Gallstones, Cholecystectomy, and Kidney Cancer: Observational and Mendelian Randomization Results Based on Large Cohorts.

BACKGROUND & AIMS: Gallstones (cholelithiasis) constitute a major health burden with high costs related to surgical removal of the gallbladder (cholecystectomy), generally indicated for symptomatic gallstones. The association between gallstones and cholecystectomy and kidney cancer is controversial. We comprehensively investigated this association, considering age at cholecystectomy and time from cholecystectomy to kidney cancer diagnosis, and assessed the causal effect of gallstones on kidney cancer risk by Mendelian randomization (MR). METHODS: We compared the risk of kidney cancer in cholecystectomized and noncholecystectomized patients (16.6 million in total) from the Swedish nationwide cancer, census, patient, and death registries using hazard ratios (HRs). For 2-sample and multivariable MR, we used summary statistics based on 408,567 UK Biobank participants. RESULTS: During a median follow-up of 13 years, 2627 of 627,870 cholecystectomized Swedish patients developed kidney cancer (HR, 1.17; 95% CI, 1.12-1.22). Kidney cancer risk was particularly increased in the first 6 months after cholecystectomy (HR, 3.79; 95% CI, 3.18-4.52) and in patients cholecystectomized before age 40 years (HR, 1.55; 95% CI, 1.39-1.72). MR results based on 18,417 patients with gallstones and 1788 patients with kidney cancer from the United Kingdom revealed a causal effect of gallstones on kidney cancer risk (9.6% risk increase per doubling in gallstone prevalence; 95% CI, 1.2%-18.8%). CONCLUSIONS: Both observational and causal MR estimates based on large prospective cohorts support an increased risk of kidney cancer in patients with gallstones. Our findings provide solid evidence for the compelling need to diagnostically rule out kidney cancer before and during gallbladder removal, to prioritize kidney cancer screening in patients undergoing cholecystectomy in their 30s, and to investigate the underlying mechanisms linking gallstones and kidney cancer in future studies.

Risk of prostate cancer in relatives of prostate cancer patients in Sweden: A nationwide cohort study.

BACKGROUND: Evidence-based guidance for starting ages of screening for first-degree relatives (FDRs) of patients with prostate cancer (PCa) to prevent stage III/IV or fatal PCa is lacking in current PCa screening guidelines. We aimed to provide evidence for risk-adapted starting age of screening for relatives of patients with PCa. METHODS AND FINDINGS: In this register-based nationwide cohort study, all men (aged 0 to 96 years at baseline) residing in Sweden who were born after 1931 along with their fathers were included. During the follow-up (1958 to 2015) of 6,343,727 men, 88,999 were diagnosed with stage III/IV PCa or died of PCa. The outcomes were defined as the diagnosis of stage III/IV PCa or death due to PCa, stratified by age at diagnosis. Using 10-year cumulative risk curves, we calculated risk-adapted starting ages of screening for men with different constellations of family history of PCa. The 10-year cumulative risk of stage III/IV or fatal PCa in men at age 50 in the general population (a common recommended starting age of screening) was 0.2%. Men with ≥2 FDRs diagnosed with PCa reached this screening level at age 41 (95% confidence interval (CI): 39 to 44), i.e., 9 years earlier, when the youngest one was diagnosed before age 60; at age 43 (41 to 47), i.e., 7 years earlier, when ≥2 FDRs were diagnosed after age 59, which was similar to that of men with 1 FDR diagnosed before age 60 (41 to 45); and at age 45 (44 to 46), when 1 FDR was diagnosed at age 60 to 69 and 47 (46 to 47), when 1 FDR was diagnosed after age 69. We also calculated risk-adapted starting ages for other benchmark screening ages, such as 45, 55, and 60 years, and compared our findings with those in the guidelines. Study limitations include the lack of genetic data, information on lifestyle, and external validation. CONCLUSIONS: Our study provides practical information for risk-tailored starting ages of PCa screening based on nationwide cancer data with valid genealogical information. Our clinically relevant findings could be used for evidence-based personalized PCa screening guidance and supplement current PCa screening guidelines for relatives of patients with PCa.

Risk-adapted starting age of breast cancer screening in women with a family history of ovarian or other cancers: A nationwide cohort study.

