Familial aggregation of breast cancer with early onset lung cancer

Smoking and the Risk of Second Primary Lung Cancer Among Breast Cancer Survivors from the Population-Based UK Biobank Study

OBJECTIVE

Long-term breast cancer (BC) survivors are known to develop second malignancies, with second primary lung cancer (SPLC) one common type. Smoking was identified as a main risk factor for SPLC among BC survivors. These findings were limited to the U.S. and focused on smoking status, not incorporating cumulative smoking exposures (eg, pack-years). We examine SPLC incidence and evaluate the associations between SPLC risk and cumulative cigarette smoking exposures and other potential factors among BC survivors in a prospective European cohort.

METHODS

Of 502,505 participants enrolled in the UK Biobank in 2006 to 2010, we identified 8429 patients diagnosed with BC between 2006 and 2016 and followed for second malignancies through 2016. Smoking information was collected at enrollment, and treatment data were collected using electronic health records. Multivariable cause-specific Cox regression (CSC) evaluated the association between each factor and SPLC risk.

RESULTS

Of 8429 BC patients, 40 (0.47%) developed SPLC over 45,376 person-years. The 10-year cumulative SPLC incidence was 0.48% (95% CI = 0.33%-0.62%). The CSC analysis confirmed the association between SPLC and ever-smoking status (adjusted hazard-ratio (aHR) = 3.46 (P < .001). The analysis showed a 24% increment in SPLC risk per 10 smoking pack-years among BC survivors (aHR = 1.24 per-10 pack-years, P = .01). The associations between SPLC and other variables remained statistically insignificant. We applied the USPSTF lung cancer screening eligibility criteria and found that 80% of the 40 BC survivors who developed SPLC would have been ineligible for lung cancer screening.

CONCLUSION

In a large, European cohort, cumulative smoking exposure is significantly associated with SPLC risk among BC survivors.

Reproductive factors and lung cancer risk: a comprehensive systematic review and meta-analysis

BACKGROUND

A number of studies have investigated the association between reproductive factors and lung cancer risk, however findings are inconsistent. This meta-analysis aimed to evaluate the association between female reproductive factors and lung cancer risk.

METHODS

We conducted a comprehensive systematic search to identify relevant and eligible studies published before 18th December 2019. Inter-study heterogeneity was assessed using the Q test and I2 statistic. Based on the heterogeneity of each reproductive factor, fixed or random effects models were used to calculate the summary odds ratios (ORs) and 95% confidence intervals (CIs). Subgroup analyses by study design, lung cancer subtypes, smoking status, and ethnicity were also performed.

RESULTS

A total of 66 studies with 20 distinct reproductive factors were included in this meta-analysis. Comparing the highest and lowest categories (reference) of each reproductive factor, parity (OR = 0.83, 95% CI = 0.72-0.96), menstrual cycle length (OR = 0.79, 95% CI = 0.65-0.96), and age at first birth (OR = 0.85, 95% CI = 0.74-0.98), were significantly associated with a lower risk of overall lung cancer. On the contrary, non-natural menopause was significantly associated with higher lung cancer risk (OR = 1.52, 95% CI = 1.25-1.86). Among never-smokers, a significant negative association was found between parity and lung cancer risk. Both parity and non-natural menopause were statistically significant in case-control studies.

CONCLUSION

These results suggest that certain reproductive factors may be associated with lung cancer risk. Future studies should further validate the associations, and investigate the underlying mechanisms.

Incidence and natural course of CT-detected pulmonary ground-glass nodules in Chinese women with breast cancer: a retrospective, single-center, long-term follow-up study in 4682 consecutive patients

Background

Increased use of thin-section computed tomography (CT) scans has revealed that small lung nodules, termed ground-glass nodules, are frequent in primary breast cancer patients and are associated with pre-invasive or invasive pulmonary adenocarcinomas. However, little is known of the incidence and fate of ground-glass nodules.

Purpose

To elucidate the incidence and natural course of CT-detected pulmonary ground-glass nodules in Chinese women with breast cancer.

