Breast Cancer Risk Among Users of Antidepressant Medications

The incidence risk of breast and gynecological cancer by antidepressant use: A systematic review and dose-response meta-analysis of epidemiological studies involving 160,727 patients

Background and objective

Antidepressants are widely prescribed to treat depression and anxiety disorders that may become chronic conditions among women. Epidemiological studies have yielded inconsistent results on the correlation between antidepressant use and the incidence risk of female breast and gynecological cancer, along with uncertain dose-response relationship. Therefore, we performed a systematic review and dose-response meta-analysis to investigate the association.

Methods

Web of Science, Embase, PubMed, The Cochrane Library, and PsycINFO were systematically searched in January 2022, with no language limits. Random-effect models were used to calculate pooled effect sizes and 95% confidence intervals between studies. Linear and non-linear dose-response analyses were performed to evaluate the dose or duration of antidepressant use affecting the incidence risk of female breast and gynecological cancer. Further subgroup analyses were systematically performed by stratifying almost all study characteristics and important potential confounders, in order to further clarify and validate the important potential hypotheses regarding the biological mechanism underlying this association.

Results

Based on a systematic literature search, 34 eligible studies (27 case-control studies and 7 cohort studies) involving 160,727 female breast and gynecological cancer patients found that antidepressant use did not increase the incidence risk of female breast and gynecological cancer (pooled OR: 1.01; 95% CI: 0.97, 1.04, I² = 71.5%, p < 0.001), and even decreased the incidence risk of ovarian cancer (pooled OR: 0.91; 95% CI: 0.83, 1, I² = 17.4%, p = 0.293). There were a non-linear dose-response relationship (p non-linearity < 0.05) between the duration of antidepressant use and incidence risk of female breast cancer, and an inverse linear dose-response relationship between antidepressant use and the incidence risk of gynecological cancer, specifically with an increase of cumulative defined daily dose or duration to a high level, like 25,550 doses (OR: 0.91, 95% CI: 0.85-0.98, p linearity < 0.05) or 4,380 days (OR: 0.82; 95% CI: 0.7, 0.96, p linearity < 0.05), compared to never antidepressant users.

Conclusion

This systematic review and dose-response meta-analysis found that antidepressant use did not increase the incidence risk of female breast and gynecological cancer and even decreased the incidence risk of ovarian cancer, along with a non-linear or linear dose-response relationship.

Systematic Review Registration

PROSPERO https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=313364, identifier CRD42022313364.

Antitumoral Effects of Tricyclic Antidepressants: Beyond Neuropathic Pain Treatment

Simple Summary

Tricyclic antidepressants (TCAs) are old and known therapeutic agents whose good safety profile makes them good candidates for drug repurposing. As the relevance of nerves in cancer development and progression is being unveiled, attention now turns to the use of nerve-targeting drugs, such as TCAs, as an interesting approach to combat cancer. In this review, we discuss current evidence about the safety of TCAs, their application to treat neuropathic pain in cancer patients, and in vitro and in vivo demonstrations of the antitumoral effects of TCAs. Finally, the results of ongoing clinical trials and future directions are discussed.

Abstract

Growing evidence shows that nerves play an active role in cancer development and progression by altering crucial molecular pathways and cell functions. Conversely, the use of neurotropic drugs, such as tricyclic antidepressants (TCAs), may modulate these molecular signals with a therapeutic purpose based on a direct antitumoral effect and beyond the TCA use to treat neuropathic pain in oncology patients. In this review, we discuss the TCAs’ safety and their central effects against neuropathic pain in cancer, and the antitumoral effects of TCAs in in vitro and preclinical studies, as well as in the clinical setting. The current evidence points out that TCAs are safe and beneficial to treat neuropathic pain associated with cancer and chemotherapy, and they block different molecular pathways used by cancer cells from different locations for tumor growth and promotion. Likewise, ongoing clinical trials evaluating the antineoplastic effects of TCAs are discussed. TCAs are very biologically active compounds, and their repurposing as antitumoral drugs is a promising and straightforward approach to treat specific cancer subtypes and to further define their molecular targets, as well as an interesting starting point to design analogues with increased antitumoral activity.

