This week, the American Cancer Society announced the results from a report on cancer death rates in the US. In past years, this has been a source of some good news, as the annual reports have shown the overall death rates to be declining for cancer overall since 1993, at a little more than 1% rate. This is felt to be due to a wide range of factors, ranging from less use of hormone replacement therapy in post-menopausal women (felt to contribute to higher rates of breast cancer) to better detection (screening in some cancers, still controversial for lung cancer) to more effective treatments once cancer has been diagnosed. Importantly, this year’s report describes how the decline in recent years has averaged 2.1% per year from 2002 to 2004, the last year that we have numbers available, so the improvements are accelerating compared with 10-15 years ago. And the statistics for lung cancer are actually contributing to those favorable results.

   The full report appears online in the journal Cancer (abstract here) and was developed as a collaboration among the American Cancer Society, the National Cancer Institute, Centers for Disease Control (CDC), and the North American Association of Central Cancer Registries. It includes trends for both new cases (incidence) and death rates.

   Results were broken down by cancer type and by sex. For men, who have shown declining smoking trends for decades, the rate of new lung cancers declined by 1.8% per year over the period from 1991 through 2004. Not bad. Meanwhile, women, who had shown trends of increasing tobacco use while men were starting to quit in large numbers several decades ago, are now showing a plateau in their lung cancer incidence rates after seeing growing numbers up until about 1998. The rate of lung cancer deaths dropped 2.0% yearly in men, and were essentially unchanged, actually up minimally (by 0.2%), in women.   While some of this may reflect more effective treatments, much of this, and especially the sex-based trends, are likely due very largely to smoking patterns, with lung cancer incidence and then death rates lagging behind the tobacco trends. Yes, some studies are seeing more never-smokers, and it’s one of my leading clinical research interests, but smoking patterns dwarf our effects on cancer once it’s developed. Putting some of this into perspective, David Espey of the CDC noted, “The big picture is that the single most important cause of cancer (all cancer, not just lung) is tobacco use. Tobacco use is such a scourge.”

   In the meantime, these aren’t miracles, but the numbers are actually moving in the right direction. And it’s great to have lung cancer be part of some positive news.