Palliative Radiation Cures Some Lung Cancers

Approximately one in one hundred patients with apparently incurable non-small cell lung cancer (NSCLC) survive five or more years after being given comparatively small doses of radiation therapy (RT) used to alleviate symptoms, according to a new study.

The study, published in the March 1, 2006, issue of the journal Cancer, found that a new subset of patients with NSCLC appears to have disease that is curable with minimal therapy, and may explain sporadic cures attributed to unconventional therapies or faith healing. NSCLC is the most common type of lung cancer. With an overall five-year survival of only 40%, it is also one of the most lethal. If detected early, five-year survival can reach 60%. Five-year survival in further advanced disease is approximately 15%.

Patients who are diagnosed with disease that is too advanced for curative treatment remain eligible for palliative therapies intended to provide symptom relief, including relatively low doses of localized RT. Clinicians have for a long time made clinical observations that some patients receiving palliative RT long outlive their estimated survival and a few even report cures. Given that therapeutic doses of RT are much higher, it is not unexpected that these reports require evidence-based confirmation.

Michael Mac Manus, M.D., a radiation oncologist at the University of Melbourne Peter MacCallum Cancer Center (Australia), and colleagues clinically monitored 2,337 confirmed and apparently incurable NSCLC patients who had received palliative dose RT.

About 1.1% of the 2,337 survived five or more years, including 18 who achieved an evident cure. Even though five year survivors were more likely to have higher functional scores at diagnosis and less likely to have metastatic disease compared to patients who lived less than five years, there were no other traditional prognostic factors to predict survival with palliative-dosed RT.

"Our data show that close to 1% of patients with NSCLC have prolonged survival with doses of palliative RT that would not normally be considered sufficient for long term disease control.” Future research should concentrate on identifying patient characteristics because "prospective identification of such patients could potentially profoundly influence treatment,” concluded the investigators.


Related Links:
U. of Melbourne Peter MacCallum Cancer Center