Retrospective study of pelvic and para-aortic lymph nodes positivity in stage 1A to 2A cervical cancer patients

BACKGROUND: The significance of pelvic and para-aortic lymph nodes (retroperitoneal lymph nodes) metastasis in the five-year survival of early stage cervical cancer (CC) patients is well established. The previous International Federation of Gynaecology and Obstetrics (FIGO) 2009 staging of CC was clinical and excluded advanced radiological assessment in assigning a stage. However, with the current FIGO 2018 staging, advanced radiological assessment and pathological findings were allowed to assign a stage which would alter the subsequent management. This pilot study aims to obtain local data on the correlation between radiological retroperitoneal lymph node positivity and histological lymph node positivity in early stage CC (stage 1A2 to 2A1) and seeks to correlate independent prognostic factors for recurrence to histological lymph node positivity.

MATERIALS AND METHODS: In this retrospective cross-sectional analysis, clinical data, including clinical staging, Computed Tomography (CT) scan findings and histopathological results were collected and analysed in the Department of Obstetrics and Gynaecology, Hospital Ampang, Ministry of Health Malaysia.

RESULTS: A total of 31 patients had surgery for CC from 1st August 2018 till 31st August 2020. Radical hysterectomy was done on 23 of them as primary treatment for early stage cervical cancer. Both pelvic and para-aortic lymph node dissection was done in 6 patients while 17 patients had only pelvic lymph node dissection. All patients had thoracoabdomino- pelvic CT scans done preoperatively. Among the 82.6% patients with no enlarged pelvic lymph nodes on CT scan, all were confirmed by histology to be negative of malignancy. In the remainder 17.4% of patients with enlarged pelvic nodes on CT scan, three quarters had histology positive pelvic nodes for malignancy (p=0.002). Among patients with no enlarged para-aortic lymph nodes on CT scan, 83.3% had histologically negative para-aortic nodes. Among patients with clinical tumour diameter 2- 3.9 cm, 14.3% had positive pelvic nodes while a quarter of patients with clinical tumour diameter ≥ 4cm had histological positive pelvic nodes. None of the patients with tumour diameter < 2cm had positive pelvic nodes (p=0.993). Positive pelvic lymph nodes involvement was present in 37.5% of those with positive lymphovascular space invasion (LVSI). All patients with negative LVSI had no histological positive pelvic nodes (p=0.103). Among patients with tumour invasion involving the inner third of the stroma, 16.7% had histological positive pelvic nodes while 18.2% with outer third stromal invasion had positive nodes (p=0.977). None of the patients had histologically positive para-aortic lymph nodes with negative pelvic lymph nodes. Among patients with clinical stage 1B2, 20% would have been upstaged to stage 3C based on radiological imaging and final histology confirmation.

CONCLUSION: This study shows that in early stage CC, there is a statistically significant correlation between CT scan findings of enlarged pelvic lymph nodes and histological positive pelvic lymph nodes.