The noninvasive staging of non-small cell lung cancer: the guidelines

Correctly staging lung cancer is extremely important because the treatment options and the prognosis differ significantly by stage. Several noninvasive imaging studies are available to aid in identifying disease both within and outside of the chest. Chest CT scanning is useful in providing anatomic detail that better identifies the location of the tumor, its proximity to local structures, and whether or not lymph nodes in the mediastinum are enlarged. Unfortunately, the accuracy of chest CT scanning in differentiating benign from malignant lymph nodes in the mediastinum is unacceptably low. Whole-body positron emission tomography (PET) scanning provides functional information on tissue activity and has much better sensitivity and specificity than chest CT scanning for staging lung cancer in the mediastinum. In addition, metastatic disease can be detected by PET scan. Still, positive findings of PET scans can occur from nonmalignant etiologies (eg, infections), so that tissue sampling to confirm the suspected malignancy must be performed. The clinical evaluation tool, which is composed of a thorough history and physical examination, remains the best predictor of metastatic disease. If the findings from the clinical evaluation are negative, then imaging studies such as a CT scan of the head, a bone scan, or an abdominal CT scan are unnecessary, and the search for metastatic disease is complete. If signs, symptoms, or findings from the physical examination suggest the presence of malignancy, then sequential imaging, starting with the most appropriate study based on the clues obtained by the clinical evaluation, should be performed. Abnormalities detected by all of the aforementioned imaging studies are not always cancer. Unless overwhelming evidence of metastatic disease is present on an imaging study, in situations in which it will make a difference in treatment, all abnormal scan findings require tissue confirmation of malignancy so that patients are not precluded from having potentially curative surgery.

Induction chemoradiation and surgical resection for non-small cell lung carcinomas of the superior sulcus: Initial results of Southwest Oncology Group Trial 9416 (Intergroup Trial 0160)

OBJECTIVE

The rate of complete resection (50%) and the 5-year survival (30%) for non-small cell lung carcinomas of the superior sulcus have not changed for 40 years. Recently, combined modality therapy has improved outcome in other subsets of locally advanced non-small cell lung carcinoma. This trial tested the feasibility of induction chemoradiation and surgical resection in non-small cell lung carcinoma of the superior sulcus with the ultimate aim of improving resectability and survival.

METHODS

Patients with mediastinoscopy-negative T3-4 N0-1 superior sulcus non-small cell lung carcinoma received 2 cycles of cisplatin and etoposide chemotherapy concurrent with 45 Gy of radiation. Patients with stable or responding disease underwent thoracotomy 3 to 5 weeks later. All patients received 2 more cycles of chemotherapy and were followed up by serial radiographs and scans. Survival was calculated by the Kaplan-Meier method and prognostic factors were assessed for significance by Cox regression analysis.

RESULTS

From April 1995 to September 1999, 111 eligible patients (77 men, 34 women) were entered in the study, including 80 (72.1%) with T3 and 31 with T4 tumors. Induction therapy was completed as planned in 102 (92%) patients. There were 3 treatment-related deaths (2.7%). Cytopenia was the main grade 3 to 4 toxicity. Of 95 patients eligible for surgery, 83 underwent thoracotomy, 2 (2.4%) died postoperatively, and 76 (92%) had a complete resection. Fifty-four (65%) thoracotomy specimens showed either a pathologic complete response or minimal microscopic disease. The 2-year survival was 55% for all eligible patients and 70% for patients who had a complete resection. To date, survival is not significantly influenced by patient sex, T status, or pathologic response.

CONCLUSIONS

(1) This combined modality treatment is feasible in a multi-institutional setting; (2) the pathologic complete response rates were high; and (3) resectability and overall survival were improved compared with historical experience, especially for T4 tumors, which usually have a grim prognosis.

The role of induction therapy in the management of resectable non-small cell lung cancer

BACKGROUND

Combined-modality therapy has become standard for many patients with non-small cell lung cancer. Although surgical resection offers the best chance for long-term survival, the limited number of resectable patients and the presence of occult micrometastatic disease has limited the effectiveness of this modality alone.

METHODS

The authors reviewed several trials involving the use of induction chemotherapy in managing resectable non-small cell lung cancer.

RESULTS

Extensive phase II experience in patients with stage III disease has confirmed the feasibility of this approach. Unfortunately, heterogeneous patient populations and treatment regimens limit the ability to draw firm conclusions from these trials alone. While the phase III experience has been limited, long-term follow-up is now available suggesting that induction therapy may have a beneficial impact on survival, especially for those patients who can be sufficiently downstaged. Recent phase II trials have included stage III patients who have traditionally been considered inoperable. Although encouraging, the role of surgery after chemoradiotherapy for this population of patients remains undefined.

CONCLUSIONS

Results from ongoing randomized trials studying the impact of induction therapy on well-defined patient populations will be necessary before the optimal regimen and patient population can be identified.

Transsternal thymectomy for myasthenia gravis

A consistent, planned approach to thymectomy for patients with myasthenia gravis has been used at the University of North Carolina since 1977. This involves a sternotomy, with excision of the entire thymus and adjacent fatty tissues from the thyroid to the diaphragm and laterally to 1 cm from each phrenic nerve. Between 1977 and 1993, 100 consecutive patients were treated in this manner with no mortality. Eight-four percent of patients were extubated in the operating room or within 1 hour of surgery, and no patients experienced postoperative respiratory difficulty. After a mean follow-up of 65 months, 78% of all patients improved by at least one modified Osserman classification, and 69% of patients with preoperative class I, II, or III disease (maximal preoperative severity) are in pharmacological remission. We conclude that transsternal thymectomy is associated with minimal morbidity and no mortality, and results in long-term improvement in symptoms for patients with myasthenia gravis.

Routine computed tomographic scans, selective mediastinoscopy, and other factors in evaluation of lung cancer

Routine computed tomographic scan is advocated as the best noninvasive method of evaluating mediastinal nodes for cancer spread. Positive studies should be confirmed histologically. Large size, central location, unfavorable cell type, poor cellular differentiation of the primary cancer, and weight loss also correlate with increased likelihood of mediastinal involvement.