Stages IA and IB NSCLC Treatment
Although there is sufficient evidence that postoperative chemotherapy is effective in patients with stage II or stage IIIA NSCLC, its usefulness in patients with stage IB NSCLC is less clear.
Evidence (adjuvant chemotherapy for stage IB NSCLC):
- The Cancer and Leukemia Group B study (CALGB-9633) addressed the results of adjuvant carboplatin and paclitaxel versus observation for OS in 344 patients with resected stage IB (i.e., pathological T2, N0) NSCLC. Within 4 to 8 weeks of resection, patients were randomly assigned to postoperative chemotherapy or observation.
- Survival was not significantly different (HR, 0.83; CI, 0.64–1.08; P = .12) at a median follow-up of 74 months.
- Grades 3 to 4 neutropenia were the predominant toxicity; there were no treatment-related deaths.
- A post-hoc exploratory analysis demonstrated a significant survival difference in favor of postoperative chemotherapy for patients who had tumors 4 cm or greater in diameter (HR, 0.69; CI, 0.48–0.99; P = .043).
Given the magnitude of observed survival differences, CALGB-9633 may have been underpowered to detect small but clinically meaningful improvements in survival. In addition, the use of a carboplatin versus a cisplatin combination might have affected the results. At present, there is no reliable evidence that postoperative chemotherapy improves survival of patients with stage IB NSCLC. [Level of evidence: 1iiA]
Patients with potentially resectable tumors with medical contraindications to surgery or those with inoperable stage I disease and with sufficient pulmonary reserve may be candidates for radiation therapy with curative intent. Primary radiation therapy often consists of approximately 60 Gy delivered with megavoltage equipment to the midplane of the known tumor volume using conventional fractionation. A boost to the cone down field of the primary tumor is frequently used to enhance local control. Careful treatment planning with precise definition of target volume and avoidance of critical normal structures to the extent possible is needed for optimal results; this requires the use of a simulator.
In the two largest retrospective radiation therapy series, patients with inoperable disease treated with definitive radiation therapy achieved 5-year survival rates of 10% and 27%.[19,20] Both series found that patients with T1, N0 tumors had better outcomes, and 5-year survival rates of 60% and 32% were found in this subgroup.