Prediagnostic use of menopausal hormone therapy and long-term survival of localized epithelial ovarian cancer: The Extreme study.

Use of menopausal hormone therapy (MHT) prior to an epithelial ovarian cancer (EOC) diagnosis has been suggested to be associated with improved survival. In a recent nationwide cohort study, we found that prediagnostic long-term MHT use, especially estrogen therapy (ET), was associated with improved long-term survival in women with nonlocalized EOC. Our aim was to investigate the influence of prediagnostic MHT use on long-term survival among women with localized EOC in the same nationwide study. Our study cohort comprised all women aged 50 years or older with an EOC diagnosis in Denmark 2000-2014 (n = 2097) identified from the Extreme study. We collected information on usage of systemic ET and estrogen plus progestin therapy (EPT) from the Danish National Prescription Registry. By using pseudo-values, 5- and 10-year absolute and relative survival probabilities were estimated with 95% confidence intervals (CIs) while adjusting for histology, comorbidity, and income. Relative survival probabilities >1 indicate better survival. The 5-year absolute survival probabilities were 61% and 56%, respectively, among women who were nonusers and users of prediagnostic MHT, whereas these numbers were 46% and 41%, respectively, regarding 10-year survival. Use of MHT was not significantly associated with an improved 5- or 10-year survival in women with localized EOC (5-year relative survival probability = 0.95, 95% CI: 0.89-1.02; 10-year relative survival probability = 0.92, 95% CI: 0.84-1.02). Similar findings were seen for systemic ET or EPT use. Our findings do not suggest a positive benefit from prediagnostic MHT use on long-term survival of localized EOC.

Low-dose aspirin use and risk of ovarian cancer: a combined analysis from two nationwide studies in Denmark and Sweden.

BACKGROUND: Studies on association between low-dose aspirin use and ovarian cancer risk were mostly based on self-reported medication use and few had large enough sample size to investigate the potential modification effect by ovarian cancer risk factors. METHODS: In these two nationwide nested case-control studies among the Danish and Swedish female population, 11,874 women with ovarian cancer (30-84 years old) (Denmark: 7328 diagnosed in 2000-2019, Sweden: 4546 diagnosed in 2010-2018) were randomly age- matched with 473,960 female controls (293,120 from Denmark, and 181,840 from Sweden). We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) and combined the estimates based the fixed-effect assumption. Effect modification by inflammation-related risk factors and by indication (cardiovascular disease, CVD) were also investigated. RESULTS: Ever use of low-dose aspirin was not strongly associated with the overall risk of ovarian cancer (OR = 0.97; 95%CI: 0.92-1.03). However, the association differed according to parity (nulliparous: OR = 0.80, 95%CI: 0.70-0.92; parous: OR = 1.00, 95%CI: 0.94-1.07; p-interaction = 0.0024), and according to history of CVD (no CVD: OR = 0.91, 95%CI: 0.82-1.00; ever CVD: OR = 1.05, 95%CI: 0.97-1.13; p-interaction =0.0204). CONCLUSIONS: Low-dose aspirin use was associated with a decreased ovarian cancer risk especially in nulliparous women and in women without CVD diagnosis.

Paracetamol use and risk of epithelial ovarian cancer: A nationwide nested case-control study.

OBJECTIVE: To investigate whether paracetamol use is associated with a reduced risk of epithelial ovarian cancer (EOC). DESIGN: A nationwide nested case-control study. SETTING: Danish female population. POPULATION: A total of 9589 EOC cases diagnosed from 2000 to 2019 were age-matched with 383 549 randomly selected female controls using risk set sampling. METHODS: Paracetamol use, reproductive history, history of medication and history of surgery were retrieved from Danish national registers. Paracetamol use was defined as at least two prescriptions for up to 1 year before the index date, and was further classified according to recency, duration, cumulative dose and intensity of dose. MAIN OUTCOME MEASURES: Conditional logistic regression was used to estimate odds ratios and 95% confidence intervals for the association between paracetamol and EOC risk, overall and by histological subtypes. RESULTS: 'Ever' use of paracetamol was associated with a reduced EOC risk after adjusting for potential confounding factors (OR 0.92, 95% CI 0.87-0.97). The association was only significant among recent users (OR 0.89, 95% CI 0.84-0.95). The risk declined further with the increasing level of cumulative dose and intensity; women from the group with a high cumulative dose and a high intensity had a 13% (OR 0.87, 95% CI 0.80-0.94) and 14% (OR 0.86, 95% CI 0.79-0.93) reduced risk, respectively. In the histological subtype analysis, reduced risk with 'ever' use was most pronounced for serous and clear cell tumours. CONCLUSIONS: Paracetamol use was associated with a decreased risk of EOC in a dose-response manner. Future studies are needed to validate the findings and investigate the mechanisms behind the association.

