HISTOLOGY OF LUNG CANCER IN RELATION TO PROGNOSIS

Primary adenocarcinoma of the lung--histological subtypes and outcome after surgery, using the IASLC/ATS/ERS classification of lung adenocarcinoma

Adenocarcinoma is the most common histological type of lung carcinoma. Recently the histologic classification of adenocarcinomas in the lung was modified to better reflect biologic properties and prognosis. We reviewed the histology of all primary lung adenocarcinomas operated on in Iceland during a 20-year period and assessed the impact of histology on survival. This nationwide study included 285 patients (mean age 67 years, 57% female), who underwent resection in Iceland from 1991 to 2010. Tumors were reclassified according to the current IASLC/ATS/ERS classification system. Overall survival was estimated by the Kaplan-Meier method and Cox regression analysis used to evaluate prognostic factors of overall mortality. Acinar predominant adenocarcinoma was the most common histological subtype (46%) followed by solid-predominant (SPA) with mucin production comprised (23%). Non-invasive carcinomas were rare. A difference in survival between the histological adenocarcinoma subtypes was not seen (p = 0.32) and multivariate analysis showed that advanced stage and age predicted worse outcome, but histologic subtyping of adenocarcinoma did not. In this nation-wide study there was not a statistical difference in survival according to adenocarcinoma subtypes and the histological subtype did not predict mortality. Preinvasive and minimally invasive adenocarcinomas were rare.

Surgical treatment of small cell lung cancer

Chemoradiotherapy remains a gold standard in the treatment of limited-disease small cell lung cancer. Currently, three indications for the surgical treatment of very limited disease (stage I, II, or highly selected IIIa) small cell lung cancer can be identified: (1) primary surgery in peripheral clinical N0 lesions followed by adjuvant chemotherapy or chemoradiotherapy; (2) primary chemotherapy or chemoradiotherapy followed by surgery +/- radiotherapy in patients with a good response to initial treatment; and (3) salvage operations in patients who recur or persist at the primary site but still have resectable disease. The value of these approaches has been assessed in retrospective analyses and prospective nonrandomized trials. A large prospective randomized trial failed to prove any added value for surgery in the multidisciplinary treatment of limited-disease small cell lung cancer, but very few very-limited-disease patients were included.

Surgical resection in the management of small-cell carcinoma of the lung

Surgery has had little impact on long-term survival in patients with small-cell lung cancer (SCLC). With the evolution of modern techniques, however, surgery may play an increasingly valuable role in SCLC. Surgery may potentially cure a select minority of SCLC patients. Patients with peripheral nodules and those with regional disease achieving a complete response to chemotherapy may benefit from adjuvant surgical resection for removal of residual disease. In some cases, surgery may also be preferred over adjuvant radiotherapy, since the latter necessitates lowering the total chemotherapy dose administered to SCLC patients.

Results of operation without adjuvant therapy in the treatment of small cell lung cancer

The role of surgery in the treatment of small cell lung cancer remains a subject of debate. We carried out a retrospective review of 87 patients with small cell lung cancer referred to one surgeon for staging and treatment. Thirty patients (34.5%) were deemed suitable for thoracotomy. Fourteen patients had stage I disease, 5 patients had stage II disease, and 11 patients had stage III disease. Twenty-eight of the 30 patients (93.3%) went on to have surgical resection. The actual overall 5-year survival in all patients who underwent thoracotomy was 43.3%. The actual 5-year survival for patients in stages I and III was 57.1% and 55.5%, respectively. No patients with stage II disease survived 5 years. We conclude that there is a small group of patients with small cell lung cancer in whom, with careful preoperative staging, the prospects of cure by operation are similar to those with non-small lung cancer.

