High tumor volume and local recurrence following surgery in osteosarcoma: A retrospective study

Osteosarcoma is a high grade malignant, osteoid forming, primary bone tumor affecting the metaphysis of long bones. Local recurrence (LR) in osteosarcomas is a sinister. Theoretically, a high tumor volume at the time of presentation will limit surgical margins, involve vital neurovascular bundles and show poor response to chemotherapy thereby causing high rates of amputations (as against limb salvage surgery) and should be associated with poor survival rates. This study evaluated objectively if high tumor volume is a significant predictor of local recurrence (LR) in operated cases of osteosarcomas.

Operated cases of osteosarcoma (presenting to the Orthopedic outpatient or the Medical Oncology outpatient between January 1, 2004 and January 1, 2011 were included in the study. Their preoperative clinical data and investigations along with the operative notes were traced from the medical/departmental records. Details of chemotherapy received in the neo-adjuvant and postoperative periods were noted. Besides, all demographic data were also noted. Tumor volume was calculated using the available magnetic resonance images using the formula: ([π/6] × length × width × depth). Post data extraction, patients were divided in two groups, Groups I (without LR) and Group II (with LR).

A total of 95 cases of biopsy proven osteosarcomas were identified. Of which 64 were male and 31 females. There were 15 (15.8%) local recurrences. 71% (57/80) patients without LR fell in the age group of 10-20 years, while 66% (10/15) patients with LR were in the age group of 10-20 years. Limb salvage surgery was done in 81.05% (77/95) patients while a total of 18 patients underwent amputation. Of the 80 cases in Group I (without LR), 40 (50%) patients had tumor volume >200 c.c., 30 patients (37.5%) had tumor volume between 50 and 200 c.c. while only 10 patients had tumor volumes <50 c.c. This was in contrast to the tumor volume noted in Group II (with LR) of 15 patients where 8 patients had a tumor volume between 50 and 200 c.c., five had bigger tumor volumes of >200 c.c. and only two patients were smaller in size, with a tumor volume <50 c.c. The mean tumor volume in the group without LR was 406.74 ± 771.67 c.c. as compared with 195.77 ± 226.8 c.c. in the group with local recurrence. Using Mann-Whitney test, the difference between the two groups was found to be statistically insignificant (P = 1.403).

We conclude that high tumor volume is not a significant predictor of LR in osteosarcomas thus patients with high tumor masses should not be denied limb salvage. However, we recommend that the decision on attempting limb salvage should not only be based on the tumor volume alone.