Lung cancer in women: exploring sex differences in susceptibility, biology, and therapeutic response

Sex differences in prognosis factors in patients with lung cancer: A nationwide retrospective cohort study in Korea

Large-scale studies elucidating sex differences in factors impacting prognosis and sex-specific prognossis factors scoring in patients with lung cancer are insufficient. The present study aimed to develop a model to predict sex-specific prognosis factors in Korean patients with lung cancer. This nationwide cohort study included 96,255 patients aged ≥19 years diagnosed with lung cancer and underwent Korean National Health Insurance Service health examinations between January 1, 2005 and December 31, 2015 and followed until 2020. Factors associated with prognosis were estimated using multivariable Cox proportional hazards regression analyses, and separate prognosis scores were calculated for male and female patients. The sex-specific risk scoring models were validated with Kaplan-Meier survival curves and c-statistic. During a mean follow-up of 2.8 years, 60.5% of the patients died. In male patients with lung cancer, age ≥ 65 years (24 points) had the highest mortality risk score, followed by chemotherapy in combination with radiotherapy (16 points), chemotherapy (14 points), and radiotherapy (11 points). In female patients with lung cancer, chemotherapy in combination with radiotherapy (19 points) had the highest mortality risk score, followed by chemotherapy (16 points), age ≥ 65 years (13 points), and radiotherapy (13 points). The analysis of patients categorized into three risk groups based on risk scores revealed that the fatality rates within 5 years were 7%, 54%, and 89% in the low-, intermediate-, and high-risk groups for male patients and 3%, 46%, 85% in the low-, intermediate-, and high-risk groups for female patients, respectively. The c-statistic was 0.86 for male patients and 0.85 for female patients. The strongest fatality risk factors in lung cancer were age ≥ 65 years in male patients and chemotherapy in female patients. The present study developed sex-specific prognosis scoring models to predict fatality risk in patients with lung cancer.

Clinical Significance of Dual-Block Elastic Stain Evaluating Visceral Pleural Invasion in Peripheral Non-Small Cell Lung Cancer

Visceral pleural invasion (VPI) is a critical component in the staging of peripheral non-small cell lung carcinoma (NSCLC). We aim to investigate whether dual-block elastic stain increases visceral pleural invasion positivity compared with single-block elastic stain. We further analyze the potential predictors of visceral pleural invasion. 8419 peripheral NSCLC patients (including 6008 patients with tumor size≤3 cm in stage I) were divided into a cohort using one paraffin block (single-block group, n = 5184) and a cohort using dual paraffin blocks (dual-block group, n = 3235) for elastic stain. The VPI-positive rate demonstrated by the dual-block elastic stains group was significantly higher than that of the single-block elastic stain group (17.7% (573/3235) versus 9.1% (474/5184), respectively, P < .001). The presence of visceral pleural invasion in T1 (≤3 cm) patients detected by single- and dual-block elastic stain was 6.3% (235/3730) and 12.0% (273/2278), respectively (P < .001). 5.7% of T1 patients (stage IA) were additionally upstaged to T2a (stage IB) by dual-block elastic stain. However, the incidence of visceral pleural invasion in pT2a patients showed no significant difference between the single-block group and the dual-block group (16.8% vs. 17.1%, P = .916). Lymphovascular invasion, lymph node metastasis, dedifferentiated carcinomas, the presence of spread through airspaces (STAS) and a poorly differentiated adenocarcinomatous growth pattern could be significant predictors of visceral pleural invasion (P < .001). Our results indicate that using dual-block elastic stain identifies more visceral pleural invasion positive T1 NSCLC patients who are upstaged to T2a, and who could benefit from optimal management post-operatively. The application of dual-block elastic stain is an efficient and practical method to detect visceral pleural invasion status.

A practical and adaptive approach to lung cancer screening: a review of international evidence and position on CT lung cancer screening in the Singaporean population by the College of Radiologists Singapore

Lung cancer is the leading cause of cancer-related death around the world, being the top cause of cancer-related deaths among men and the second most common cause of cancer-related deaths among women in Singapore. Currently, no screening programme for lung cancer exists in Singapore. Since there is mounting evidence indicating a different epidemiology of lung cancer in Asian countries, including Singapore, compared to the rest of the world, a unique and adaptive approach must be taken for a screening programme to be successful at reducing mortality while maintaining cost-effectiveness and a favourable risk-benefit ratio. This review article promotes the use of low-dose computed tomography of the chest and explores the radiological challenges and future directions.

Smoking and Pancreatic Cancer Incidence: A Pooled Analysis of 10 Population-Based Cohort Studies in Japan

BACKGROUND

Detailed prospective evaluation of cigarette smoking associated with pancreatic cancer risk in large Asian populations is limited. The aim of this study was to examine this association in a Japanese population, with a particular focus on evaluating sex differences.

METHODS

We performed a pooled analysis of 10 population-based cohort studies. We calculated study-specific HRs and 95% confidence intervals (CI) using Cox proportional hazards regression, and then estimated summary HRs by pooling these estimates with a random effects model.

RESULTS

During 4,695,593 person-years of follow-up in 354,154 participants, 1,779 incident pancreatic cancer cases were identified. We observed an increased pancreatic cancer risk for current smoking compared with never smoking in both males [HR (95% CI), 1.59 (1.32-1.91)] and females [HR (95% CI), 1.81 (1.43-2.30)]. Significant risk elevations for former smoking and small cumulative dose of ≤20 pack-years (PY) were observed only among females, regardless of environmental tobacco smoke exposure. Trend analysis indicated significant 6% and nonsignificant 6% increases in pancreatic cancer risk for every 10 PYs in males and females, respectively. Risk became comparable with never smokers after 5 years of smoking cessation in males. In females, however, we observed no risk attenuation by smoking cessation.

CONCLUSIONS

This study supports the well-known association between smoking and pancreatic cancer and indicates potential sex differences in a Japanese population. Quitting smoking would be beneficial for pancreatic cancer prevention, especially in males.

IMPACT

Pancreatic cancer risk is increased with cumulative smoking exposure and decreased with smoking cessation, with potential sex differences.

Long-term exposure to fine particulate matter air pollution and the risk of lung cancer among participants of the Canadian National Breast Screening Study

Recently, air pollution has been classified as a carcinogen largely on the evidence of epidemiological studies of lung cancer. However, there have been few prospective studies that have evaluated associations between fine particulate matter (PM2.5 ) and cancer at lower concentrations. We conducted a prospective analysis of 89,234 women enrolled in the Canadian National Breast Screening Study between 1980 and 1985, and for whom residential measures of PM2.5 could be assigned. The cohort was linked to the Canadian Cancer Registry to identify incident lung cancers through 2004. Surface PM2.5 concentrations were estimated using satellite data. Cox proportional hazards models were used to characterize associations between PM2.5 and lung cancer. Hazard ratios (HRs) and 95% confidence intervals (CIs) computed from these models were adjusted for several individual-level characteristics, including smoking. The cohort was composed predominantly of Canadian-born (82%), married (80%) women with a median PM2.5 exposure of 9.1 µg/m(3) . In total, 932 participants developed lung cancer. In fully adjusted models, a 10 µg/m(3) increase in PM2.5 was associated with an elevated risk of lung cancer (HR: 1.34; 95% CI = 1.10, 1.65). The strongest associations were observed with small cell carcinoma (HR: 1.53; 95% CI = 0.93, 2.53) and adenocarcinoma (HR: 1.44; 95% CI = 1.06, 1.97). Stratified analyses suggested increased PM2.5 risks were limited to those who smoked cigarettes. Our findings are consistent with previous epidemiological investigations of long-term exposure to PM2.5 and lung cancer. Importantly, they suggest associations persist at lower concentrations such as those currently found in Canadian cities.

[The future incidence of colorectal and lung cancers: results of the calculation of different scenarios for the year 2020]

BACKGROUND

Cancer is a common disease that places a large burden on health-care systems. Although the rise of incident cancer cases over recent decades in Germany can largely be explained by demographic ageing, other factors also affect these numbers. The aim of this work was to calculate the incidence of colorectal and lung cancers, two of the most common cancer sites, for the year 2020 under different scenarios.

MATERIALS AND METHODS

The calculations were based on national incidence estimates by the Centre for Cancer Registry Data at the Robert Koch Institute. Two scenarios were calculated for each of the two cancer sites and by gender. The "status quo" scenario accounts only for demographic ageing, assuming constant age-specific incidence rates. The second scenario additionally assumes that trends in incidence rates observed from 2000 to 2009 continue up to the year 2020.

RESULTS

The "status quo" scenarios showed an increase in incident cancer cases of between 12 and 24%, depending on gender and cancer site. The "continuing trends" scenarios resulted in smaller increases for colorectal cancer (+3 to + 17%), while the results for lung cancer differed widely between women (+ 64%) and men (+ 2%). In general, large increases are expected for the highest age groups and the age groups of the baby boomer generation.

DISCUSSION

Changes in the age structure of the German population will lead to an increase in incident cancer cases and a higher portion of geriatric patients. Additionally, further increasing incidence rates would result in a dramatic growth in the number of female lung cancer patients.

Do female cancer patients display better survival rates compared with males? Analysis of the Korean National Registry data, 2005-2009

Background

Sex differences have been reported in the prognosis of certain cancers. In this study, we investigated whether Korean females display better survival rates compared with male patients for solid tumor sites.

Methods

We analyzed data from the Korean National Cancer Incidence Database from 599,288 adult patients diagnosed with solid cancers between 2005 and 2009. Patients were followed until December 2010. We applied a relative excess risk (RER) model adjusting for year of follow-up, age at diagnosis, and stage at diagnosis.

Results

For all solid cancer sites combined, women displayed an 11% lower risk of death compared to men (RER 0.89; 95% CI 0.88–0.90) after adjusting for year of follow-up, age, stage, and case mix. Women showed significantly lower RERs for the following sites: head/neck, esophagus, small intestine, liver, nasal cavities, lung, bone/cartilages, melanoma of skin, soft tissue, brain and CNS, and thyroid. In contrast, women displayed a poorer prognosis than did men for colorectal, laryngeal, kidney and bladder cancer. However, the survival gaps between men and women narrowed by increase in age; female patients over 75 years of age displayed a 3% higher RER of death compared with males in this age group.

Conclusions

Female cancer patients display an improved survival for the majority of solid tumor sites, even after adjustment for age and stage. Age at diagnosis was the major contributor to the women’s survival advantage.

The significance of visceral pleural surface invasion in 321 cases of non-small cell lung cancers with pleural retraction

BACKGROUND

In order to improve prognostic applications and treatment decisions, we report our experiences of visceral pleural surface invasion (VPSI) in non-small cell lung cancers (NSCLCs) with pleural retraction.

METHODS

A total of 321 NSCLCs with pleural retraction were identified by carefully inspecting surgically resected specimens. The extent of pleural invasion, including the use of elastic stain, was evaluated. Patients with and without VPSI were compared for clinicopathologic parameters and survival.

RESULTS

VPSI was identified in 170 (53.0 %) of the stage I-III cases and 98 (43.4 %) of the patients with stage I disease. VPSI was associated with a higher frequency of tumor size greater than 3 cm, moderate/poor differentiation, vascular invasion, mediastinal lymph node metastasis, extranodal involvement, and higher TNM stages. Multivariate analysis revealed VPSI to be a significant independent predictor of unfavorable prognosis. The 5-year survival of patients with and without VPSI was 57.9 and 83.0 %, respectively (P = 0.001), and was 74.3 and 88.5 % (P = 0.005) in stages I-III and stage I disease, respectively.