BACKGROUND: There is a lack of evidence-based recommendations for the age at which women with a family history of cancers other than breast cancer should start breast cancer screening. METHODS: Using Swedish family cancer data sets, the authors conducted a nationwide cohort study including 5,099,172 Swedish women born after 1931 (follow-up, 1958-2015). Accounting for calendar time, they calculated the relative risk of breast cancer for women with a family history of a discordant cancer in 1 first-degree relative. Furthermore, the authors used 10-year cumulative risk to determine the ages at which women with a family history of discordant cancer reached risk thresholds at which women in the general population were recommended to start breast cancer screening. RESULTS: A family history of cancer at 15 sites was associated with an increased risk of breast cancer. Among women younger than 50 years, the highest risk of breast cancer was observed for those with a family history of ovarian cancer (standardized incidence ratio, 1.44; 95% confidence interval, 1.26-1.64). In these women, the risk of breast cancer associated with a family history at other cancer sites ranged from 1.08-fold for prostate cancer to 1.18-fold for liver cancer. When breast cancer screening was recommended to be started at the age of 50 years for the general population, women with 1 first-degree relative with ovarian cancer attained the threshold risk for screening at the age of 46 years. Women with a family history of other discordant cancers did not reach the risk thresholds for screening at younger ages. CONCLUSIONS: Many cancers showed familial associations with breast cancer, but women with a family history of these cancers (except for ovarian cancer) did not reach risk thresholds for screening at younger ages.

Calculating the Starting Age for Screening in Relatives of Patients With Colorectal Cancer Based on Data From Large Nationwide Data Sets.

BACKGROUND & AIMS: Although colorectal cancer (CRC) screening guidelines acknowledge the need for earlier screening for high-risk individuals, such as those with family history of CRC, there is limited information on how many years earlier these high-risk individuals should be screened; current practice is based on weak evidence. We aimed to provide risk-adapted recommendations on the starting age of CRC screening for individuals with different family histories. METHODS: We collected data from nationwide family-cancer data sets in Sweden and calculated risk-adapted starting ages of screening for individuals with different family histories of CRC. Family history was defined as a dynamic (time-dependent) variable, allowing for changes during the follow-up period of 1958 through 2015. RESULTS: During a follow-up of 12,829,251 individuals with genealogy information, 173,796 developed CRC. The 10-year cumulative risk for the average-risk population at age 50 years (the guideline-recommended age for screening) was 0.44%. Individuals with different family histories of CRC attained this equivalent 0.44% risk 3-29 years earlier than their peers in the general population without such a family history. For example, individuals with 1 affected first-degree relative diagnosed before age 45 years reached the corresponding risk level 16 years earlier. CONCLUSIONS: We determined risk-adapted starting ages of CRC screening for close or distant relatives of patients with CRC, using high quality nationwide data sets. These findings might be used in counselling individuals about the appropriate age to start CRC screening, to optimize screening practice, and to supplement guidelines for CRC screening.

Importance of Family History of Colorectal Carcinoma In Situ Versus Invasive Colorectal Cancer: A Nationwide Cohort Study.

BACKGROUND: The aim of this study was to explore the risk of invasive colorectal cancer (CRC) in relatives of patients with colorectal carcinoma in situ (CCIS), which is lacking in the literature. PATIENTS AND METHODS: We collected data from Swedish family-cancer datasets and calculated standardized incidence ratio (SIR) and cumulative risk of CRC in family histories of CCIS in first- and second-degree relatives. Family history was defined as a dynamic (time-dependent) variable allowing for changes during the follow-up period from 1958 to 2015. Of 12,829,251 individuals with available genealogical data, 173,796 were diagnosed with CRC and 40,558 with CCIS. RESULTS: The lifetime (0-79 years) cumulative risk of CRC in first-degree relatives of patients with CCIS was 6.5%, which represents a 1.6-fold (95% CI, 1.5-1.7; n=752) increased risk. A similarly increased lifetime cumulative risk (6.7%) was found among first-degree relatives of patients with CRC (SIR, 1.6; 95% CI, 1.6-1.7; n=6,965). An increased risk of CRC was also found in half-siblings of patients with CCIS (SIR, 1.9; 95% CI, 1.1-3.0; n=18) and also in half-siblings of patients with CRC (SIR, 1.7; 95% CI, 1.3-2.1; n=78). Moreover, the increased risk of CRC was higher for younger age at diagnosis of CCIS in the affected first-degree relative and for younger age at diagnosis of CRC in the index person. CONCLUSIONS: Results of this study show that first-degree relatives and half-siblings of patients with CCIS have an increased risk of CRC, which is comparable in magnitude to the risk of those with a family history of invasive CRC. These findings extend available evidence on familial risk of CRC and may help to refine guidelines and recommendations for CRC screening.

