Erlotinib: a brief overview
Lung cancer kills more Americans per year than any other type of cancer (Clay et al., 2005; Simon et al. 2001). There are two prevalent types of lung cancer: Small cell cancers and non-small cell cancers (Simon et al. 2001). Small cell cancers make up only 15-25% of the lung cancer cases that occur in the United States each year with non-small cell cancers making up the majority of the remainder of the cases (Clay et al. 2005; Simon et al. 2001).
While not all lung cancers are malignant or terminal, the majority of non small cell lung cancer cases lead to death of the patient (Simon et al. 2001). It is of utmost importance that new pharmaceutical drugs be produced in order for the quality of life of terminal non small cell lung cancer patients to be enhanced.
Genentech is one of many pharmaceutical companies that continue to support research and development of medications used to treat the more prevalent non small cell lung cancer. One new medication that has just gained the approval of the Food and Drug Administration (FDA) is Erlotnib. Used as an alternative or additive procedure to chemotherapeutic practices, Erlotnib can help to alleviate some of the symptoms that are associated with some non small cell types of cancer and claims to add to the quality of life of its adherents (Clay et al. 2005). There are several drawbacks to using Erlotnib and the drug is still in the preliminary stages of treatment development, but it is possible that for some cancer sufferers Erlotnib can help to make life with cancer a little more bearable.
Non-small Cell Lung Cancer and its Symptoms
Squamous cell carcinoma, adenocarcinoma, and large cell carcinoma are the three types or groupings of non-small cell cancers, all of which can be treated surgically if caught in the early stages of development (Simon et al. 2001; Clay et al. 2005). Formerly the most common type of lung cancer, Squamous cell carcinoma is a type of cancer that is usually formed in the center of the main lobes or bronchi of the lungs (Simon et al. 2001). The cancerous tumors form from mutated reserve cells, which replace damaged cells of the epithelial lining of the bronchi, and can form large cavities in the lungs (Simon et al. 2001). When Squamous cancer metastasizes it can affect the kidneys, brain, adrenal system, and bones (Simon et al. 2001).
Adenocarcinoma cancer is the predominant lung cancer type in women, forming large masses of malignant mucous cells in the outer and central regions of the lung tissues (Simon et al. 2001). Once a fairly rare type of lung cancer, Adenocarcinoma now accounts for more than 50% of all lung cancer in the United States and could be considered the most common type of lung cancer known today (Simon et al. 2001). It is a slowly developing cancer that often does not have any visible symptoms until the later stages of development, often metastasizing in the brain, adrenal glands, or the liver (Simon et al. 2001). Large cell carcinomas are cancers that are not readily identifiable as Squamous or Adenocarcinomas and do not have a certain set of characteristics or symptoms since they can be any myriad of different cancers, some of which have not been studied yet (Simon et al. 2001).
Non-small cell lung cancers have a unique set of symptoms that are incurred by patients at various periods during the course of the cancer development. However, noticeable symptoms may not arise until the later stages of development when they may show up due to the interactions of the tumor tissue with surrounding lung tissue or from the spread of malignant cells to other organs (Simon et al. 2001). Some of the frequently expressed early symptoms of cancer development include frequent bouts of pneumonia, coughing up blood, unexpected weight loss, fever, frequent shortness of breath, and chest pains (Simon et al. 2001). Not all of the aforementioned symptoms will appear at once and some patients may never experience early warning signs of the developing cancer.
Treatments
Once a patient has been diagnosed with lung cancer, immediate action is imperative for the highest chance of effective treatment. The cancer is usually diagnosed from one of many laboratory tests followed including what is known as the staging procedure (Clay et al. 2005; Simon et al. 2001). The staging procedure is the point prior to treatment when the patient’s doctor will attempt to determine what particular stage of development the cancer is in. If the cancer is fairly localized and was diagnosed at an early stage, then there is higher likelihood of cure compared to a cancer that was diagnosed at a later stage (Simon et al. 2001). Once the cancer’s stage is determined, the first procedures that will attempted will be surgery followed by radiation in an attempt to stem the spread of the disease (Simon et al. 2001). At this point in the treatment regime, survival is likely a possibility, however if the cancer was diagnosed at a later stage of development the chances of mortality increase exponentially (Simon et al. 2001). Also, even if a cancerous tumor has been removed and radiation treatments have been administered the chance of recurrence is very high, especially in patients who continue to smoke after treatment (Simon et al. 2001).
Cancer that is diagnosed at a later stage of development usually is not localized and cannot easily be surgically removed, requiring much more complicated treatment procedures. Procedures such as wedgectomy, segmentectomy, and photodynamic therapy (Simon et al. 2001). Lobectomy (removal of all or part of a lobe) is a common procedure for later stage cancers as well and is often employed in the treatment of Stage 1 cancers (Simon et al. 2001). The latest and consequently the most fatal stages of lung cancers are mainly treated with chemotherapeutic practices in an effort to simply make the patient comfortable rather than cure the cancer (Simon et al. 2001). Due to the large scientific and pharmaceutical interests in new treatments and potential cures for cancer, patients with later stage development cancers are regularly approached by companies with opportunities to participate in newly developed technologies and treatments in order to determine the effectiveness of the new procedures in sutu (Simon et al. 2001).
Drug Update
Erlotinib(Tarceva) is one such newly developed cancer treatment drug that was recently approved for trial by the FDA (Clay et al. 2005). P and T Journal recently published an article outlining the preliminary tests that have been performed with Erlotinib and the experimental results that have been achieved thus far in the drug’s development. The article’s authors stress that the drug can be used as a substitute or in conjunction with traditional chemotherapy for the treatment of later stage non-small cell lung cancer. The drug has several documented trials with a marked increase in survival appearing in each trial (Clay et al. 2005). Erlotinib offers the convenience of oral administration and lower toxicities compared to chemotherapy and is the only targeted therapy approved thus far with an increase in survival rate (Clay et al. 2005). The most common adverse effects that were seen in the series of trials were rash and diarrhea, with the level of severity of the rash being indicative of treatment effectiveness (Clay et al. 2005). The actual mechanism of treatment by Erlotinib is not yet truly understood, but it is believed to be a phosphorylization blocker in the tyrosine kinase domain (effectively inhibiting further cell growth by cancerous cells) (Clay et al. 2005). Its effects on children have not been thoroughly studied at this point and therefore its potential danger to development is also still a mystery (Clay et al. 2005).
Erlotinib is a drug that has shown positive results associated with survival, however the main pharmaceutical treatments that have been administered to non-small cell lung cancer patients up to this point in time have mainly been painkilling medications or bisphosphates to try to alleviate some of the complications associated with lung cancer (Clay et al. 2005; Simon et al. 2001). In particular, Oxycontin and other opioids have been used as fairly safe high level painkillers for cancer patients for many years and the zoledronic acid drug, Zometa has shown to be useful in the treatment/prevention of metastasis of cancer in bones (Simon et al. 2001).
Conclusion
In conclusion, it is clear that Erlotinib is a drug that has many beneficial attributes that could be useful in the treatment procedures of most non-small cell lung cancers. The P and T journal article is evidence of the giant leaps that cancer research science is making with regard to new drugs and treatment technologies. The authors of the article appeared to be unbiased and subjective in their review of Erlotinib. They cited its weaknesses as well as its strengths, eventually producing a favorable overall review of Erlotinib and its applications. The favorable review is warranted due to Erlotnib’s usefulness in the field of cancer treatment and potential future cure developments. While the most effective treatment for lung cancer is always prevention, cancer patients can be given renewed hope since new pharmaceutical drugs are being developed every day to help alleviate pain and eventually to produce a treatment that will cure the silent killer known as cancer.
Bibliography
Clay, D., Lipman, YM, and Bonk, ME. 2005. Erlotinib(Tarceva): A brief overview. P&T Journal.30:10. pg. 562-602.
Simon, H., Cannistra, SA, Etkin, MJ, Godine, JE, Huang, E, Heller, D, Shellito, PC, Stern, TA. 2001.What is lung cancer?. Non-Small Cell Lung Cancer. 12: 1-27.
