Surgical margin should guide adjuvant radiation use for osteosarcomas of head and neck

WAILEA, Hawaii — Surgical margin status is the only key factor that should guide decisions about adjuvant radiation therapy for patients with surgically resected osteosarcomas of the head and neck, according to study results presented at Connective Tissue Oncology Society Annual Meeting.

“Radiotherapy improved local control rates [for] patients with osteosarcomas of the head and neck who had positive resection margins after surgery,” Guy Savir, MD, of the department of radiation oncology at Massachusetts General Hospital, and colleagues wrote. “The addition of radiation therapy after surgery should be considered when surgical margins are positive.”

Osteosarcomas of the head and neck (OSHN) account for less than 10% of all osteosarcomas. Surgery is the standard treatment approach, and margin status has proved to be an important prognostic factor for DFS and OS.

The ability to achieve negative margins is limited due to anatomical challenges within the head and neck. Rates of positive margins are high and also are associated with shorter OS.

Previous studies have yielded conflicting results about the benefit of adjuvant radiation as it pertains to margin status, according to study background.

Savir and colleagues conducted a retrospective review of patients with OSHN treated at Massachusetts General Hospital. Researchers analyzed factors that affected local control, DFS and OS.

The analysis included 100 patients (median age, 36.5; range, 3-85; 55% male) referred to the institution between 1979 and 2015. Two patients underwent treatment for recurrence; the other 98 received treatment for primary tumors. Represented disease sites were maxilla (29%), mandible (28%), skull and face (28%), or other (15%).

The majority (83%) of patients had high-grade tumors, whereas 10% had low-grade tumors and 7% had undetermined grade. Median clinical size was 4.4 cm (range, 0.5-14).

Eighty-seven patients underwent surgery. Fifty-one patients (58.6%) had negative margins, including 14 (16.1%) who had margins less than 1 mm. Thirty-one (35.6%) patients had positive margins, and five (5.7%) had undetermined margin status.

Fifty-nine patients (59%) underwent prior chemotherapy; of these, 35 (59.3%) received methotrexate/cisplatin/adriamycin.

Fifty-two (52%) patients received radiation therapy. The majority (n = 45) received radiation plus surgery; of these patients, 34 received radiation postoperatively, nine received it preoperatively, and two received it pre- and postoperatively.

Median radiation dose was 67.6 Gy (mean, 63.1 Gy; range, 25.8-80).

After median follow-up of 48 months, researchers reported a 5-year OS rate of 60.6% and a 5-year DFS rate of 40.6%.

Researchers identified the following factors as having statistically significant associations with OS: age younger than 30 years vs. older than 30 years (HR = 0.38; 95% CI, 0.18-0.82); receipt of radiation alone instead of surgery with or without radiation (HR = 2.94; 95% CI, 1.13-7.67); no surgery vs. surgery (HR = 3.43; 95% CI, 1.6-7.35); and negative margin instead of positive margin (HR = 0.45; 95% CI, 0.21-0.97).

Factors significantly associated with DFS included no surgery vs. surgery (HR = 2.4; 95% CI, 2.43-4.66); no chemotherapy vs. chemotherapy receipt (HR = 2.02; 95% CI, 1.19-3.46); and clinical tumor size (HR = 1.22; 95% CI, 1.17-1.34). – by Mark Leiser

For more information:

Savir G, et al. Poster 111. Presented at: Connective Tissue Oncology Society Annual Meeting; Nov. 8-11, 2017; Maui.

Di sclosure: The researchers report support from the MGH Sarcoma Data Repository from the Jennifer Hunter Yates Foundation, Cassandra Moseley Family Foundation and Kenneth Stanton Fund.