Should soft tissue sarcomas be treated at high volume centres?

Jul 9 2007

Soft tissue sarcomas -rare tumours of the connective tissue- should be treated at the few centres which see most cases, in order to give patients the best chance of good outcomes, concludes an analysis of sarcoma management in Florida, published in the Annals of Surgery last month.

“STS [soft tissue sarcomas] are rare. This paucity leaves most health care institutions with low case volumes and outdated or inadequate resources, which impede the ability to offer optimal treatment of these rare and often complicated tumours,” the authors explain.

Using an analysis of a large population-based state cancer registry in Florida, the Juan Gutierrez and colleagues tested the hypothesis that soft tissue sarcomas are better treated at institutions with higher volumes of cases. They used the Florida cancer data system, a prospective database of all cancer cases in the state of Florida since 1981, to identify all records of soft tissue sarcomas up to 2001. A total of 6259 cases were extracted and, after duplicates were removed, the researchers arrived at a total of 5564 unique cases. A final study sample of 4205 cases was created by excluding individuals who had non-surgical treatments.

Next, the researchers looked at the medical facilities where each person’s treatment was done. A total of 256 institutions in Florida performed at least one resection of a soft tissue sarcoma between 1981 and 2001; these were grouped into percentile ranges by surgical procedure volume. Of 4673 surgical procedures recorded (including repeat procedures, which were excluded from the main analysis), 7 institutions performed 1504 cases (32.2%) and were classified as high volume centres. The remaining two thirds of institutions did 3169 cases (67.8% of the total) and were classed as low volume. “Our analysis of 20 years’ surgical management of STS in Florida…[showed that] volumes in 213 facilities amounted to less than 1 case per year and less than 2 cases per year were managed at an additional 79 health care institutions,” reported the authors.

Patients at high volume centres were generally younger, with a higher proportion of women, were more likely to have high-grade tumours and were more likely to receive radiation therapy and chemotherapy. When the authors looked at outcomes, they found that 30-day mortality rates were twice as high in low volume centres than in high volume institutions; there was a similar disparity with the 90-day mortality rate. Median 5-year and 10-year survival was significantly better for patients treated at high volume centres (40 months versus 37 months); however, survival of patients with extremity tumours was equal among the two groups of institutions. There was a slight selection bias in favour of the low volume centres because tumours managed at high volume places were higher grade and larger in size but despite this, higher volume centres achieved superior outcomes in patients with high grade lesions and those with tumours over 10 cm in size.

In an additional analysis, the researchers examined outcomes from treatment of extremity tumours alone to establish whether the volume of surgeries done at a centre affected the likelihood of patients keeping their limbs. A total of 1937 extremity tumours were analysed. At high volume centres, 90.6% of procedures for these tumours were limb sparing operations compared with 86.2% at low volume centres, suggesting that physicians at low-volume centres were more likely to resort to amputation to protect the patient’s survival chances.

“This analysis reveals a direct correlation between hospital surgical volume and both short-term and long-term treatment outcomes for STS. While the observations reported here require confirmation with additional independent data sets they argue persuasively for exclusive referral of patients with STS to high volume specialised centres for optimal treatment, survival, and functional outcomes,” conclude the authors.

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