Relationship between antidepressive agents and incidence risk of breast cancer: systematic review and meta-analysis

Purpose: This study aimed to review the association between antidepressive agent (AD) use and the incidence risk of breast cancer. Methods: CBM, WOS, Embase, PubMed and Cochrane Library were systematically searched in July 2019. The methodological quality of the studies was assessed through the Newcastle-Ottawa Scale. Results: We included 19 studies from six countries or regions with relationships between breast cancer and ADs. Subgroup analysis showed no significant association in nested case-control or case-control studies; however, cohort studies revealed a significant association (odds ratio = 1.11; 95% CI: 1.04-1.17). Conclusions: This meta-analysis indicates that breast cancer was not associated with the use of ADs when considering all types of studies, but an association was observed if we considered cohort studies.

Antidepressants in association with reducing risk of oral cancer occurrence: a nationwide population-based cohort and nested case-control studies

Objectives

Several studies suggested that antidepressant use may increase or decrease the risk of cancer occurrence, depending on specific cancer types. The possible carcinogenic effect of antidepressants has received substantial attention; however, evidence remains inconclusive. Here we investigated associations between the use of antidepressants and occurrences of oral cancer (OC).

Methods

Two million samples were randomly collected from the National Health Insurance Research Database in Taiwan, which covers 98% of the total population (23 million). All patients from2000 to 2009 were followed up. We identified 5103 patients newly diagnosed with OC after antidepressants use in addition to 20,412 non-OC matched subjects and 95,452 unmatched non-OC subjects.

Results

In nested case control analysis, factors associating with OC, including age [OR = 1.02; 95% confidence interval (CI) = 1.01–1.03) and male (OR = 5.30; 95% CI = 4.92–5.70) were independently associated with increased risk of OC. Based on the functions of antidepressants, antidepressants treatment medications were further classified to investigate risk of OC. Selective serotonin reuptake inhibitors (OR = 0.61; 95% CI = 0.53–0.70) and tricyclic antidepressants (OR = 0.57; 95% CI = 0.52–0.63) were associated with reduced risk of OC. The risk of developing OC among subjects taking antidepressants was less than 26% [hazard ratio (HR) =0.74; 95% CI = 0.68–0.81] in prospective cohort study. The effect of a cumulative duration and dose was a significantly reduced risk of OC.

Conclusions

The association between antidepressant use and decreasing OC risk were demonstrated by both prospective and nested case–control studies.

Depression, Antidepressant Use, and Postmenopausal Breast Cancer Risk

BACKGROUND

Whether depression and antidepressant (AD) use might influence breast cancer risk is unclear, and these exposures have not been evaluated together in a single, prospective cohort study of breast cancer risk.

METHODS

Among 71,439 postmenopausal women in the Women's Health Initiative Observational Study (WHI-OS), we estimated multivariable-adjusted HRs for the independent and joint effects of depressive symptoms and AD use on breast cancer risk using Cox proportional hazards regression.

RESULTS

When analyzed separately, neither depressive symptoms nor AD use at baseline were associated with a significantly increased risk of total breast cancer (HR = 0.96, 95% CI, 0.85-1.08; HR = 1.04, 95% CI, 0.92-1.20, respectively) or invasive breast cancer (HR = 0.98, 95% CI, 0.86-1.12; HR = 1.00, 95% CI, 0.86-1.16, respectively). Current AD use was associated with a borderline-significant increase of in situ breast cancer (HR = 1.30, 95% CI, 0.99-1.75) after adjustment for depressive symptoms; however, this relationship was attenuated after adjustment for mammographic screening (HR = 1.08, 95% CI, 0.76-1.51). No significant variation in total breast cancer risk was observed when the separate and joint effects of depressive symptoms and AD use were explored (P for interaction = 0.14).

