Click here to view next page of this article


Lung Cancer 

Lung cancer is the leading cause of cancer death. Prostate is now the second leading cause of cancer death in men - stomach is the one that has the big decrease. Now if you break the epidemiology data down and look at trends overall, the first thing you see - this is the overall curve, this is all ages both sexes - is that there has been a slight decrease in cancer mortality. This is seen more overall for the curve in males than in the curve for females, but there is an overall slight decrease in lung cancer.

Large carcinoma of the lung. Lung cancer is divided into about four histologic types and the reason for understanding that is simply to recognize the unique syndromes that are associated with each of these tumor types. The squamous or epidermoid cancer is usually a central tumor, compatible with the last x-ray I showed you. This is a tumor that often cavitates locally and may also erode vessels producing hemoptysis or so-called Rasmussenís aneurysm. It is certainly related to smoking, which all of these types are. And all of these types of lung cancer have fairly striking perineoplastic syndromes that are associated with the squamous or epidermal type. The main thing is hypercalcemia, which is due to production of the PTH-like growth factor, the stimulants. Itís interesting that squamous within a lung less commonly metastasis to bone, and the adenocarcinoma or small cell carcinoma, which is much more commonly associated with hypercalcemia, which is on this perineoplastic basis.

The adenocarcinoma of the lung is the disease that is most often seen in the periphery of the lung or scars in the lungs that are associated with migratory thrombophlebitis with acanthosis. Also with the syndrome of pulmonary hypertrophic osteoarthropathy, which is usually associated with plumbing. This is likely to lead to the production of growth hormone. And the final type of lung cancer, the so-called large cell cancer of the lung.

Now the management of lung cancer, other than small cell lung cancer - which is really split off in all instances as a separate entity - the management of the other types is primarily surgical if possible. That is the treatment of choice for stage I and II disease, is to be able to resect it. There are studies that have been done and continue to be done to look at the role of adjuvant radiation therapy and systemic therapy, particularly for stage II disease; which means involvement of bronchial or hyaloid nodes. I think that although they are suggestive it remains somewhat inconclusive as to the value of adjuvant treatments. If you look at surgical management, you have to say "All right, who gets an operation and who doesnít?" Thatís something in terms that you need to understand what are the complications of surgery in lung cancer. I think one of the greatest areas of progress in small cell lung cancer is realizing the factors that are on the slide. I donít know that we can improve the numerator greatly surgically, but we decreased the denominator by realizing which patient shouldnít be taken for a thoracotomy and I think spared a lot of unnecessary useless morbidity.

If you look at data with surgical management of lung cancer what you see is that the results are relatively dismal overall. These are the histologic types. These are stage I cases where patients had a tumor mass under 2 cm and no nodal involvement. These are bigger. If you look at all these data for patients with complete resections you can see that less than half of all patients who are surviving five years later despite resection. If you look at the small cell, as I said, it is clearly not a surgical disease. Data couldnít get any worse than that. So that doesnít work for small cell carcinoma of the lung. If you look as squamous and adenocarcinoma for stage I in acute patients you can see that somewhere between 15-30% of patients.

If you look at more extensive lung cancer - again, we are still staying with non small cell cancer - disease that spreads to the mediastinum is known as stage III disease and these patients donít have just a metastasis but they have an involvement with either ipsilateral or contralateral mediastinum. For patients with involved ipsilateral mediastinum, there has been a great deal of effort to try to shrink the disease down with preoperative chemotherapy and/or radiation therapy and then take patients to surgery and then either finish up with some radiation if it wasnít given pre-op, or some additional chemotherapy. There have been many many single institutions and some cooperative group studies done looking at this.

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.

In terms of the management, we have developed increasingly better drug and radiotherapy combinations for dealing with this. Patients who have disease which is limited in presentation, clinically limited to the ipsilateral hemithorax. That is we donít have clinical evidence of spread even though itís thought to be there microscopically, about half of these patients will be able to go into complete remission and the overall remission duration for these patients is somewhere on the order of 15 to 20 months.