CONCLUSIONS

VPSI is an independent factor for poor prognosis in NSCLCs, regardless of lymph node status. Stage IB NSCLCs with PL1 pleural invasion are associated with a survival rate similar to that of stage IA NSCLCs and could be classified as T1 lesions. While surgical treatment is adequate in these patients, stage IB NSCLCs with VPSI have poor prognosis, and these patients should be considered for adjuvant chemotherapy.

Population aging and hospitalization for chronic disease in Germany

BACKGROUND

The population of Germany is aging, i.e., the elderly currently make up an increasing percentage of the population from year to year. Furthermore, many common chronic diseases mainly affect the elderly. For these two reasons, the overall cost of health care in Germany is expected to increase. We studied the effect that population aging has had on the number of hospitalizations for major types of chronic disease in Germany since the year 2000.

METHODS

This study is based on nationwide hospitalization statistics, classified by diagnosis, that were published by the German Federal Statistical Office. We analyzed data for three classes of diagnoses--malignant neoplasia, cardiovascular diseases, and diseases of the musculoskeletal system and connective tissue--which were further broken down into nine diagnostic subgroups. Changes in inpatient case numbers might be due either to population aging or to changing rates of hospitalization for individual diagnoses. We used index decomposition analysis to determine the relative influence of these two factors on changing case numbers.

RESULTS

The author found that the aging of the population increased the number of hospitalizations for all of the diagnoses studied. This was particularly evident with respect to the large birth cohorts born in the 1920s (with the diagnosis of congestive heart failure) and in the period 1934-1944 (with the diagnoses ischemic heart disease, lung cancer, colorectal cancer, and osteoarthritis). On the other hand, changing rates of hospitalization for individual diagnoses increased the number of hospitalizations for some diagnoses (congestive heart failure, diseases of the spine and back) and decreased it for others (ischemic heart disease, cerebrovascular diseases, colorectal cancer, breast cancer).

CONCLUSION

The aging of the population and the changing rates of hospitalization for various diagnoses are exerting separate effects on the number of hospitalizations for chronic diseases in Germany. Predictions of hospital case numbers in the future must take both factors into account.

[Gender-associated differences of lung cancer and mechanism]

肺癌是全球发病率、死亡率最高、治疗效果差的恶性肿瘤。肺癌在流行病学、病理类型、疗效和预后、甚至发病机制等多方面均表现出明显性别差异。对这些差异的深入剖析能更好地认识男女性别肺癌各自的特点，为肺癌防治采用不同的性别化措施提供新线索和思路；而对导致性别差异的具体机制进行深入研究，有助于阐明肺癌的发病机制。

Outcome and treatment strategy in female lung cancer: a single institution experience

PURPOSE

To assess the survival rate of female lung cancer treated at the Institute of Oncology of the Vilnius University, Lithuania during the period between 1996-2005.

MATERIALS AND METHODS

During the period between 1996-2005, 471 women diagnosed with lung cancer were treated at the Department of Thoracic Surgery and Oncology of the Institute of Oncology, Vilnius University. Data on morphology, stage and treatment was collected from the medical records. All lung cancer cases by histology were classified in two groups: non-small cell lung cancer (includes squamous cell carcinoma, large cell carcinoma, adenocarcinoma and other less common types) and small cell lung cancer. The vital status of the study group was assessed as of December 31, 2007, by passive follow-up, using data from the population registry. It was found that 411 (87.3%) of the patients had died. Survival was estimated according to the Kaplan-Meier method.

RESULTS

The median survival of female lung cancer diagnosed during 1996-2005 in Lithuania show to be 8.7 months (8.4 (95% CI 7.2-10.8) months with non-small cell lung cancer and 9.3 (95% CI 6.3-13.0) months with small-cell lung cancer). Survival was more than 20 months in resectable non-small cell lung cancer (stages I, II, IIIA). Non-small cell lung cancer survival in advanced stages was less than 7 months. Small-cell lung cancer patients median survival at limited and extended stages of the disease were 9.5 (95% CI 2.9-18.4) compared to 9.2 (95% CI 6.2-13.7) months. Non-small cell lung cancer patients most frequently were treated by surgery (27.0%), surgery and chemotherapy or radiotherapy (19.6%). Small cell lung cancer patient treatment included chemo and radiotherapy (27.0%), chemotherapy (19.0%), radiotherapy (17.5%), surgery (27.9%).

