Natural course of distant metastases following radiotherapy or chemoradiotherapy in HPV-related oropharyngeal cancer.
OBJECTIVE
To describe the natural course of distant metastases (DMs) following radiotherapy (RT) or chemoradiotherapy (CRT) in HPV(+) oropharyngeal carcinoma (OPC).


METHODS
OPC treated with RT/CRT from 1/1/2000 to 5/31/2010 were reviewed. The natural course of DM were compared between HPV(+) and HPV(-) cohorts.


RESULTS
Median follow-up was 3.9 years. The DM rate were similar (11% vs. 15% at 3-years, p=0.25) between the HPV(+) (n=457) vs. the HPV(-) (n=167) cases. While almost all (24/25) HPV(-) DM occurred within 2-years following RT (1 was at 2.1 years), 7/54 (13%) of HPV(+) DM were detected beyond 3 years (up to 5.3 years). Disseminating to >2 organs occurred in 18 (33%) HPV(+) vs. none in HPV(-). Post-DM survival rates were 11% vs. 4% at 2-years (p=0.02) for the HPV(+) vs. HPV(-) cases respectively. 5/6 HPV(+) with lung oligo-metastasis were still alive with stable disease beyond 2-years after salvage procedures for DM (chemotherapy: 3; surgical resection: 2; radiotherapy: 1).


CONCLUSIONS
Although DM rates are similar, the natural course of HPV(+) DM differs from that of HPV(-) patients: it may occur after a longer interval, often with a "disseminating" phenotype, and a small number may have prolonged survival after salvage for DM.
Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Canada.
Shao Hui
SH
Huang
Bayardo
B
Perez-Ordonez
Ilan
I
Weinreb
Andrew
A
Hope
Christine
C
Massey
John N
JN
Waldron
John
J
Kim
Andrew J
AJ
Bayley
Bernard
B
Cummings
B C John
BC
Cho
Jolie
J
Ringash
Laura A
LA
Dawson
Lillian L
LL
Siu
Eric
E
Chen
Jonathan
J
Irish
Patrick
P
Gullane
Angela
A
Hui
Fei-Fei
FF
Liu
Xiaowei
X
Shen
Wei
W
Xu
Brian
B
O'Sullivan
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D052685:Alphapapillomavirus / Q000145:classification*; D002277:Carcinoma / Q000532:radiotherapy / Q000556:secondary* / Q000628:therapy / Q000821:virology; D059248:Chemoradiotherapy; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary / Q000821:virology; D008175:Lung Neoplasms / Q000556:secondary / Q000821:virology; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000473:pathology; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000532:radiotherapy / Q000628:therapy / Q000821:virology*; D030361:Papillomavirus Infections / Q000532:radiotherapy* / Q000628:therapy; D011446:Prospective Studies; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D016879:Salvage Therapy; D012878:Skin Neoplasms / Q000556:secondary / Q000821:virology; D015996:Survival Rate; D014062:Tongue Neoplasms / Q000532:radiotherapy / Q000628:therapy / Q000821:virology; D014067:Tonsillar Neoplasms / Q000532:radiotherapy / Q000628:therapy / Q000821:virology