radiation-associated malignancies of the ear canal

RADIATION-ASSOCIATED MALIGNANCIES OF THE EAR CANAL AND TEMPORAL BONE
ELTON M.
1
LAMBERT , ADAM
S.
2
GARDEN ,
FRANCO
3
DEMONTE ,
DIANNA B.
1
ROBERTS ,
PAUL W.
1
GIDLEY
OF HEAD AND NECK SURGERY 2DEPARTMENT OF RADIATION ONCOLOGY 3DEPARTMENT OF NEUROSURGERY UT MD
ANDERSON CANCER CENTER 1515 HOLCOMBE BLVD, UNIT 1445 HOUSTON, TEXAS 77030
1DEPARTMENT
ABSTRACT
Objective: To examine our experience of surgically treated radiation
associated malignancies (RAM) of the temporal bone
Setting: Tertiary Care Referral Center
Study Design: Retrospective review
Methods: Thirteen patients who underwent surgical treatment for
radiation associated malignancies of the temporal bone were identified
from our database of temporal bone malignancies between 1999 and
2012. Average age at presentation was 54.84 with average follow up of
25.6 months. The presenting symptoms, pathology; interval between
initial radiation treatment and development of radiation associated
malignancy, treatment regimens; recurrences and outcomes were
measured
Results: Of the thirteen cases of RAM’s of the temporal bone, ten
patients had squamous cell carcinoma (76%) while three (23%) had
sarcomas. The average latency between completion of radiation and
diagnosis of the RAM was 13.38 (range 4 – 33 years). We divided the
patients into those with RAM limited to the external auditory canal (LEAC)
and those with malignancies that extended beyond the external auditory
canal (EEAC). Seven patients (54%) had malignancies that were LEAC.
The average age of patients with LEAC malignancies was 66 years versus
41.8 years for EEAC patients (p=0.02). These two groups also differed
in their rate of negative margins (p=0.007) and need for post-operative
adjuvant therapy (p=0.02). The proportion of squamous cell carcinomas
and overall survival rates were higher in the LEAC group, but not
significantly so. Overall five of our thirteen patients recurred (38.4%),
and three (23%) died of their disease during the follow-up period.
Conclusion: To our knowledge this is the largest reported series of
surgically treated radiation associated malignancies of the temporal
bone. This study highlights the need for vigilance for RAM in postradiation patients. Outcomes are more favorable when the tumor is
confined to the EAC. Outcomes are poorer for patients when the RAM is
a sarcoma, when negative margin cannot be obtained, or when
additional postoperative radiotherapy is required
INTRODUCTION
• Cahan et al defined the radiation associated malignancy
• Arising within prior radiation field
• Distinct from the primary tumor
• Latency period of at least 5 years
• Sarcomas classically described as radiation associated
• Radiation Associated Squamous Cell Carcinoma has been
described especially in low radiation dose regions (50 Gy)
• Otorrhea, otalgia, bloody discharge and in some cases facial palsy
are presenting symptoms
Table 1 Characteristics of patients with Malignancies limited to
the external auditory canal (LEAC) and those with malignancies
extending beyond the external auditory canal (EEAC)
CONCLUSION
• Average age at presentation was 54.84 with average follow up of
25.6 months
• Of the thirteen cases of RAM’s of the temporal bone, ten patients
had squamous cell carcinoma (76%) while three (23%) had sarcomas
• The median interval in months from radiation for the previous
malignancy to diagnosis of the temporal bone RAM was 128.55
months
• The overall survival of all patients from the time of diagnosis of the
temporal bone RAM to death or last contact was 65% at both 3 and 5
Years
• Patients with malignancies extending beyond the ear canal were
younger, had higher recurrence rates and lower rates of survival
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