Value of FDG PET in the management of NSCLC

Positron emission tomography: clinical applications in oncology. Part 1

Positron emission tomography is a functional diagnostic imaging technique, which can accurately measure in vivo distribution of a radiopharmaceutical with high resolution. The ability of positron emission tomography to study various biologic processes opens up new possibilities for both research and day-to-day clinical use. Positron emission tomography has progressed rapidly from being a research technique in laboratories to a routine clinical imaging modality becoming part of armamentarium for the medical profession. The most widely used radiotracer in positron emission tomography is 18F-fluoro-2-deoxy-D-glucose (FDG), which is an analog of glucose. FDG uptake in cells is directly proportional to glucose metabolism of cells. Since glucose metabolism is increased many fold in malignant tumors, positron emission tomography has a high sensitivity and high negative predictive value. Positron emission tomography with FDG is now the standard of care in initial staging, monitoring the response to therapy and management of lung cancer, colorectal cancer, lymphoma, melanoma, esophageal cancer, head and neck cancer and breast cancer. The aim of this article is to review the clinical applications of positron emission tomography in oncology.

Infected tracheal diverticulum mimicking an aggressive mediastinal lesion on FDG PET/CT: an interesting case with review of the literature

The differential diagnosis for intense hypermetabolic mediastinal lesions on positron emission tomography (PET) could benefit from the combined morphological and metabolic information present in a fluorodeoxyglucose (FDG) PET/CT study. We report a case of an infected tracheal diverticulum mimicking an FDG-avid malignancy in a patient with a history of chronic lymphoproliferative disease. We review the literature for a systematic approach in the differential diagnosis of cystic mediastinal lesions. The embryological development of the normal tracheobronchial tree is reviewed, followed by a presentation of various congenital and acquired mediastinal lesions. The characteristic CT findings are described for each lesion and the avidity for FDG on PET is mentioned when references are available. This case emphasises that complicated benign processes should be considered in the differential diagnosis of an FDG-avid mediastinal lesion, even in subgroups of patients with significant risk factors for malignancy.

Remediastinoscopy in restaging of lung cancer after induction therapy

OBJECTIVES

The aim of the present study was to evaluate the feasibility and diagnostic value of repeat mediastinoscopy as part of the response-evaluation protocol of 2 phase II multimodality studies for either stage IIIA/B non-small cell lung cancer or small cell lung cancer.

METHODS

From January 1991 through December 1998, 104 patients (79 men and 25 women) with stage IIIA/B non-small cell lung cancer (84 patients) or small cell lung cancer (17 patients) were enrolled in 2 different multimodality trials and underwent remediastinoscopy after induction chemoradiotherapy. The median age was 56 years (range, 34-72 years). Sensitivity, specificity, accuracy, and predictive values of remediastinoscopy were calculated by using standard definitions.

RESULTS

Remediastinoscopy was feasible in 98% of cases. Mortality was nil, and morbidity very low (1.9%). Lymph node downstaging (N0) was observed in 84 patients, persisting N2 disease was observed in 15 patients, and N3 disease was observed in 5 patients. Sensitivity was 61%, specificity was 100%, and accuracy was 88%. Positive predictive and negative predictive values reached 100% and 85%, respectively. According to the results of remediastinoscopy, 81 patients underwent surgical intervention, 3 refused the operation, and an unnecessary thoracotomy could be avoided in the remaining 20.

CONCLUSIONS

Remediastinoscopy provides a histologic proof of mediastinal downstaging with high diagnostic accuracy, is technically feasible with low morbidity, and still remains a valuable tool, even in an era of highly sophisticated imaging and endoscopic procedures. Persisting nodal disease at repeat mediastinoscopy carries a poor survival in the majority of cases because of occult metastases, so that indication for surgical intervention in such an unfavorable group of patients should be evaluated very carefully.

