Clinical aspects of lung cancer

Clinical and organizational factors in the initial evaluation of patients with lung cancer: Diagnosis and management of lung cancer, 3rd ed: American College of Chest Physicians evidence-based clinical practice guidelines

BACKGROUND

This guideline is intended to provide an evidence-based approach to the initial evaluation of patients with known or suspected lung cancer. It also includes an assessment of the impact of timeliness of care and multidisciplinary teams on outcome.

METHODS

The applicable current medical literature was identified by a computerized search and evaluated using standardized methods. Recommendations were framed using the approach described by the Guidelines Oversight Committee of the American College of Chest Physicians. Data sources included MEDLINE and the Cochrane Database of Systematic Reviews.

RESULTS

Initial evaluation should include a thorough history and physical examination; CT imaging; pulmonary function tests; and hemoglobin, electrolyte, liver function, and calcium levels. Additional testing for distant metastases and paraneoplastic syndromes should be determined on the basis of these results. Paraneoplastic syndromes may have an adverse impact on cancer treatment, so they should be controlled rapidly with the goal of proceeding with definitive cancer treatment in a timely manner. Although the relationship between timeliness of care and survival is difficult to quantify, efforts to deliver timely care are reasonable and should be balanced with the need to attend to other dimensions of health-care quality (eg, safety, effectiveness, efficiency, equality, consistency with patient values and preferences). Quality care will require multiple disciplines. Although it is difficult to assess the impact, we suggest that a multidisciplinary team approach to care be used, particularly for patients requiring multimodality therapy.

CONCLUSIONS

The initial evaluation of patients with lung cancer should include a thorough history and physical examination, pulmonary function tests, CT imaging, basic laboratory tests, and selective testing for distant metastases and paraneoplastic syndromes.

Clinical management of pain in advanced lung cancer

Lung cancer is the most common cancer in the world and pain is its most common symptom. Pain can be brought about by several different causes including local effects of the tumor, regional or distant spread of the tumor, or from anti-cancer treatment. Patients with lung cancer experience more symptom distress than patients with other types of cancer. Symptoms such as pain may be associated with worsening of other symptoms and may affect quality of life. Pain management adheres to the principles set out by the World Health Organization's analgesic ladder along with adjuvant analgesics. As pain can be caused by multiple factors, its treatment requires pharmacological and non-pharmacological measures from a multidisciplinary team linked in with specialist palliative pain management. This review article examines pain management in lung cancer.

Initial evaluation of the patient with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes: ACCP evidenced-based clinical practice guidelines (2nd edition)

BACKGROUND

This chapter of the guidelines is intended to provide an evidence-based assessment of the initial evaluation of patients recognized as having lung cancer and the recognition of paraneoplastic syndromes.

METHODS

The current medical literature that is applicable to this issue was identified by a computerized search and was evaluated using standardized methods. Recommendations were framed using the approach described by the Health and Science Policy Committee of the American College of Chest Physicians.

RESULTS

Patients with lung cancer usually present with multiple symptoms, both respiratory related and constitutional. There is usually a time delay between symptom recognition by the patient and the ultimate diagnosis of lung cancer by the physician. Whether this time delay impacts prognosis is unclear, but delivering timely and efficient care is an important component in its own right. Lung cancer may be accompanied by a variety of paraneoplastic syndromes. These syndromes may not necessarily preclude treatment with a curative intent.

CONCLUSIONS

The initial evaluation of the patient with known or suspected lung cancer should include an assessment of symptoms, signs, and laboratory test results in a standardized manner as a screen for identifying those patients with paraneoplastic syndromes and a higher likelihood of metastatic disease.

Palliative care in lung cancer: ACCP evidence-based clinical practice guidelines (2nd edition)

GOALS/OBJECTIVES: To review the scientific evidence on symptoms and specific complications that are associated with lung cancer, and the methods available to palliate those symptoms and complications.

METHODS

MEDLINE literature review (through March 2006) for all studies published in the English language, including case series and case reports, since 1966 using the following medical subject heading terms: bone metastases; brain metastases; cough; dyspnea; electrocautery; hemoptysis; interventional bronchoscopy; laser; pain management; pleural effusions; spinal cord metastases; superior vena cava syndrome; and tracheoesophageal fistula.