CONCLUSION

We found no evidence that either depression or AD use influences breast cancer risk. An elevated risk of in situ disease among AD users could not be ruled out, though is likely due to increased screening in this subgroup.

IMPACT

Given the high prevalence of these exposures, these results may provide reassurance to the millions of women who are depressed and/or use ADs each year.

Anti-depressant therapy and cancer risk: a nested case-control study

Previous studies demonstrated a possible association between anti-depressant therapy with selective serotonin reuptake inhibitors (SSRI) and tricyclic anti-depressants (TCA), several genetic and hormonal pathways and cancer risk, with inconsistent results. Exposure to serotonin-norepinephrine reuptake inhibitors (SNRI) was not studied extensively. We sought to evaluate the association between exposure to SSRIs, TCAs and SNRIs and the five most common solid tumors. We conducted nested case-control studies using a large UK population-representative database. Cases were those with any medical code for the specific malignancy. For every case, four controls matched on age, sex, practice site, and duration of follow-up before index date were selected using incidence-density sampling. Exposure of interest was SSRI, SNRI or TCA therapy before index date. Odds ratios (ORs) and 95% CIs were estimated for each anti-depressant class using conditional logistic-regression analysis, adjusted for potential confounders, such as obesity, smoking history and alcohol consumption.

RESULTS

109,096 cancer patients and 426,402 matched controls were included. Current SSRI users with treatment initiation>one year before index date had modestly higher risk for lung and breast cancers with ORs of 1.27 (95% CI 1.16-1.38) and 1.12 (95% CI 1.06-1.18), respectively. Among current TCA users, there was a higher risk only for lung cancers with OR of 1.45 (95% CI 1.31-1.6). There was no statistically significant association between current SNRI therapy and cancer risk.

DISCUSSION

Treatment with SSRI and TCA might be associated with increased lung cancer risk. SSRI therapy might be associated with modest increase in breast cancer risk.

The identification of incident cancers in UK primary care databases: a systematic review

PURPOSE

UK primary care databases are frequently used in observational studies with cancer outcomes. We aimed to systematically review methods used by such studies to identify and validate incident cancers of the breast, colorectum, and prostate.

METHODS

Medline and Embase (1980-2013) were searched for UK primary care database studies with incident breast, colorectal, or prostate cancer outcomes. Data on the methods used for case ascertainment were extracted and summarised. Questionnaires were sent to corresponding authors to obtain details about case ascertainment.

RESULTS

Eighty-four studies of breast (n = 51), colorectal (n = 54), and prostate cancer (n = 31) were identified; 30 examined >1 cancer type. Among the 84 studies, 57 defined cancers using only diagnosis codes, while 27 required further evidence such as chemotherapy. Few studies described methods used to create cancer code lists (n = 5); or made lists available directly (n = 5). Twenty-eight code lists were received on request from study authors. All included malignant neoplasm diagnosis codes, but there was considerable variation in the specific codes included which was not explained by coding dictionary changes. Code lists also varied in terms of other types of codes included, such as in-situ, cancer morphology, history of cancer, and secondary/suspected/borderline cancer codes.

CONCLUSIONS

In UK primary care database studies, methods for identifying breast, colorectal, and prostate cancers were often unclear. Code lists were often unavailable, and where provided, we observed variation in the individual codes and types of codes included. Clearer reporting of methods and publication of code lists would improve transparency and reproducibility of studies.

Is amisulpride safe when prescribed to breast and prostate cancer patients?