Material and Methods

We retrospectively reviewed data from female breast cancer patients who underwent lung CT scans and who were followed for ≥3 months after the initial scan to identify the incidence of ground-glass nodules and any changes in them during the follow-up period.

Results

Between January 2008 and April 2018, 693 out of 4682 breast cancer patients (14.8%) had persistent lung ground-glass nodules as detected by CT scan. The median age was 52 years (interquartile range [IQR] = 45–62 years). Median nodule size was 4.9 mm in diameter on initial CT scan. Frequency of growth was 7.5% (52/693 patients). Median volume doubling time was 1092 days (IQR = 719–1808 days) for 39 growing in size nodules. Initial nodule size, nodule type, and follow-up period were independent predictors of nodule growth.

Conclusion

Most pulmonary ground-glass nodules in breast cancer patients were stable during long-term follow-up; most growing nodules had an indolent clinical course, suggesting that nodules should be monitored until growth is detected. This information is clinically relevant for accurate diagnosis of cancer stage and for appropriate treatment plans for patients with lung ground-glass nodules.

International trends in lung cancer incidence from 1973 to 2007

Lung cancer is the commonly diagnosed cancer and one of the most important avoidable causes of death around the world. We conducted the study to investigate the pattern of lung cancer incidence worldwide. Joinpoint analysis was used to extend international lung cancer incidence rates by the latest data from Cancer Incidence in Five Continents over the 35‐year period 1973–2007 from 24 populations from Americas, Asia, Europe, and Oceania. Age‐standardized incidence rates (ASRs) of lung cancer were from 33.3 to 66.8 per 100,000 among males and 10.5 to 37.4 per 100,000 among females in most of Americas, Europe, and Oceania populations during the period 2003–2007. In Asia, ASRs in China (Hong Kong) were the highest, up to 53.3 per 100,000 in males and 21.9 per 100,000 in females during the period 2003–2007. The international trends between 1973 and 2007 showed that ASRs of lung cancer among males were declining in 13 of 18 selected Americas, Oceania, and Europe populations, with AAPC from −0.7% to −2.9%, whereas the rates among females in 18 selected populations were increasing, with AAPC from 1.3% to 5.0%. The increasing and decreasing trends of ASRs of lung cancer in Asia have a geographic variation but no gender differences. Although the decreasing trends in ASRs of lung cancer for males were observed, the ASRs were higher than females. The declining trends in males were mainly attributed to tobacco control, whereas the increasing trends in females should be given more concern and need to be further studied in etiology factors.

Pleiotropic associations of risk variants identified for other cancers with lung cancer risk: the PAGE and TRICL consortia

BACKGROUND

Genome-wide association studies have identified hundreds of genetic variants associated with specific cancers. A few of these risk regions have been associated with more than one cancer site; however, a systematic evaluation of the associations between risk variants for other cancers and lung cancer risk has yet to be performed.

METHODS

We included 18023 patients with lung cancer and 60543 control subjects from two consortia, Population Architecture using Genomics and Epidemiology (PAGE) and Transdisciplinary Research in Cancer of the Lung (TRICL). We examined 165 single-nucleotide polymorphisms (SNPs) that were previously associated with at least one of 16 non-lung cancer sites. Study-specific logistic regression results underwent meta-analysis, and associations were also examined by race/ethnicity, histological cell type, sex, and smoking status. A Bonferroni-corrected P value of 2.5×10(-5) was used to assign statistical significance.

RESULTS

The breast cancer SNP LSP1 rs3817198 was associated with an increased risk of lung cancer (odds ratio [OR] = 1.10; 95% confidence interval [CI] = 1.05 to 1.14; P = 2.8×10(-6)). This association was strongest for women with adenocarcinoma (P = 1.2×10(-4)) and not statistically significant in men (P = .14) with this cell type (P het by sex = .10). Two glioma risk variants, TERT rs2853676 and CDKN2BAS1 rs4977756, which are located in regions previously associated with lung cancer, were associated with increased risk of adenocarcinoma (OR = 1.16; 95% CI = 1.10 to 1.22; P = 1.1×10(-8)) and squamous cell carcinoma (OR = 1.13; CI = 1.07 to 1.19; P = 2.5×10(-5)), respectively.

