Reliability of Self-Reported Family History of Cancer in a Large Case–Control Study of Lymphoma

Effect of familial history and smoking on common cancer risks in Japan

BACKGROUND

Inherited genetic predispositions are important risk factors for the development of cancer in general. To determine genetic susceptibility for 14 common cancers, a case-control study of the impact of a family history of cancer in first-degree relatives was conducted. The authors further evaluated the effect modification by habitual smoking with adjustment for other confounding environmental factors.

METHODS

In total, 18,836 cancer cases and 28,125 age-matched and sex-matched controls, confirmed as being free of cancer, were recruited. Odds ratios (ORs) and 95% confidence intervals were determined by multiple logistic regression analysis, including stratification by family history for 14 cancer sites and interactions with a smoking history.

RESULTS

The associations between family history and risk of cancer were generally stronger at the same sites than across cancer sites. Risks to first-degree relatives at the same sites were found to be significantly elevated with 8 of 14 cancer sites; especially high ORs were found for prostate and thyroid cancers. Some across-site associations were observed; in particular, a reciprocal association between breast and prostate cancer was found. The interaction between family history and smoking history for breast cancer was found to be statistically significant. There was no statistical evidence for the interactions in other sites, but among subjects with a family history, the ORs were found to be higher in smokers compared with nonsmokers.

CONCLUSIONS

The results of the current study support the hypothesis of a genetic susceptibility to cancers in family members. For breast cancer, the interaction between family history and smoking history was observed to be significant.

The updated Swedish family-cancer database used to assess familial risks of prostate cancer during rapidly increasing incidence

The Swedish Family-Cancer Database has been used for some 10 years in the study of familial risks at all common sites. In the present paper we describe some of the main features of version VII of this Database, assembled in year 2006. This update included all residents in Sweden born or immigrated in 1932 and later (offspring) with their biological parents, a total of 11.5 million individuals. Cancer cases were retrieved from the Swedish Cancer Registry from years 1958 to 2004, including over 1.2 million first and multiple primary cancers and in situ tumours. We show one application of the Database in the study of familial risks in prostate cancer, with special reference to the modification of familial risk at the time of about 50% increase in incidence due to prostate specific antigen (PSA) screening. The familial risks for prostate cancer were 1.92 for sons of affected fathers, 3.03 for brothers and 5.44 for men with an affected father and an affected brother. Familial risk for prostate cancer according to the time since the first family member was diagnosed showed significant increases for two family members being diagnosed in the same year compared to 5+ years apart. Increased surveillance and the availability of PSA screening are the likely reasons for the overestimated familial relative risk shortly after the first diagnosis. This lead time bias should be considered in clinical counselling.

Family history and risk of lung cancer: age-at-diagnosis in cases and first-degree relatives

To investigate the little known risk of lung cancer at an early age when a first-degree relative has had such a diagnosis, 579 incident cases and 1157 population controls were studied in Liverpool between 1998 and 2004 using standardised questionnaires covering demography and lifestyle. A history of lung cancer in first-degree relatives was associated with a significantly increased risk in the proband where in both individuals the cancers were diagnosed before the age of 60 years (odds ratio (OR)=4.89; 95% confidence interval (CI): 1.47–16.25). A significantly elevated risk of lung cancer was also observed in association with a relative affected before the age of 60 years, regardless of age-at-onset of the disease (OR=2.08; 95% CI: 1.20–3.59). This finding is strongly consistent with a genetic component in early-onset lung cancer risk.

Influence of familial cancer history on lymphoid neoplasms risk validated in the large European case-control study epilymph

Lymphomas have a potentially important familial component; large studies using recent classification systems are lacking. Based on a multicentre case-control study in seven European countries, we recruited 2480 cases of lymphoid neoplasms (LN) and 2540 controls, matched by country, age and sex. Diagnoses were established according to the World Health Organisation (WHO) classification. We estimated odds ratios (OR) and 95% confidence intervals (CI) for cancer in first-degree relatives and for the kind of relative affected. The OR of LN for a family history of haematological cancer was 1.6 (OR=1.2-2.1). The OR was particularly high for chronic lymphocytic leukaemia (CLL) (OR=2.9 [1.9-4.5]). A familial case of lymphoma increased the risk of Hodgkin's lymphoma (HL) (OR=3.4 [1.5-7.8]). No increased risk was observed for diffuse large B-cell and follicular lymphomas. For CLL and HL, the risk was similar in parents, offspring and siblings. Our study suggests familial aggregation of CLL with a family history of haematological cancer and of HL with a family history of lymphoma. The transmission pattern suggests a dominant model of heredity.