[Remission rate of mediastinal lymph nodes after multimodal therapy of lung cancer--is it a prognostic factor?].

Objective: General acceptance in the oncologic community has been gained for combined modality treatment of non-small cell lung (NSCLC) cancer in locally advanced stage IIIA and IIIB disease. However, no optimal regimen has been established. This study (chemotherapy and radiochemotherapy followed by operation) assesses feasibility, response, resectability, and survival in patients with stage IIIA and IIIB lung cancer. Currently, only little data is available about the prognostic significance of tumor clearance of mediastinal nodes. Thus, an important aim of our study was to evaluate the prognostic significance of the extent of tumor reduction in mediastinal nodes by a neoadjuvant multimodality protocol.

Patients: In a phase II protocol, 26 patients underwent neoadjuvant radiochemotherapy. Subsequently, a radical lymphadenectomy was performed during surgery. The extent of tumor regression was determined according to the methodology initially described by Salzer-Kuntschik for osteosarcoma: Grade I: no vital tumor cells, grade II: some tumor cells, grade III: less than 10 % vital tumor cells, grade IV: 10-50 % vital tumor cells, grade V: more than 50 % vital tumor cells, grade VI: no effect of chemotherapy.

Results: Complete pathologic response was seen in 30.7 % of primary tumors, in 38.5 % of mediastinal lymph nodes, and in 23 % of corresponding specimens simultaneously. Median survival was 34.7 months for those patients with grade I, 12.6 months with grade II, and 8.9 months for patients showing a grade III/IV regression in mediastinal nodes. Response rate to neoadjuvant chemotherapy in mediastinal nodes proved to be the only statistically significant parameter for long-term survival: In cases with no vital tumor cells in the operation specimen, median survival was 34.7 months in comparison to those with vital cells showing a median survival of only 11.4 months (P = 0.01).

Conclusion: Patients with locally advanced NSCLCs can enjoy long-term survival after multimodal therapy. However, the complications related to therapy are considerably. Especially, clearance of tumor cells from mediastinal lymph nodes is an important independent prognostic factor.