Increased cancer risk among relatives of nonsmoking lung cancer cases

Family History of Cancer in Relation to Breast Cancer Subtypes in African American Women

BACKGROUND

The evidence on the relation of family history of cancers other than breast cancer to breast cancer risk is conflicting, and most studies have not assessed specific breast cancer subtypes.

METHODS

We assessed the relation of first-degree family history of breast, prostate, lung, colorectal, ovarian, and cervical cancer and lymphoma or leukemia, to the risk of estrogen receptor-positive (ER(+)), ER(-), and triple-negative breast cancer in data from the African American Breast Cancer Epidemiology and Risk Consortium. Multivariable logistic regression models were used to calculate ORs and 95% confidence intervals (CI).

RESULTS

There were 3,023 ER(+) and 1,497 ER(-) breast cancer cases (including 696 triple-negative cases) and 17,420 controls. First-degree family history of breast cancer was associated with increased risk of each subtype: OR = 1.76 (95% CI, 1.57-1.97) for ER(+), 1.67 (1.42-1.95) for ER(-), and 1.72 (1.38-2.13) for triple-negative breast cancer. Family history of cervical cancer was associated with increased risk of ER(-) (OR = 2.39; 95% CI, 1.36-4.20), but not ER(+) cancer. Family history of both breast and prostate cancer was associated with increased risk of ER(+) (3.40; 2.42-4.79) and ER(-) (2.09; 1.21-3.63) cancer, but family history of both breast and lung cancer was associated only with ER(-) cancer (2.11; 1.29-3.46).

CONCLUSIONS

A family history of cancers other than breast may influence the risk of breast cancer, and associations may differ by subtype.

IMPACT

Greater surveillance and counseling for additional screening may be warranted for women with a family history of cancer.

R331W Missense Mutation of Oncogene YAP1 Is a Germline Risk Allele for Lung Adenocarcinoma With Medical Actionability

PURPOSE

Adenocarcinoma is the most dominant type of lung cancer in never-smoker patients. The risk alleles from genome-wide association studies have small odds ratios and unclear biologic roles. Here we have taken an approach featuring suitable medical actionability to identify alleles with low population frequency but high disease-causing potential.

PATIENTS AND METHODS

Whole-genome sequencing was performed for a family with an unusually high density of lung adenocarcinoma with available DNA from the affected mother, four affected daughters, and one nonaffected son. Candidate risk alleles were confirmed by matrix-assisted laser desorption ionization time of flight mass spectroscopy. Validation was conducted in an external cohort of 1,135 participants without cancer and 1,312 patients with lung adenocarcinoma. Family follow-ups were performed by genotyping the relatives of the original proband and the relatives of the identified risk-allele carriers. Low-dose computed tomography scans of the chest were evaluated for lung abnormalities.

RESULTS

YAP1 R331W missense mutation from the original family was identified and validated in the external controls and the cohort with lung adenocarcinoma. The YAP1 mutant-allele carrier frequency was 1.1% in patients with lung adenocarcinoma compared with 0.18% in controls (P = .0095), yielding an odds ratio (adjusted for age, sex, and smoking status) of 5.9. Among the relatives, YAP1-mutant carriers have overwhelmingly higher frequencies of developing lung adenocarcinoma or ground-glass opacity lung lesions than those who do not carry the mutation (10:0 v 1:7; P < .001). YAP1 mutation was shown to increase the colony formation ability and invasion potential of lung cancer cells.

CONCLUSION

These results implicated YAP1 R331W as an allele predisposed for lung adenocarcinoma with high familial penetrance. Low-dose computed tomography scans may be recommended to this subpopulation, which is at high risk for lung cancer, for personalized prevention and health management.

