Bronchial carcinoma in men detected by selective and unselective miniature radiography: a review of 228 cases

[Lung cancer screening with thoracic X‑ray and CT : Current situation]

CLINICAL/METHODICAL ISSUE

Attempts at the early detection of lung cancer using imaging methods began as far back as the 1950s.

STANDARD RADIOLOGICAL METHODS

Several studies attempted to demonstrate a reduction of lung cancer mortality by chest radiography screening but all were unsuccessful.

METHODICAL INNOVATIONS

Even the first small screening studies using computed tomography (CT) could not demonstrate a reduction in lung cancer-specific mortality until in 2011 the results of the largest randomized controlled low-dose CT screening study in the USA (NLST) were published. The NLST results could show a significant 20 % reduction of lung cancer mortality in elderly and heavy smokers using CT.

PERFORMANCE

Confirmation of the NLST results are urgently needed so that the data of the largest European study (NELSON) are eagerly awaited.

ACHIEVEMENTS

Pooled with the data from several smaller European studies these results will provide important information and evidence for the establishment of future CT screening programs in Europe.

PRACTICAL RECOMMENDATIONS

Randomized controlled trials are the basis of evidence-based medicine; therefore, the positive results of the methodologically very good NLST study cannot be ignored, even if it is the only such study completed so far with highly convincing conclusions. The NLST results clearly demonstrate that positive effects for the health of the population can only be expected if the processes are clearly defined and the quality is assured.

Pulmonary nodules and CT screening: the past, present and future

Lung cancer screening has come a long way since the early studies with chest X-ray. Advancing technology and progress in the processing of images have enabled low dose CT to be tried and tested, and evidence suggests its use can result in a significant mortality benefit. There are several issues that need refining in order to successfully implement screening in the UK and elsewhere. Some countries have started patchy implementation of screening and there is increased recognition that the appropriate management of pulmonary nodules is crucial to optimise benefits of early detection, while reducing harm caused by inappropriate medical intervention. This review summarises and differentiates the many recent guidelines on pulmonary nodule management, discusses screening activity in other countries and exposes the present barriers to implementation in the UK.

Screening, Early Detection, and Early Intervention Strategies for Lung Cancer

Screening for lung cancer has been utilized for several decades without demonstrating overall survival benefit. However, recent advances in treatment of lung cancer, improvements in our biologic understanding of lung cancer development, and an increasing population of healthy ex-smokers provide cause for optimism. Several chemoprevention trials suggest that it may be possible to intervene in the oncologic process prior to the development of invasive malignancy, resulting in a delay or reversal of these changes.

Routine preoperative chest X-rays

687 patients presenting for routine and emergency anaesthesia were studied. 297 were found to have a chest X-ray. Abnormalities on chest X-ray were scattered amongst most age groups. Patients in American Society of Anaesthesiologists grade I were found to have abnormalities in only 4% of cases, and the abnormalities were of no anaesthetic significance. The incidence of abnormalities increased to 25% in grade II, 52% in grade III and 81% in grades IV and V. Patients in American Society of Anaesthesiologists grades III, IV and V, and those suffering from trauma should have a preoperative chest X-ray.

Symptoms and Survival in Lung Cancer

From the analysis of 167 patients with lung cancer operated by radical resection at the National Cancer Institute of Milan and from the review of the literature, the authors reach the following conclusions: a) Prognosis of lung cancer is related to symptoms. Prognosis is better in asymptomatic patients and in those with long-term primary symptoms than in patients with short-term symptoms, or with clinical signs of mediastinal involvement or metastases. Symptomatologic classification is therefore useful also in a pretherapeutic phase. b) Although in asymptomatic patients there are better chances of cure, mass screening in asymptomatic people may be unsuccessful because of the limited number of asymptomatic cancers and the limits in radiographic diagnosis. This latter, in fact, even if rouled out in a preclinical phase, is not early. c) We need new epidemiological trends to improve both the effectiveness of mass screening and therapy in asymptomatic people.

Earlier diagnosis and survival in lung cancer

In a controlled investigation the survival prospects of lung cancer in a population of men aged 40 and over who had been offered six-monthly chest radiographs over a period of three years were compared with lung cancer in a similar population without such x-ray facilities. The five-year survival rate of lung cancer in the study series was 15%, and in cases discovered by six-monthly examination 23%, compared with 6% in the control series. The average expectation of life after diagnosis was 2.5 years for the test cases and 1.2 for the control cases. Survival declined with age. Of resected lung cancer, 32% survived five years in the test series and 23% in the control series. The five-year survival rate for squamous carcinoma and adenocarcinoma in the test series was 28% and 25% respectively, compared with 15% and nil in the control series.On the basis of these results it is concluded that through earlier radiological detection a modest improvement in the prognosis of lung cancer can be achieved.

The value of lung cancer detection by six-monthly chest radiographs

Results are reported of a prospective study, carried out by the Mass Radiography Service of the North-West Metropolitan Region for the purpose of evaluating early lung cancer detection by six-monthly chest radiographs. The lung cancer experience of a test group of 29,723 men aged 40 and over who were offered six-monthly chest radiographs over a period of three years is compared with a similarly constituted control group of 25,311 men who were radiographed only at the beginning and the end of the study. In the test group 29,416 men (98·9%) and in the control group 25,044 men (99%) were followed up. The methods employed to achieve this result are analysed. The six-monthly surveys of the test group yielded 65 cases of lung cancer, giving an annual incidence and detection rate of 0·9 per thousand examined. Of these cases 65% were resected. Of all cases of lung cancer in the test group, irrespective of their source of detection, 43·6% were operable, compared with 29% in the control group. The difference (P=0·03) is statistically significant. The annual mortality rate from lung cancer based on 62 deaths in the test group and 59 deaths in the control was 0·7 and 0·8 per thousand respectively. The conclusions are reached that since early detection by six-monthly chest radiographs has not significantly reduced the mortality from lung cancer in a population at risk, a policy of such large-scale surveys of men in the cancer age would not seem justified, but that the increased discovery of resectable lung cancer by this method forms a reasonable basis for encouraging individuals in high-risk groups to make regular use of existing mass radiography facilities.