CONCLUSIONS

Our findings demonstrate a novel pleiotropic association between the breast cancer LSP1 risk region marked by variant rs3817198 and lung cancer risk.

Parity and risk of lung cancer in women: systematic review and meta-analysis of epidemiological studies

Multiple studies have assessed parity as a risk factor for lung cancer but results have been inconclusive. We searched MEDLINE (through August 2010) and the Institute of Scientific Information Web of Knowledge database (through April 2011) to identify studies investigating the association of parity with lung cancer and allowing the calculation of dose-response trends using a linear model. Between-study heterogeneity was assessed using Cochran's Q statistic and the I(2) index. Summary per-child relative risks (RRs) with their 95% confidence interval (CI) were estimated using random effects meta-analysis. Sixteen eligible studies (8077 lung cancer patients; 350,295 unaffected individuals) provided data for meta-analysis. There was significant between-study heterogeneity (p<0.001; I(2)=73%). The summary per livebirth RR was 0.98 (95% CI, 0.95-1.02), indicating no effect of parity on lung cancer risk. Results were consistent in case-control (n=11), RR=0.99 (95% CI, 0.94-1.04), and cohort studies (n=5), RR=0.97 (95% CI, 0.92-1.03). Studies not including small-cell lung cancer patients found a borderline protective effect of parity, RR=0.94 (95% CI, 0.88-1.00). In contrast, no effect was observed in studies including small-cell lung cancer patients, RR=1.00 (95% CI, 0.98-1.03); p for difference=0.05. Overall, there was little evidence of a dose-response relationship between increasing number of livebirths and lung cancer; however, studies have produced heterogeneous results. Future studies should include analyses in well-defined histological disease subgroups.

Early changes in pulmonary gene expression following tobacco exposure shed light on the role of estrogen metabolism in lung carcinogenesis

This perspective on Meireles et al. (beginning on p. 707 in this issue of the journal) discusses the increasing evidence for the role of female steroid hormones in lung cancer development and progression. The novel work of Meireles et al. is the first evidence for the rapid upregulation by tobacco smoke of a key cytochrome P450 gene that can metabolize estrogens such as beta-estradiol to potentially carcinogenic catechol and quinine forms, as well as the first evidence for the colocalization of beta-estradiol and estrogen receptors in murine airway epithelium. Actions of estrogens that contribute to lung carcinogenesis, especially in the presence of tobacco smoke, may involve both reactive intermediates that damage DNA and steroid hormone receptor signaling that promotes growth.

Family history of cancer and risk of lung cancer among nonsmoking Chinese women

The relationship between family cancer history in first-degree relatives and risk of lung cancer was evaluated among a population-based cohort of 71,392 female nonsmokers in Shanghai, China. A total of 179 newly diagnosed lung cancer patients were identified during 441,410 person-years of follow-up. Lung cancer risk was not elevated among those with a family history of lung cancer. However, risk of lung cancer was increased among subjects who had two or more first-degree relatives with any type of cancers {rate ratio [RR], 1.95 [95% confidence intervals (95% CI), 1.08-3.54] for two relatives with any cancers and RR, 3.17 [95% CI, 1.00-10.03] for three or more relatives with any cancer}. Having a family history of colorectal cancer (RR, 2.38; 95% CI, 1.21-4.70) and having siblings with stomach cancer (RR, 2.16; 95% CI, 1.01-4.65) and pancreatic cancer (RR, 4.19; 95% CI, 1.04-16.95) were also found to be associated with lung cancer risk. This cohort study indicated a moderate association of lung cancer risk with a family cancer history in general, but not with a family history of lung cancer specifically. The associations were stronger when a sibling, rather than a parent, was affected. The apparent link between lung cancer risk and a family history of colorectal, stomach, and pancreas cancers may be worth further investigation.