Risk of colorectal cancer in patients with diabetes mellitus: A Swedish nationwide cohort study.

BACKGROUND: Colorectal cancer (CRC) incidence is increasing among young adults below screening age, despite the effectiveness of screening in older populations. Individuals with diabetes mellitus are at increased risk of early-onset CRC. We aimed to determine how many years earlier than the general population patients with diabetes with/without family history of CRC reach the threshold risk at which CRC screening is recommended to the general population. METHODS AND FINDINGS: A nationwide cohort study (follow-up:1964-2015) involving all Swedish residents born after 1931 and their parents was carried out using record linkage of Swedish Population Register, Cancer Registry, National Patient Register, and Multi-Generation Register. Of 12,614,256 individuals who were followed between 1964 and 2015 (51% men; age range at baseline 0-107 years), 162,226 developed CRC, and 559,375 developed diabetes. Age-specific 10-year cumulative risk curves were used to draw conclusions about how many years earlier patients with diabetes reach the 10-year cumulative risks of CRC in 50-year-old men and women (most common age of first screening), which were 0.44% and 0.41%, respectively. Diabetic patients attained the screening level of CRC risk earlier than the general Swedish population. Men with diabetes reached 0.44% risk at age 45 (5 years earlier than the recommended age of screening). In women with diabetes, the risk advancement was 4 years. Risk was more pronounced for those with additional family history of CRC (12-21 years earlier depending on sex and benchmark starting age of screening). The study limitations include lack of detailed information on diabetes type, lifestyle factors, and colonoscopy data. CONCLUSIONS: Using high-quality registers, this study is, to our knowledge, the first one that provides novel evidence-based information for risk-adapted starting ages of CRC screening for patients with diabetes, who are at higher risk of early-onset CRC than the general population.

Familial risk of breast cancer by dynamic, accumulative, and static definitions of family history.

BACKGROUND: Familial breast cancer risk studies usually overlook the dynamic nature of family history. METHODS: The authors assessed the effect of incorporating the timing of cancer diagnosis events into the assessment of familial risks of breast cancer in first-degree and second-degree relatives in a nationwide cohort study of 5,099,172 women (follow-up was between 1958-2015). Family history was assessed using 3 approaches: 1) as a static variable (ever having a relative with breast cancer); 2) as accumulative history; and 3) as a dynamic variable (time-dependent variable). RESULTS: For women aged <50 years, familial risk was mostly higher when family history was assessed as a dynamic variable compared with using a static or accumulative family history. For example, the cumulative risk of receiving a breast cancer diagnosis until age 50 years for women with a history of breast cancer in 1 first-degree relative was 2.6% (95% CI, 2.5%-2.7%) using the static method, 2.4% (95% CI, 2.3%-2.4%) using the accumulative method, and 3.1% (95% CI, 3.0%-3.2%) using the dynamic method. Relative risk in women aged <50 years with a breast cancer diagnosis in a sister was 1.40-fold (95% CI, 1.31-fold to 1.48-fold) using the static method, 1.66-fold (95% CI, 1.57-fold to 1.76-fold) using the accumulative method, and 2.28-fold (95% CI, 2.07-fold to 2.51-fold) using the dynamic method. CONCLUSIONS: The results of the current study demonstrated that assessing family history as static, accumulative, or dynamic results in different familial risk estimates. The answer as to which method to use for family history assessment depends on the implications of the study, with the dynamic method appearing to be better suited for risk stratification studies, the accumulative method being the most convenient in practice and the least favored for risk prediction, and the static method being suitable for etiological impact and risk attribution studies.

Risk of invasive prostate cancer and prostate cancer death in relatives of patients with prostatic borderline or in situ neoplasia: A nationwide cohort study.

