The five-year survival rate of patients with lung cancer is twice as high among those between the ages of 15 and 39 years as in those 40 years of age and older, according to data...

from the California Cancer Registry Database.

The findings of lung cancer prevalence, incidence and survival in the database between 1988 and 2006 were presented here by Dr. Laveena Chhatwani of the Stanford Cancer Center, California, during the 74th annual scientific assembly of the American College of Chest Physicians.

There were 2,728 patients with lung cancer who were between 15 and 39 years of age, comprising 0.08 per cent of the lung cancer population. Dr. Chhatwani reported that the incidence of lung cancer in 15-39 year olds was 1.2 cases per 100,000, and in the 40-and-older age group it was 141 cases per 100,000.

Ethnic distribution was markedly different in the two age groups. In the young lung cancer patients, 55 per cent were white, 19 per cent were Hispanic, 12 per cent were black and 12 per cent were Asian. In contrast, 78 per cent of lung cancer patients aged 40 years and older were white, eight per cent were Hispanic, seven per cent were black and six per cent were Asian.

Distant disease was found at first diagnosis in 57 per cent of the younger population compared with 51 per cent of the older group.

Distribution of histologic subtypes differed by age, as well. Among younger patients, 39 per cent had adenocarcinoma, nine per cent had squamous-cell carcinoma, seven per cent had small-cell carcinoma, six per cent had large-cell carcinoma, three per cent had bronchioloalveolar carcinoma and 35 per cent had various other histologic subtypes.

Among older patients, 30 per cent had adenocarcinoma, 19 per cent had squamous-cell carcinoma, 13 per cent had small-cell carcinoma and 28 per cent had various other subtypes.

"Mean five-year cause-specific survival was 34 per cent in the 15-39 year age group and 16 per cent in the 40-and-older age group," Dr. Chhatwani reported. "At each disease stage, mean one- and five-year cause-specific survival rates were better in the younger group," she added.

"These findings suggest that lung cancer in the very young exhibits distinct clinical features," Dr. Chhatwani concluded. She attributed the better survival in the younger group to a higher prevalence of histologic subtypes that are associated with better survival.