Antihypertensive drug targets and breast cancer risk: a two-sample Mendelian randomization study.

Findings on the correlation between the use of antihypertensive medication and the risk of breast cancer (BC) have been inconsistent. We performed a two-sample Mendelian randomization (MR) using instrumental variables to proxy changes in gene expressions of antihypertensive medication targets to interrogate this. Genetic instruments for expression of antihypertensive drug target genes were identified with expression quantitative trait loci in blood, which should be associated with systolic blood pressure to proxy for the effect of antihypertensive drug. The association between genetic variants and BC risk were obtained from genome-wide association study summary statistics. The summary-based MR was employed to estimate the drug effects on BC risk. We further performed sensitivity analyses to confirm the discovered MR associations such as assessment of horizontal pleiotropy, colocalization, and multiple tissue enrichment analyses. The overall BC risk was only associated with SLC12A2 gene expression at a Bonferroni-corrected threshold. One standard deviation (SD) decrease of SLC12A2 gene expression in blood was associated with a decrease of 1.12 (95%CI, 0.80-1.58) mmHg of systolic blood pressure, but a 16% increased BC risk (odds ratio, 1.16, 95% confidential interval, 1.06-1.28). This signal was further observed for estrogen receptor positive (ER +) BC (1.17, 1.06-1.28). In addition, one SD decrease in expression of PDE1B in blood was associated with 7% decreased risk of ER + BC (0.93, 0.90-0.97). We detected no evidence of horizontal pleiotropy for these associations and the probability of the causal variants being shared between the gene expression and BC risk was 81.5, 40.5 and 66.8%, respectively. No significant association was observed between other target gene expressions and BC risk. Changes in expression of SLC12A2 and PDE1B mediated possibly via antihypertensive drugs may result in increased and decreased BC risk, respectively.

Risk of ovarian cancer after salpingectomy and tubal ligation: Prospects on histology and time since the procedure.

OBJECTIVE: Recent theories propose that most epithelial ovarian cancer (EOC), depending on histological type, originate from other gynecological tissues and involve the ovary secondarily. According to these theories, any protective effect of salpingectomy and tubal ligation may vary by histological type. The study aim was to examine the association between salpingectomy and tubal ligation, respectively, and risk of EOC, with a focus on associations specific for histological types. METHODS: We identified EOC cases and matching controls in national registries and gathered information on surgical procedures and potential confounders. Conditional logistic regression was used to estimate odds ratio (OR) with 95% confidence interval (CI) of EOC related to salpingectomy and tubal ligation, respectively, overall and stratified by histological type. Furthermore, we investigated the association according to timing of the procedures. RESULTS: Our study comprised 16,822 EOC cases. Each case was matched with 40 controls. There was an overall EOC risk reduction after unilateral (OR = 0.73; 95% CI: 0.60-0.87) and bilateral salpingectomy (OR = 0.46; 95% CI: 0.31-0.67). A slight risk reduction was seen among women with previous tubal ligation (OR = 0.91; 95% CI: 0.83-0.99). For salpingectomy, the risk reduction increased with increasing time since the surgical procedure and was only present among women younger than 50 years at salpingectomy. Unilateral and bilateral salpingectomy was associated with a risk reduction for most histological types. CONCLUSION: The association between previous salpingectomy and reduced risk of several histological subtypes of EOC supports the suggested theories about the site of origin of EOC and may be of clinical importance.

Colorectal cancer risk in association with colorectal cancer as a second malignancy in relatives: a nationwide cohort study.