Influence of surgical resection before and after chemotherapy on survival in small cell lung cancer

We attempted to define the role of surgery in the treatment of small cell lung cancer (SCLC). Of 81 patients with clinically localized SCLC, 36 underwent surgical resection: 19 underwent initial resection with postoperative chemotherapy, while the remaining 17 were treated initially with chemotherapy, then resection. The remaining 45 patients were treated with a combination of chemotherapy and radiotherapy. The 5-year survival for the 36 surgical patients was 38%; median survival time (MST) was 33 months. Nineteen patients treated with postoperative chemotherapy showed a 42% 5-year survival, while 17 patients treated with preoperative chemotherapy showed a 33% 5-year survival. This difference was not significant. However, stage III survival tended to be better in patients with preoperative chemotherapy (MST, 29 months) than in those who had had postoperative chemotherapy only (MST, 17 months). Although survival of the 45 nonsurgical patients was poor, stage I and II patients, or those with complete remission showed a 25% 5-year survival with an MST of 33 months, and a 21% 5-year survival with an MST of 25 months, respectively. We thus concluded that initial resection combined with postoperative chemotherapy is beneficial for patients with stage I, and probably stage II disease. For resectable stage III, particularly in patients with N2 disease, adjuvant resection after chemotherapy may be a favorable choice in the management of SCLC. For advanced stage III, complete remission by chemotherapy should be attempted in combination with radiotherapy.

Evolving role of surgical treatment in limited-disease small cell lung carcinoma

The diagnostic role of surgical procedures in small cell lung carcinoma (SCLC) is well established. The therapeutic role of surgery has changed over the years. At present, curative resection is the treatment of choice in peripheral T1-2 N0M0 SCLC, and adjuvant chemotherapy may be beneficial. Surgery is also indicated in SCLC patients diagnosed by a limited pathologic sample in whom the clinical course suggests nonsmall cell lung carcinoma (NSCLC). The resection may reveal either a mixed tumor or an alternate diagnosis and may be potentially curative. Surgery, at the time of maximal response to chemotherapy in T3N0M0 SCLC, may be curative and reveal the presence of NSCLC elements. The best survival is in patients found to be tumor-free at surgery, and the worst survival is in N2 patients.

Surgery in small cell lung cancer

Surgery in small cell lung cancer (SCLC) was abandoned in the late 1960s but is currently being cautiously reassessed, after the Armed Forces Asymptomatic Pulmonary Nodule Study demonstrated an unexpectedly prolonged 5-year survival (36%) with surgery. Subsequent prospective studies have reported five-year survival following resection in 22 to 83% of patients with Stage I disease and in 0 to 50% of patients with Stages II and III disease. Ten percent of patients with SCLC may be amenable to this approach. Additional patients may become candidates for resection following intensive combination chemotherapy. The optimal postoperative management remains unsettled. Combination chemotherapy and prophylactic cranial irradiation is recommended following complete resection. Postoperative thoracic irradiation may benefit patients with pathologically involved mediastinal nodes. Correlation of clinical response with our new understanding of the molecular biology of SCLC may further improve our approach to this disease.

Influence of surgical resection prior to chemotherapy on the long-term results in small cell lung cancer. A study of 150 operable patients

The effect of surgical resection, prior to chemotherapy, on the long-term results obtained in treatment of operable patients with small cell lung cancer (SCC) was evaluated in a consecutive series of 874 patients treated with intensive combination chemotherapy with or without irradiation between 1973 and 1981. Evaluation of disease stage and operability was based on broncho-mediastinoscopy, chest X-ray, bone marrow examination, peritoneoscopy with liver biopsy and lung function tests. The same staging procedures were applied for restaging performed after 18 months of chemotherapy. The series comprised 440 patients with extensive disease and 437 with limited disease of whom 150 were regarded operable. Fifty-four operable patients received no thoracotomy because the treatment policy of SCC did not include surgery at the hospitals from which they were referred. These patients served as a reference with which data on operated patients were compared. Resections were performed in 52 patients while 44 were regarded to be irresectable at the thoracotomy. Thirty-six resections were regarded histologically complete while 16 patients proved to have microscopic (9 pts) or macroscopic (7 pts) residual tumor. The number and per cent of 30 months disease-free survivors in the various categories of the 874 patients were as follows: Completely resected, 12/36 patients (33%); Resected with residual tumor, 2/16 (12.5%); Operable but non-operated, 7/54 (13%); Irresectable, 3/44 (6.8%); Non-operable patients with limited disease, 15/284 (5.3%) and with extensive disease, 11/440 (2.5%). The similarity between rates of long-term survival observed in resected patients with residual tumor and operable, non-operated patients suggests that resection, per se, has no significant influence on long-term results in SCC. The relatively high rate of long-term survival in completely resected patients may therefore primarily be a result of early stage disease at the initiation of chemotherapy.

