NEW YORK, Jun 14 (Reuters Health) - Using x-rays to screen for lung cancer
does not improve patient survival rates, new study findings suggest.
In a report released Tuesday, US researchers found that using x-rays to
detect lung cancers at the earliest stage did not improve the survival of these
patients.
However, one of the investigators noted that it is not yet clear if using
computed tomography (CT) scans, which can find smaller tumors than x-rays can,
would help cut death rates from lung cancer.
In their report, published in the June issue of the journal Chest, Dr.
Edward F. Patz, Jr., and colleagues at the Duke University Medical Center in
Durham, North Carolina, present the results of their study of 510 patients with
stage IA non-small-cell lung cancer. The patients ranged in age from 31 to 90
years.
The team found that detecting the cancer at a very early stage, when it was
less than 3 centimeters in diameter, did not improve the patient's chance of
survival. While some researchers believe that small tumors are less likely to
have spread, Patz and colleagues suggest that the size of the tumor may not
reflect the chance that it has already spread, or metastasized, elsewhere in the
body, noting that "studies have shown that metastases can be seen in tumors of
any size."
The North Carolina team suggests that by the time a lung tumor has grown to
5 mm, about the size at which it can be picked up on a CT scan, the cancer may
already have spread. Scientists have speculated that using CT scans to detect
early lung cancer might help boost survival rates, and studies of this issue are
ongoing.
"Unfortunately, these data caution that improved small nodule detection with
screening CT may not significantly improve lung cancer mortality," Patz and
co-authors write.
"Despite continued advances in diagnostic techniques, treatment protocols
and tumor biology, the survival rate for lung cancer has shown only minimal
improvement over the past several decades," Patz noted in a statement.
The researchers conclude that screening for lung cancer is still a
controversial issue, "and imaging alone may not be the solution to improve lung
cancer mortality. As more is understood about the biology of lung cancer, it
seems that an integration of imaging findings, molecular characteristics of the
tumor, and (body) response to the malignancy will be necessary to have an impact
on this disease."
Lung cancer is the leading cause of cancer deaths in both men and women in
the US. This year, the disease will claim about 160,000 lives in this country.