RESULTS

Pulmonary symptoms that may require palliation in patients who have lung cancer include those caused by the primary cancer itself (dyspnea, wheezing, cough, hemoptysis, chest pain), or locoregional metastases within the thorax (superior vena cava syndrome, tracheoesophageal fistula, pleural effusions, ribs, and pleura). Respiratory symptoms can also result from complications of lung cancer treatment or from comorbid conditions. Constitutional symptoms are common and require attention and care. Symptoms referable to distant extrathoracic metastases to bone, brain, spinal cord, and liver pose additional problems that require a specific response for optimal symptom control. There are excellent scientific data regarding the management of many of these issues, with lesser evidence from case series or expert opinion on other aspects of providing palliative care for lung cancer patients.

CONCLUSIONS

Palliation of symptoms and complications in lung cancer patients is possible, and physicians who provide such care must be knowledgeable about these issues.

Pulmonary Adenocarcinoma: The Expanding Spectrum of Histologic Variants

Pulmonary adenocarcinoma is one of the most common types of lung cancer. Traditionally, adenocarcinomas have been divided based on their degree of resemblance to their parent tissues into 3 histopathologic types: well, moderately, and poorly differentiated. In the majority of cases, this schema is sufficient to categorize these lung tumors. However, there is a considerable group of tumors in which the histology is not that of the classic gland-forming neoplasm. Thus, although the terminology of adenocarcinoma is applied in such cases, the histopathologic features are different from those of the more conventional variants. The current review addresses these unusual variants and the importance of recognizing and properly categorizing them to avoid unnecessary additional workup or possible misdiagnosis.

Lung cancer detected in patients presenting to the Emergency Department studies for suspected pulmonary embolism on computed tomography pulmonary angiography

PURPOSE

To study the frequency and demographics of lung cancer on CT pulmonary angiography in patients with suspected pulmonary embolism referred from the Emergency Department.

MATERIALS AND METHODS

Retrospective review of the medical records and radiology reports, clinical and imaging follow-up studies and pathological reports revealed 1106 CT pulmonary angiography studies referred from our Emergency Department during the 15-month period between March 2003 and June 2004.

RESULTS

Five incidental lung cancer cases were found in 1106 studies from 1081 patients (0.47%). Pulmonary embolism was found in 95 patients (8.5%). Among the five incidental cases three patients were female and two were male (62-81 years old; mean 73 years, 17-130 packs year; mean 51 packs year). Tumor size ranged from 1.8 to 4.5 cm (mean 3.3 cm). The stagings of the lung cancers were IIIB in one patient and IV in four patients.

CONCLUSION

Previously undiagnosed lung cancer was detected in 0.45% of patients among 1081 patients referred from Emergency Department, one of whom had coexistent pulmonary embolism. All five patients presented at advanced lung cancer stages of IIIB and IV.

Lung cancer. Palliative care

The majority of patients who acquire lung cancer will have troublesome symptoms at some time during the course of their disease. Some of the symptoms are common to many types of cancers, while others are more often encountered with lung cancer than other primary sites. The most common symptoms are pain, dyspnea, and cough. This document will address the management of these symptoms, and it will also address the palliation of specific problems that are commonly seen in lung cancer: metastases to the brain, spinal cord, and bones; hemoptysis; tracheoesophageal fistula; and obstruction of the superior vena cava.

Initial evaluation of the patient with lung cancer: symptoms, signs, laboratory tests, and paraneoplastic syndromes

This chapter describes the components of the initial evaluation for a patient either suspected or known to have lung cancer. The components of the initial evaluation are based on the recognized manifestations of localized lung cancer, ie, symptoms referable to the primary tumor, intrathoracic spread of lung cancer, and patterns of metastatic dissemination. Features of the history and physical signs may be useful indicators of the extent of disease. A standardized evaluation, relying on symptoms, signs, and routinely available laboratory tests, can serve as a useful screen for metastatic disease. Also described are the common features of the various paraneoplastic syndromes associated with lung cancer.