In the last decades, the potential association between antidepressants and cancer risk has been increasingly investigated. Fundamental researches, performed on animal models and cell tumoral lines, have highlighted several biological mechanisms possibly supporting this association. Nevertheless, the epidemiological studies investigating the risk of cancer in patients receiving selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants (TCAs) have provided conflicting and inconclusive results. Therefore, the prescription of several antidepressants in oncologic patients still remains a matter of discussion. The aim of this review is to present and discuss available evidence concerning the association between the risk of breast and prostate cancer and the use of antidepressant medications. Thus, consistencies, differences, and contradictions of available data are reported. A special focus is addressed to amisulpiride, a widely prescribed drug still poorly investigated with regard to the risk of cancer occurrence and recurrence. Overall, there is no definitive evidence of increased risk of breast and prostate cancer among patients exposed to SSRIs and TCAs. The association between amisulpiride and cancer risk has been to date scarcely explored and considered in clinical settings. Nevertheless, the hyperprolactinemia frequently resulting from its adoption has been repeatedly associated, to increased cancer risk and poorer prognosis in cancer patients. Thus, the use of amisulpiride among cancer patients should be carefully considered.

Antidepressants: influence on cancer and immunity?

Two decades ago, it was hypothesized that antidepressants could alter the course of neoplastic diseases. However, contradictory findings indicated that antidepressants could either have carcinogenic properties or improve the disease outcome. Intriguingly, controversial results were reported on the action of antidepressant drugs on immune function. Further hypotheses proposed that antidepressants could indirectly affect the cancer prognosis through the modulation of antitumor activity. Here we review the literature in order to elucidate the influence of antidepressants on cancer and immunity.

Selective Serotonin Reuptake Inhibitor (SSRI) Antidepressants, Prolactin and Breast Cancer

Selective serotonin reuptake inhibitors (SSRIs) are a widely prescribed class of antidepressants. Laboratory and epidemiologic evidence suggests that a prolactin-mediated mechanism secondary to increased serotonin levels at neuronal synapses could lead to a potentially carcinogenic effect of SSRIs. In this population-based case-control study, we evaluated the association between SSRI use and breast cancer risk as a function of their relative degree of inhibition of serotonin reuptake as a proxy for their impact on prolactin levels. Cases were 2,129 women with primary invasive breast cancer diagnosed from 2003 to 2007, and controls were 21,297 women randomly selected from the population registry. Detailed information for each SSRI prescription dispensed was compiled using the Saskatchewan prescription database. Logistic regression was used to evaluate the impact of use of high and lower inhibitors of serotonin reuptake and duration of use, as well as to assess the effect of individual high inhibitors on the risk of breast cancer. Exclusive users of high or lower inhibitors of serotonin reuptake were not at increased risk for breast cancer compared with non-users of SSRIs (OR = 1.01, CI = 0.88–1.17 and OR = 0.91, CI = 0.67–1.25 respectively), regardless of their duration of use or menopausal status. While we cannot rule out the possibility of a clinically important risk increase (OR = 1.83, CI = 0.99–3.40) for long-term users of sertraline (≥24 prescriptions), given the small number of exposed cases (n = 12), the borderline statistical significance, and the wide confidence interval, these results need to be interpreted cautiously. In this large population-based case-control study, we found no conclusive evidence of breast cancer risk associated with the use of SSRIs even after assessing the degree of serotonin reuptake inhibition and duration of use. Our results do not support the serotonin-mediated pathway for the prolactin-breast cancer hypothesis.

Use of antidepressants and the risk of breast cancer: a meta-analysis

The goal of this study was to perform a meta-analysis to examine the association between the use of antidepressants (AD) and the risk of breast cancer. We searched the EMBASE and MEDLINE databases from inception through February 25, 2012, using search terms related to ADs and breast cancer. Two evaluators independently reviewed and selected articles and extracted data based on predetermined selection criteria. Pooled effect estimates were obtained by using random- and fixed effects meta-analyses. Of the 3,209 titles identified, 18 articles met the inclusion criteria. The overall risk of breast cancer did not increase among AD users [adjusted odds ratio (aOR) 1.02; 95 % CI 0.96-1.08]. Those who took tricyclic antidepressants (TCAs) or selective serotonin reuptake inhibitors (SSRIs) were not at increased risks of breast cancer. In subgroup meta-analyses, null associations were consistent across the type of AD, funding sources, the number of adjusted variables, medication dose, the ascertainment of exposure, and methodological quality. In subgroup analyses based on exposure duration, a marginal association was observed for the use of SSRIs < 1-2 years (aOR 1.10; 95 % CI 1.02-1.19). However, this effect was attenuated over time and those using SSRIs for more than 1-2 years had no elevated breast cancer risk. These results support the lack of a clinically meaningful association between AD use and the development of breast cancer and provide considerable reassurance. Given that the data collected to date do not support changing the current prescribing patterns for ADs, the important benefits of AD therapy must be considered.

