Radiologically occult lung cancer. Report of 26 cases

Endobronchial squamous cell carcinoma presenting as localized, long, continuous bronchial thickening on CT

OBJECTIVE

To report pulmonary squamous cell carcinomas presenting as localized, long, continuous, bronchial thickening on computed tomography (CT).

MATERIALS AND METHODS

This study comprised five men (mean age, 66 years; range, 60-79 years) with pulmonary squamous cell carcinoma, including two (0.6%) selected from 310 consecutive patients with the diagnosis. Inclusion criteria were as follows: histological diagnosis obtained from thickened bronchi; continuous bronchial thickening >5cm in longitudinal extension on CT. CT scans were retrospectively reviewed, focusing on bronchial abnormalities. They were correlated with histopathological findings in four patients who underwent lobectomy.

RESULTS

On initial CT, bronchial thickening was continuous without skip area (n=5), measured 56-114mm in maximum longitudinal length, involved lobar (n=3) or segmental and distal bronchi (n=5) of the right upper (n=4) or lower (n=1) lobe, and was focally bulbous (n=2). Follow-up CT before treatment, available in two, showed progression of bronchial thickening in its thickness and longitudinal length (n=2) and a new bulbous portion (n=1) and peribronchial nodules (n=1) along the thickened bronchi. Cancer recurred after lobectomy in two, one of which manifested as continuous bronchial thickening extending from the bronchial stump on CT. On CT-histopathological correlation, bronchial thickening was mostly due to tumor spreading along the bronchus. A focal or short segmental tumor outgrowth from the thickened bronchi corresponded to a nodule or bulbous portion along thickened bronchi on CT, respectively.

CONCLUSION

Pulmonary squamous cell carcinoma may present as localized, long, continuous, bronchial thickening on CT, simulating benign infectious or inflammatory diseases.

Pathologic review of the Mayo Lung Project cancers [corrected]. Is there a case for misdiagnosis or overdiagnosis of lung carcinoma in the screened group?

BACKGROUND

In the Mayo Lung Project Screening Trial, there were more carcinomas identified in the screened group compared with the control group. The screened group had better survival, but there was no difference in lung carcinoma mortality between the screened group and the control group. The purpose of this study was to review all available original pathology from the trial to determine whether overdiagnosis (carcinomas that do not result in the death of the patient) or misdiagnosis of lung carcinoma may explain this discrepancy.

METHODS

All available lung pathology slides from patients who underwent surgery at the Mayo Clinic were reviewed independently by three blinded lung pathologists. Tumors were classified according to the 1999 World Health Organization criteria. In addition, agreement among the pathologists was assessed.

RESULTS

Among 106 patients who underwent surgery at the Mayo Clinic, slides were available for review from 105 patients, including 77 slides from the screened group and 28 slides from the control group. The original diagnosis of carcinoma was confirmed in all patients. In 7 patients (6.7%), there was unanimous agreement that the lesion was preinvasive (carcinoma in situ), and these lesions all were from the screened group. In 90 patients (85.5%), there was unanimous agreement that the tumors were invasive. In 8 patients (7.8%), there was some disagreement between the observers about whether lesions were invasive or preinvasive; 7 of these 8 lesions were from the screened group. The level of agreement among pathologists for invasive carcinomas was > 94% for all comparisons, and the kappa statistic ranged from 0.67 (substantial agreement) to 0.84 (almost perfect agreement). There was good agreement among the pathologists about tumor cell type with the kappa statistic >/= 0.65.

CONCLUSIONS

The histologic diagnosis of carcinoma was confirmed for all 105 slides that were reviewed. The results of this study indicate that misdiagnosis does not explain the increased numbers of carcinomas identified in the screened group. The increased numbers of in situ carcinomas in the screened group resulted in increased numbers of squamous carcinomas in the screened group compared with the control group and may have contributed to the better survival. It is possible that carcinoma in situ accounted for some instances of overdiagnosis.

Superficial endobronchial lung cancer: radiologic-pathologic correlation

OBJECTIVE

To analyze the plain chest radiographic and CT findings of superficial endobronchial lung cancer and to correlate these with the findings of histopathology.

MATERIALS AND METHODS

This study involved 19 consecutive patients with pathologically proven lung cancer confined to the bronchial wall. Chest radiographs and CT scans were reviewed for the presence of parenchymal abnormalities, endobronchial nodules, bronchial obstruction, and bronchial wall thickening and stenosis. The CT and histopathologic findings were compared.