Lung cancer mutations and use of targeted agents in Hispanics

Hispanic/Latinos (H/L) are expected to grow to over 24% of the USA population by 2050 and lung cancer is the number one cause of cancer death among H/L men. Due to the information that is becoming available via genetic testing, lung cancer molecular profiling is allowing for increasing application of personalized lung cancer therapies. However, to benefit the most people, development of these therapies and genetic tests must include research on as many racial and ethnic groups as possible. The purpose of this review is to bring attention to the fact that the mutations driving lung cancer in H/Ls differ in frequency and nature relative to the non-Hispanic White (WNH) majority that dominate current databases and participate in clinical trials that test new therapies. Clinical trials using new agents targeting genetic alterations (driver mutations) in lung cancer have demonstrated significant improvements in patient outcomes (for example, gefitinib, erlotinib or crizotinib for lung adenocarcinomas harboring EGFR mutations or EML4-ALK fusions, respectively). The nature and frequencies of some lung cancer driver mutations have been shown to be considerably different among racial and ethnic groups. This is particularly true for H/Ls. For example, several reports suggest a dramatic shift in the mutation pattern from predominantly KRAS in a WNH population to predominantly EGFR in multiple H/L populations. However, these studies are limited, and the effects of racial and ethnic differences on the incidence of mutations in lung cancer remain incompletely understood. This review serves as a call to address this problem.

Association between smoking and p53 mutation in lung cancer: a meta-analysis

AIMS

To carry out a meta-analysis on the relationship between smoking and p53 gene mutation in lung cancer patients.

MATERIALS AND METHODS

PubMed, Web of Science, ProQest and Medline were searched by using the key words: 'lung cancer or lung neoplasm or lung carcinoma', 'p53 mutation' and 'smoking'. According to the selection criteria, 15 articles were identified and methodologically analysed by stata 12.0 software package. Crude odds ratios with 95% confidence intervals calculated using the fixed-effects model were used to assess the strength of association between smoking and p53 mutation in lung cancer.

RESULTS

In total, 15 articles with 1770 lung cancer patients were identified; 69.6% of the patients were smokers, 30.4% were non-smokers. Overall, smokers with lung cancer had a 2.70-fold (95% confidence interval 2.04-3.59) higher risk for mutation than the non-smokers with lung cancer. In subgroup analyses, the increased risk of p53 mutation in smokers than in non-smokers was found in the non-small cell lung cancer (NSCLC) group (odds ratio = 2.38, 95% confidence interval = 1.71-3.32) and in the NSCLC and SCLC group (odds ratio = 3.82, 95% confidence interval = 2.19-6.69).

CONCLUSIONS

This meta-analysis strongly suggests that p53 mutation is associated with smoking-induced lung cancer. Smokers with lung cancer had a higher risk for p53 mutation than non-smokers.

The impact of positive cancer family history on the clinical features and outcome of patients with non-small cell lung cancer

The purpose of this study is to investigate the impact of positive cancer/lung cancer family history (FH) on clinical features and outcome in non-small cell lung cancer (NSCLC) patients. We analyzed 4,491 NSCLC patients with NSCLC who presented from January 1999-December 2005. Chi-square test and Wilcoxon test were used for univariate comparisons, while Cox Proportional Hazards regression analysis was performed to evaluate the adjusted risk of death. Univariate probability of survival was calculated using Kaplan-Meier estimate and compared using the log-rank test. Of 4,491 patients, 579 patients (12.89%) had positive FH, including 233 patients (5.19%) with FH of lung cancer. Patients with positive lung cancer FH, compared to those with negative FH, were diagnosed at earlier age (57 vs. 60; P < 0.001), presented more cases of adenocarcinoma (58.80 vs. 50.69%; P = 0.016), and at more advanced stage (Stage IIIB/IV 45.74 vs. 36.79%; P < 0.001). These differences were also detected in patients with positive cancer FH. In addition, more females and non-smokers were among patients with positive cancer FH (30.05 vs. 26.15%; P = 0.045 and 39.90 vs. 33.82%; P = 0.008, respectively). Furthermore, patients with advanced cancer (stage IIIB/IV) who had positive FH had lower response rate to chemotherapy (CR&PR 24.68 vs. 34.42%; P = 0.024). Nevertheless, patients with positive lung cancer FH had better prognosis (P = 0.015), especially if diagnosed at an early stage (P = 0.035), and their adjusted relative risk of death was lower (RR 0.69; 95% CI: 0.51-0.93; P = 0.015). Definite epidemiologic and survival differences exist between NSCLC patients with positive or negative FH of cancer. Our results suggest that cancer FH is an important factor of clinical features, and could serve as a prognostic indicator for NSCLC.