Efficacy and safety of single-agent pertuzumab, a human epidermal receptor dimerization inhibitor, in patients with non small cell lung cancer

PURPOSE

Pertuzumab, a first-in-class human epidermal receptor 2 (HER2) dimerization inhibitor, is a humanized monoclonal anti-HER2 antibody that binds HER2's dimerization domain and inhibits HER2 signaling. Based on supporting preclinical studies, we undertook a Phase II trial of pertuzumab in patients with recurrent non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Patients with previously treated NSCLC accessible for core biopsy and naive to HER pathway inhibitors were treated with pertuzumab i.v. once every 3 weeks. Tumor assessments were done at 6 and 12 weeks and then every 3 months thereafter. The primary efficacy end point was overall response rate by Response Evaluation Criteria in Solid Tumors. Measurement of tumor glucose metabolism (SUVmax) by F-18-fluorodeoxyglucose positron emission tomography was used as an exploratory pharmacodynamic marker of drug activity.

RESULTS

Of 43 patients treated with pertuzumab, no responses were seen; 18 of 43 (41.9%) and 9 of 43 (20.9%) patients had stable disease at 6 and 12 weeks, respectively. The median and 3-month progression-free survival rates (PFS) were 6.1 weeks (95% confidence interval, 5.3-11.3 weeks) and 28.4% (95% confidence interval, 14.4-44.2%), respectively. Of 22 patients who underwent F-18-fluorodeoxyglucose positron emission tomography, six (27.3%) had a metabolic response to pertuzumab as evidenced by decreased SUV max. These patients had prolonged PFS (HR = 0.11, log-rank P value = 0.018) compared with the 16 patients who had no metabolic response. Four patients (9.3%) experienced a grade 3/grade 4 adverse event judged related to pertuzumab; none exhibited grade 3/grade 4 cardiac toxicity.

CONCLUSIONS

Pertuzumab is well tolerated as monotherapy. Pharmacodynamic activity correlated with prolonged PFS was detected in a moderate percentage of patients (27.3%). Further clinical development of pertuzumab should focus on rational combinations of pertuzumab with other drugs active in NSCLC.

Surgery of non-small cell lung cancer in the elderly

PURPOSE OF REVIEW

The aim of this review is to analyze recent evidence for optimal treatment of elderly patients with non-small cell lung cancer, focusing on surgery, and possibly to foresee the future strategies to apply in these patients.

RECENT FINDINGS

Surgery in elderly patients affected by non-small cell lung cancer is safe and feasible when careful preoperative respiratory and cardiac studies have been carried out and the disease has been properly staged. The surgical treatment is not to be denied in elderly patients due to age per se, but when a major contraindication to surgery has been recognized. Long term survival for elderly patients with early stage lung cancer treated by anatomical pulmonary resection is comparable to the survival rate of younger patients. Pneumonectomy, extended surgical procedure or preoperative induction chemotherapy are major risk factors for an increased postoperative morbidity and mortality rate. When co-morbidities are present or a patient is 80 years or older, there is evidence that a non-anatomical resection can be performed without affecting long-term results.

SUMMARY

Due to the aging of the general population, elderly patients will become a large percentage of the cases of non-small cell lung cancer to be treated. Implementing preoperative cardiologic studies and redefining selective respiratory criteria specifically could dramatically improve results.

Problems in pathologic staging of lung cancer

CONTEXT

Tumor stage is the most important prognostic and predictive factor for patients with lung cancer, the most lethal neoplasm in the United States. It is used by thoracic surgeons, radiation therapists, and oncologists to determine whether patients with these neoplasms will be treated surgically with curative intent or with palliative radiation therapy and/or chemotherapy.

OBJECTIVE

To review the variety of practical problems that can arise during the assessment of the pathologic stage and other prognostic/predictive factors included in the College of American Pathologist checklist for evaluation of resected lung neoplasms.

DATA SOURCES

Potential practical difficulties that can arise during the pathologic staging of lung cancer patients include the distinction between pT1, pT2, and pT3 lesions based on their location and the presence of visceral pleura and/or parietal pleura invasion; the differential diagnosis between multiple synchronous or metachronous primary lung neoplasms (pT1m) and intrapulmonary metastasis of non-small cell carcinoma of the lung (pT4 or pM1 according to their location); and the role of the recent American Joint Committee on Cancer terminology for the classification of lymph nodes (isolated tumor cells, micrometastases, and metastases).

CONCLUSIONS

The variety of practical problems that can arise during the assessment of important prognostic and predictive features such as resection margin status and evaluation of lymphovascular invasion are reviewed. A brief discussion of the assessment of the effects of neoadjuvant therapy on resected lung neoplasms is also included.