Surgery of small cell lung cancer

The role of surgical resection in the management of patients with small cell lung cancer remains to be defined. Some data suggest the potential benefit of resection in the few patients with very limited disease (peripheral T1N0 and T2N0 lesions), and there are chemotherapy regimens with 80-85% response rates in patients with more extensive but still localized disease. Interest has been reawakened in the role of adjuvant surgical resection in selected patients by 2 approaches: in patients with peripheral T1 or T2 lesions with negative mediastinal exploration, initial surgical resection followed by an adequate chemotherapeutic regimen and prophylactic cranial irradiation has resulted in an 80% disease-free survival at 30 months; initial chemotherapy in patients with only localized disease is followed by resection in the responders. Approximately 30% of the responders have undergone exploratory thoracotomy after completion of the chemotherapy. Local irradiation, as well as prophylactic cranial irradiation, generally has been used postoperatively. Early pilot studies suggest benefit of this approach in patients found to have T1-3 N0-1 disease but not in those with N2 disease. Prospective, randomized, clinical trials by the Lung Cancer Study Group in North America and its counterparts in Europe are now being carried out in hopes of supplying definitive data relative to this multi-modality therapy in small cell lung cancer. Unfortunately, no data are available to date.

Treatment policy of surgery in small cell carcinoma of the lung: retrospective analysis of a series of 874 consecutive patients

A therapeutic policy of surgery in the treatment of small cell carcinoma of the lung was evaluated in a retrospective series of 874 consecutive patients. All patients were included in one of six clinical trials of intensive combination chemotherapy and radiotherapy, carried out during 1973-81. General criteria of resectability, including normal appearances at mediastinoscopy, were fulfilled in 33 electively operated patients and in 46 non-operated patients. An elective operation was defined as a thoracotomy performed with the intention of pulmonary resection in a patient known to have small cell carcinoma. Pneumonectomy or lobectomy was performed in 73% of the electively operated patients. Residual macroscopic or microscopic tumour tissue was left after half of these resections. Both operated patients and non-operated patients with operable tumours survived significantly longer than 696 patients deemed to have been inoperable. There was no significant difference, however, in the duration of survival between the two subsets of operable patients. According to this analysis, a treatment policy of surgery for resectable small cell carcinoma does not lead to better overall results than treatment with chemotherapy and radiotherapy alone.

Surgical resection in the management of small cell carcinoma of the lung

In an attempt to define the role of initial surgical resection in patients with undifferentiated small cell carcinoma of the lung, we reviewed the experience of the Veterans Administration Surgical Oncology Group (VASOG). One hundred forty-eight patients with small cell carcinoma of the lung had undergone a potentially "curative" resection. This represented 4.7% of "curative" resections carried out in four major prospective adjuvant chemotherapy trials. In the early trials (101 patients), 16 patients (15.8%) died within the first 30 postoperative days. These patients have been excluded from the analysis of long-term survival, since in the more recent trials postoperative deaths were excluded prior to randomization. In the 132 patients remaining, the 5 year survival rate by the life-table method was 23.0%. The tumor of each was classified pathologically by the TNM system. Five-year survival rates for each category were as follows: T1 N0 M0 59.9%, T1 N1 M0 31.3%, T2 N0 M0 27.9%, T2 N1 M0 9.0%, and any T3 or N2 3.6%. The effect of postoperative adjuvant chemotherapy was evaluated in each of the trials. No beneficial effect of the adjuvant therapy was noted with a one or two course regimen of either nitrogen mustard or cyclophosphamide, but possible benefit, although not significant, was noted in a prolonged intermittent chemotherapy trial of cyclophosphamide either alone or alternating with methotrexate. In the most recent trial of prolonged intermittent courses of 1-(2-chlorethyl)-3-cyclohexyl-l-nitrosourea (CCNU) and hydroxyurea, a 5 year survival rate of 80.8% was noted in those receiving adjuvant chemotherapy as compared to a 38.1% in the control group. We conclude that resection is definitely indicated in patients with T1 N0 M0 lesions and probably indicated in those with T1 N1 M0 or T2 N0 M0 lesions. Primary surgical resection is contraindicated in patients with any other TNM category.

