Lung cancer is often dramatically different in women than it is in men, U.S. researchers reported on Tuesday in another study that suggests ways to tailor treatment for cancer patients.

They also found that some elderly patients have forms of lung cancer that make them likely to benefit from chemotherapy, even though the treatments can be harsh.

The study, published in the Journal of the American Medical Association, is the latest in a string of experiments that show cancer is far more complex genetically than doctors dreamed of even a few years ago.