Para-aortic lymph node status at initial assessment is the most important prognostic factor and a key point for the therapeutic strategy in patients with locally advanced cervical cancer. Undiagnosed lymph node metastasis is a major clinical problem as the finding of positive para-aortic lymph nodes leads to treatment modification, with a possible impact on disease free survival. When aortic lymph node disease is discovered, radiotherapy is extended to the para-aortic area, and other treatment modalities may be considered. Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) is the most accurate imaging examination to assess para-aortic extension in patients with locally advanced cervical cancer. The gold standard to identify para-aortic extension remains histologic evaluation of the lymph nodes. Indeed, PET/CT fails to detect approximately 10–15% of patients with negative PET/CT aortic nodes who have lymph node metastasis on pathologic staging. Patients with positive pelvic lymph nodes have para-aortic extension in 25–30% of cases, and surgical staging will lead to treatment modification and probably to improved para-aortic and distant control. Surgical staging also avoids unnecessary toxicity associated with extended field radiation in approximately 75% of patients with pelvic lymph node metastasis. The best modality to identify para-aortic extension is histological evaluation of the lymph nodes, but the survival benefit of surgical staging remains controversial. On the other hand, current studies include a majority of patients without pelvic lymph node spread, who are likely to be those who will benefit the least from surgical staging.
Patterns of lymph node metastasis in locally advanced cervical cancer