Prognostic effect of diaphyseal location in osteosarcoma: a cohort case-control study at a single institute.
BACKGROUND
Little is known about the clinical outcome or prognosis of diaphyseal osteosarcoma treated with modern therapeutic strategies.


METHODS
We conducted both cohort (n=400) and case-control (n=102) studies on 34 American Joint Committee on Cancer stage II diaphyseal osteosarcomas of the extremities.


RESULTS
In the cohort study, 34 patients with a diaphyseal osteosarcoma showed significantly better survival than 366 patients with metaphyseal osteosarcoma (5-year metastasis-free survival rates, 87% for cases vs. 59% for controls, P=0.01; 5-year overall survival rates, 90% for cases vs. 71% for controls, P=0.04). The case-control study conducted on 34 patients with diaphyseal osteosarcoma and 68 controls (recruited from among the 366 patients with metaphyseal osteosarcoma by matching for age, tumor volume, and location) showed no survival difference between cases and controls (5-year metastasis- free survival rates, P=0.07; 5-year overall survival rates, P=0.26).


CONCLUSIONS
Location differences between the diaphysis and metaphysis may have no prognostic relevance.
Kong
Chang-Bae
CB
Department of Orthopedic Surgery, Korea Cancer Center Hospital, Seoul, Korea.
Kim
Min Suk
MS
Lee
Soo-Yong
SY
Cho
Wan Hyeong
WH
Song
Won Seok
WS
Lee
Jun Ah
JA
Yoo
Ji Young
JY
Chung
So Hak
SH
Jeon
Dae-Geun
DG
D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000473:pathology* / Q000628:therapy; D016022:Case-Control Studies; D015331:Cohort Studies; D018483:Diaphyses / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D012516:Osteosarcoma / Q000473:pathology* / Q000628:therapy; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult