The Effect of Gender, Histology, and Stage on Radiotherapy Versus Surgery Treatment of Lung Cancer

Lung cancer continues to be the most common cause of death in the United States, despite vast public health campaigns warning of the dangers of smoking and increasingly stringent anti-smoking laws. Patients diagnosed with lung cancer have also benefited from significant clinical advancements in a 51 variety of biological, surgical, and radiological therapies, yet certain varieties of lung cancer continue to have high morbidity and mortality rates throughout the U.S. We answered the following research question: what is the effect of gender, histology, and cancer stage on the survival ratio of radiotherapy vs. surgery? A subset of the Florida Cancer Registry of 14003 individuals with lung cancer, diagnosed in the state of Florida between 1994 and 2002 was considered. The two main methods of treatment for lung cancer investigated in this study are radiation therapy and surgery. In order to maximize the survival rate post-treatment and present a complete picture, previous outcomes are analyzed here. The outcome is solely decided on the mortality of the patient post treatment. Gender of the patients, histology of the cancer cells, and stage of cancer were used to categorize each patient. The survival rate of each category is analyzed and determined if they are effective modifiers of surgery treatment. This crosssectional study uses survival rate as a factor in determining the relative risk of each factor. Once a variable is proven to be an effective modifier the relative risks is stratified to show the likelihood of the variables affecting mortality ratio. Our statistical analysis shows that the patient’s gender, as well as the histology and stage of cancer should be factors in calculating the risk ratio when determining if radiotherapy should be administered as a treatment. The most important factor in determining the use of radiotherapy is the local or regionalized stage of cancer. For localized tumors, the risks of radiotherapy outweigh the benefits; treatment of non-metastatic lung tumors should be treated with surgery alone. Adenocarcinoma of the lung is the most common histological type of lung cancer in lifelong non-smokers. It also has the highest risk ratio of radiotherapy compared to the other histological types of lung cancer with greatest difference being a 98% increased risk in radiotherapy. Overall, females with adenocarcinoma of the lung are 69% more likely to die from radiotherapy than males, with a risk ratio of 3.59. The type of lung cancer with the lowest risk ratio was regionalized small cell lung carcinoma in females; its risk ratio is 1.40. There is an increased risk of radiation therapy that is modified by various factors. When considering the use of radiation therapy versus surgery one must consider the gender of patient, histology of cancer, and stage of development. These four variable are all effective modifiers that result in different rate of survival in patients. When treating a new patient with lung cancer, risk ratio should be calculated from Table 4 and determined if the survival rate is high enough for the treatment to be administered.