Prognostic nomogram for predicting the 5-year probability of developing metastasis after neo-adjuvant chemotherapy and definitive surgery for AJCC stage II extremity osteosarcoma.
BACKGROUND
In this retrospective study, we developed and internally validate a nomogram for predicting 5-year metastasis probability for nonmetastatic extremity osteosarcoma.


METHODS
We reviewed 365 osteosarcoma patients treated at our institute from 1990 to 2003. Clinicopathologic variables were recorded. Multivariate analysis using Cox proportional hazards regression was done and this Cox model was used as the basis for the nomogram.


RESULTS
By American Joint Committee on Cancer (AJCC) staging system, 141 patients (38.6%) were stage IIA and 224 (61.4%) were stage IIB. Multivariate Cox model identified patient age at diagnosis, tumor size, humeral location, and tumor necrosis rate after chemotherapy as correlated with metastasis-free survival. The degree of contribution of each covariate to the total point was tumor location, tumor necrosis rate, maximal tumor diameter, and age in decreasing order. The concordance index for the model was 0.78. Nomogram discrimination was superior to that of AJCC stage (concordance index 0.78 versus 0.68; P = 0.02) and histologic response grouping (concordance index 0.78 versus 0.69; P = 0.0004).


CONCLUSIONS
We devised a nomogram for nonmetastatic osteosarcoma that proposes improved estimates of metastasis over AJCC staging system or tumor necrosis rate. We suggest that this nomogram allows individualized risk assessments and could be used as the basis for risk-adapted therapy.
Kim
M S
MS
Department of Pathology, Korea Cancer Center Hospital, Seoul, Korea.
Lee
S-Y
SY
Lee
T R
TR
Cho
W H
WH
Song
W S
WS
Koh
J-S
JS
Lee
J A
JA
Yoo
J Y
JY
Jeon
D-G
DG
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D005121:Extremities; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009336:Necrosis; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D049451:Nomograms; D019637:Orthopedic Procedures; D012516:Osteosarcoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D018579:Patient Selection; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult
D000970:Antineoplastic Agents