Skip metastasis in bone sarcoma. Epidemiology pronostic value and surgical incidences
Gérard Delepine, Salwah Alkhallaf, Helene Cornille, Nicole Delepine
Service d ’oncologie pédiatrique Hôpital Raymond Poincaré Garches France
CTOS London 2008 november 13-15

Introduction

30 years ago Ennecking
described Skip metastases
by but till now few papers
have tried to evaluate their actual
incidence prognostic value and
surgical implications
that is the aim of this
Monocentric retrospective study

Material

 520 patients with bone sarcoma of limbs, scapula or innominate bone
 255 OS , 135 CS, 130 EW and other
 Have been treated and/or followed up by the same team in 23 years.
 503 of these were treated by limb salvage

Method

 Preoperative screening of patients included standard X rays, CT and bone technetium scan in all cases and MRI in 350 cases

 Diagnosis of skip was made on preoperative screening and confirmed by postoperative histologic examination

 This research was supplemented by careful examination of imaging of patients who suffered of regional relapse after surger

 Median follow up is 16 years (minimal 4) excet for 4 disease free survivors lost for follow after 3 years

Results

 Frequency : 21 skip metastases (4%) have been observed

 12 out of 255 patients with Ostéosarcoma (5%

 8 Out 120 patients with Ewing’s sarcoma (6%)

 Only one in 135 chondrosarcoma

 Most of the skip lesion were unique but 3 patients had 2 and one 3 skip

Proximal skip in osteosarcoma

Trans articular skip

Osteosarcoma of distal femur with 2 distal skip

Skip in Ewing’s sarcoma

 The 6 other have been discovered on preoperative MRI of Ewing’s sarcoma of innominate bone

 In half of these patients the skip lesions could not be seen on X Rays, CT and Technetium Scan
Skip metastasis unrecognized before amputation

Unrecognized skip before resection

 4 patients did not benefit of an efficient preoperative screening (no total bone MRI)

 the diagnosis of skip metastase was done only after local recurrence (one after transtibial amputation)

Consequence of skip from distal femur

Consequence of skip lesion from tibia(OS)

Femoral skip metastasis of pubic Ewing

Consequences and outcome

3 Skip from Ewing’s sarcoma of tibia

 Out 130 patients with Ewing’s sarcoma 8 (6%) presented with skip lesions
 6 in pelvic primary
 Two for a long bone primary
 One patient had three skips on the same knee

Consequence and outcome of solitary lumbar skip metastasis from iliac Ew

Consequences of 3 skip lesions from tibia

Unrecognised skip metastasis from tibial OS

In this patients the prognostic value of skip lesion was directly correlated with the adequacy of resection and the efficacy of the chemotherapy when chemotherapy is suboptimal or some skip not resected the prognosis is dismal

Prognostic value of skip

With our most effective protocols and when all visible lesion could be resected , the presence of skip lesions did not affect the disease free survival of our patients

Conclusion

Skip metastases are rare in Osteosarcoma and Ewing’s
sarcoma (5%) and very rare in chondrosarcoma (1%).
Pelvic Ewing’s presents a very high risk of regional skip (20%)

With effective preoperative screening and optimal
chemotherapies the skip lesions are no longer adverse prognostic
factor