Effect of increases in tumor volume after neoadjuvant chemotherapy on the outcome of stage II osteosarcoma regardless of histological response.
BACKGROUND
We assessed volume changes after neoadjuvant chemotherapy and evaluated relations between tumor size changes and clinical characteristics. In addition, we sought to determine whether tumor size change influences patient outcome.


METHODS
The records of 127 patients with stage II osteosarcoma who showed more than a 15% volume change after chemotherapy were retrospectively reviewed. Patients were divided into two groups depending on whether tumors increased or decreased in size. Fisher's exact test was performed to analyze correlations between tumor size changes and clinicopathological variables. Five-year metastasis-free survival and overall survival were evaluated using univariate and multivariate analyses.


RESULTS
A total of 71 patients (55.9%) showed a decrease in tumor volume, and 56 patients (44.1%) showed an increase. An increase in tumor volume after neoadjuvant chemotherapy was found to be positively correlated with a poor histological response and subsequent metastasis. Univariate analysis identified the following parameters as poor prognostic factors: age < or = 15 years (P = 0.03), American Joint Committee on Cancer (AJCC) stage IIB (P = 0.02), a subtype other than osteoblastic (P < 0.01), a poor histological response (P < 0.001), and increased tumor volume after preoperative chemotherapy (P < 0.0001). Multivariate analysis revealed that AJCC stage IIB (P = 0.006) and an increase in tumor volume after preoperative chemotherapy (P < 0.001) both independently shortened metastasis-free survival. However, a poor histological response lost its prognostic significance (P = 0.34).


CONCLUSIONS
Increased tumor volume after neoadjuvant chemotherapy independently shortened metastasis-free and overall survival in AJCC stage II osteosarcoma patients. Tumor volume changes may serve as a basis for risk-adapted therapy when used in combination with other prognostic factors.
Kim
Min Suk
MS
Department of Pathology, Korea Cancer Center Hospital, Seoul, Korea.
Lee
Soo-Yong
SY
Cho
Wan Hyeong
WH
Song
Won Seok
WS
Koh
Jae-Soo
JS
Lee
Jun Ah
JA
Yoo
Ji Young
JY
Jung
Sung Taek
ST
Jeon
Dae-Geun
DG
D000293:Adolescent; D000328:Adult; D017024:Chemotherapy, Adjuvant; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D020360:Neoadjuvant Therapy; D009362:Neoplasm Metastasis; D012516:Osteosarcoma / Q000188:drug therapy* / Q000473:pathology*; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D055815:Young Adult