Outcome of carcinoma in situ and early invasive carcinoma of the bronchus

Seventeen patients in whom a squamous carcinoma in situ of the bronchus had been resected have been followed for up to 16 years. The crude mortality rate for these patients is remarkably high, with seven (41%) dead after five years and 14 (82%) after 10 years. Half the patients had died as a direct result of malignant disease by 10 years--because of recurrence, metastatic disease, or the development of a second tumour. A guarded long-term prognosis must be given in these patients owing to the many deaths (mainly from other respiratory diseases) besides those from recurrent cancer.

Respiratory cytodiagnosis: study in observer variation and its relation to quality of material

Sensitivity and accuracy of cytodiagnosis were assessed in a multicentre study. Six centres each provided sputum cytological material from 20 cases. Each centre screened and reported on the 100 slides provided by the other five centres. The reports were assessed against consensus reference diagnoses, reached by discussion with transparencies, histological sections, and closed-circuit television. False positive rates of 0-4% (average 1.3%) and false negative rates of 0-12% (average 5.0%) of slides examined were recorded. The order of agreement on the three common cell types was adenocarcinoma 75% (50-91%), squamous cell carcinoma 80% (59-94%) and small carcinoma 95% (71-100%). The effect of quality of material on cytological opinion was assessed by comparing disagreement rates on each of the different sets of 20 slides. Disagreement varied from 1% to 23% depending on which set of material was examined.

Clinical indicators of prognosis in unresected lung cancer

A prognosis estimate in palliative treatment for inoperable lung cancer is thought to be of value. Performance status is now recognized as being of major importance, but only recently has been consistently available. We examined other simple information not requiring clinical or laboratory tests that is available in the clinical histories of a series of 1,839 patients with unresected lung cancer. Actuarial survivals at 1, 2, and 5 years were 21.9, 7.8, and 2.0 percent, respectively. The median survival rate was 24 weeks. Squamous cell histology and an increasing interval between the first symptoms and diagnosis were associated with a better prognosis. The number of symptoms recorded at the time of assessment had strong negative association with survival; asymptomatic patients had a two-year survival of 26 percent compared with 6 percent or less with four or more symptoms. A similar discrimination is given by Feinstein's index, which combines information on the number and type of symptoms and on the interval between first symptom and diagnosis. The clinical stage was strongly related to survival. Additional statistical analysis showed that the prognostic value of each of the most powerful prognostic factors, the number of symptoms, and Feinstein's index was little altered by the use of data on stage and histology in addition. The data show a range of median survival of 18 to 60 weeks for Feinstein's indices from 6 to 1, suggesting that the symptom index is useful particularly in the relatively well patients and the performance status particularly in those more ill. The combination may be better than either alone, and it is recommended that such information be recorded for all lung cancer patients.

Survival after resection of small cell carcinoma of the bronchus

Forty patients who underwent curative resection for oat cell carcinoma of the bronchus between 1959 and 1974 are reviewed. During the same period there were 24 patients who underwent thoracotomy but who were found to have inoperable lesions. Of the 40 patients who underwent curative resection, 11 patients remain alive and well with no evidence of recurrence. Ten of these patients have survived five years or more, an overall five-year survival rate of 25%. We consider that surgery should be considered as a possible first line of treatment in patients with small cell carcinoma of the bronchus.

