Risk Factors and Clinical Features of Fistula after Concurrent Chemoradiation and Brachytherapy for Locally Advanced Cervical Cancer

PURPOSE/OBJECTIVE(S)

The standard treatment for locally advanced cervical cancer (LACC) is concurrent chemoradiation and brachytherapy (CRT-B). Fistula formation is a serious complication of treatment; however, risk factors and clinical outcomes are not well described. We sought to identify the incidence, risk factors and prognosis of radiation-induced fistula in women who underwent CRT-B for LACC.

MATERIALS/METHODS

A single institution retrospective review of patients treated with CRT-B for LACC from July 2013 to August 2022 across 3 centers was performed. Inclusion criteria were Stage IB-IVB cervical cancer treated with definitive intent. Patients with upfront or adjuvant surgery were excluded. Cox-proportional hazards model was performed to assess factors associated with fistula. Local control and fistula-free survival were estimated using the Kaplan-Meyer method. Clinical significance was defined as p < 0.05.

RESULTS

A total of 105 patients met the inclusion criteria and were included in this analysis. Patients consisted of FIGO Stage I (n = 20, 19%), Stage II (n = 22, 21%), Stage III (n = 46, 43.8%) or Stage IV disease (n = 17, 16.2%). 12 (11.4%) patients developed fistula following CRT-B; 1/12 patients (8.3%) had fistula present at time of diagnosis. Median time to fistula development was 12 months. Fistula was characterized as vesicovaginal/urethrovaginal in 58.3% (n = 7) and rectovaginal/intestinovaginal in 83.3% (n = 10), including 8 patients (66.7%) who had more than one type of fistula. 4/12 (33.3%) of patients with fistula had concurrent local recurrence. Patients were treated with conservative management (41.7%), hyperbaric oxygen (16.7%) and/or surgery (83.3%). Complications included infection (50.0%), urinary/bowel diversion (83.3%), hospitalization (50.0%) and death (8.3%). Fistula was resolved in 7/12 patients (58.3%) at time of last follow up. Higher BMI (p = 0.04) and use of hybrid applicators (p = 0.02) were associated with decreased likelihood of fistula development. Disease extension into bladder was associated with increased likelihood of fistula development (p = 0.03). Compared to former and never smoking, current smoking was associated with a higher risk of developing fistula (p = 0.04, OR 4.42, CI:1.07-18.34). Compared to intracavitary and hybrid applicators, the use of a Syed applicator was associated with increased likelihood of fistula development (p = 0.02, OR 8.00, CI: 1.37-46.55). Two-year local control was 82.5% (CI: 64.5-91.9) for Stage I-II, 80.7% (CI: 62.8-90.6) for Stage III, and 62.2% (CI: 30.1-82.9) for Stage IV. Two-year fistula free survival was 89.9% (CI: 80.6 - 94.9).

CONCLUSION

Women who undergo definitive chemoradiation for treatment of LACC have a 11.4% risk of fistula formation overall. The risk is higher amongst patients with current smoking, disease extension into bladder and Syed applicators. Overall two-year local control was 78.7% and fistula free survival was 89.9%.

Single Institution Experience of the Effect of Adjuvant Radiation on Outcomes for Patients with Uterine Carcinosarcoma

PURPOSE/OBJECTIVE(S)

Uterine carcinosarcoma (UCS) is a rare but aggressive malignancy with poor outcomes. Due to its low incidence, there is no well-established optimal treatment. Standard treatment involves surgery and chemotherapy (CT) +/- adjuvant radiation therapy (RT). Our primary aim was to determine if patients who underwent adjuvant RT had improved distant metastasis free survival (DMFS) and locoregional recurrence free survival (LRRFS). Our secondary aim was to determine the effect of adjuvant RT on overall survival (OS).

MATERIALS/METHODS

We performed a single institutional retrospective review of all patients with UCS who underwent primary surgical resection +/- CT and +/- RT between 2007 to 2021. Patients without at least 3 months of documented follow-up were excluded. We assessed DMFS, LRRFS, and OS between patients who did and did not receive adjuvant RT, consisting of vaginal brachytherapy (VBT), external beam radiation therapy (EBRT), or EBRT + VBT. Statistical analysis was performed with spreadsheet and statistical software.

RESULTS

Sixty-four patients underwent primary surgical resection for FIGO stage I-IV UCS. Sixty six percent (n = 42) had early stage, FIGO I-II disease and 34% (n = 22) had late stage, FIGO III-IV disease. Eleven percent (n = 7) underwent surgery alone, 28% (n = 18) underwent surgery + CT, 6% (n = 4) underwent surgery + adjuvant RT, and 55% (n = 35) underwent surgery + CT + RT. Most patients who underwent surgery + CT + EBRT + VBT (n = 9) had worse clinicopathologic features including late stage (56%), lymphovascular invasion positive (78%) disease with 50% or greater myometrial invasion (56%). EBRT doses ranged from 45-50.4 Gray (Gy) in 1.8 Gy per fraction. VBT doses ranged from 21-25 Gy in 3-5 fractions when delivered alone and 10-15 Gy in 2-3 fractions when delivered as a boost. Median DMFS was 20.3 months, median LRRFS was 22.6 months, median DFS was 19.4 months, and median OS was 24.7 months. Rate of distant metastasis appeared to drive rate of disease-free survival (Table 1). Patients who underwent adjuvant RT had improved median DMFS (71.5 vs. 11.3 months, p = .002), median LRRFS (71.5 vs 22.5 months, p = .002), and median OS (60.7 vs. 22.5 months, p = .002) compared to those who did not receive RT.

CONCLUSION

Prognosis of patients with UCS remains poor; however, adjuvant RT delivered after CT may offer potential benefit in survival outcomes despite worse clinicopathologic features in these patients.