Breast cancer in first-degree relatives and risk of lung cancer: assessment of the existence of gene sex interactions

BACKGROUND

Previous studies have shown the sex differences in lung cancer and the associations between estrogen-related genes and non-small cell lung cancer. In the present study, we assumed the existence of shared candidate genes that are common in lung and breast cancers, and examined whether women with a family history of breast cancer are at increased risk of lung cancer compared with men, especially adenocarcinoma, in a case-only study.

METHODS

This case-only study was conducted based on the Lung Cancer Database Project at the National Cancer Center Hospital East. A total of 1566 patients with newly diagnosed primary lung cancer were consecutively recruited between 1999 and 2003. Information on their family history of cancer and smoking habit was obtained from a self-administered questionnaire. To assess an interactions between two factors, odds ratios for interaction (ORis) and 95% confidence intervals (CIs) were calculated by case-only contingency table.

RESULTS

A statistically significant ORi was observed between a family history of breast cancer in first-degree relatives (parent and siblings, not including children) and the sex of a patient (ORi: 2.22, 95% CI: 1.02-4.81). A stratified analysis by histologic subtypes showed a statistically significant ORi only for adenocarcinoma (ORi: 3.27, 95% CI: 1.19-8.98). No other family history of cancer, such as stomach, colon and lung cancer, showed a statistically significant ORi.

CONCLUSION

This study suggests the possibility of gene-sex interaction in lung cancer.

Aggregation of cancer among relatives of never-smoking lung cancer patients

The authors evaluated the familial aggregation of lung and other cancers in first-degree relatives of lung cancer patients self-reported to be lifetime never smokers. The data, derived from a large lung cancer case-control study, included 2,465 first-degree relatives of 316 never smoker lung cancer cases and 2,441 first-degree relatives of 318 never smoker controls, frequency matched to the cases on age, gender and ethnicity. The median age of the cases and the controls was 61 years, about 2/3 were women, and about 80% were Caucasian. Overall, there was a 25% excess risk [95% CI (1.05-1.50)] of any type of cancer among the first-degree relatives of cases, and case offspring exhibited a 2-fold excess cancer risk (1.03-4.10) compared with control offspring. There was also a 44% excess risk (1.05-1.97) of young onset cancers (before age 50) among relatives of cases. Smoking case relatives had an increased risk of any cancer [odds ratio (OR) = 1.36 (1.03-1.81)] and a 5.52-fold risk (1.19-25.51) of young onset lung cancer compared with smoking control relatives. Female case relatives had a 58% excess breast cancer risk (1.04-2.43), and case mothers a 2.57-fold breast cancer risk (1.16-4.24). A significant excess of testicular cancer was observed among case male relatives [OR = 12.32 (1.71-88.90)], although based on only 9 cases. The age at lung cancer diagnosis tended to be earlier in case relatives (61.4, SD = 12.9) compared with control relatives (66.2, SD = 11.4; p = 0.07). Our analysis provides further evidence for the importance of genetic factors for lung cancer in never smokers.

Racial Differences in Cancer Risk Among Relatives of Patients With Early Onset Lung Cancer

BACKGROUND

Relatives of patients with early onset lung cancer are at increased risk for lung cancer, and this risk varies by race. This study evaluates whether first-degree relatives of patients with early onset lung cancer are at increased risk for cancer at sites other than lung.

METHODS

Family histories were ascertained from 673 lung cancer patients < 50 years of age identified from the Metropolitan Detroit Surveillance, Epidemiology and End Results program, and 773 age-, race-, and sex-matched control subjects were obtained via random-digit dialing. Data were collected for 3,556 case relatives (mothers, fathers, and siblings) and 3,943 control relatives, and unconditional logistic regression models using generalized estimating equations were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Among case relatives, African Americans were 2.44-fold more likely to have head and neck cancers and 1.86-fold more likely to have any tobacco-related cancer compared to white case relatives (95% CI, 1.04 to 5.69% and 95% CI, 1.25 to 2.76, respectively). African-American case relatives were at increased risk for head and neck cancers (OR, 13.42; 95% CI, 1.65 to 109.01), all tobacco-related cancers (OR, 3.77; 95% CI, 2.16 to 6.55), tobacco-related cancers other than lung (OR, 4.10; 95% CI, 1.56 to 10.79), and cancer at any site (OR, 1.45, 95% CI, 1.04 to 2.02) compared to African-American control relatives.