FAMILIAL RISK FOR LUNG CANCER BY HISTOLOGY AND AGE OF ONSET: EVIDENCE FOR RECESSIVE INHERITANCE

The authors used the Swedish Family-Cancer Database to search for evidence for a genetic predisposition in lung cancer. Familial risks in offspring were increased for all lung cancer to 1.77 when a parent was affected with any lung cancers; the comparable risk among siblings was 2.15. At young age, risks between siblings were higher than those between offspring and parents for all histological types of lung cancer. The present data suggest that 1.7% of lung cancers up to age 68 years are heritable and probably due to a high-penetrant recessive gene or genes that predispose to tobacco carcinogens.

Family history of cancer and nonmalignant lung diseases as risk factors for lung cancer

Family history (FH) of lung cancer is an established risk factor for lung cancer, but the modifying effect of smoking in relatives has been rarely examined. Also, the role of FH of nonmalignant lung diseases on lung cancer risk is not well known. We examined the role of FH of cancer and nonmalignant lung diseases in lung cancer risk overall, and by personal smoking, FH of smoking and histology in 1,946 cases and 2,116 population-based controls within the Environment And Genetics in Lung cancer Etiology (EAGLE) study. Odds ratios (ORs) and 95% CI from logistic regression were calculated adjusting for age, gender, residence, education and cigarette smoking. FH of lung cancer in any family member was associated with increased lung cancer risk (OR = 1.57, 95% CI = 1.25-1.98). The odds associated with fathers', mothers' and siblings' history of lung cancer were 1.41, 2.14 and 1.53, respectively. The associations were generally stronger in never smokers, younger subjects and for the adenocarcinoma and squamous cell carcinoma subtypes. FH of chronic bronchitis and pneumonia was associated with increased (OR = 1.49, 95% CI = 1.23-1.80) and decreased (OR = 0.73, 95% CI = 0.61-0.87) lung cancer risk, respectively. FH of lung cancer and nonmalignant lung diseases affected lung cancer risk independently, and did not appear to be modified by FH of smoking.

The changing epidemiology of lung cancer

The 20th century witnessed the scourge of lung cancer as the disease rapidly rose the ranks to become the commonest cause of cancer mortality in the world. Epidemiological evidence conclusively associated cigarette smoking with the causation of lung cancer in the 1950s. Since then and the few decades after, lung cancer of the squamous cell or small cell histological subtypes was mainly diagnosed among male smokers in developed countries. As we move into the 21st century, the incidence of lung cancer is unlikely to abate but the burden will shift from the developed to the less-developed countries. Other epi-demiological changes of lung cancer include the narrowing of the gap between men and women affected by the disease, predominance of the adenocarcinoma histological subtypes as well as more never-smokers afflicted with the disease. Unless we eliminate tobacco smoking completely, lung cancer will continue its wrath into the 21st century.

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.

Systematic review of the relationship between family history and lung cancer risk

We performed a systematic review of 28 case–control, 17 cohort and seven twin studies of the relationship between family history and risk of lung cancer and a meta-analysis of risk estimates. Data from both case–control and cohort studies show a significantly increased lung cancer risk associated with having an affected relative. Risk appears to be greater in relatives of cases diagnosed at a young age and in those with multiple affected family members. Increased lung cancer risk was observed in association with an affected spouse and twin studies, while limited, favour shared environmental exposures. The limitations of the currently published epidemiological studies to infer genetic susceptibility are discussed.