BACKGROUND: The question of whether having a family history of prostatic borderline or in situ neoplasia (PBISN) is associated with an increased risk of invasive prostate cancer (PCa) or death from PCa remains unanswered. The objective of the current study was to provide an evidence-based risk estimation for the relatives of patients with PBISN. METHODS: Nationwide Swedish family cancer data sets were used for the current study, including data regarding all residents of Sweden who were born after 1931 and their parents. Standardized incidence ratios (SIRs), standardized mortality ratios (SMRs), and lifetime cumulative risks of PCa were calculated for men with different constellations of family history. Family history was defined as a dynamic (time-dependent) variable considering changes during follow-up (1958-2015). RESULTS: Of the 6,343,727 men in the current study, a total of 238,961 developed invasive PCa and 5756 were diagnosed with PBISN during the follow-up. Men with 1 first-degree relative who was diagnosed with PBISN had a 70% increased risk of invasive PCa (SIR, 1.7; 95% confidence interval, 1.5-1.9) and PCa death (SMR, 1.7; 95% confidence interval, 1.3-2.2) compared with men with no family history of PBISN or invasive PCa. These were rather close to estimates in men with 1 first-degree relative diagnosed with invasive PCa (SIR, 2.1 and SMR, 1.8). A higher risk of PCa in family members was found among patients with a family history of PBISN and/or PCa diagnosed before age 60 years. The results in terms of cumulative risk resembled this trend. CONCLUSIONS: A family history of PBISN appears to be as important as a family history of invasive PCa with regard to an increased risk of invasive PCa or PCa mortality. Such a history should not be overlooked in PCa screening recommendations or in future research regarding familial PCa.

Personal History of Diabetes as Important as Family History of Colorectal Cancer for Risk of Colorectal Cancer: A Nationwide Cohort Study.

INTRODUCTION: Diabetes mellitus (DM) and colorectal cancer (CRC) share some risk factors, including lifestyle and metabolic disturbances. We aimed to provide in-depth information on the association of CRC risk, especially early-onset CRC, with DM, family history of CRC, and age at DM diagnosis. METHODS: A nationwide cohort study was conducted using Swedish family cancer data sets, inpatient, and outpatient registers (follow-up: 1964-2015), including all individuals born after 1931 and their parents (12,614,256 individuals; 559,375 diabetic patients; 162,226 CRC patients). RESULTS: DM diagnosis before the age of 50 years was associated with a 1.9-fold increased risk of CRC before the age of 50 years (95% CI for standardized incidence ratio: 1.6-2.3) vs 1.3-fold risk of CRC at/after the age of 50 years (1.2-1.4). DM diagnosis before the age of 50 years in those with a family history of CRC was associated with 6.9-fold risk of CRC before the age of 50 years (4.1-12) and 1.9-fold risk of CRC at/after the age of 50 years (1.4-2.5). Diabetic patients had a similar lifetime risk of CRC before the age of 50 years (0.4%, 95% CI: 0.3%-0.4%) to those with only a family history of CRC (0.5%, 0.5%-0.5%), double that of the population (0.2%, 0.2%-0.2%). DISCUSSION: Our large cohort with valid information on DM and family history of cancer showed that DM is associated with increased risk of CRC in a magnitude close to having family history of CRC. Associations of DM and CRC family history with increased CRC risk were most prominent in young adults. These findings warrant further studies on harms, benefits, and cost-effectiveness of CRC screening in patients with diabetes, especially type 2, at earlier ages than in the general population.

Risk of invasive breast cancer in relatives of patients with breast carcinoma in situ: a prospective cohort study.

BACKGROUND: Wide implementation of mammography screening has resulted in increased numbers of women diagnosed with breast carcinoma in situ. We aimed to determine the risk of invasive breast cancer in relatives of patients with breast carcinoma in situ in comparison to the risk in relatives of patients with invasive breast cancer. METHODS: We analyzed the occurrence of cancer in a nationwide cohort including all 5,099,172 Swedish women born after 1931 with at least one known first-degree relative. This was a record linkage study of Swedish family cancer datasets, including cancer registry data collected from January 1, 1958, to December 31, 2015. We calculated standardized incidence ratios (SIRs) and 10-year cumulative risk of breast cancer diagnosis for women with a family history of in situ and invasive breast cancer. RESULTS: Having one first-degree relative with breast carcinoma in situ was associated with 50% increased risk of invasive breast cancer (SIR = 1.5, 95% CI 1.4-1.7) when compared to those who had no family history of invasive breast cancer or breast carcinoma in situ in either first- or second-degree relatives. Similarly, having one first-degree relative with invasive breast cancer was associated with 70% (1.7, 1.7-1.8) increased risk. The 10-year cumulative risk for women at age 50 with a relative with breast carcinoma in situ was 3.5% (2.9-3.9%) and was not significantly different from 3.7% (3.6-3.8%) risk for 50-year-old women with a relative with invasive breast cancer (95% confidence intervals overlapped). CONCLUSIONS: The risk of invasive breast cancer for women with a family history of breast carcinoma in situ was comparable to that for women with a family history of invasive breast cancer. Therefore, family history of breast carcinoma in situ should not be overlooked in recommendations for breast cancer prevention for women with a family history of breast cancer.