CONCLUSIONS

These results can be used to counsel family members of patients with early onset lung cancer, and suggest target populations for preventive strategies, including smoking cessation and appropriate screening.

Hormone replacement therapy and lung cancer risk in Chinese

BACKGROUND

The association between hormone replacement therapy (HRT) and a reduced lung cancer risk has been reported in previous studies. There is a high female to male ratio in Chinese lung cancer patients, and female patients have different clinicopathological characteristics compared with Western patient populations. The authors investigated whether HRT may reduce lung cancer risk in Taiwan.

METHODS

The authors used a case-control study design to investigate 826 women with lung cancer and 531 healthy controls. Personal interviews based on a structured questionnaire were performed to collect information on HRT use of at least 3 months, age, ethnicity, active and passive smoking, exposure to air pollution, cooking or incense fumes, body mass index (BMI), menopause, and family history of cancers.

RESULTS

HRT use was associated with reduced lung cancer risk with a multivariate, adjusted odds ratio of 0.70 (95% CI, 0.53-0.94; P = .019). HRT use was associated with reduced odds ratio of lung cancer in all subset analyses stratified by histology, active and passive cigarette smoking, BMI, history of incense burning, cooking, and motorcycle riding, as well as family history of certain cancers.

CONCLUSIONS

This study confirmed that HRT is associated with a reduced lung cancer risk. The results appeared to be applicable to Chinese female population groups.

Lung cancer in women

Lung cancer is one of the most important avoidable causes of death around the world, it is the most widespread carcinoma with a very poor prognosis, and is the leading cause of cancer death in both developed and developing countries. At present more men than women die each year from lung cancer, but in recent years a rapid increase in lung cancer mortality has been observed among women in developed countries, contrasting with a levelling off or decrease among men. The rising trend in female lung cancer mortality has been observed to parallel with the past and current prevalence of cigarette smoking among women in the United States and elsewhere. An important role of other factors acting either as independent risk factors or interacting with the effect of smoking has been suggested by some studies among women, among them genetic, biologic and hormonal factors, and probably some factors related to the environment and lifestyle. There is a controversy concerning the claim that women have a different susceptibility to tobacco carcinogens, which might or might not be greater than men do. Since tobacco is far and away the strongest epidemiological risk factor for the development of lung cancer, comprehensive smoking control efforts are the priority in the prevention of lung cancer among women.

Racial differences in the familial aggregation of breast cancer and other female cancers

Although breast cancer familial aggregation has been studied in Caucasians, information for African-Americans is scant. We used family cancer history from the Women's Contraceptive and Reproductive Experiences study to assess the aggregation of breast and gynecological cancers in African-American and Caucasian families. Information was available on 41,825 first and second-degree relatives of Caucasian and 28,956 relatives of African-American participants. We used a cohort approach in which the relative's cancer status was the outcome in unconditional logistic regression and adjusted for correlated data using generalized estimating equations. Race-specific models included a family history indicator, the relative's age, and type. Relative risk (RR) estimates for breast cancer were highest for first-degree relatives, and the overall RR for breast cancer among case relatives was 1.96 (95% CI = 1.68-2.30) for Caucasian and 1.78 (95% CI = 1.41-2.25) for African-Americans. The effect of CARE participants' reference age on their relatives' breast cancer risk was greatest among first-degree relatives of African-American patients with RRs (95% CI) for ages <45 and > or =45 of 2.97 (1.86-4.74) and 1.48 (1.14-1.92), respectively. Among Caucasians, first-degree relatives of case subjects were at greater risk for ovarian cancer, particularly relatives younger than 45 years (RR (95% CI) = 2.06 (1.02-4.12)), whereas African-American first-degree relatives of case subjects were at increased cervical cancer risk (RR (95% CI) = 2.17 (1.22-3.85). In conclusion, these racially distinct aggregation patterns may reflect different modes of inheritance and/or environmental factors that impact cancer risk.

