Comparative outcomes in oral cavity cancer with resected pT4a and pT4b.
OBJECTIVE
We have previously shown that the resection outcomes of cT4a and cT4b oral cavity squamous cell carcinoma (OSCC) are comparable, but whether similar conclusions can be applied for the pathological stage of this disease needs investigation. In this study, we sought to compare the outcomes and to identify the risk factors for both pT4a and pT4b tumors.


METHODS
We retrospectively examined 181 pT4 OSCC patients who had radical resections between 2003 and 2010. The 5-year control and survival rates were the main outcome measures.


RESULTS
Of the 181 resected pT4 OSCC patients, 133 (73%) had pT4a disease, and 48 (27%) had pT4b disease. All of the resected T4b tumors were below the mandibular notch (infra-notch pT4b). The 5-year outcomes of the patients with infra-notch pT4b and pT4a were comparable: local control, 80% vs. 78%, p=0.7275; neck control, 87% vs. 82%, p=0.4798; distant metastases, 22% vs. 23%, p=0.8871; disease-free survival, 63% vs. 55%, p=0.2813; disease-specific survival, 68% vs. 60%, p=0.3526; and overall survival, 62% vs. 44%, p=0.2643, respectively. Extracapsular spread was the only independent prognostic factor for 5-year survival rates in pT4a patients. Poor tumor differentiation and pN2 status were the independent 5-year survival prognostic factors for the infra-notch pT4b tumor patients.


CONCLUSIONS
Infra-notch pT4b had outcomes comparable with those of pT4a tumors, although they displayed different risk factors. We therefore recommend that resectable infra-notch pT4b tumors should be classified as pT4a disease in the AJCC tumor staging.
Department of Otorhinolaryngology, Head and Neck Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan, ROC.
Chun-Ta
CT
Liao
Li-Yu
LY
Lee
Chuen
C
Hsueh
Chien-Yu
CY
Lin
Kang-Hsing
KH
Fan
Hung-Ming
HM
Wang
Shu-Hang
SH
Ng
Chih-Hung
CH
Lin
Chung-Kan
CK
Tsao
I-How
IH
Chen
Kai-Ping
KP
Chang
Shiang-Fu
SF
Huang
Chung-Jan
CJ
Kang
Ku-Hao
KH
Fang
Yu-Chien
YC
Wang
Yu-Liang
YL
Chang
Yu-Chen
YC
Huang
Chi-Ying
CY
Tsai
Tzu-Chen
TC
Yen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000556:secondary / Q000601:surgery*; D059248:Chemoradiotherapy; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology; D008297:Male; D008334:Mandible / Q000473:pathology; D008406:Masseter Muscle / Q000473:pathology; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology / Q000601:surgery*; D020360:Neoadjuvant Therapy; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D011626:Pterygoid Muscles / Q000473:pathology; D018714:Radiotherapy, Adjuvant; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D014062:Tongue Neoplasms / Q000473:pathology / Q000601:surgery; D016896:Treatment Outcome