Imaging investigations before referral to a sarcoma center delay the final diagnosis of musculoskeletal sarcoma

Background and purpose - The use of point-of-care or local investigations before referral to specialist sarcoma centers as part of a fast-track diagnostic pathway varies, and may affect the time to diagnosis. We wanted to investigate differences in time intervals and proportion of malignancy in patients who were referred after initial diagnostic investigations were performed locally and in patients who were referred without these investigations. Patients and methods - We included 545 consecutive patients who were referred to Aarhus Sarcoma Center for suspected musculoskeletal sarcoma. Data on time intervals and investigations performed were collected from questionnaires and patient records. Patients who were referred from outside Aarhus uptake area after initial MRI/CT or histology performed locally were compared with patients who were referred from Aarhus uptake area without these investigations. Results - The median total interval from first symptom to diagnosis was 166 days for outside patients referred with MRI/CT or histology, which was 91 (95% CI: 76-106) days longer than for local patients who were referred without MRI/CT or histology. Comparing the same groups, the median diagnostic interval was 41 (95% CI: 30-51) days longer for outside patients including both primary care and hospital intervals. Both the proportion of malignancies (38% vs. 14%) and the proportion of sarcomas (24% vs. 7%) were higher in the outside group referred with MRI/CT or histology than in the local group without MRI/CT or histology. Interpretation - Pre-referral investigations at a local hospital increased the diagnostic interval by at least 1 month for 50% of the patients, and the proportion of malignancy was more than doubled-to almost 40%. If investigations are to be performed before referral to a sarcoma center, they should be part of the fast-track pathway in order to ensure timely diagnosis.