Selection by mediastinoscopy and long-term survival in bronchial carcinoma

In order to reduce the high rate of inoperability in patients with bronchial carcinoma, mediastinoscopy was carried out as a routine preoperative selection in 874 patients during 13 years. Two hundred thirty-six patients (27%) were found to have involved lymph nodes at mediastinoscopy and were not treated surgically. Follow-up data were available on 210 of them: 165 (79%) died within a year, 16 survived for 2 years, and 4 for 5 years. Pulmonary resection was carried out in 638 patients. Five-year survival in the series was 24.5% and 10-year survival (based on 104 eligible patients), 16.3%, including the operative mortality of 5.5%. Mediastinoscopy has not improved long-term survival to any great extent. However, it has raised the rate of resectability to 97.1% and lowered the operative mortality without denying the patient a chance of cure.

Prognostic features of large cell anaplastic carcinoma of the bronchus

The clinical features of 208 patients with large cell anaplastic carcinoma of the bronchus are reviewed. Of the sample 47.6% had disseminated disease at presentation, and 95% were cigarette smokers. The median survival was 6.0 months and five-year survival was 5.9%. Twenty-seven per cent of the patients had surgical resection of tumour. The median survival of resected patients was 13.0 months and five-year-survival was 21%. Radiotherapy was ineffective in controlling the disease in this series.

Small cell lung cancer. Complete remission and improved survival

Thirty-two patients with limited-stage small cell lung cancer were treated with combined supervoltage radiotherapy and a combination of cyclophosphamide, doxorubicin and vincristine chemotherapy. The goal of obtaining a complete remission, the necessary step which precedes improved survival, was successful in 26 of 27 of completely re-evaluated patients. Fiberoptic bronchoscopy was useful in substantiating complete remission status. Seventeen of the 32 patients remain alive from 8+ to 28+ months (median 16+ months). Ten patients are alive and relapse-free from 12+ to 28+ months (median 19+ months). Transient granulocytopenia (mean nadir 650 cells/mm3) during induction therapy and the associated risk of infection were the most serious toxicities encountered. This therapy produces complete remission on roentgenography and bronchoscopy, symtomatic improvement and improved survival in the majority of patients with limited-stage small cell lung cancer. A portion of these patients may have their disease eradicated.

Squamous cell carcinoma of the lung. Clinicopathologic study

This study was undertaken to investigate the diagnostic, therapeutic, and prognostic features of squamous cell carcinoma of the lung. The overall five-year survival rate for 734 patients was 5 percent, with a median survival of 5.9 months. Surgical excision for early-stage disease was particularly effective therapy. In 151 of 201 patients having surgical excision, the resections were deemed curative. Other modes of therapy proved ineffective, although a combination of radiation and chemotherapy provided cure in one of 39 patients; that patient is alive today after 11 years and three months.

Cancer of the lung in women

A study from Wales of 132 women with cancer of the lung admitted consecutively during the five years 1964-68, and of 13 other women submitted to surgery at an earlier period, showed that the prognosis for women was worse than for men. Every woman except one was followed up for more than five years. Of the 132 women in the consecutive series only five survived for five years, while the five-year survival rate after resection in 35 women was less than one-half of that of men. The cause of the worse prognosis for women in Wales appears to be due to some sex-linked factor. It cannot be explained by the age of the patient or by the histology, location, early or resectability of the growth. The prognosis of cancer of the lung in English, French, and American women is considered. The relative incidence of the disease in women and men is discussed. Sex and nationality appear to be of importance, but the influence of tobacco and other atmospheric carcinogens is obscure.