Telomere length, telomerase reverse transcriptase promoter mutations, and melanoma risk.

Telomere repeats at chromosomal ends, critical for genomic integrity, undergo age-dependent attrition and telomere length has been associated with different disorders including cancers. In this study, based on 1469 patients and 1158 healthy controls, we show a statistically significant (P = 6 × 10-10 ) association between increased telomere length and melanoma risk. Mendelian randomization, using 5 telomere length-associated polymorphisms, ruled out confounding factors or reverse causality and showed association between increased telomere length and melanoma risk with odds ratio of 2.66 (95% confidence interval: 2.07-3.25). Age-dependent telomere attrition was faster in melanoma cases than controls (P = .01). The carriers of a highly penetrant germline -57A>C TERT promoter mutation, in a previously reported melanoma family, had longer telomeres than the noncarriers. The mutation causes increased TERT and telomerase levels through creation of a binding motif for E-twenty six (ETS) transcription factors and the carriers develop melanoma with an early age of onset and rapid progression to metastasis. In analogy, we hypothesize that increased telomere length in melanoma patients reflects stochastic increased telomerase levels due to common genetic variation. Paradoxically, we observed shorter telomeres (P = 1 × 10-5 ) in primary tumors from unrelated melanoma patients with (121) than without (170) somatic TERT promoter mutations that similar to the germline mutation, also create binding motifs for ETS transcription factors. However, the age-dependent telomere attrition was faster in tumors with the TERT promoter mutations than in those without such mutations. Besides a robust association between increased telomere length and risk, our data show a perturbed telomere homeostasis in melanoma.

Risk of second primary cancers in women diagnosed with endometrial cancer in German and Swedish cancer registries.

Along with the increasing incidence and favorable prognosis, more women diagnosed with endometrial cancer may develop second primary cancers (SPCs). We aimed at investigating risk of SPCs after endometrial cancer in Germany and Sweden to provide insight into prevention strategies for SPCs. Endometrial cancer patients diagnosed at age ≥15 years in Germany during 1997-2011 and in Sweden nationwide during 1997-2012 were selected. Standardized incidence ratios (SIRs), calculated as the ratio of observed to expected numbers of cases, were used to assess the risk of a specific second cancer after endometrial cancer for both German and Swedish datasets. Among 46,929 endometrial cancer survivors in Germany and 18,646 in Sweden, overall 2,897 and 1,706 SPCs were recorded, respectively. Significantly elevated SIRs were observed in Germany for ovarian (SIR = 1.3; 95%CI:1.1-1.5) and kidney cancers [1.6 (1.3-1.8)], while in Sweden the SIRs were 5.4 (4.6-6.3) and1.4 (1.0-1.9), respectively. Elevated risk for second ovarian endometrioid carcinoma was pronounced after early (<55 years) onset endometrial cancer in Germany [9.0 (4.8-15)] and Sweden [7.7 (5.1-11)]. In Germany elevated risks were found for second ovarian endometrioid carcinoma after endometrioid histology of first endometrial cancer [6.3 (4.0-9.4)] and for second kidney cancer after clear cell histology of endometrial cancer [4.9 (1.6-11)]. We found exceptionally elevated risk of second ovarian endometrioid carcinoma after endometrial cancer of the same histology or of early onset. Risk for second kidney cancer was also increased, particularly after endometrial cancer of clear cell histology. Cancer prevention strategies should focus on these cancers after endometrial cancer diagnosis.

Risk of familial classical Hodgkin lymphoma by relationship, histology, age, and sex: a joint study from five Nordic countries.