Radiologic evaluation in chest malignancies. A review of imaging modalities

Radiologic evaluation of the patient with non-small cell lung cancer (NSCLC) includes chest radiographs for detecting nodules, computed tomography (CT) for further characterizing them, CT and magnetic resonance imaging (MRI) to evaluate the mediastinum, and extrathoracic imaging of bones, the adrenal gland, the central nervous system, and liver. The current practice standards for each are reviewed. Asymptomatic solitary pulmonary nodules, which are usually detected on chest radiographs obtained for other indications, inevitably require a precise diagnosis. The radiologic characteristics that differentiate benign from malignant pulmonary lesions are given. Mediastinal CT is the preferred modality for examining the mediastinum in patients with NSCLC. Magnetic resonance imaging is used selectively, eg, in patients with superior sulcus tumors who are candidates for surgery. When evaluation for N2/N3 disease is requested, mediastinoscopy should replace CT using the latter as a "roadmap." The role of extrathoracic imaging in evaluating asymptomatic patients with NSCLC at initial presentation is equivocal. Computed tomographic scanning of the head is reasonable in most patients with lung cancer, given the significant incidence of occult brain metastases in this population and that solitary brain lesions may be resected in some protocol settings. Routine liver and adrenal gland scanning is similarly controversial. Bone scans do not appear to be useful in patients with NSCLC unless they have clinical signs, symptoms, or laboratory findings to indicate possible metastases. Although heavily affected by local practice, radiologic evaluation of the patient with NSCLC should attempt to provide accurate determination of local disease and a search for distant metastases.

K-ras oncogene activation in lung adenocarcinomas from former smokers. Evidence that K-ras mutations are an early and irreversible event in the development of adenocarcinoma of the lung

BACKGROUND

Point mutations in codon 12 of the K-ras protooncogene occur more frequently in lung adenocarcinomas from smokers (30%) than they do in lung adenocarcinomas from nonsmokers (7%), suggesting that smoking is an important factor in the induction of these mutations. The lack of well defined "early" premalignant or in situ glandular neoplasms of the lung, however, has not permitted direct evaluation of the chronology of ras activation in the development of lung adenocarcinomas. To circumvent the need to evaluate precursor lesions, we examined lung adenocarcinomas from former smokers for point mutations in K-ras.

METHODS

Mutations in codon 12 of K-ras were detected using polymerase chain reaction amplification and mutation-specific oligonucleotide probes. The types and frequencies of mutations found in adenocarcinomas obtained from 57 former smokers were compared to those found in 27 adenocarcinomas from patients who never smoked and to those found in 27 adenocarcinomas from patients who were current smokers.

RESULTS

The overall prevalence of K-ras point mutations in lung adenocarcinomas obtained from former smokers (32%) was not different from that seen in adenocarcinomas from patients who were current smokers (30%, P = 0.83), and was greater than that seen in adenocarcinomas from patients who never smoked (7%, P = 0.015). This pattern was independent of the duration of abstinence from smoking. Furthermore, the predominant type of mutation found in tumors from former smokers was a guanine-to-thymine transversion, the specific type of mutation induced by benzo(a)pyrene, one of the chemical carcinogens found in tobacco smoke.

CONCLUSIONS

These findings support previous findings that suggest that codon 12 of the K-ras oncogene may be a specific target of the mutagenic activity of tobacco smoke, and suggest that DNA alterations at this site can occur early and irreversibly during the development of adenocarcinomas of the lung.

Paraneoplastic syndromes associated with lung cancer

Paraneoplastic phenomena associated with primary lung cancer have diverse initial manifestations and epitomize the systemic nature of human malignant disease. The spectrum of clinical features in patients with paraneoplastic syndromes ranges from mild systemic or cutaneous disease to hypercoagulability and severe neuromyopathic disorders. Although the diagnosis is often one of exclusion, an improved understanding of the pathogenesis involved in some of these syndromes has provided another means of recognizing the disorders and perhaps treating the affected patients. Proposed mechanisms of paraneoplastic processes include the aberrant release of humoral mediators such as hormones and hormone-like peptides, cytokines, and antibodies. In this update, we review the potential mechanisms, diagnosis, and treatment of paraneoplastic syndromes associated with lung cancer.

Clinical manifestations of lung cancer

The initial clinical manifestations of lung cancer are diverse and may occur with or without symptoms. Manifestations of pulmonary malignant lesions are produced by local growth or invasion, metastatic disease, or paraneoplastic processes. Patterns of local invasion such as Pancoast's syndrome or the superior vena cava syndrome are relatively uncommon but well recognized. Metastatic lung cancer can involve almost any anatomic area by hematogenous, lymphatic, or, occasionally, interalveolar dissemination. Complications related to malnutrition, infection, electrolyte disturbances, and coexisting diseases influence the initial manifestations. Although individual tumor cell types are associated with characteristic features, no constellation of findings is pathognomonic for a specific histologic variant. Because successful treatment of pulmonary carcinoma depends on early detection, awareness of the typical clinical manifestations is important.