Patients diagnosed with lung cancer that is considered incurable appear to misunderstand the purpose and likely effect of a treatment aimed at making them more comfortable, a new study says. The result may not only be a failure of communication between physicians and their patients: The misunderstanding also may prompt some lung cancer patients and their families to choose aggressive treatments near the end of life rather than opt for care that makes their final days more comfortable.

The authors of the study, presented Monday at the American Society for Radiation Oncology’s annual meeting, found that among 832 patients newly diagnosed with stage IIIB (wet) or stage IV lung cancer, 78% believed that radiation therapy would likely help them live longer and 43% believed that such treatment was “very” or “somewhat” likely to cure their cancer.

Among those with lung cancer diagnosed at this stage, median survival time is 11.5 months, and radiotherapy is generally provided to check the growth of tumors that are disrupting breathing or causing pain and to slow the metastasis of cancer to the brain. Its aim in these cases is therefore “palliative” -- intended to increase a patient’s comfort level, not treat the underlying disease.

But patients and their families often hope for more, and oncologists may be failing to communicate to them the limits of measures being offered, said study authors from UCLA, the University of Iowa, the University of Michigan and the Dana Farber Cancer Institute in Boston.

Medical specialists in palliative care can often bridge this communication gap by taking the time to ensure that patients and their families understand the possibilities and limits of treatment and what options exist for their comfort. An increasing number of hospitals use palliative care experts, whose specialty is to treat or prevent the symptoms and side effects of a disease.

Recently diagnosed with a difficult illness? Learn more about palliative care here:

The promise and pitfalls of palliative care: Forming teams that can help the chronically or terminally ill has show tremendous benefit and is a growing field. But questions, mostly about costs, remain.