We aimed to provide the familial risk of classical Hodgkin lymphoma (HL) by relationship, histology, age at diagnosis, and sex. A cohort of 57,475 first-degree relatives of 13,922 HL patients diagnosed between 1955 and 2009 in 5 European countries was observed for HL incidence. The overall lifetime cumulative risk (CR) of HL in first-degree relatives of a patient with HL was 0.6%, which represents a threefold (standardized incidence ratio [SIR], 3.3; 95% confidence interval [CI], 2.8-3.9) increased risk over the general population risk. The risk in siblings (6.0-fold; 95% CI, 4.8- to 7.4-fold) was significantly higher than in parents and/or children (2.1-fold; 95% CI, 1.6- to 2.6-fold). Very high lifetime risk of HL was found for those with multiple affected first-degree relatives (13-fold; 95% CI, 2.8- to 39-fold) and for same-sex twins (57-fold; 95% CI, 21- to 125-fold). We found high familial risks between some concordant histologic subtypes of HL such as lymphocyte-rich (81-fold; 95% CI, 30- to 177-fold) and nodular sclerosis (4.6-fold; 95% CI, 2.9- to 7.0-fold) and also between some discordant subtypes. The familial risk in sisters (9.4-fold; 95% CI, 5.9- to 14-fold) was higher than in brothers (4.5-fold; 95% CI, 2.9- to 6.7-fold) or unlike-sex siblings (5.9-fold; 95% CI, 4.3- to 8.1-fold). The lifetime risk of HL was higher when first-degree relatives were diagnosed at early ages (before age 30 years). This study provides tangible absolute risk estimates for relatives of HL patients, which can be used as a sex-, age-, and family history-based risk calculator for classical HL by oncologists and genetic counselors.

TERT promoter mutations in bladder cancer affect patient survival and disease recurrence through modification by a common polymorphism.

The telomerase reverse transcriptase (TERT) promoter, an important element of telomerase expression, has emerged as a target of cancer-specific mutations. Originally described in melanoma, the mutations in TERT promoter have been shown to be common in certain other tumor types that include glioblastoma, hepatocellular carcinoma, and bladder cancer. To fully define the occurrence and effect of the TERT promoter mutations, we investigated tumors from a well-characterized series of 327 patients with urothelial cell carcinoma of bladder. The somatic mutations, mainly at positions -124 and -146 bp from ATG start site that create binding motifs for E-twenty six/ternary complex factors (Ets/TCF), affected 65.4% of the tumors, with even distribution across different stages and grades. Our data showed that a common polymorphism rs2853669, within a preexisting Ets2 binding site in the TERT promoter, acts as a modifier of the effect of the mutations on survival and tumor recurrence. The patients with the mutations showed poor survival in the absence [hazard ratio (HR) 2.19, 95% confidence interval (CI) 1.02-4.70] but not in the presence (HR 0.42, 95% CI 0.18-1.01) of the variant allele of the polymorphism. The mutations in the absence of the variant allele were highly associated with the disease recurrence in patients with Tis, Ta, and T1 tumors (HR 1.85, 95% CI 1.11-3.08). The TERT promoter mutations are the most common somatic lesions in bladder cancer with clinical implications. The association of the mutations with patient survival and disease recurrence, subject to modification by a common polymorphism, can be a unique putative marker with individualized prognostic potential.

Incorporation of detailed family history from the Swedish Family Cancer Database into the PCPT risk calculator.

PURPOSE: A detailed family history provides an inexpensive alternative to genetic profiling for individual risk assessment. We updated the PCPT Risk Calculator to include detailed family histories. MATERIALS AND METHODS: The study included 55,168 prostate cancer cases and 638,218 controls from the Swedish Family Cancer Database who were 55 years old or older in 1999 and had at least 1 male first-degree relative 40 years old or older and 1 female first-degree relative 30 years old or older. Likelihood ratios, calculated as the ratio of risk of observing a specific family history pattern in a prostate cancer case compared to a control, were used to update the PCPT Risk Calculator. RESULTS: Having at least 1 relative with prostate cancer increased the risk of prostate cancer. The likelihood ratio was 1.63 for 1 first-degree relative 60 years old or older at diagnosis (10.1% of cancer cases vs 6.2% of controls), 2.47 if the relative was younger than 60 years (1.5% vs 0.6%), 3.46 for 2 or more relatives 60 years old or older (1.2% vs 0.3%) and 5.68 for 2 or more relatives younger than 60 years (0.05% vs 0.009%). Among men with no diagnosed first-degree relatives the likelihood ratio was 1.09 for 1 or more second-degree relatives diagnosed with prostate cancer (12.7% vs 11.7%). Additional first-degree relatives with breast cancer, or first-degree or second-degree relatives with prostate cancer compounded these risks. CONCLUSIONS: A detailed family history is an independent predictor of prostate cancer compared to commonly used risk factors. It should be incorporated into decision making for biopsy. Compared with other costly biomarkers it is inexpensive and universally available.

