Adjuvant chemotherapy does not provide a statistically significant survival advantage for patients with Stage IB non–small cell lung cancer (NSCLC), according to the results of a study published in the Journal of Clinical Oncology.
Lung cancer remains the leading cause of cancer-related deaths in the United States. Non–small cell lung cancer is the most common type of lung cancer. “Non–small cell” refers to the type of cell within the lung in which the cancer originated. Stage I NSCLC is located in only one lung and has not spread to the adjacent lymph nodes or outside the chest. The mainstay of treatment for patients diagnosed with a Stage I NSCLC has been surgical removal of the cancer; however, in more recent years, treatment with chemotherapy after surgery (referred to as adjuvant therapy) has emerged as an accepted treatment strategy.
Although adjuvant chemotherapy has generally become accepted as a treatment strategy for early-stage NSCLC, results from trials have not consistently demonstrated improved survival with this treatment approach. The Cancer and Leukemia Group B (CALGB) 9633 study is the only randomized clinical trial designed specifically for Stage IB NSCLC. Within four to eight weeks after surgery to remove their cancer, 344 patients with Stage IB NSCLC were randomly assigned to receive either adjuvant chemotherapy (paclitaxel plus carboplatin) or observation. Median follow-up of patients was 74 months. In the group that received chemotherapy (173 patients), the treatment was well-tolerated and there were no treatment-related deaths. The main toxicity was grade 3-4 neutropenia, which was observed in 35% of patients.
After analyzing the data, the researchers found that survival was not statistically significantly different between the two groups: 74 patients in the chemotherapy group died compared with 81 patients in the observation group. The researchers performed an exploratory analysis to examine the relationship between tumor size and the derived benefit from chemotherapy. This analysis revealed a significant survival benefit for patients with tumors greater than 4 centimeters in diameter who received adjuvant chemotherapy.
The researchers concluded that adjuvant chemotherapy should not be considered standard care for the treatment of stage IB NSCLC because it did not demonstrate a significant survival advantage. However, they suggest that adjuvant chemotherapy should be considered for patients with Stage IB NSCLC who have large tumors.
 Strauss GM, Herndon JE, Maddaus MA, et al. Adjuvant paclitaxel plus carboplatin compared with observation in stage IB non-small cell lung cancer: CALGB 9633 with the Cancer and Leukemia Group B, Radiation Therapy Oncology Group and Nort Central Cancer Treatment Group study groups. Journal of Clinical Oncology. 2008; 26: 5043 – 5051.