A standard treatment option for Limited Small Cell Lung Cancer

Authors Avatar

A standard treatment option for Limited Small Cell Lung Cancer

Lung cancer, as with all other cancers, arises from an abnormal growth of normal cells, which have lost their function and their regulatory mechanisms that would under normal circumstances control growth. Essential for tumour growth is maintenance of sufficient blood supply. At early stages of cancers, with a small tumour, nutrients and blood will enter the cancerous growth by diffusion. At later stages, the tumour will develop new blood vessels as a response to a growth factor from the tumour. (Patrick G., 2009).

Signs and symptoms of lung cancer depend on the size of the tumour, the location and the degree of spread outside the lungs. Symptoms connected with the primary tumour are coughing, wheezing, chest pain and dyspnoea. In cases of a larger tumour (late detection of cancer) symptoms also include airway obstruction, fever and pneumonia. Metastases can occur outside the primary tumour – these are secondary tumours that have been released from the primary tumour and are positioned in other parts of the body, travelling through the blood vessels or the lymphatic system. (Koda-Kimble A. et al, 2008). A regional spread means that the cancer has spread to the lymph nodes and elsewhere in the thorax, and the symptoms are often dysphagia, superior vena cava obstruction and plural effusion. If the secondary tumours have spread to other organs or structures, the spread is defined as distant, such as spreading to the liver or brain.

In terms of lung cancer, there are two different types. One is non-small cell lung cancer which is a group of lung cancers, the different forms being adenocarcinoma, bronchioloalveolar carcinoma, squamous cell carcinoma, large cell carcinoma, and differentiated and undifferentiated lung carcinoma. The non-small cell lung cancer is thought to develop from the foci of the dysplastic surface of the bronchial tree. (Cowell J.K., 2001). This type of lung cancer is not very likely to metastasise to other structures and parts of the body in the early stages. However, it is not very sensitive to chemotherapy but combination chemotherapy can improve survival. (Koda-Kimble M. et al, 2008). Surgery is normally used as a curative treatment in non-small cell lung cancer. The other type of cancer is defined as small cell lung cancer, the use of small cell being linked to the image of small, condensed cell in diagnostics. It is a very fast progressive form of cancer. These cells have been examined and shown to have overexpression of some neuroendocrine peptides such as gastrin-releasing peptide, insulin-like growth factor and growth-hormone releasing peptide, all serving to be factors in a positive feedback loop, making the cells unable to inhibit their own growth. (Cowell J.K., 2001). This form of cancer is very sensitive to chemotherapy, where most patients will respond to it, but there is a high rate of patients to relapse.

There are two stages in small cell lung cancer.

  1. Limited: Cancer is confined to one hemi-thorax and only the regional lymph nodes.
  2. Extended: The disease has spread to areas beyond the thorax.

The type of chemotherapy treatment is decided by the stage of cancer and an evaluation of the patient’s nutritional state, the cardiac and pulmonary status respectively, and the renal and hepatic functions. (Koda-Kimble M. et al, 2008). Follow-up care must be continued after initiation of chemotherapy treatment to evaluate the toxic effects of the drug on the patient, which can include myelosuppression and renal dysfunction. It is very important to monitor any bone marrow depression. The reason for this is that cancer cells grow rapidly and will accumulate a larger amount of cytotoxic drugs compared with normal cells. However, bone marrow cells grow very rapidly as well, so cytotoxic drugs can accumulate in normal, healthy cells giving rise to toxicity and weakening the immune system.

A commonly used chemotherapy combination for limited small cell lung cancer is CAV– a combination of three drugs which are cyclophosphamide - an alkylating agent , doxorubicin – an anthracycline  and vincristine – a vinca alkaloid which inhibits microtubule function.

Join now!

Cyclophosphamide is a synthetic anti-neoplastic drug chemically related to the nitrogen mustards. Cyclophosphamide has the following structural formula:

() Accessed: 30 October 2009.

Cyclophosphamide is biotransformed by the microsomal enzyme oxidation system (CYP 450) to active alkylating metabolites. The principal site of cyclophosphamide activation is the liver. The active metabolites interfere with the growth of malignant cells. (www.drugs.com).

Cyclophosphamide is bifunctional, i.e. contains two alkylating groups that can form covalent bonds with particular nucleophilic substances in the cell. Cyclophosphamide is a cell cycle phase nonspecific agent. Thus cyclophosphamide prevents cell division by cross-linking DNA strands. Its ...

This is a preview of the whole essay