Lung cancer in women

[Lung cancer in women: surgical aspects related to gender]

INTRODUCTION

Lung cancer is becoming more and more common in women where it presents significant differences at both clinical and therapeutic levels. Our purpose was to study those associated with surgical treatment.

PATIENTS AND METHODS

2972 patients were operated on between 1984 and 2002: 2480 men and 492 women. These two populations were compared (age, past history, investigations, interventions, TNM stage, long term survival and causes of death).

RESULTS

The number of women increased with time; they were younger than the men, smoked less, had the same past history of cancer but less past medical history, and comorbidity. They underwent less pneumonectomies and had a lower postoperative mortality. Tumour size was smaller (39.5 vs 43.5cm, p=0.0001); N0 and stage I tumours were more frequent (52.6% vs 46% p=0.0074). Long term survival was better (48.6% vs 43.1%, p=0.016), particularly in stage I and with a past history of cancer. It was identical in stage III despite a higher incidence of multisite N2 disease. Smoking and adenocarcinoma were more frequent before the menopause and N2 prognosis deteriorated with age.

CONCLUSION

These results confirm characteristics peculiar to lung cancer in women and warrant further investigation aimed at their better understanding. However, in multivariate analysis gender does not appear to be an independent prognostic factor.

Lung cancer in women: sex-associated differences in survival of patients undergoing resection for lung cancer

STUDY OBJECTIVES

The aim of this study was to analyze various characteristics and survival in female patients treated surgically for lung cancer.

DESIGN

Retrospective clinical study.

PATIENTS

From 1,242 consecutive cases of primary non-small cell lung cancer treated with pulmonary resection between June 1984 and December 1998, 337 female patients (27.1%) were chosen.

RESULTS

Female patients had the following characteristics: a significantly younger age at onset (62.5 +/- 0.56 years vs 64.1 +/- 0.31 years for men), a higher frequency of adenocarcinoma (86.0% vs 48.3% for men), and smaller tumors (32.7 mm vs 38.3 mm in diameter for men). Peripheral tumors were significantly more common in women than men (71.8% vs 50.6%, respectively). Among 686 patients with a history of smoking, the women smoked significantly less often (12.8% vs 91.4% for men). Complete resection was achieved significantly less often in women (79.6% vs 85.2% for men); however, women having complete resection survived significantly longer than their male counterparts. Women with a postoperative negative carcinoembryonic antigen (CEA) had a significantly better prognosis than men; however, women with a postoperative positive CEA did not. Women > or = 60 years old survived significantly longer than their male counterparts, while women < 60 years old did not.

CONCLUSIONS

Once the tumor was resected completely, women survived longer, partly due to the influence of life expectancy. However, the incidence of malignant effusion was higher and the rate of complete resection was lower in women.

Lung cancer in lifelong non-smokers. Edinburgh Lung Cancer Group

The Edinburgh Lung Cancer Group registered 3070 new patients with lung cancer in the five years 1981-5 from a catchment population of 950,000. After review only 74 (2%) were classified as lifelong non-smokers. They differed significantly from the 2996 smokers with lung cancer in that far more were female (77% v 26%) and their mean age was higher (75.4 v 68.0 years). More were in the worst Karnofsky performance categories and fewer patients underwent surgery. The stages of disease were similarly distributed in the two groups and the five year survival was equally poor (5%). Histological cell type was determined in 59 of the 74 patients. All histological cell types were present. More non-smokers had adenocarcinoma than smokers (42% v 13%) and fewer had squamous cell carcinoma (32% v 49%) or small cell carcinoma (15% v 24%). Lung cancer in lifelong non-smokers is uncommon and the diagnosis should therefore always be questioned.

Longer survival after resection of non-small cell lung cancer in Japanese women

From 1974 to 1988, 492 patients (361 male and 131 female) with non-small cell lung cancer underwent pulmonary resection at our department. A retrospective study was done with special reference to the sex of the patients. There was no sex-related association with age distribution, operation, pathological T or N status, or staging. On the other hand, 77.9% of women had an adenocarcinoma and only 44.6% of men had this type of lesion. This was considered at least partly a result of sex difference in smoking habits. Women survived for a significantly longer time (p = 0.0036), and this difference could not be explained by differences in histological type. Presumably, hormonal factor(s) may contribute to the prognosis.

Clinical features of bronchogenic carcinoma in Hong Kong. Review of 480 patients

A retrospective study was made of 480 Chinese patients with proven bronchogenic carcinoma, the top cancer in Hong Kong. The male-to-female sex ratio was low (1.9:1) and the female mortality rate ranked amongst the world's highest. The four major histologic types accounted for 87% of the cases: 39% epidermoid, 12% small cell anaplastic, 29% adenocarcinoma, and 7% large cell anaplastic. History of smoking was associated with epidermoid and small cell anaplastic carcinoma only. The commonest symptoms were anorexia and malaise (67%) and cough (51%). Overall our patients presented late and only 30 (6%) had curative surgery. The relatively rare occurrence of deep vein thrombosis (0.7%) is in keeping with the known low incidence of venous thrombosis in Chinese. Adenocarcinoma was a distinct group characterized by its preponderance in females (43%), lack of association with smoking habit (61% female cases being nonsmokers), high frequency of neurologic manifestation (21%) and clinical, roentgenographic, and bronchoscopic features of a predominantly centrally situated tumor. Possible etiologic factors for the high and still increasing incidence of adenocarcinoma are discussed.

