Lung Cancer. Part 3
In stage IV lung cancer, for metastatic disease, again there has been some debate. We have gone through probably 20 or 25 years of trying chemotherapy in this disease and until fairly recently the results were dismal. Colleagues at the Princess Margaret _ study in Canada where they looked at chemotherapy versus supportive therapy only for stage IV lung cancer. I think being a very conservative group their bias was that supportive care was probably going to be better than flogging patients with chemotherapy. Much to their surprise they found out that the group of patients with metastatic non small cell lung cancer received chemotherapy not only got an improvement in survival but also an improvement in quality of life as assessed by the patients, and actually a somewhat lower cost for care for patients who were given supportive care only. I think that chemotherapy has improved a lot for lung cancer. The standard regimens often involve a taxine usually, Taxol and some kind of platinum derivative such as carboplatin. I think we are getting response rates that are high enough to justify chemotherapy for patients who at least have a good performance status for advanced lung cancer. Now patients who are very terribly ill or bedridden with marked constitutional symptoms are probably not the type of patients who are going to benefit from this type of intervention but a relatively good-health patient with advanced disease is likely to benefit in all of these ways from chemotherapy.
This is small cell carcinoma, which as I said is a different disease. This is the pulmonary bronchial epithelium at the basement membrane. This is small cell cancer smudged in here inside mucosa. Small cell cancer is usually advanced at the time that the diagnosis is made. It is at least advanced microscopically. If you can’t find it, I think this slide shows part of the problem. One part is because it is submucosal that the early signs of cough or hemoptysis are often not present. It also has a very high growth fraction, as it has an early capacity to spread and lacks early warning signs to focus a patient or physician towards a diagnostic work-up. So we think of all patients with small cell cancers essentially as having disseminated disease at the time they are diagnoses. You remember the slide I showed you a few back – it showed the surgical cure rate for this disease is under 1%. I think that that feeds into what I’ve been saying about our thinking that we really consider this to be disseminated. The only difference is you can subdivide them into those that are overtly disseminated and those where you can’t find evidence of it but you know it’s there.