BACKGROUND: Increasing number of individuals will have first-degree relatives (FDRs) diagnosed with colorectal cancer (CRC), as a second primary malignancy (CRCa-2) after a non-CRC cancer. We aimed to estimate whether and to what extent a family history of CRCa-2 is associated with an increased CRC risk. METHODS: In this Swedish nationwide cohort study, rate ratio (RR) and cumulative incidence of CRC were estimated among 172,531 individuals with a family history of CRC as a first primary malignancy (CRCa-1) and 17,830 with a family history of CRCa-2, respectively, using individuals without cancer family history as the reference group. RESULTS: A cumulative incidence of CRC by age 80 was 6.3 and 5.6% for individuals with a parental and a sibling family history of CRCa-2, respectively. RRs of CRC for one FDR diagnosed with CRCa-1 and CRCa-2 were respectively 1.72 (95% CI, 1.65-1.79) and 1.50 (1.32-1.70); the latter RR was lower than the former (P = 0.0356), but no difference was observed after adjusting age of diagnosis of CRC in FDR and family relationship (P = 0.6898). Increased RRs were found to be associated with a CRCa-2 diagnosis in FDR that occured after cancers in upper aerodigestive tract, breast, prostate, kidney and nervous system. CONCLUSIONS: Individuals who have relatives with CRCa-2 have an increased risk of CRC, but the magnitude is lower than those having relatives with CRCa-1, which is related to different ages of diagnosis of CRC in FDR and family relationships.

Familial risk associated with lung cancer as a second primary malignancy in first-degree relatives.

BACKGROUND: Aggregation of lung cancer (LCa) in family members is well-documented. However, little is known on the familial risk of LCa when first-degree relatives (FDRs, parents or siblings) are diagnosed with LCa as a second primary malignancy (LCa-2). We aimed to investigate whether and to what extent a family history of LCa-2 was associated with an increased LCa risk. METHODS: In this Swedish national cohort we identified 127,865 individuals who had one FDR affected by LCa as a first primary cancer (LCa-1) and 15,490 individuals who had one FDR affected by LCa-2, respectively. We then estimated relative risk (RR) of LCa using those without cancer family history as reference. RESULTS: The number of LCa-2 has been increasing annually and rather similarly in men and women in the last decade. Familial RR of LCa was 1.96 (95%, 1.85-2.07) for LCa-1 family history and 1.89 for LCa-2 (1.62-2.21). Risk was especially high when FDR was diagnosed with early-onset LCa-2 and when siblings were affected by LCa-2. The RR was 1.53 (1.10-2.12) when LCa-2 in FDR was diagnosed within 26 months after first primary cancer, and it increased to 2.16 (1.62-2.90) when LCa-2 was diagnosed between 74 to 154 months. Higher risk was observed for first primary cancer of the ovary (4.45, 1.85-10.7), nervous system (3.49, 1.45-8.38), upper aerodigestive tract (2.83, 1.78-4.49) and cervix (2.55, 1.41-4.61), and for non-Hodgkin lymphoma (3.13, 1.57-6.27). CONCLUSIONS: LCa risk is associated with diagnosis of LCa-2 in FDR to a similar degree as LCa-1 in FDRs.

Association of post-diagnostic use of cholera vaccine with survival outcome in breast cancer patients.

BACKGROUND: Expensive cancer treatment calls for alternative ways such as drug repurposing to develop effective drugs. The aim of this study was to analyse the effect of post-diagnostic use of cholera vaccine on survival outcome in breast cancer patients. METHODS: Cancer diagnosis and cholera vaccination were obtained by linkage of several Swedish national registries. One vaccinated patient was matched with maximum two unvaccinated individuals based on demographic, clinical and socioeconomic factors. We performed proportional Cox regression model to analyse the differences in overall and disease-specific survivals between the matched patients. RESULTS: In total, 617 patients received cholera vaccine after breast cancer diagnosis. The median (interquartile range) time from diagnosis to vaccination was 30 (15-51) months and from vaccination to the end of follow-up it was 62 (47-85) months. Among them, 603 patients were matched with 1194 unvaccinated patients. Vaccinated patients showed favourable overall survival (hazard ratio (HR): 0.54, 95% confidence interval (CI): 0.37-0.79) and disease-specific survival (HR: 0.53, 95% CI: 0.33-0.84), compared to their unvaccinated counterpart. The results were still significant in multiple sensitivity analyses. CONCLUSIONS: Post-diagnostic use of cholera vaccine is associated with a favourable survival rate in breast cancer patients; this provides evidence for repurposing it against breast cancer.

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.

Types of second primary cancer influence overall survival in cutaneous melanoma.

BACKGROUND: Favorable survival in malignant cutaneous melanoma (melanoma) has increased the likelihood of second primary cancer (SPC). We assess the influence of patient characteristics at diagnosis of first melanoma and the type of SPC (second melanoma and other SPC) on overall survival. METHODS: We used the Swedish Cancer Registry data to assess overall survival in melanoma for the period 1990 to 2015. Kaplan-Meier curves were plotted and hazard ratios (HRs) were estimated with Cox regression models by considering SPC diagnosis as a time-dependent variable. RESULTS: A total of 46,726 patients were diagnosed with melanoma, and 15.3% of them developed SPC, among which, two thirds were other SPCs. Second melanomas were diagnosed early (31% during the first year) compared to non-melanoma SPCs (9.5%). Survival for women with second melanoma or other SPC (56 and 21% alive after 25 years of follow-up, respectively) exceeded the male rates (21 and 10%, respectively) but all these figures were lower than for females (60% alive) or males (48%) without SPC. Time dependent analysis showed vastly increased HRs for cancer types that are fatal also as first cancers, but SPC-specific HRs remained relatively uniform, irrespective of SPC diagnosed soon or late after first melanoma. In early-onset melanoma, SPC diagnosis after 10 years may not negatively influence overall survival. CONCLUSIONS: As the overall survival of patients with many types of SPCs is unfavorable, advice about health lifestyle should benefit smoking patients and early detection methods may be recommended for SPCs of the breast, prostate and colorectum.

Second primary cancers in non-Hodgkin lymphoma: Family history and survival.

Second primary cancers (SPCs) account for an increasing proportion of all cancer diagnoses and family history of cancer may be a risk factor for SPCs. Using the Swedish Family-Cancer Database on non-Hodgkin lymphoma (NHL), we assessed the influence of family history on risk of SPCs and of SPCs on survival. NHL patients were identified from the years 1958 to 2015 and generalized Poisson models were used to calculate relative risks (RRs) for SPCs and familial SPCs. Among 14,393 NHL patients, a total of 1,866 (13.0%) were diagnosed with SPC. Familial risk of nine particular cancers was associated with risks of these cancers as SPCs, with twofold to fivefold increase in RRs. At the end of a 25-year follow-up period, the survival probability for persons with SPC was only 20% of that for patients without SPC; the hazard ratio for SPC was 1.59 (95% CI: 1.46-1.72). Survival could be predicted by the prognostic groups based on first cancers and HRs increase systematically with worse prognosis yielding a trend of p = 4.6 × 10-5 . SPCs had deleterious consequences for survival in NHL patients. Family history was associated with increasing numbers of SPCs. Prevention of SPCs and their early detection is an important target in the overall strategy to improve survival in NHL patients. Counseling for avoidance of risk factors and targeted screening based on family history are feasible steps in risk reduction.

Second primary cancers in patients with acute lymphoblastic, chronic lymphocytic and hairy cell leukaemia.

Improvement of survival in lymphocytic leukaemia has been accompanied by the occurrence of second primary cancer (SPCs). Based on Swedish Family Cancer Database, we applied bi-directional analyses in which relative risks (RRs) were calculated for any SPCs in patients with chronic lymphocytic leukaemia (CLL), acute lymphoblastic leukaemia (ALL) and hairy cell leukaemia (HCL) and the risks of these leukaemias as SPCs. After CLL, RRs were significant for 20 SPCs, and high for skin squamous cell cancer (24·58 for in situ and 7·63 for invasive), Merkel cell carcinoma (14·36), Hodgkin lymphoma (7·16) and Kaposi sarcoma (6·76). Conversely, 15 CLL cancer pairs were reciprocally increased. The increased risks were reciprocal for ALL and four cancers. RR for ALL was 15·35 after myeloid neoplasia. HCL showed reciprocally increased RRs with non-Hodgkin lymphoma and melanoma. The concordance between RRs for bi-directional associations between CLL and different cancers, and HCL and different cancers was highly significant. For CLL (also for HCL), the bi-directional risks with skin cancers and other immune-related cancers suggest the probable involvement of immune dysfunction. For ALL, treatment may contribute to risks of multiple SPCs. Increased risk of ALL after haematological neoplasms may indicate bone marrow dysfunction. These findings may help guide treatment decisions and prognostic assessment.

Second primary cancers in non-Hodgkin lymphoma: Bidirectional analyses suggesting role for immune dysfunction.

Second primary cancers (SPCs) account for an increasing proportion of all cancer diagnoses. It is unlikely that prior therapy is solely responsible for SPC risk. To investigate risk of SPC after diagnosis of non-Hodgkin lymphoma (NHL) and 10 of its subtypes we conducted a novel bidirectional analysis, SPCs after NHL and NHL as SPC. Using the Swedish Family-Cancer Database, we identified 19,833 individuals with primary NHL diagnosed between 1993 and 2015. We calculated relative risks (RRs) of SPCs in NHL survivors and, for bi-directional analysis, risk of NHL as SPC. The overall RRs were significantly bidirectionally increased for NHL and 7 cancers. After diagnosis of NHL risks were increased for upper aerodigestive tract (RR = 1.96), colorectal (1.35), kidney (3.10), bladder (1.54) and squamous cell skin cancer (SCC) (4.12), melanoma (1.98) and Hodgkin lymphoma (9.38). The concordance between RRs for each bidirectional association between NHL and 31 different cancers was highly significant (r = 0.86, p < 0.0001). Melanoma was bidirectionally associated with all 10 subtypes of NHL. The observed bidirectional associations between NHL and cancer suggest that therapy-related carcinogenic mechanisms cannot solely explain the findings. Considering that skin SCC and melanoma are usually treated by surgery and that these cancers and NHL are most responsive of any cancer to immune suppression, the consistent bidirectional results provide population-level evidence that immune suppressed state is a key underlying mechanism in the context of SPCs. Furthermore, the quantified risks for NHL subtypes have direct clinical application in the management of NHL patients.

Familial associations of female breast cancer with other cancers.

Familial risks of breast cancer (BC) are well established but whether BC clusters with other, i.e. discordant, cancers is less certain but of interest for the identification of common genetic and possible environmental factors contributing to a general cancer susceptibility. We apply a novel approach to search for familial associations of BC with other (discordant) cancers based on the Swedish Family-Cancer Database. Relative risks (RRs) were calculated for BC in families with increasing numbers of patients with discordant cancer X, and conversely, familial RRs for cancer X in families with increasing numbers of BC patients. Joint p-values were calculated from independent analyses. The total number of familial BCs was 12,266, 14.9% with one first-degree relative with BC and 1.2% with at least 2 affected relatives. Ovarian and prostate cancers showed the strongest associations with BC (p-value <10-11 ). The p-value for melanoma was <10-6 , for stomach and male colorectal cancer <2.5 × 10-6 , for cancer of unknown primary <2.5 × 10-5 and for lung cancer <5 × 10-5 . Significance level <5 × 10-4 was reached with pancreatic cancer. The remaining associations (p < 0.0025) included thyroid, endometrial, testicular, eye cancers (uveal melanoma), nervous system and endocrine tumors and non-Hodgkin lymphoma. The RR for BC increased by increasing numbers of patients with any cancer in family members and it reached 1.62 when three or more family members were affected. The results suggest that BC shares susceptibility with a number of other cancers. This might alert genetic counselors and challenge approaches for gene and gene-environment identification.

Familial associations of male breast cancer with other cancers.

PURPOSE: Male breast cancer is associated with female breast cancer in families but whether male breast cancer clusters with other discordant cancers has not been studied. As concordant male breast cancers are utterly rare, discordant associations of male breast cancer with other cancers may reveal genetic and possible environmental risk factors contributing to male breast cancer susceptibility. METHODS: We calculated relative risks (RRs) for male breast cancer in families with discordant cancers, and conversely, for discordant cancers in families of male breast cancer patients, based on 15.7 million individuals in the Swedish Family-Cancer Database. RESULTS: Among 1428 male breast cancer patients, 16.2% had a female relative diagnosed with breast cancer. Ovarian and female anal cancers showed the strongest associations with male breast cancer (p value < 0.0005). The other significant associations included colorectal, small intestinal, and thyroid cancers, cancer of unknown primary and non-Hodgkin lymphoma but these were each based on a single positive association with male breast cancer. The RRs for male breast cancer were increased in families in which multiple patients were diagnosed with diverse cancers, reaching an RR of 2.58 when three or more family members were affected. CONCLUSIONS: The results suggest that male breast cancer shares susceptibility with a number of other cancers but confirmation is needed in other datasets.

Antidepressant use and ovarian cancer risk: Evidence from nationwide studies with >14,000 cases from Denmark and Sweden.

OBJECTIVE: Given that the evidence regarding the link between antidepressant use and ovarian cancer risk is equivocal, we investigated this research question by conducting two nationwide nested case-control studies among the Danish and Swedish populations. METHODS: Altogether, 14,121 women with epithelial ovarian cancer (30-84 years old) (Denmark: 8976 diagnosed 2000-2019, Sweden: 5145 diagnosed 2010-2018) were randomly age-matched with 564,840 female controls (359,040 from Denmark, and 205,800 from Sweden) using risk set sampling. We used conditional logistic regression to estimate odds ratios (OR) with 95 % confidence intervals (CI) and combined the estimates based on the fixed-effect assumption. We also investigated potential effect modification by well-established risk factors for ovarian cancer. RESULTS: Antidepressant use was associated with an overall reduced risk of ovarian cancer (OR = 0.92, 95%CI: 0.88-0.96), and that reduction was more pronounced in postmenopausal women and long-term users. The effect was most pronounced for serous ovarian tumors (OR = 0.90, 95%CI: 0.86-0.95) but was also observed in other subtypes, although not statistically significant. Among different types of antidepressants, selective serotonin reuptake inhibitors in general and citalopram in particular exhibited a noteworthy reduction in ovarian cancer risk (OR = 0.89, 95%CI: 0.82-0.96). Additionally, use of oral contraceptives and hormone replacement therapy individually modified the association between antidepressant use and ovarian cancer risk. CONCLUSIONS: Use of an antidepressant was associated with a slight, but statistically significant, decrease in ovarian cancer risk. Given the morbidity and mortality associated with ovarian cancer, and increasing use of antidepressants, these findings may be of significance to cancer prevention and should be studied in more detail mechanistically.

Ovarian cancer risk factors in relation to family history.

BACKGROUND: Women with a family history of breast and/or ovarian cancer have an increased ovarian cancer risk. Yet it remains uncertain if common ovarian cancer risk factors-especially those which are modifiable-affect this high-risk population similarly to the general population. METHODS: Using the Danish and Swedish nationwide registers, we established two nested case-control study populations in women with a family history of breast and/or ovarian cancer (2,138 ovarian cancers, 85,240 controls) and women without (10,730 ovarian cancers, 429,200 controls). The overall and histology-specific associations were assessed with conditional logistic regression. The country-specific estimates were combined based on a fixed-effect assumption. RESULTS: Multiparity, hysterectomy, tubal ligation, salpingectomy, and oral contraceptive (OC) use were associated with a reduced risk of ovarian cancer in both women with and without a family history, while endometriosis and menopausal hormone treatment (MHT) were associated with increased risk. Multiparity and OC use presented protective effects across all histologic subtypes except mucinous ovarian cancer which was not associated with OC use. MHT increased the risk of serous ovarian cancer but decreased the risk of the mucinous and clear cell cancers. Endometriosis was especially related to an increased risk of endometrioid and clear cell ovarian cancer. CONCLUSION: Factors associated with a decreased ovarian cancer risk were similar between women with and without a family history of breast and/or ovarian cancer. Given the higher baseline risk for women with a family history, special attention should be paid to risk factors like endometriosis and nulliparity in this high-risk population.

Hysterectomy and risk of epithelial ovarian cancer by histologic type, endometriosis, and menopausal hormone therapy.

BACKGROUND: This nationwide, register-based case-control study investigated the association between hysterectomy and risk of epithelial ovarian cancer according to histology and by history of endometriosis and menopausal hormone therapy (MHT) use. METHODS: From the Danish Cancer Registry, all women registered with epithelial ovarian cancer at age 40-79 years during 1998-2016 were identified (n = 6738). Each case was sex- and age-matched to 15 population controls using risk-set sampling. Information on previous hysterectomy on benign indication and potential confounders was retrieved from nationwide registers. Conditional logistic regression was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for the association between hysterectomy and ovarian cancer according to histology, endometriosis, and use of MHT. RESULTS: Hysterectomy was not associated with risk of epithelial ovarian cancer overall (OR=0.99; 95% CI 0.91 -1.09) but was associated with reduced risk of clear cell ovarian cancer (OR=0.46; 95% CI 0.28-0.78). In stratified analyses, decreased ORs associated with hysterectomy were seen in women with endometriosis (OR=0.74; 95% CI 0.50-1.10) and in non-users of MHT (OR=0.87; 95% CI 0.76-1.01). In contrast, among long-term MHT users, hysterectomy was associated with increased odds for ovarian cancer (OR=1.20; 95% CI 1.03-1.39). CONCLUSION: Hysterectomy was not associated with epithelial ovarian cancer overall but with reduced risk of clear cell ovarian cancer. Our findings may suggest a reduced risk of ovarian cancer after hysterectomy in women with endometriosis and in MHT non-users. Interestingly our data pointed to an increased ovarian cancer risk associated with hysterectomy among long-term users of MHT.

Prostate cancer incidence and survival in relation to prostate cancer as second cancer in relatives.

OBJECTIVES: To investigate if the risk of prostate cancer (PC) differs based on the order of primary PC diagnosed in first-degree relatives (FDRs) given possibly different risk factors for PC as first primary cancer (PCa-1) and second primary cancer (PCa-2). SUBJECTS AND METHODS: In this Swedish nationwide cohort, PC diagnosis was followed for among 149,985 men with one FDR affected by PCa-1, 10,972 with one FDR affected by PCa-2 and 2,896,561 without any FDRs affected by cancer in a maximum of 57 years. PC patients were further followed for death due to PC since diagnosis. Relative risk (RR) of PC was estimated with Poisson regression and hazard ratio (HR) with Cox proportional hazard model. RESULTS: Compared to men without any FDRs affected by cancer, the RRs of PC in men with one FDR affected by PCa-1 and PCa-2 were 2.12 (95% confidence interval [CI]: 2.07-2.17) and 1.69 (1.54-1.85), respectively. The risk in men with one FDR affected by PCa-2 was significantly lower than those with one FDR affected by PCa-1 after additionally adjusting for family relationship (father-son and brothers) and age at diagnosis of PC in FDR (RR PCa-2 vs PCa-1 , 0.85, 95% CI, 0.78-0.94). PC patients with a family history of PCa-2 were more likely to be detected at late-stage and less likely to be diagnosed by screening, compared to those with a family history of PCa-1. Patients whose PC was diagnosed after the diagnosis of PCa-1 in FDRs had a better survival than those without a family history of cancer (HR, 0.88, 95% CI, 0.80-0.97), but no such association was observed among patients with a family history of PCa-2. CONCLUSION: Our study indicates a discrepancy between PC risks associated with a family history of PCa-1 and PC-2 and the reason behind it may be multifactorial.

Beta-Blockers Use and Risk of Breast Cancer in Women with Hypertension.

BACKGROUND: The risk of breast cancer among hypertensive patients who use beta-blockers has attracted attention. However, the evidence is inconsistent and investigation of the dose-specific associations for subtypes of beta-blockers is limited. METHODS: By incorporating Swedish national registers, breast cancer risk was estimated in women with hypertension who used nonselective beta-blockers and beta-1 selective blockers compared with propensity score-matched nonusers. The cumulative defined daily dose was used to study the dose-response association. Test of interaction between beta-blocker use and other antihypertensive medications was performed. RESULTS: Hypertensive patients taking beta-1 selective blockers (metoprolol, atenolol, bisoprolol) had an increased risk of breast cancer with a HR and 95% confidence interval (CI) of 2.39 (1.95-2.94), 2.31 (1.46-3.64), and 3.02 (2.09-4.36), respectively. All of the observed associations were dose-dependent (P trend < 0.0001). No significant association was found for the nonselective beta-blocker (propranolol) except that among users of agents acting on the renin-angiotensin system, those who used propranolol had increased breast cancer risk. Modification of agents acting on the renin-angiotensin system on breast cancer risk was also observed for atenolol. CONCLUSIONS: The increased risk of breast cancer associates with the use of beta-1 selective blockers in a dose-response manner. IMPACT: Breast cancer surveillance is recommended for hypertensive female patients using beta-1 selective blockers.