Carcinoma of the lung in women

The 5-year survival of 293 men and of 78 women undergoing pulmonary resection and mediastinal lymph node dissection is compared. These patients were broken into two age groups: Group 1, 40 through 49 years of age, and Group 2, 50 years of age and older. They were subdivided further according to clinical stage, cell type, and sex. Of the 25 men in Group 1, 15 (60%) survived 5 years, while 98 (37%) of the 268 men in Group 2 survived 5 years. Among the 31 women in Group 1, 5 (16%) survived for 5 years, while 15 (32%) of the 47 women in Group 2 survived for that length of time. The survival among women in the younger age group was significantly lower than for both groups of women in the older age group (p = 0.0335) and men in the younger age group (p = 0.0033). This is believed to be due to the higher incidence of both Stage III disease and adenocarcinoma in the younger women. Twenty-two of the younger women (71%) were classified Stage III compared with 14 (30%) of the older women. Fourteen younger men (56%) had reached Stage III, and 101 older men (38%) were classified as Stage III. These data suggest that sex is an important factor in determining survival because there appears to be a relationship between it and the stage of the disease, and cell type. Overall, women had a poorer 5-year survival than men. Younger women have a strikingly lower survival than any other group, which is explained by their higher incidence of both Stage III classification and adenocarcinoma.

The changing histopathology of lung cancer: a review of 1682 cases

We have reviewed the histopathology of lung cancer patients seen over the past 13 years at RPMI. Assessment of this data indicates that adenocarcinoma is becoming progressively more prevalent as related to the other forms of lung cancer. Factors which in part may account for this increased prevalence are: 1) changes in criteria for reading histopathology of lung cancer, particularly since 1967; 2) the increased incidence of lung cancer among the female population who have a propensity for adenocarcinoma; and 3) occupational and environmental factors. In 1974 adenocarcinoma for the first time became the most prevalent type of lung cancer at RPMI. Whatever the reason, if our data are truly representative of a national trend, adenocarcinoma will soon become the most prevalent type of lung cancer in the United States. This fact may result in an increasing death rate since the present 18-month survival rate for adenocarcinoma is substantially less than for squamous cell carcinoma, which has in the past been the prevalent form of the disease. As the smoking habits of women more closely approximate those of men, we expect that the incidence and mortality of lung cancer will prove to be quite similar in both sexes.

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.

Changing epidemiology of lung cancer. Increasing incidence in women

Recent worldwide reports show a large increase in the incidence of lung cancer in both men and women. To detail changes in the epidemiology of lung cancer relating to the incidence in men and women, we reviewed the patterns of diagnosis of 1145 patients with lung cancer seen at the Lahey Clinic between 1956 and 1972, during which time the proportion of all men and women seen was unchanged. The total number of women with lung cancer increased greatly and has almost doubled during this period. Lung cancer in women is now increasing at a faster rate than in men so that the male to female incidence has decreased from 6.8/1 (1957 to 1960) to 2.4/1 (1969 to 1972). We reviewed in detail the case histories and pathology of 231 women with lung cancer. No significant change was evident in cell type distribution during the study years. The most frequently seen tumors in women were adenocarcinoma (31 per cent), undifferentiated large cell cancer (22 per cent), epidermoid carcinoma (16 per cent), and undifferentiated small cell carcinoma (12 per cent). Among those women with known smoking histories, the group most responsible for the recent increase in women with lung cancer was comprised of smoking women in whom Kreyberg group 1 (smoking-related) tumors developed.

Relationship between cigarette smoking and histological type of lung cancer in women

In recent years there has been an increase in the incidence of lung cancer in women so much so that the rate of increase exceeds the rate of increase in men. This change in incidence has been associated with cigarette smoking and as it is considered that smoking is connected mainly with the squamous and undifferentiated forms of tumour it might be expected that a recent change in the proportions of the different histological groups would be demonstrable.

All histological sections of proven cases of lung cancer in women seen between 1955 and 1971 at the Sheffield Royal Infirmary have been reviewed. A rise in the proportion of female cases attending hospital was noted but this rise has been associated with an increase in the proportion of cigarette smokers only in recent years. However, there is no good evidence of a change in the histological pattern of the disease and no statistically significant evidence of a connection between cigarette smoking and any particular cell type in the cases studied. Comparison with other studies confirms that cigarette smoking has only a small influence on the cell type of lung cancers in British women, but in American women there is a strong association between smoking and tumours of Kreyberg's group I. This appears to be a real and unexplained difference between the behaviour of lung cancers in British and American women.