Familial multiple primary lung cancers: a population-based analysis from Sweden

Multiple primary cancers arise because of inherited or acquired deficiencies, and their causes may depend on the first primary cancer, or they may be entirely independent. We used a nation-wide family dataset to search for evidence for a genetic predisposition to lung cancer. The Swedish Family-Cancer Database includes all Swedes born in 1932 and later with their parents, totalling over 10.2 million individuals. Cancer cases were retrieved from the Swedish Cancer Registry up to year 2000. Standardized incidence ratios (SIR) and 95% confidence limits (CI) were calculated for first and second primary lung cancers by a family history. The incidence of second primary lung cancer was nine times higher among cases with familial lung cancer compare to that of first primary lung cancer. The proportion of multiple primary lung cancer patients with family history for lung cancer was 4.7% (9/190) for men and 6.5% (5/77) for women. Lung cancer patients with a family history of lung cancer were at a significantly increased risk for subsequent primary lung cancer among both men (SIR=9.89, 95%CI 4.48-18.66) and women (SIR=17.86, 95%CI 5.63-42.00). The corresponding SIRs in patients without a family history were 2.04 (95%CI 1.75-2.36) and 5.10 (95%CI 3.99-6.43) for men and women, respectively. The present study suggests that the development from the first primary lung cancer to the second primary lung cancer may be more strongly affected by genetic factor than the first primary lung cancer.

Lung cancer risk in germline p53 mutation carriers: association between an inherited cancer predisposition, cigarette smoking, and cancer risk

We recently observed a significantly increased risk for lung cancer in carriers of p53 germline mutations. Because cigarette smoking is known to play an important role in increasing the risk for lung cancer in the general population, we wanted to determine the role of cigarette smoking in lung cancer risk in people with a genetic susceptibility based on a p53 germline mutation. We studied 1263 people from 97 families enrolled in a cohort study of families systematically ascertained through childhood soft-tissue sarcoma patients treated at the M.D. Anderson Cancer Center, University of Texas, between 1944 and 1975. We assessed the incidence of lung and smoking-related cancers in 33 carriers of germline p53 mutations and in 1,230 noncarriers to determine whether there was an association between an inherited cancer predisposition, cigarette smoking, and cancer risk. We analyzed the association between cigarette smoking, mutation status, and lung and other smoking-related cancers by the Kaplan-Meier method and the Cox proportional hazards model with adjustments for birth year, race, and sex. In the hazards model, we incorporated a robust variance estimation to adjust for familial correlation. We observed an increased risk of a variety of histological types of lung cancer in the carriers of the p53 germline mutation. Mutation carriers who smoked had a 3.16-fold (95% confidence interval =1.48-6.78) higher risk for lung cancer than the mutation carriers who did not smoke. Our results demonstrate that cigarette smoking significantly increases lung cancer risk in carriers of a germline p53 mutation. This finding could be useful in designing strategies for early detection and treatment of lung and smoking-related cancers in individuals with this inherited cancer predisposition.

Association between self-reported environmental tobacco smoke exposure and lung cancer: modification by GSTP1 polymorphism