Adenocarcinoma of the lung: clinicopathological study

A review of our 247 patients with adenocarcinoma of the lung revealed the overall five year survival rate to be only 0.81%. Lung resection offers the chance of cure if the lesion is peripherally located and without lymph node involvement. Direct chest wall invasion by tumor is not contraindication to surgery. Radiation therapy was not especially effective in our series. Several chemotherapeutic agents gave an overall response of 31.1%.

Benign and malignant mixed tumours of the lung

Ten patients are presented with tumours complying with the criteria established by the World Health Organization for `mixed tumours of the lung'.

A slowly growing intrabronchial neoplasm indistinguishable from a pleomorphic adenoma (mixed salivary tumour) and a peripheral circumscribed tumour with most of the features of a chondromatous hamartoma were considered benign.

Of eight malignant neoplasms two were regarded as `pulmonary blastomas', one with a benign epithelial tubular component and the other with cytological evidence of malignancy in the tubular epithelium; in both, the stroma was `embryonic' and pleomorphic. Three tumours were considered carcinosarcomas with a mainly epidermoid epithelial component and a pleomorphic spindle-cell connective tissue component. In the remaining three tumours the malignant epithelial component showed mixed, viz., epidermoid, tubular, and a variety of undifferentiated appearances, while the `stroma' exhibited features seen in both blastomas and carcinosarcomas. These three neoplasms were considered `transitional'.

The spectrum of appearances encountered constitutes, in our opinion, a serious objection to the thesis that peripheral pulmonary blastomas and carcinosarcomas are distinct entities with a separate histogenesis. Exceptions were found to `blastomas' being peripheral and carcinosarcomas being central growths. A case is made for reclassification of the benign and malignant neoplasms included in the WHO group IX `mixed tumours of the lung'.

Post-irradiation surgery for bronchogenic carcinoma

In an attempt to improve both the resectability and survival rates for bronchogenic carcinoma, pre-operative supervoltage radiotherapy was introduced in 1961 and continued for a period of three years. Patients with either a histological or cytological diagnosis were given a tumour dose of 4,500 r over six weeks and then a two-month period elapsed before surgery. A follow-up of cases treated during the period revealed a five-year survival rate of 15·7%. This rate is low when compared with the results achieved at this hospital with surgery alone. This finding is attributed to the harmful effects of radiotherapy which have led to a high bronchopleural fistula rate of 15·5%. A single case of myocardial radionecrosis also occurred. No improvement is noted in the resectability rate. An overall assessment is that radiotherapy has provided no benefits but has in fact greatly increased both the morbidity and mortality rates.

Adenocarcinoma of the lung

The clinical and histological features of 53 cases of adenocarcinoma of the lung are presented. In more than one-third of the patients the tumour was a solitary nodule, raising the possibility that it might be a metastatic focus. Although histological features may suggest an origin from such sources as the kidney, uterus, ovary or bowel, nearly all such cancers are, in fact, primary bronchial tumours. It is seldom justifiable to submit the patient with a nodular adenocarcinoma in the lung to a search for a possible extrathoracic primary neoplasm.

A review of some important problems concerning lung cancer. The importance of complete preoperative assessment in bronchogenic carcinoma

Part I of this review described the pathogenesis of lung cancer and emphasized that it was largely a preventable disease. In the present paper, attention is drawn to the prevalent but false impression that treatment of established disease is quite in-effective. In eight consecutive series of cases (over 2300 patients) the authors have seen a change in the clinical environment in which lung cancer is treated-from one of discouragement and apathy to one of outspoken encouragement and enthusiasm.Complete preoperative assessment-an evaluation of the biology of the tumour-host relationship as well as technical resectability-avoids unnecessary surgical intervention and stimulates a trend to earlier referral. This has permitted increasing use of resection with a declining mortality and a continuing improvement in overall survival. On the basis of present resectability rates (37.5%) and a 39% five-year survival rate in those who have had curative resection, it is estimated that current over-all five-year salvage should exceed 13%. This is more than a five-fold increase in survival for all patients compared to that achieved by treatment before 1952.