Early Lung Cancer Detection

"The findings reported by the I-ELCAP are encouraging and add to the knowledge base that is building related to the value of screening for lung cancer. This is a solid, well established program that has a long track record of international leadership in developing the algorithms for screening and the management of small lung lesions detected on CT.

The study shows that use of a powerful imaging tool, i.e., spiral CT, finds lung cancers when they are very small, and when prognosis is measurably better than when tumors are larger and advanced. The findings reported here are from multiple institutions, providing confidence that their model can duplicated in other settings, and the authors have shown that concerns about excessive false positive rates can be addressed by adherence to protocols for measuring lesion size and growth as a criteria for biopsy. Positivity rates are quite modest, and the predictive value at time of biopsy is quite high.

The authors also show that survival is more favorable when treatment is initiated rapidly after diagnosis (the literature shows that even small delays in treating lung cancer can adversely affect the survival rate). With respect to the question of whether the cancers they are finding are truly life threatening, all patients who had treatable lung cancers and refused treatment have died. The excellent survival of those with small cancers isn't countered by poor survival of similar size cancers. If this is the pattern of survival for screen detected lung cancers, that is very good news.

"Still, the study has some limitations. Because it is an observational study of volunteers (this population is not randomized), we don't know much about who they are, i.e., how representative are they of the high risk population that we might recommend for regular screening? If they are healthier on average, then these results could be more favorable than we ultimately would expect if screening were to be recommended to all adults with a significant smoking history. Still, it's highly unlikely that this completely invalidates the observation of a favorable benefit from early diagnosis. There are also unanswered questions about some other aspects of the study: We don't really know much about the period of observation beyond a baseline and repeat screening; how many people had more than two exams, for example - How complete is the ascertainment of cases and deaths among all participants? There are less incident screens than prevalent screens, so probably quite a few of them haven't had a screen in a few years. Can we be certain that cancers and deaths haven't occurred in the group that isn't under constant surveillance? The five interval cancers reported in this paper also seems to be a smaller number than we would expect. Still, even if more were identified, those would be unlikely to completely null these results. Also, one has to wonder why there weren't more large cancers detected on the initial screening.

"These are very exciting findings that show real promise for reducing this country's top cause of cancer death. But health policy isn't made on the basis of one study, or by one organization. In an era of evidence based medicine, it is a collective process. It is quite reasonable to be enthusiastic about these findings, and yet still recognize that the weight of expert opinion about the efficacy of lung cancer screening will require results from the on-going prospective randomized trials, including the National Lung Screening trial (NLST), from which experimental results are expected before the end of the decade.

"The bottom line for people at risk for lung cancer who hear this news: Talk with your doctor about your risk of lung cancer screening. After a discussion about what is and is not known about the value of testing for early lung cancer detection, if you and your doctor decide in favor of testing, then be sure to chose an institution that has experience in lung scanning and that supports a multidisciplinary program dedicated to evaluation of high risk individuals."

Provided by www.cancer.org

The following is an addition about lung cancer from www.lungusa.org

Lung cancer is the leading cancer killer in both men and women. An estimated 173,700 new cases of lung cancer and an estimated 160,440 deaths from lung cancer will occur in the United States during 2004.

The rate of lung cancer cases appears to be dropping among white and African-American men in the United States, while it continues to rise among both white and African-American women.

There are two major types of lung cancer: non-small cell lung cancer and small cell lung cancer. Non-small cell lung cancer is much more common. It usually spreads to different parts of the body more slowly than small cell lung cancer. Squamous cell carcinoma, adenocarcinoma, and large cell carcinoma are three types of non-small cell lung cancer. Small cell lung cancer also called oat cell cancer, accounts for about 20% of all lung cancer.

By: American Cancer Society