Environmental Tobacco Smoke (ETS) exposure has been associated with lung cancer risk. ETS is composed of emissions from cigarette smoke and contains a higher concentration of tobacco smoke carcinogens than mainstream smoke. Polymorphisms in genes that metabolize tobacco smoke carcinogens have been studied as effect modifiers of the association between active smoking and lung cancer risk. GSTP1 is a polymorphic gene that encodes for GST pi, a detoxification enzyme and has a high expression in the lung. We investigated the association between ETS and lung cancer risk and the modification of this association by the GSTP1 polymorphism. Using a case-control design, individuals were genotyped for GSTP1 using PCR-RFLP techniques. All analyses were carried out using multiple logistic regression. The association between ETS exposure and lung cancer risk was evaluated in different strata based on smoking habits to evaluate the consistency of results. The effect of the GSTP1 polymorphisms on lung cancer risk was evaluated by considering the joint effect of having both an ETS exposure and the GSTP1 GG genotype compared to the absence of ETS exposure and the GSTP1 AA genotype as a reference group as well as doing stratified analysis by genotype. ETS exposure was associated consistently with higher lung cancer risk in all the strata considered. The adjusted odds ratios (AOR) evaluating the association between ETS and lung cancer risk for the different strata were: nonsmokers (Cases/Controls 66/413; AOR = 1.38; 95% CI = 0.78-2.43), ex-smokers (Cases/Controls 560/527; AOR = 1.66; 95% CI = 1.22-2.25), current smokers (Cases/Controls 415/219; AOR = 1.56; 95% CI = 1.00-2.41). The AORs for ex-smokers and light smoking subgroups were: ex-smokers who quit for 19 years or more (Cases/Controls 144/244; AOR = 2.64; 95% CI = 1.55-4.50), ex-smokers who quit for 10-19 years (Cases/Controls 141/128; AOR = 1.16; 95% CI = 0.66-2.04), ex-smokers who quit for 10 years or less (Cases/Controls 247/122; AOR = 1.45; 95% CI = 0.83-2.55) and participants who had <15 packyears and nonsmokers combined (Cases/Controls 143/640; AOR = 1.52; 95% CI = 1.02-2.28). Among those with the GSTP1 GG genotype the ETS-lung cancer risk association was greater than those with the GSTP1 AA genotype: nonsmokers (GSTP1 GG AOR = 7.84; 95% CI = 0.80-76.68; GSTP1 AA AOR = 1.15; 95% CI = 0.46-2.90), ex-smokers (GSTP1 GG AOR = 2.32; 95% CI = 0.90-5.96; GSTP1 AA AOR = 2.15; 95% CI = 1.34-3.44), current smokers (GSTP1 GG AOR = 1.75; 95% CI = 0.42-7.32; GSTP1 AA AOR = 1.32; 95% CI = 0.67-2.58) and participants who had <15 packyears and nonsmokers (GSTP1 GG AOR = 1.93; 95% CI = 0.54-6.97; GSTP1 AA AOR = 1.58; 95% CI = 0.83-3.01). We found that ETS exposure is associated with higher lung cancer risk. Furthermore, the presence of the GSTP1 GG genotype appears to enhance the magnitude of the association between ETS exposure and lung cancer. Larger studies will be needed to confirm these preliminary findings.

Familial cancer aggregation and the risk of lung cancer

CONTEXT

Around 90% of lung cancer worldwide is attributable to cigarette smoking, although less than 20% of cigarette smokers develop lung cancer. Other factors such as diet, chronic lung diseases, occupation and possibly environmental agents also contribute to this cancer. Genetic factors seem to play a role in lung cancer, but the precise characteristics influencing lung cancer susceptibility are not known, since genetic factors are easily obscured by the strong environmental determinants of lung cancer, particularly smoking.

OBJECTIVE

To estimate the effect that cancer occurrence among first-degree relatives has on the risk of lung cancer.

DESIGN

Hospital-based case-control study.

SETTING

The metropolitan region of São Paulo, Brazil.

PARTICIPANTS

334 incident lung cancer cases and 578 controls matched by hospitals.

MAIN MEASUREMENTS

By means of a structured questionnaire, cases and controls were interviewed about cancer occurrence in first-degree relatives, tobacco smoking, exposure to passive smoking, occupation, migration and socioeconomic status. Non-conditional logistic regression was used to calculate the risk of familial cancer aggregation, the effect of cancer in first-degree relatives and smoking in conjunction, and for controlling confounders.

RESULTS

The adjusted odds ratio (OR) revealed a slight, but not statistically significant, excess risk of lung cancer for subjects with a history of lung cancer in relatives (OR 1.21; 95% confidence interval [CI] 0.50 - 2.92). The same was found among those with a history of other tobacco-related cancers in relatives (OR 1.36; 95% CI 0.87 - 2.14). A step gradient effect was observed regarding lung cancer risk, in accordance with increases in the number of pack-years of cigarette consumption. An interaction between familial cancer aggregation and tobacco smoking was detected.

CONCLUSIONS

A mildly elevated risk of lung cancer among persons with a positive history of lung and other tobacco-related cancers was observed. The finding of an interaction between the variables of familial cancer aggregation and smoking suggests that familial cancer aggregation could be considered as a marker of susceptibility, increasing the risk of lung cancer among smokers. These results improve our knowledge of lung carcinogenesis and can guide future cancer genetic studies.