Hormonal factors and risk of lung cancer among women?

BACKGROUND

Gender differences in the histological distribution of lung carcinoma and a possibly greater susceptibility of women than men to tobacco carcinogens, suggest a possible influence of sex-specific hormones. This study examines endocrine factors and risk of lung cancer among women by smoking status and histology.

METHODS

We used data of a case-control study on lung cancer conducted from 1990 to 1996 in Germany, including 811 histologically confirmed female cases and 912 female population controls. Information on various menstrual and reproductive factors, use of oral contraceptives (OC), hormone replacement therapy (HRT), and smoking was gathered through personal interviews using a structured questionnaire. Odds ratios (OR) and 95% CI adjusted for age, region, smoking, and education were calculated via logistic regression.

RESULTS

A reduction in lung cancer risk was observed with the use of OC (OR = 0.69; 95% CI: 0.51-0.92), but no trend in risk with increasing duration of use, age at first use, or calendar year of first use was present. A history of HRT was associated with a reduced risk (OR = 0.83; 95% CI: 0.64-1.09), particularly after long duration (>/=7 years) (OR = 0.59; 95% CI: 0.37-0.93). No clear association was found with regard to age at menarche, length of menstrual cycle, number of live-births, and age at menopause. Overall results did not differ much by histological cell subtype. The reduction in lung cancer risk associated with the use of exogenous hormones was primarily seen among smoking women.

CONCLUSIONS

Our data provide evidence for a possible role of hormonal factors in the aetiology of lung cancer in women.

Polymorphisms in CYP1A1, GSTM1, GSTT1 and lung cancer below the age of 45 years

BACKGROUND

A genetic component of early-onset lung cancer has been suggested. The role of metabolic gene polymorphisms has never been studied in young lung cancer cases. Phase 1 and Phase 2 gene polymorphisms are involved in tobacco carcinogens' metabolism and therefore in lung cancer risk.

METHODS

The effect of metabolic gene polymorphisms on lung cancer at young ages was studied by pooling data from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database. All primary lung cancer cases of both sexes who were Caucasian and </=45 years of age at diagnosis, and the corresponding controls were selected. We obtained 261 cases and 1452 controls.

RESULTS

There was a marginally significant association between lung cancer and GSTT1 null genotype (OR=1.2; 95% CI:1.0-1.6), and a significant association between lung cancer and the homozygous CYP1A1 Msp1 variant allele (CYP1A1*2A and *2B) genotype (OR=4.7 95% CI:1.2-19.0). When data were stratified by smoking status, the association between CYP1A1 genotype and lung cancer was confined to never smokers.

CONCLUSIONS

These results suggest that metabolic genetic factors play a role in lung cancer developing at young ages.

Epidemiology of lung cancer

There are few relationships in the epidemiology of cancer between an exposure and disease that are as consistent as those observed between tobacco and lung cancer. The health consequences of tobacco use are not limited to lung cancer; the 1990 Surgeon General's Report described that the use of cigarettes was the leading cause of avoidable mortality in the United States, with about 434,000 preventable deaths per year. Although a majority of the adults in the United States are current or former smokers, smoking cessation and prevention efforts have been successful, although currently about one in four adults still smoke cigarettes. The decline in ever-smoking has reached a plateau in the past few years, however, and rates of teenage smoking have begun to increase. In 1997, smoking rates among high school students in the United States were 32% higher compared with 1991. As noted by Cinciripini et al, adult smokers who quit or die are being replaced by children who smoke. Until recently, lung cancer control efforts primarily have focused on smoking prevention in youth and cessation among adults, with little obvious potential for reducing deaths through early detection. With the recent publication of early results from the Early Lung Cancer Action Project showing remarkably more favorable screening performance compared with chest radiography, the potential to detect lung cancer early and save lives is being revisited. Ultimately, the preferred disease control strategy is the prevention of lung cancer through the elimination of tobacco use altogether, but for the foreseeable future a legacy of decades of tobacco use in a significant proportion of the US population means we are still challenged to develop public health strategies to reduce deaths and suffering from those destined to develop lung cancer.