Prognostic significance of the various classifications for parapharyngeal space involvement in nasopharyngeal carcinoma.
CONCLUSIONS
Advanced parapharyngeal space (PPS) involvement showed stronger prognostic value than PPS involvement. The classification of PPS involvement proposed by Min or Sham was the most appropriate classification for parapharyngeal extension in nasopharyngeal carcinoma (NPC). The degree of tumor extension into the PPS should be considered in future TNM staging revisions.


OBJECTIVE
This study was conducted to evaluate the prognostic significance of the various classifications for PPS involvement in patients with NPC.


METHODS
From January to July 2000, a total of 176 patients with pathologically diagnosed NPC were prospectively enrolled in this study. The extent of PPS involvement was examined by contrast-enhanced computed tomography (CT) scan and graded according to the four previously reported classifications (Min, Sham, Xiao, and Heng).


RESULTS
The incidence of PPS involvement was 81.8%. The 5-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and local relapse-free survival rates (LRFS) of the patients with and without PPS involvement were 68.1% and 90.2% (p = 0.010), 66.1% and 87.2% (p = 0.013), 76.7% and 93.6% (p = 0.032), and 84.9% and 93.1% (p = 0.220), respectively. Multivariate analysis showed that PPS involvement (yes vs no) was not an independent prognostic factor. However, graded PPS involvement was an independent factor affecting the prognosis of NPC. When the four classifications were included in a Cox model, it was shown that PPS involvement based on Min's classification was an independent factor for OS (p = 0.001). PPS involvement based on Sham's classification was an independent factor for PFS (p = 0.010) and DMFS (p = 0.009).
State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, China.
Pei-Yu
PY
Huang
Zhe-Yu
ZY
Sun
Chuan-Miao
CM
Xie
Qiu-Yan
QY
Chen
Yue-Feng
YF
Wen
Juan
J
Li
Hui-Zhi
HZ
Qiu
Huai
H
Liu
Zong-Liang
ZL
Zhong
Hai-Qiang
HQ
Mai
Hao-Yuan
HY
Mo
D000293:Adolescent; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000145:classification / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000145:classification / Q000473:pathology*; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D010614:Pharynx / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D055815:Young Adult