Morbidity after induction therapy and surgery in non small cell lung cancer. Focus on pulmonary function

The recently reported experiences by Doddoli [1], Novoa [2], Martin [3] and Voltolini [4], add useful informations on post-operative morbi-mortality when patients with non small cell lung cancer (NSCLC) are operated after induction treatment (IT). Even if the variability of reported ITs is a limiting factor to draw valuable conclusions the general idea is that an higher morbidity rate is expected when radiotherapy is included in the IT and when a pneumonectomy is performed at the time of operation. The importance of the impact of these two variables post-operatively has, however, never been confirmed with functional evidences. In fact, a comprehensive pulmonary function evaluation in an IT series remains hitherto unreported. We reviewed the records of 22 stage IIIa patients, operated after IT with concurrent radiochemotherapy as described elsewhere [5] between June 1992 and May 1994 (group 1). We selected (1:3 ratio) 61 control cases among the NSCLC patients operated in the same period without a prior IT (group 2). Patients whose functional data (FVC, FEV1, TLC, RV, TLC, KCO, PaO2, PaCO2 and PA-aO2) were not complete as measured before IT, prior and after (1 month) surgery, were priorily excluded. Functional differences pre and post-operatively have been analysed (Student's t-test). Differences before and after surgery in group 1 and 2 were compared using analysis of variance (χ2-test to compare type of surgery and staging). A multiple regression analysis was performed using the parameters measured post-operatively as dependent variables and age, sex, height, entity of resection (pneumonectomy as a risk factor), IT and baseline functionality as independent variables. No differences were detected among the two groups pre-operatively. Thirty days after surgery, regardless of the entity of resection, a significant functional reduction was observed in the group 1 versus group 2 (FVC=−1.42 vs. −0.958 l; FEV1=−0.91 vs. −0.64 l; TLC=−2.45 vs. −1.64 l; PaO2=−2.87 vs. +3.86 mmHg; PA-aO2=+5.05 vs. −3.99 mmHg). In patients who underwent pneumonectomy, changes in lung volumes showed an overlap among the two groups. In patients who underwent lesser resections, function of the group 2 was better either in volumes, either in gas exchanges. Multiple regression (changes in post-operative function), after normalising data for age, entity of resection and pre-operative IT, showed a significant drop in pulmonary volumes and a worsening of intrapulmonary gas exchanges in group 1 patients (Table 1).