Radiation-induced cancer after radiotherapy for non-Hodgkin's lymphoma of the head and neck: a retrospective study.
BACKGROUND
survivors of non-Hodgkin's lymphoma (NHL) are well known to be at an increased risk of second malignancies. In this study, we evaluated the incidence and clinical features of head and neck cancer (HNC) occurring after radiotherapy (RT) for NHL.


METHODS
We investigated the clinical records of 322 patients who had received RT for early-stage NHL of the head and neck at our institute between 1952 and 2000.


RESULTS
There were 4 patients with a second HNC developing in the irradiated field, consisting of 2 patients with gum cancer, 1 case with tongue cancer and 1 case with maxillary sinus cancer. The pathological diagnosis in all the 4 patients was squamous cell carcinoma (SCC). Two of the patients (one with gum cancer and one with maxillary sinus cancer) died of the second HNC, while the remaining 2 patients are still living at the time of writing after therapy for the second HNC, with neither recurrence of the second tumor nor relapse of the primary tumor. The ratio of the observed to the expected number (O/E ratio) of a second HNC was calculated to be 12.7 (95%CI, 4.07-35.0), and the absolute excess risk (AER) per 10,000 person-years was 13.3. The median interval between the RT and the diagnosis of the second HNC was 17.0 years (range, 8.7 to 22.7 years).


CONCLUSIONS
The risk of HNC significantly increased after RT for early-stage NHL. These results suggest that second HNC can be regarded as one of the late complications of RT for NHL of the head and neck.
Toda
Kazuma
K
Department of Radiology, Tokyo Medical and Dental University, Bunkyo-ku, Tokyo, Japan. tdmrad@tmd.ac.jp
Shibuya
Hitoshi
H
Hayashi
Keiji
K
Ayukawa
Fumio
F
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000532:radiotherapy*; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006258:Head and Neck Neoplasms / Q000209:etiology / Q000532:radiotherapy*; D006801:Humans; D008228:Lymphoma, Non-Hodgkin / Q000209:etiology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009381:Neoplasms, Radiation-Induced / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000209:etiology* / Q000473:pathology / Q000628:therapy; D011379:Prognosis; D011878:Radiotherapy / Q000009:adverse effects*; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult