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

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.

Breast cancer incidence among women with a family history of breast cancer by relative's age at diagnosis

BACKGROUND

Women with a first-degree family history of breast cancer are often advised to begin screening when they are 10 years younger than the age at which their relative was diagnosed. Evidence is lacking to determine how much earlier they should begin.

METHODS

Using Breast Cancer Surveillance Consortium data on screening mammograms from 1996 to 2016, the authors constructed a cohort of 306,147 women 30-59 years of age with information on first-degree family history of breast cancer and relative's age at diagnosis. The authors compared cumulative 5-year breast cancer incidence among women with and without a first-degree family history of breast by relative's age at diagnosis and by screening age.

RESULTS

Among 306,147 women included in the study, approximately 11% reported a first-degree family history of breast cancer with 3885 breast cancer cases identified. Women reporting a relative diagnosed between 40 and 49 years and undergoing screening between ages 30 and 39 or 40 and 49 had similar 5-year cumulative incidences of breast cancer (respectively, 18.6/1000; 95% confidence interval [CI], 12.1, 25.7; 18.4/1000; 95% CI, 13.7, 23.5) as women without a family history undergoing screening between 50-59 years of age (18.0/1000; 95% CI, 17.0, 19.1). For relative's diagnosis age from 35 to 45 years of age, initiating screening 5-8 years before diagnosis age resulted in a 5-year cumulative incidence of breast cancer of 15.2/1000, that of an average 50-year-old woman.

CONCLUSION

Women with a relative diagnosed at or before age 45 may wish to consider, in consultation with their provider, initiating screening 5-8 years earlier than their relative's diagnosis age.

Family history of breast cancer as a second primary malignancy in relatives: a nationwide cohort study

Background

With the increasing number of breast cancer (BC) diagnosed as a second primary malignancy after a first primary non-breast cancer (BCa-2), it is unclear about the familial risk of BC among women with a first-degree relative (FDR, parents or siblings) affected by a BCa-2.

Methods

In this Swedish nationwide cohort study, 5315 women with a FDR affected by BCa-2 and 115,048 women with a FDR affected by BC as the first primary cancer (BCa-1) were followed for the first primary invasive BC diagnosis. Relative risk (RR) of BC was estimated through Poisson regression by using 2,743,777 women without a family history of cancer as reference. The risk was stratified by the diagnostic age of BC in FDR, proband type, the time interval between the first primary cancer and BCa-2 in FDR as well as the site of first primary cancer diagnosed in FDR before BCa-2. We also calculated the cumulative incidence of BC from birth to a specific age for the three groups.

Results

The cumulative incidence from birth to age 70 was 10% among women with a family history of BCa-2. The RR of BC with a family history of BCa-2 (RR, 1.68, 95%CI, 1.49 to 1.88) was comparable to that with BCa-1 (1.68, 1.63 to 1.73). The risk was largely consistent irrespective of proband type. The age of onset of BCa-2 in FDR (RR _early-onset, 1.72 vs. RR _late-onset 1.67) had less influence on the risk compared to BCa-1 in FDR (1.89 vs. 1.63). In the analysis stratified by the time between the first primary cancer and BCa-2 in relatives, the risks were largely similar. For the site of first primary cancer diagnosed in FDR before BCa-2, the increased BC risk was found in women whose FDRs were diagnosed with first primary gastric, colorectal, endometrial, ovarian, nervous system and endocrine gland cancers, and non-Hodgkin lymphoma.

Conclusions

Women with a family history of BCa-2 have a similar overall BC risk as those with a family history of BCa-1. The risk varied according to the site of first primary cancer diagnosed in FDR before BCa-2.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08925-y.

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.

Association of Family History with the Development of Breast Cancer: A Cohort Study of 129,374 Women in KoGES Data

Background: Breast cancer is the most common cancer among women. The Korean Genome and Epidemiology Study (KoGES) is a large cohort study that is available to the public. Using this large cohort study, we aimed to unravel the relationship between breast cancer development and a family history of breast cancer in Korea. Methods: This cohort study relied on data from the KoGES from 2001 through 2013. A total of 211,725 participants were screened. Of these, 129,374 women were evaluated. They were divided into two groups, including participants with and without breast cancer. A logistic regression model was used to retrospectively analyze the odds ratio of breast cancer history in families of women with and without breast cancer. Results: Of 129,374 women, 981 had breast cancer. The breast cancer group had more mothers and siblings with histories of breast cancer (p < 0.001). A history of breast cancer in the participant’s mother resulted in an odds ratio of 3.12 (1.75–5.59), and a history of breast cancer in the participant’s sibling resulted in an odds ratio of 2.63 (1.85–3.74). There was no interaction between the history of maternal breast cancer and the history of sibling breast cancer. Based on the subgroup analysis, family history was a stronger factor in premenopausal women than in menopausal and postmenopausal women. Conclusions: A family history of breast cancer is a significant risk factor for breast cancer in Korea. Premenopausal women with a maternal history of breast cancer are of particular concern. Intensive screening and risk-reducing strategies should be considered for this vulnerable subpopulation.

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.

Correlation between family history and characteristics of breast cancer

Family history is a major risk factor for breast cancer; approximately 5–10% cases of breast cancer are associated with a family history. Herein, we investigated the link between family history and breast cancer features to elucidate the importance of family history in the diagnosis and treatment of breast cancer. Data from 10,549 patients with breast cancer were collected from 2014 to 2017. Detailed information about the family history of the patients including the degree and number of relatives affected and the types of cancer was recorded. The tumors were pathologically and clinically classified based on the stage, grade, ER, PR, HER2, Ki-67 status, and subtypes, according to standard guidelines. Data were analyzed using χ² test and multiple logistic regression. Patients with a family history of other cancer types were significantly older at diagnosis than patients with a family history of breast/ovarian cancer (p = 0.002) and those without a family history of cancer (p < 0.001). Patients without a family history of cancer were typically diagnosed at a later stage, including high frequency in N2 (p = 0.035) and TNM stage III (p = 0.015). Compared with patients with second-/third-degree relatives, those with first-degree relatives having breast/ovarian cancer had a higher median age (54.1, p < 0.001) at diagnosis and showed more advanced disease. No significant difference was found between ER, PR, and HER2 status in patients with and without a family history of cancer. Family history of breast cancer can influence the cancer characteristics of the patients at diagnosis, especially patient age, tumor stage, and grade.

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.

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.

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.

Age at initiation of screening mammography by family history of breast cancer in the breast cancer surveillance consortium

PURPOSE

Women with a first-degree family history of breast cancer (FHBC) are sometimes advised to initiate screening mammography when they are 10 years younger than the age at which their youngest relative was diagnosed, despite a lack of unambiguous evidence that this is an effective strategy. It is unknown how often this results in women initiating screening earlier (< 40 years) than screening guidelines recommend for average-risk women.

METHODS

We examined screening initiation age by FHBC and age at diagnosis of the youngest relative using data collected by the Breast Cancer Surveillance Consortium on 74,838 first screening mammograms performed between 1996 and 2016.

RESULTS

Of the 74,838 women included in the study, nearly 9% reported a FHBC. Approximately 16.8% of women who initiated mammography before 40 years reported a FHBC. More women with a FHBC than without initiated screening < 40 years (48% vs. 23%, respectively). Among women with a FHBC who initiated screening < 40 years, 65% were 10 years younger than the age at which their relative was diagnosed.

CONCLUSION

Women with a first-degree relative diagnosed with breast cancer were more likely to start screening before 40 years than women reporting no FHBC, especially if their relative was diagnosed before 50 years.

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.