(P 076) FOLLOW-UP AFTER CURATIVE SURGICAL TREATMENT OF SOFT-TISSUE SARCOMAS: PATIENTS RECEIVING MORE OR LESS VISITIS THAN PROTOCOL AND ASSOCIATIONS WITH RECURRENCE

Objective: Follow-up (FU) in soft tissue sarcomas (STS) patients is recommended to allow detection of recurrence at an early stage. European FU guidelines are not altered to patient or tumor characteristics, and therefore remains controversial, particularly given concerns about cost, radiation frequency and over-testing. This study assessed the extent to which STS patients after curative surgical treatment received FU visits according to protocol in relation to recurrence in a single tertiary referral center.

Methods: All patients with a malignant STS treated surgically at the Leiden University Medical Center between 2000 and 2020 were included. For each patient, along with patient- and tumor characteristics, all radiological examinations from the start of FU (defined as date of surgery) up to 5 years were included and compared to protocol, which required patients to receive 3 annual visits in the first three years and 2 annual visits in subsequent years. Recurrence was defined as either a local or regional recurrence or a metastasis.

Results: In total 396 STS patients were included of which 252 patients had a high-grade tumor (63.6%). In the first year, only 89 (22%) of patients received the required 3 FU visits, with 187 (47%) having fewer visits particularly among patients with a low grade tumor (75% versus 31% among patients with a high-grade tumor). In subsequent years, the percentage of patients with fewer FU visits than protocol varied between 66% and 85%. Among 60 patients with a recurrence in the first year, 31 (52%) patients received more but also 6 (10%) had fewer FU visits than protocol. In contrast, among patients without a recurrence, 91 (29%) received more than protocol which may suggest possible over-testing and 161 (51%) received less than protocol.

Conclusion: FU patterns of STS patients after curative surgery vary widely. Future research is needed to investigate whether and for which patients it is safe to have a less frequent FU pattern.