MARIJUANA, CRACK SMOKING LINKED TO LUNG CANCER

LOS ANGELES (Reuters) - Smoking marijuana or crack cocaine may increase a
person's chance of developing lung cancer, researchers said Tuesday.

``Our study suggests for the first time that we should think differently
about marijuana and crack cocaine,'' said Dr. Sanford Barsky, co-author of
a new study. ``We often think of these as mood-altering drugs, but they are
taken through the respiratory tract,'' he told Reuters.

``Therefore the finding of pre-cancerous changes leads to the hypothesis
that they might raise the possibility the subjects will go on to develop
lung cancer,'' said Barsky, a professor of pathology at the University of
California, Los Angeles (UCLA) School of Medicine.

The study published in the Journal of the National Cancer Institute, shows
that habitual smoking of more than one substance -- marijuana or crack
cocaine -- induces more potentially cancerous molecular alterations.

Crack is a highly-addictive form of cocaine cooked into ''rocks'' that can
be smoked and is much cheaper than powder cocaine.

``For the first time, our investigation shows tobacco is not the only
smoked substance that sets in motion the molecular events which can lead to
lung cancer,'' said Barsky.

The analysis of respiratory tract tissue from 104 people concluded that
smokers and drug users had a markedly higher incidence of six types of
genetic markers associated with increased risk of lung cancer.

For example, the study found that 10.7 percent of non-smokers had evidence
of basal cell hyperplasia, but that increased to 46.2 percent of cocaine
smokers, 53.8 percent of tobacco smokers and 66.7 percent of marijuana
smokers.

Among smokers of both marijuana and tobacco, there was a 100 percent
incidence of basal cell hyperplasia, the study found.

``This is the first work to demonstrate that smokers of marijuana and crack
cocaine have an increased frequency of molecular abnormalities in bronchial
epithelium (tissue) that are similar to those identified in cigarette
smokers,'' said an editorial in the NCI Journal.

It noted that anti-tobacco campaigns might have the unintended effect of
leading teenagers to use marijuana. It said the percentage of high-school
students using the drug daily had risen from 1.9 in 1992 to 4.6 in 1995.

The test sampled marijuana smokers who admitted smoking 10 joints or more
per week for the past five years, crack smokers who smoked one gram or more
per week for nine months in the past year and tobacco smokers who smoked 20
or more cigarettes a day for the past five years.

Barsky said since most of the volunteers were young adults, it was too
early to say whether they would go on to develop lung cancer. But he said
subjects would be monitored in the future.

He noted that since all the volunteers lived in the Los Angeles area --
``not exactly the cleanest air'' - it was not clear if environmental
factors also played a part.

^REUTERS@

Checked-by: Mike Gogulski