DIFFERENCES IN BIOLOGICAL CHARACTERISTICS OF VARIOUS HISTOLOGICAL TYPES OF LOWER RESPIRATORY TRACT TUMOURS

Outcome of carcinoma in situ and early invasive carcinoma of the bronchus

Seventeen patients in whom a squamous carcinoma in situ of the bronchus had been resected have been followed for up to 16 years. The crude mortality rate for these patients is remarkably high, with seven (41%) dead after five years and 14 (82%) after 10 years. Half the patients had died as a direct result of malignant disease by 10 years--because of recurrence, metastatic disease, or the development of a second tumour. A guarded long-term prognosis must be given in these patients owing to the many deaths (mainly from other respiratory diseases) besides those from recurrent cancer.

Lung cancer in women

Eighty-three instances of lung cancer in women are presented. The frequency of the condition is lower in women than in men but the tumours in women tend to be less well differentiated and are less likely to be resectable than in men. The frequency of extrathoracic metastases at the time of diagnosis is greater in women than in men. It is suggested that the immunological defences of women are better than those of men because of sex-linked genes, present in double dose in the female, which are concerned with the immunological mechanisms, and that the clinically apparent tumours are those which, by virtue of their greater intrinsic malignancy, can overcome the defence mechanisms.