RESULTS

Sixteen of the 19 patients had abnormal chest radiographic findings, while in 15 (79%), CT revealed bronchial abnormalities: an endobronchial nodule in seven, bronchial obstruction in five, and bronchial wall thickening and stenosis in three. Histopathologically, the lesions appeared as endobronchial nodules in 11 patients, irregular thickening of the bronchial wall in six, elevated mucosa in one, and carcinoma in situ in one.

CONCLUSION

CT helps detect superficial endobronchial lung cancer in 79% of these patients, though there is some disagreement between the CT findings and the pathologic pattern of bronchial lesions. Although nonspecific, findings of bronchial obstruction or bronchial wall thickening and stenosis should not be overlooked, and if clinically necessary, bronchoscopy should be performed.

Early lung cancer as a potential target for chemoprevention

Carcinoma of the lung is the most common cause of death from cancer in the United States. In considering lung cancer for possible chemoprevention trials, we have analyzed the data collected by the collaborative NCI program on early lung cancer. The data indicate that at least 12 years of study of 80,000 people at risk for lung cancer (adult male cigarette smokers) would be required to establish a 25% reduction in squamous carcinoma of the lung. No intermediate markers of developing lung cancer are presently available to shorten the observation period. It is concluded that a study of the magnitude required is not feasible at the present time.

Non-small cell lung cancer. Part I: Biology, diagnosis, and staging

Squamous, large cell, and adenocarcinoma, collectively termed non-small cell lung cancer (NSCLC), are diagnosed in approximately 75% of patients with lung cancer in the United States. The treatment of these three tumor cell types is approached in virtually identical fashion because, in contrast to small cell carcinoma of the lung, NSCLC more frequently presents with localized disease at the time of diagnosis and is thus more often amenable to surgical resection but less frequently responds to chemotherapy and irradiation. Cigarette smoking is etiologically related to the development of NSCLC in the great majority of cases. Genetic mutations in dominant oncogenes such as K-ras, loss of genetic material on chromosomes 3p, 11p, and 17p, and deletions or mutations in tumor suppressor genes such as rb and p53 have been documented in NSCLC tumors and tumor cell lines. NSCLC is diagnosed because of symptoms related to the primary tumor or regional or distant metastases, as an incidental finding on chest radiograph, or rarely because of a paraneoplastic syndrome such as hypercalcemia or hypertrophic pulmonary osteoarthropathy. Screening smokers with periodic chest radiographs and sputum cytologic examination has not been shown to reduce mortality. The diagnosis of NSCLC is usually established by fiberoptic bronchoscopy or percutaneous fine-needle aspiration, by biopsy of a regional or distant metastatic site, or at the time of thoracotomy. Pathologically, NSCLC arises in a setting of bronchial mucosal metaplasia and dysplasia that progressively increase over time. Squamous carcinoma more often presents as a central endobronchial lesion, while large cell and adenocarcinoma have a tendency to arise in the lung periphery and invade the pleura. Once the diagnosis is made, the extent of tumor dissemination is determined. Since most NSCLC patients who survive 5 years or longer have undergone surgical resection of their cancers, the focus of the staging process is to determine whether the patient is a candidate for thoracotomy with curative intent. The dominant prognostic factors in NSCLC are extent of tumor dissemination, ambulatory or performance status, and degree of weight loss. Stages I and II NSCLC, which are confined within the pleural reflection, are managed by surgical resection whenever possible, with approximate 5-year survival of 45% and 25%, respectively. Patients with stage IIIa cancers, in which the primary tumor has extended through the pleura or metastasized to ipsilateral or subcarinal lymph nodes, can occasionally be surgically resected but are often managed with definitive thoracic irradiation and have 5-year survival of approximately 15%.(ABSTRACT TRUNCATED AT 400 WORDS)

Occult carcinomas of the lung

In 1974, we reported 26 patients with roentgenographically occult lung carcinomas. In 13 (50%) of them, the tumor was localized and treated by resection while the disease was still early (Stage I). These patients have done well, and the median survival has reached 8 years. We have added 21 patients to the series since our last report. Localization was by fiberoptic bronchoscopy in all 21. Fourteen of these patients had Stage I disease and were treated by resection. Of a total of 27 patients with early disease treated by resection, none has had recurrence after follow-up extending from 2 months to 20 years. However, in 21 of the entire 47 patients (45%) a second carcinoma developed, 15 (71%) of which were second lung carcinomas.

