is critical for the optimal therapeutic ratio of prophylactic para-aortic radiotherapy. We aimed to evaluate the para-aortic control and patient-reported gastrointestinal toxicity in patients with locally advanced cervical cancer who received anatomy-based or margin-based prophylactic para-aortic radiotherapy.

METHODS

We analyzed 160 patients with locally advanced cervical cancer who received prophylactic extended-field radiotherapy between January 2014 and November 2019 at two tertiary centers. Para-aortic nodal regions were delineated based on the anatomic principle-based atlas or marginal expansion from the aorta and inferior vena cava. The Patient-Reported Outcome version of the Common Terminology Criteria for Adverse Events was used to assess acute gastrointestinal toxicity, and a score of ≥3 was defined as severe gastrointestinal toxicity.

RESULTS

Seventy-six (47.5%) and 84 (52.5%) patients received anatomy-based and margin-based prophylactic para-aortic radiotherapy, respectively. The median follow-up was 40.1 months (IQR 25.5-58.9). Para-aortic nodal failures occurred in one (1.3%) patient in the anatomy-based para-aortic radiotherapy group and in one (1.2%) patient in the margin-based para-aortic radiotherapy group (p=1.00). There was no in-field or marginal para-aortic nodal failure. The 3-year para-aortic recurrence-free survival for anatomy-based and margin-based para-aortic radiotherapy was 98.6% and 98.8%, respectively (p=0.94). Patients who received anatomy-based para-aortic radiotherapy reported less severe acute gastrointestinal toxicity than those who received margin-based para-aortic radiotherapy (13.2% vs 29.8%, p=0.01). A comparison of gastrointestinal toxicities showed that patients who received anatomy-based para-aortic radiotherapy reported significantly less severe gastrointestinal toxicity than those who received margin-based para-aortic radiotherapy in terms of frequency of diarrhea (7.9% vs 20.2%, p=0.03), severity of abdominal pain (3.9% vs 14.3%, p=0.03), and interference of abdominal pain (2.6% vs 11.9%, p=0.03).

CONCLUSION

Anatomy-based prophylactic para-aortic radiotherapy achieved excellent para-aortic control and a lower incidence of severe patient-reported gastrointestinal toxicity. These findings suggest that anatomy-based delineation optimizes clinical outcomes of prophylactic para-aortic radiotherapy in locally advanced cervical cancer.