The population impact of familial cancer, a major cause of cancer.

The population attributable fraction (PAF) defines the proportion of a disease that would be prevented if the exposure to a particular risk factor was avoided. Familial risk is a known risk factor for many cancers, but an unbiased estimation of the PAF for familial risk requires a large study population to include rare cancers. PAFs and their corresponding standardized incidence ratios (SIRs) were calculated for familial relative risk among first-degree relatives (FDRs) and second-degree relatives (SDRs) diagnosed with the same (concordant) invasive or in situ cancers. Calculations were based on the Swedish Family-Cancer Database considering 8,148,737 individuals. To assess environmental effects, PAFs were also calculated for concordant cancers among spouses. Almost all cancers showed a significant familial risk. The highest PAFs were found for the common cancers of the prostate (13.94%), breast (7.46%) and colorectum (6.78%) among the FDRs. In the FDRs, the overall PAF for any concordant cancer was 4.20%, but in the SDRs, it was only 0.34%. The overall PAFs for in situ cancers were 0.86% and 0.56% for the FDRs and SDRs, respectively. The overall independent familial PAF was 5.96% for the invasive and in situ cancers in the FDRs and SDRs. The cancers between spouses yielded an overall PAF of 0.14%. For esophageal cancer, the risk among spouses was higher than the familial risk. Our study shows that the overall familial PAF of 5.96%, although underestimated for sex-specific cancers, ranks as the third most common population burden after tobacco smoking and unhealthy diet.

Risk of cancer in patients with medically diagnosed hay fever or allergic rhinitis.

Data on allergic conditions as risk or protective factors for cancer are controversial probably because most studies have used self-reported data on mixed groups of allergies in a case-control setting. We define cancer risks in medically diagnosed hay fever/allergic rhinitis patients in a nationwide cohort study. A total of 138,723 hay fever/allergic rhinitis patients were identified from three Swedish health care databases and standardized incidence ratios (SIRs) were calculated for subsequent cancers identified from the Swedish Cancer Registry. Overall cancer risk was not changed (SIR 1.03). For individual cancers, the highest SIR was observed for nasal cancer (SIR 2.63), followed by testicular (1.46) and endocrine tumors (1.42), and kidney (1.31), prostate (1.18) and breast (1.11) cancers. The results were consistent in the three sources of data and all SIRs were above unity, albeit mainly not statistically significant. The SIRs for nervous system tumors were above unity and of borderline significance. SIRs were decreased for esophageal (0.50), liver (0.62) and lung (0.78) cancers, and the three sources of data agreed in the direction of the effect. The increased risks for testicular, renal, prostate and endocrine cancers may be explained by immunological mechanisms. Excess risk for these cancer accounts for a significant population attributable fraction. Nervous system cancers showed a borderline increase and none of the histological types were significantly decreased, providing strong evidence against the published case-control studies, which have reported protective effects. The reasons for the reduced risks for esophageal, liver and lung cancer remain to be explained.

Risk of thyroid cancer in first-degree relatives of patients with non-medullary thyroid cancer by histology type and age at diagnosis: a joint study from five Nordic countries.

