Low incidence of pulmonary metastases in vulvar cancer patients: limited value of routine chest imaging based on a cohort study.

Objective: To evaluate the incidence of pulmonary metastases in the preoperative work-up of patients with primary vulvar squamous cell carcinoma (SCC).

Design: Retrospective cohort study.

Setting: Tertiary referral centre.

Population: Patients treated for primary vulvar SCC from 2000 to 2018.

Methods: The pre-operative chest imaging of 452 consecutively treated patients was documented with a minimal follow-up period of 2 years.

Mean Outcome Measures: Incidence of pulmonary metastases, frequency of chest imaging and subsequent coincidental findings.

Results: In total, 80.8% of patients underwent pre-operative chest imaging. Seven patients (1.9%), with a median tumour size of 80 mm, presented with pulmonary metastases. None of the patients with early stage disease and tumour size <40 mm who underwent radical local excision (RLE) with sentinel node (SN)-procedure, was diagnosed with pulmonary metastasis. Chest imaging was performed by radiography (58.9%) and computerised tomography (CT) (41.1%). Coincidental findings were reported in 40.7% of patients who underwent CT, compared with 15.8% of patients undergoing radiography, resulting in additional diagnostics in 14.7 and 19.7% and being of limited consequence for outcome in 2.9 and 3.3%, respectively.

Conclusions: The incidence of pulmonary metastases in patients with primary vulvar SCC is extremely low, and none in patients with early stage disease undergoing the SN procedure. Chest imaging was performed in the majority of patients and was associated with frequent coincidental findings leading to clinically irrelevant diagnostic procedures. Therefore, we recommend omitting chest imaging in patients with early stage disease and tumours <40 mm, considering chest CT only in patients with large tumours and/or advanced stage disease.

Tweetable Abstract: The incidence of pulmonary metastases is 1.9%, none in early stage disease planned for SN. Omitting chest imaging in this group is advised.