Respiratory squamous cell carcinomas in vibroacoustic disease

In 1987, the autopsy of a vibroacoustic disease (VAD) patient disclosed two tumours: a renal cell carcinoma and a malignant glioma in the brain. Since 1987, malignancy in VAD patients has been under close surveillance. To date, in a universe of 945 individuals, there are 46 cases of malignancies, of which 11 are multiple. Of the 11 cases of respiratory tract tumours, all were squamous cell carcinomas (SqCC). This report focuses on the morphological features of these tumours.

Tumour fragments were collected (endoscopic biopsy or surgery) from 11 male VAD patients (ave. age: 58+/-9 years, 3 non-smokers): 2 in glottis and 9 in the lung. In the 3 non-smokers, 2 had lung tumours and 1 had a glottis tumour. All were employed as or retired aircraft technicians, military or commercial pilots. Fragments were fixed either for light and electron microscopy. Immunohistochemistry studies used chromagranine and synaptophysine staining.

All lung tumours were located in the upper right lobe bronchi and were histologically poorly differentiated SqCC (Figs. 1, 2). The search with neuroendocrine markers was negative. The average age of tumour onset in helicopter pilots was below 50 years old while for the other professional groups it was above 50. Nine patients are deceased. The 2 surviving patients are heavy smokers (> 2 packs/day). Smoking habits had no influence on tumour outcome and progression.

Epidemiological studies indicate that squamous cell carcinomas account for approximately 40% of all lung tumours in men. It seems to be highly relevant that all VAD patient respiratory tract tumours are squamous cell carcinomas. It is not surprising that helicopter pilots are the ones who are affected the earliest because previous studies have shown that helicopter pilots exhibited the highest values for the frequency of sister chromatid exchanges. Generally, epidemiological tumor studies do not take histological tumor type into account, but given the results herein, it would seem of the utmost importance to begin specifiying the exact histological type of tumor in all statistical studies.