Diagnosis and significance of liver metastases in small cell carcinoma of the lung

Classification, staging and prognosis of lung cancer

Lung cancer has increased in incidence throughout the twentieth century and is now the most common cancer in the Western World. It has a poor prognosis, only 10-15% of patients survive 5 years or longer. Outcome is dependent on clinical stage and cancer cell type. Lung cancer is broadly subclassified on the basis of histological features into squamous cell carcinoma, adenocarcinoma, large cell carcinoma and small cell carcinoma. The histopathological type of lung cancer correlates with tumour behaviour and prognosis. Staging based on prognosis is essential in clinical trials comparing different management strategies, and enables universal communication regarding the efficacy of different treatments in specific patient groups. The anatomic extent of disease determined either preoperatively using imaging supplemented by invasive procedures such as mediastinoscopy, and anterior mediastinotomy or following resection are described according to the T-primary tumour, N-regional lymph nodes, M-distant metastasis classification. The International System for Staging Lung Cancer attempts to group together patients with similar prognosis and treatment options. Various combinations of T, N, and M define different clinical or surgical-pathological stages (IA-IV) characterised by different survival characteristics. Refinements in staging based on imaging findings have enabled clinical staging to more accurately reflect the surgical-pathological stage and therefore more accurately predict prognosis. Recent advances including the use of positron emission tomography in combination with conventional staging promises to increase the accuracy of staging and therefore to reduce the number of invasive staging procedures and inappropriate thoracotomies.

Management of small cell lung cancer

Small cell lung carcinoma typically presents as a central endobronchial lesion in chronic cigarette smokers with hilar enlargement and disseminated disease. The diagnostic pathology should be reviewed by a pathologist accomplished in reading pulmonary pathology, and, if any doubt exists in the diagnosis, additional special stains or diagnostic material should be obtained. Patients with extensive stage disease should be managed by combination chemotherapy, whereas patients with limited stage disease should be treated with etoposide/cisplatin plus concurrent chest irradiation. The chemotherapy should be administered for 4 to 6 months and then should be discontinued. Prophylactic cranial irradiation should be given to patients who achieve a complete remission. Patients should be retreated with chemotherapy if they develop a relapse of their small cell lung cancer. The patients who are followed in complete remission should be observed carefully for second cancers, and appropriate therapy should be administered if the cancer reappears.

Metastatic small cell lung cancer causing biliary obstruction

We report a case with metastatic small cell lung cancer which first manifested with biliary obstruction due to metastasis. Prognosis of patients presenting with jaundice due to hepatic parenchyma involvement is thought to be poor. However, the patient was successfully treated with percutaneous transhepatic biliary drainage and combination chemotherapy with reduced dosage. We believe this to be the first such case report, despite the frequency of metastasis to the liver from small cell lung cancer.

Small-cell carcinoma of the lung manifesting as acute hepatic failure

In this report, we describe four cases of small-cell carcinoma of the lung manifesting as acute hepatic failure. These cases were noteworthy for the presence of hepatomegaly and substantially increased serum lactate dehydrogenase and uric acid levels. The ratio of normalized serum lactate dehydrogenase to normalized serum alanine aminotransferase from the 4 cases reported herein (mean +/- SE, 3.63 +/- 1.10) was significantly greater than the ratio obtained from the 12 cases of nonmalignant fulminant hepatic failure (mean +/- SE, 0.46 +/- 0.18; P < 0.001). Chest radiographs and abdominal imaging studies showed no neoplastic process in three of the four cases. Postmortem examinations disclosed extensive infiltration of the liver by metastatic small-cell carcinoma of the lung. A review of the literature revealed 13 additional similar cases. We conclude that metastatic small-cell carcinoma of the lung should be considered in cases of acute hepatic failure associated with hepatomegaly, substantially increased lactate dehydrogenase levels in comparison with alanine aminotransferase values, and increased uric acid levels even if imaging studies show no lesion. A liver biopsy done early during the hospital course is appropriate for diagnosis and for prevention of inappropriate transfer of the patient to a liver transplant center.

Small cell lung cancer

Lung cancer is the most common cause of cancer death in the United States, with approximately 135,000 men and women dying each year. While much has been learned about the etiologic risk factors, less progress has been made in therapy. Five-year survival rates remain at less than 10%. However, there has been some progress in the therapy of one histological subtype of lung cancer, small cell lung cancer. Totaling around 20% of lung cancer cases, small cell lung cancer is distinct from the other histologic subtypes in its biologic behavior and responsiveness to therapy. In the 1960s, the median survival for patients with small cell lung cancer was approximately 3 months. With combination chemotherapy and radiotherapy median survivals now range from 1 to 2 years, and there is evidence for a curative potential since approximately 10% of patients who initially present with limited disease survive greater than 2 years. The unique clinical aspects of this histological subtype potentially relate to its underlying cell of origin. This behavior is reflected in the numerous paraneoplastic syndromes that frequently accompany small cell lung cancer. Its propensity for early dissemination have made staging the extent of disease an important part of the clinical evaluation. Since small cell lung cancer is sensitive to both chemotherapy and radiation therapy, there have been multiple clinical trials evaluating drug/radiotherapy combinations. This article will briefly describe the unique aspects of small cell lung cancer as opposed to other histological subtypes of lung cancer and give an overview of the current clinical approach and treatment of this disease.

Current staging of lung cancer: an overview of current and newer approaches

The purpose of this chapter is to update some of the current approaches to the pretreatment assessment of patients with lung cancer. We will place emphasis on both standard staging and newer techniques. Because of their clinical relevancy, small-cell (SCLC) and non-small-cell (NSCLC) lung cancers have been divided to emphasize the special needs and approaches to each.

Small cell carcinoma of the lung

Small cell lung cancer is a common, usually fatal neoplasm. Although palliative therapy is available for the majority of patients, only a very small minority enjoy long-term survival. Ironically, this neoplasm is nearly entirely preventable and a successful antismoking program is desperately needed. Our efforts to understand the basic biology of this tumor should continue, and, hopefully, will eventually translate into improvements in therapy. In addition to following the leads provided by basic research, a concerted clinical research effort needs to continue to build upon the advances already achieved.