BACKGROUND: We aimed to estimate lifetime cumulative risk of thyroid cancer (CRTC) in first-degree relatives of patients with non-medullary thyroid cancers (NMTC), including papillary (PTC)/follicular/oxyphilic/anaplastic thyroid carcinoma, by histology and age at diagnosis in patients and their relatives. DESIGN: A population-based cohort of 63 495 first-degree relatives of 11 206 NMTC patients diagnosed in 1955-2009 in Nordic countries was followed for cancer incidence. Standardised incidence ratios (SIRs) were calculated using histology-specific, age-specific, sex-specific, period-specific and country-specific incidence rates as reference. RESULTS: The 0-84-year CRTC in female relatives of a patient with PTC was 2%, representing a threefold increase over the general population risk (SIR=2.9, 95% CI 2.4 to 3.4; Men: CRTC=1%, SIR=2.5, 95% CI 1.9 to 3.3). When there were ≥2 PTC patients diagnosed at age <60 years in a family, CRTC for female relatives was 10% (male 24%). Twins had a 23-fold increased risk of concordant PTC. Family history of follicular/oxyphilic/anaplastic carcinoma increased CRTC in relatives to about 1-2%. Although no familial case of concordant oxyphilic/anaplastic carcinoma was found, familial risks of discordant histology types of NMTC were interchangeably high for most of the types, for example, higher risk of PTC when a first-degree relative had follicular (SIR=3.0, 95%CI 1.7 to 4.9) or anaplastic (SIR=3.6, 95% CI 1.2 to 8.4) carcinoma. The earlier a patient was diagnosed with PTC in a family, the higher was the SIR in his/her younger relatives. There was a tendency towards concordant age at diagnosis of thyroid cancer among relatives of PTC patients. CONCLUSIONS: This study provides clinically relevant risk estimates for family members of NMTC patients.

Longer Interval Between First Colonoscopy With Negative Findings for Colorectal Cancer and Repeat Colonoscopy.

Importance: For individuals without a family history of colorectal cancer (CRC), colonoscopy screening every 10 years is recommended to reduce CRC incidence and mortality. However, debate exists about whether and for how long this 10-year interval could be safely expanded. Objective: To assess how many years after a first colonoscopy with findings negative for CRC a second colonoscopy can be performed. Design, Setting, and Participants: This cohort study leveraged Swedish nationwide register-based data to examine CRC diagnoses and CRC-specific mortality among individuals without a family history of CRC. The exposed group included individuals who had a first colonoscopy with findings negative for CRC at age 45 to 69 years between 1990 and 2016. The control group included individuals matched by sex, birth year, and baseline age (ie, the age of their matched exposed individual when the exposed individual's first colonoscopy with findings negative for CRC was performed). Individuals in the control group either did not have a colonoscopy during the follow-up or underwent colonoscopy that resulted in a CRC diagnosis. Up to 18 controls were matched with each exposed individual. Individuals were followed up from 1990 to 2018, and data were analyzed from November 2022 to November 2023. Exposure: A first colonoscopy with findings negative for CRC, defined as a first colonoscopy without a diagnosis of colorectal polyp, adenoma, carcinoma in situ, or CRC before or within 6 months after screening. Main Outcomes and Measures: The primary outcomes were CRC diagnosis and CRC-specific death. The 10-year standardized incidence ratio and standardized mortality ratio were calculated to compare risks of CRC and CRC-specific death in the exposed and control groups based on different follow-up screening intervals. Results: The sample included 110 074 individuals (65 147 females [59.2%]) in the exposed group and 1 981 332 (1 172 646 females [59.2%]) in the control group. The median (IQR) age for individuals in both groups was 59 (52-64) years. During up to 29 years of follow-up of individuals with a first colonoscopy with findings negative for CRC, 484 incident CRCs and 112 CRC-specific deaths occurred. After a first colonoscopy with findings negative for CRC, the risks of CRC and CRC-specific death in the exposed group were significantly lower than those in their matched controls for 15 years. At 15 years after a first colonoscopy with findings negative for CRC, the 10-year standardized incidence ratio was 0.72 (95% CI, 0.54-0.94) and the 10-year standardized mortality ratio was 0.55 (95% CI, 0.29-0.94). In other words, the 10-year cumulative risk of CRC in year 15 in the exposed group was 72% that of the 10-year cumulative risk of CRC in the control group. Extending the colonoscopy screening interval from 10 to 15 years in individuals with a first colonoscopy with findings negative for CRC could miss the early detection of only 2 CRC cases and the prevention of 1 CRC-specific death per 1000 individuals, while potentially avoiding 1000 colonoscopies. Conclusions and Relevance: This cohort study found that for the population without a family history of CRC, the 10-year interval between colonoscopy screenings for individuals with a first colonoscopy with findings negative for CRC could potentially be extended to 15 years. A longer interval between colonoscopy screenings could be beneficial in avoiding unnecessary invasive examinations.