The aim of this study was to evaluate the prognostic
and therapeutic factors which influence the oncological outcome
of parosteal osteosarcoma. A total of 80 patients with a primary parosteal osteosarcoma
were included in this retrospective study. There were 51 females
and 29 males with a mean age of 29.9 years (11 to 78). The mean follow-up was 11.2 years (1 to 40). Overall survival
was 91.8% at five years and 87.8% at ten years. Local recurrence
occurred in 14 (17.5%) patients and was associated with intralesional
surgery and a large volume of tumour. On histological examination,
80% of the local recurrences were dedifferentiated high-grade tumours.
A total of 12 (14.8%) patients developed pulmonary metastases, of
whom half had either a dedifferentiated tumour or a local recurrence.
Female gender and young age were good prognostic factors. Local
recurrence was a poor prognostic factor for survival. Medullary
involvement or the use of chemotherapy had no impact on survival. The main goal in treating a parosteal osteosarcoma must be to
achieve a wide surgical margin, as inadequate margins are associated
with local recurrence. Local recurrence has a significant negative
effect on survival, as 80% of the local recurrences are high-grade
dedifferentiated tumours, and half of these patients develop metastases. The role of chemotherapy in the treatment of parosteal osteosarcoma
is not as obvious as it is in the treatment of conventional osteosarcoma.
The mainstay of treatment is wide local excision. Cite this article:
