Multidisciplinary Approach Improves Staging of NSCLC

SEATTLE-A multidisciplinary approach may improve clinical staging (cTNM) in patients with non-small-cell lung cancer (NSCLC), Ana Rocha, MD, said at a poster session of the 99th International Conference of the American Thoracic Society (B111, poster B14). "Clinical staging is not perfect and has been shown to be inaccurate more than 50% of the time," Dr. Rocha said in an interview with ONI. "We wanted to show that we could do a better job with a multidisciplinary approach." Accurate clinical staging of NSCLC depends on a thorough clinical evaluation and interpretation of chest CT imaging, she said. However, there are clear limitations to the accuracy of a chest CT, and combined surgical and pathologic evaluations (pTNM) have been found to be more accurate in defining disease stage. Previous trials have shown discordance between cTNM and pTNM in 53% of cases. "We had a lower incidence of upstaging (35%) than what is quoted in the literature," said Dr. Rocha, a fellow in the Department of Medicine, Division of Pulmonary Diseases/Critical Care Medicine, Duke University School of Medicine. "And in a novel finding, we found that tumors located on the lower lobes were more likely to be upstaged." In a prospective cohort study, 160 male patients were diagnosed with clinical stage I/II NSCLC between September 1997 and April 2002. Half of the patients had squamous cell cancers, 56 (35%) had adenocarcinomas, 14 (8.8%) had large-cell carcinomas, and 10 (6.2%) had cancers that were not subtyped. Of 160 patients, 109 (68.1%) underwent operative resection and had pTNM determined at that time by lymph node dissection. The cTNM corresponded to pTNM in 70 of the 109 patients (64.2%); only one subject was downstaged, and 38 (34.9%) were upstaged. Unsuspected nodal involvement (N stage) was responsible for upstaging in 18 patients (47%), more extensive tumor stage (T stage) in 15 patients (40%), and both N stage and T stage in 3 patients (8%). Metastatic disease was found in 2 patients (5%). Tumors in the upper lobes were more common (78% of cases), but those located in the lower lobes were significantly more likely to be upstaged following surgery (58.3% vs 28.2%, P < .006). Location in the lower lobes was the only significant association with upstaging, and no association was found with factors such as age, smoking history, weight loss, tumor size, and histology. "That was a robust finding even when controlling for other factors," Dr. Rocha said, "and we have to see what the mechanisms are for this finding." It is very important for clinicians to pay special attention to these lower-lobe tumors, she added, and to be more aware that they have a greater propensity of being higher T stage. Future research may involve looking at gene expression on lower-lobe tumors as a possible explanation of why they are more aggressive and have a higher rate of upstaging, she said. "As a multidisciplinary group, involving pulmonary, pathology, oncology, surgery, and radiology, we did a better job of selecting the patients who went on to have a surgical resection," Dr. Rocha concluded. "The multidisciplinary approach had a better predictive value in terms of selecting the population that would most benefit from having surgery. It is a major surgery, and we don't want to send patients for surgery if they will not have a good result."