Molecular biology of lung cancer: clinical implications

This review summarizes the rapidly expanding knowledge of the molecular pathogenesis of lung cancer. It is clear that respiratory epithelial cells require many genetic alterations to become invasive and metastatic cancer. Much more is to be learned, but with modern technology. Clinicians can detect "field cancerized" regions and preneoplastic and malignant cells, therefore offering the opportunity to intercede with biomarker-monitored prevention and early detection efforts. Such molecular screening and detection efforts will likely be coupled to advances in low-dose computed tomographic imaging, positron emission tomography scans, and other imaging modalities. Although this molecular marker approach has great potential, there is not yet a molecular marker validated in large prospective trials that has major independent predictive prognostic value. There is an urgent need for large, adequately powered, carefully designed prospective studies to identify clinically useful new biomarkers. Finally, new therapeutic strategies with genetic manipulation, small molecules, antibodies, vaccines, and, particularly, new drugs targeting specific biologic pathways found to be abnormal in lung provide for future optimism. Researchers need to define their individual value, especially when integrated with standard therapies.

Familial risk of pancreatic cancer

BACKGROUND

Pancreatic cancer is the fifth leading cause of cancer-related mortality in the United STATES: Although smoking and age are known risk factors for pancreatic cancer, several case reports and case-control studies have suggested that there is also a familial risk. We evaluated whether a family history of pancreatic cancer increases the risk of pancreatic cancer in first-degree relatives and whether smoking and younger age at cancer diagnosis further increase this risk.

METHODS

We conducted in-person interviews with 247 patients ("case probands") with pancreatic cancer and 420 population-based control probands to collect risk factor data and pancreatic cancer family history for 1816 first-degree relatives of the case probands and 3157 first-degree relatives of the control probands. We analyzed the data by unconditional logistic regression models, with adjustment for correlated data by use of generalized estimating equations. All statistical tests were two-sided.

RESULTS

A positive family history of pancreatic cancer (i.e., being related to a case proband) or ever-smoking cigarettes approximately doubled the risk of pancreatic cancer (relative risk [RR] = 2.49; 95% confidence interval [CI] = 1.32 to 4.69; RR = 2.04; 95% CI = 1.09 to 3.83, respectively). The RR increased to 8.23 (95% CI = 2.18 to 31.07) for relatives who ever smoked and were related to a case proband who was diagnosed before age 60 years.

CONCLUSION

Routine questioning of patients about a family history of pancreatic cancer, the age of onset of this cancer in their relatives, and the patient's smoking status may identify individuals at high risk of pancreatic cancer. Future research exploring the genetic and environmental interactions associated with the risk of pancreatic cancer is critically important.

Familial aggregation of breast cancer with early onset lung cancer

Site-specific familial aggregation and evidence supporting Mendelian codominant inheritance have been shown in lung cancer. In characterizing lung cancer families, a number of other cancers have been observed. The current study evaluates whether first-degree relatives of early onset lung cancer cases are at increased risk of breast cancer. Families were identified through population-based lung cancer cases and controls under 40 years of age. Cases were ascertained through the Metropolitan Detroit SEER registry; controls through random-digit dialing. Data were available for 384 female relatives of 118 cases and 465 female relatives of 161 controls. Breast cancer in relatives was evaluated after adjusting for age, race, sex, and smoking status of each family member and the sex and age of the probands. A positive family history of early onset lung cancer increased breast cancer risk among first-degree relatives 5. 1-fold (95% CI, 1.7-15.1). Relatives of cases with adenocarcinoma of the lung were at highest risk (RR = 6.3, 95% CI 2.0-20). Mean age of breast cancer diagnosis among relatives of cases was 52.2 years and not statistically different from relatives of controls. Three case families also reported early ovarian cancers (mean age of diagnosis of 35 years). These findings suggest that shared susceptibility genes may act to increase risk of early onset lung and breast cancer in families.