Opportunities may exist for a more timely diagnosis of sarcoma in some patients given the patterns of primary healthcare utilisation in the previous 12 months, according to an Australian study.

It said efforts to expedite the diagnosis of sarcoma were essential to improve patient outcomes and experience. To support earlier diagnoses, the Victorian study also provides recommendations for investigation of bone pain and soft tissue lumps in primary care.

The retrospective cohort study identified 441 patients with a new sarcoma diagnosis between 2001 and 2021 and linked GP encounters recorded in the previous year.

The cohort included 377 patients with soft tissue sarcoma (STS) and 77 with bone sarcoma (BS).

The study, published in the British Journal of General Practice [link here], found high-grade disease was common in both types of sarcomas (70% in BS v 47% in STS).

Late, stage 3 and 4 diagnoses were more prevalent among STS patients than BS patients (59% v 22%; p<0.001).

As well, a considerable proportion of tumours in both groups were ≥5cm in diameter at diagnosis (59% of STS v 54% of BS).

The study found patients had a median of 3-4 GP visits in the six months pre-diagnosis and six GP visits in the 12 months pre-diagnosis.

“Repeat GP visits were common, with half of STS (50%) and BS (47%) patients visiting their GP ≥4 times in the six months pre-diagnosis.”

“In the six months pre-diagnosis, multiple imaging (≥2 scans) was requested in 21% of STS and 19% of BS patients. Repeat ultrasound scans were requested in 5% of BS and 7% of STS patients, and repeat CT and DXA scans were requested in 5% and 8% of BS patients, respectively.”

It found the monthly rate of GP imaging requests progressively increased from six months before sarcoma diagnosis to peak at eight times the baseline rate immediately before diagnosis.

There were much smaller increases in the rate of GP visits, prescriptions and blood test requests.

The investigators, led by Academic GP and Senior Clinical Research Fellow Dr Meena Rafiq from the University of Melbourne, said the increased clinical activity in the six months prior to sarcoma diagnosis demonstrated a window of opportunity.

“Furthermore, we determined that increases in GP visits and imaging requests were concentrated in the 3–6 months before sarcoma diagnosis,” they said.

“This period represents a ‘diagnostic window’ where potential opportunities exist for expediting sarcoma diagnosis in some patients, if supported by interventions to help identify these patients, optimise their investigation and overcome barriers to timely diagnosis.”

They said waiting times for imaging or specialist care were not long in the Australian healthcare system.

“Potential causes of delay may therefore exist after patients undergo imaging, including due to false negative results from using modalities with poor diagnostic accuracy for sarcoma or from onward referrals to non-sarcoma specialists.”

For example, Australia’s Sarcoma Optimal Care Pathway [link here] recommends urgent x-ray in persistent, non-mechanical bone pain in the absence of prior trauma, lasting more than 6 weeks.

“… however only 1 in 5 BS patients in this study had a GP x-ray request despite bone pain being the most common presenting feature,” the investigators said.

“Clear, high-quality reporting and avoiding downstream delays after abnormal imaging in BS and STS are also essential as GP imaging requests increased up to six months before sarcoma diagnosis.”

The study also found only half of sarcoma patients were directly referred by their GP to specialised sarcoma centres despite the evidence for this to improve outcomes.