CONCLUSIONS

The single center study of female lung cancer diagnosed during 1996-2005 in Lithuania show a significantly better chance of survival in resectable non-small cell lung cancer. Advanced stages of the disease at the time of diagnosis and choice of treatment options of female lung cancer in the country still remains an issue.

Lung cancer and women

In the early 1900s, lung cancer was a rare malignancy in women, but starting from the 1960s it has progressively reached epidemic proportions, surpassing breast cancer in 1987 and becoming the leading cause of cancer deaths in many countries. Retrospective data show that the 5-year survival rate for women who have lung cancer is 15.6%, compared with 12.5% for men, and this improved survival could have important implications in the design and interpretation of lung cancer trials. Women have major responses to therapy regardless of stage, therapeutic modalities or histology. The increase of lung cancer incidence among women is reflected in their clinical trial participation, causing a survival improvement and suggesting the need of stratification by sex in future studies. No specific drugs for women with lung cancer are currently available, but researchers are devoting energies in this area in order to better understand the implication of gender differences in epidemiology, pathogenesis, prognosis and tumor response.

Mechanisms of Disease: signal transduction in lung carcinogenesis -- a comparison of smokers and never-smokers

Although smoking has been established as the most important cause of lung cancer, approximately 10% of patients with this malignancy have no history of smoking. The pathogenesis of tobacco-related lung carcinogenesis is becoming well characterized, but the molecular mechanisms of neoplastic transformation in never-smokers have not yet been adequately elucidated. Nevertheless, numerous recent studies have revealed a distinct biological process of malignant transformation with unique epidemiological and clinicopathological characteristics in never-smokers. The molecular pathways involved in the differential pattern of lung oncogenesis according to smoking status, however, remain fairly obscure. Researchers have studied several molecular pathways implicated in lung carcinogenesis in smokers and never-smokers, examining these processes at the genomic, epigenetic and proteomic level. The differential protein expression according to smoking status in critical signal transduction pathways has attracted scientific interest because of the possibilities of therapeutic intervention. In this Review we describe the best-characterized signaling pathways implicated in the transduction of proliferative signals and discuss the activity of these pathways in smokers and never-smokers.

Lung cancer incidence in never smokers

PURPOSE

Lung cancer is a leading cause of cancer death worldwide. Although smoking remains the predominant cause of lung cancer, lung cancer in never smokers is an increasingly prominent public health issue. However, data on this topic, particularly lung cancer incidence rates in never smokers, are limited.

METHODS

We reviewed the existing literature on lung cancer incidence and mortality rates among never smokers and present new data regarding rates in never smokers from the following large, prospective cohorts: Nurses' Health Study; Health Professionals Follow-Up Study; California Teachers Study; Multiethnic Cohort Study; Swedish Lung Cancer Register in the Uppsala/Orebro region; and First National Health and Nutrition Examination Survey Epidemiologic Follow-Up Study.

RESULTS

Truncated age-adjusted incidence rates of lung cancer among never smokers age 40 to 79 years in these six cohorts ranged from 14.4 to 20.8 per 100,000 person-years in women and 4.8 to 13.7 per 100,000 person-years in men, supporting earlier observations that women are more likely than men to have non-smoking-associated lung cancer. The distinct biology of lung cancer in never smokers is apparent in differential responses to epidermal growth factor receptor inhibitors and an increased prevalence of adenocarcinoma histology in never smokers.

CONCLUSION

Lung cancer in never smokers is an important public health issue, and further exploration of its incidence patterns, etiology, and biology is needed.