Preliminary report of the lung cancer detection program in New York

The early lung cancer detection program in New York is described, and preliminary prevalence rate data are reported. Cigarette-smoking men over the age of 45, who are considered at high risk, are encouraged to enroll in the program and, to date, 6,612 have done so. These men receive PA and lateral chest x-rays annually, while a randomly selected sub-population of about half also have sputum cytology every four months. A controlled study of sputum cytology as an adjunct to the chest x-ray is now in progress. There were 15 cases of late lung cancer (pathologic stages II and III) detected at the initial examination, and 11 early cases (pathologic stages O and I). In the population of 3,387 men who had x-rays alone there were three early lung cancers detected; in the population of 3,225 men who had both examinations four early cancers were detected by x-ray and four by cytology. In addition, three cases of larynx cancer were detected by cytology. The early lung cancers detected by x-ray were peripheral and most were bronchiolar or adenocarcinoma; the early cancers detected by cytology were central epidermoid carcinoma of major bronchi. No early carcinomas were detected by both techniques. These findings suggest that a combination of chest x-rays and sputum cytology can be more effective than either one alone in detecting early lung cancer.

Soft-palate pigmentation in lung disease, including cancer

A study of patients in whom soft-palate pigmentation appeared to be associated with pulmonary disease has been reported. A significant number of these patients had diagnosed or suspected bronchogenic carcinoma. The possibility that this oral finding may be predictive of the presence of lung cancer, or of a high degree of probability of future development of lung cancer, indicates a need for additional investigation. At this point the evidence strongly suggests that when soft-palate pigmentation is seen in a patient with lung disease, cancer should be suspected until it is definitely ruled out. The paucity of patients in whom this sign is seen suggests the need for study by other investigators. ACTH levels should be evaluated, as should plasma zinc values, which have been demonstrated to decrease in lung cancer as well as other diseases. Following the patients prospectively certainly is indicated. In conjunction with the Department of Laboratory Medicine, limited initial additional investigations have been made of the carcinoembryonic antigen (CEA) levels on three of the outpatients reported. These assays used the hemagglutination-inhibition technique and are limited to investigational use by the Food and Drug Administration. In this laboratory the normal CEA level is 5.2 +/- 1.6 ng./ml. Results in two patients with known chronic obstructive pulmonary disease were 5.5 and 5.6 ng./ml. The third patient with soft-palate pigmentation and an undiagnosed pulmonary problem had a CEA level of 10.2 ng./ml. She also had clubbing of the fingers. The senior author would be particularly interested in establishing a registry of similar cases observed by others.

Early lung cancer detection and localization

The Mayo Lung Project was established to develop and evaluate a screening program for early lung cancer in high-risk subjects. Men who are more than 45 years of age and who smoke one package of cigarettes or more daily are screened by the use of thoracic roentgenograms, three-day pooled sputum cytology, and lung health questionnaires at four-month intervals. These data are compared with data from similar subjects screened only on entry into the project. During the past three years, 34 patients who had no roentgenoraphic evidence of lung cancer were identified and examined because of carcinoma cells in sputum. Of these 34 patients, 27 have had bronchoscopic localization of their tumors and definitive treatment and 3 had upper respiratory tract neoplasms and also have been treated. Of the remaining four, one patient died suddenly after myocardial infarction and three patients have not had localization or treatment because of other severe complicating medical problems. Localization of roentgenographically occult lung cancer is reliable by the use of bronchofiberoscopy and meticulous, thorough sampling from the tracheobronchial tree. A search must be made for upper airway cancers in the same high-risk population, and the possibility of second primary bronchogenic tumors also must be considered. Although follow-up is short, 22 of the 27 treated lung cancer patients were found with stage I disease. The outlook for 19 of these 27 is encouraging an average of 16 months after surgical resection.

The Mayo Lung Project for early detection and localization of bronchogenic carcinoma: a status report

The Mayo Lung Project (MLP) is a screening program designed to detect bronchogenic carcinoma at a curable stage. Screening tests include chest roentgenograms, three-day "pooled" sputum cytology studies, and lung-health questionnaires. These are being applied every four months to a study population of outpatients who have a high probability of developing lung cancer. Initial patient acceptance of the screening program has been excellent. Small asymptomatic lung cancers have been detected both roentgenographically and cytologically. The two procedures have complemented each other with little overlap. Chest roentgenography has proved most useful in diagnosing peripherally situated cancers, whereas sputum cytology studies have been most effective in identifying early squamous cancer involving major airways. At present, more cancers have been detected roentgenographically than cytologically, but the cytologically detected cases appear to have a better prognosis. Roentgenographically occult cancers have been localized with regularity, although the localization process is complicated. Theoretically, vigorous application of radiologic and cytologic screening, combined with optimum use of localizing procedures and treatment, could increase the five-year survival rate among lung cancer patients to nearly 50 percent. However, the actual survivorship attained will ultimately be determined by currently imponderable factors such as patient acceptance of longterm screening, frequency of multicentric respiratory cancers, and incidence of noncancerous smoking-related diseases, especially chronic obstructive pulmonary disease and ischemic heart disease.