Update of carcinogenicity studies in animals and humans of 535 marketed pharmaceuticals

This survey is a compendium of information retrieved on carcinogenicity in animals and humans of 535 marketed pharmaceuticals whose expected clinical use is continuous for at least 6 months or intermittent over an extended period of time. Of the 535 drugs, 530 have the result of at least one carcinogenicity assay in animals, and 279 (52.1%) of them gave a positive response in at least one assay. Only 186 drugs (34.8%) have retrievable information on carcinogenicity in humans, and 104 of them gave to a variable extent evidence of a potential carcinogenic activity. Concerning the correlation between results obtained in animals and epidemiological findings, 58 drugs gave at least one positive result in carcinogenicity assays performed in animals and to a variable extent displayed evidence of carcinogenicity in humans, but 97 drugs tested positive in animals and were noncarcinogenic in humans or vice versa. Our findings, which are in agreement with previous studies, indicate that the evaluation of the benefit/carcinogenic risk ratio should be always made in prescribing a drug.

Antidepressants and breast and ovarian cancer risk: a review of the literature and researchers' financial associations with industry

Background

Antidepressant (AD) use has been purported to increase the risk of breast and ovarian cancer, although both epidemiological and pre-clinical studies have reported mixed results [1]–[6]. Previous studies in a variety of biomedical fields have found that financial ties to drug companies are associated with favorable study conclusions [7].

Methods and Findings

We searched English-language articles in MEDLINE, PsychINFO, the Science Citations Index and the Cochrane Central Register of Controlled Clinical Trials (through November 2010). A total of 61 articles that assessed the relationship between breast and ovarian cancer and AD use and articles that examined the effect of ADs on cell growth were included. Multi-modal screening techniques were used to investigate researchers' financial ties with industry. A random effects meta-analysis was used to pool the findings from the epidemiological literature. Thirty-three percent (20/61) of the studies reported a positive association between ADs and cancer. Sixty-seven percent (41/61) of the studies reported no association or antiproliferative effect. The pooled odds ratio for the association between AD use and breast/ovarian cancer in the epidemiologic studies was 1.11 (95% CI, 1.03–1.20). Researchers with industry affiliations were significantly less likely than researchers without those ties to conclude that ADs increase the risk of breast or ovarian cancer. (0/15 [0%] vs 20/46 [43.5%] (Fisher's Exact test P = 0.0012).

Conclusions

Both the pre-clinical and clinical data are mixed in terms of showing an association between AD use and breast and ovarian cancer. The possibility that ADs may exhibit a bi-phasic effect, whereby short-term use and/or low dose antidepressants may increase the risk of breast and ovarian cancer, warrants further investigation. Industry affiliations were significantly associated with negative conclusions regarding cancer risk. The findings have implications in light of the 2009 USPSTF guidelines for breast cancer screening and for the informed consent process.

A population-based case-control study of Selective Serotonin Reuptake Inhibitors (SSRIs) and breast cancer: the impact of duration of use, cumulative dose and latency

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs), a popular class of antidepressants, may increase breast cancer risk by stimulating the secretion of prolactin, a potential tumour promoter. We evaluated the effects of duration of SSRI use, cumulative dose, and latency on the risk of breast cancer by conducting a population-based case-control study utilizing Saskatchewan health databases.

METHODS

Cases included 1,701 women with primary invasive breast cancer diagnosed from 2003 to 2006, and controls consisted of 17,017 women, randomly selected from the population registry. Use of SSRIs was compiled using the Saskatchewan prescription database. Unconditional logistic regression was conducted to evaluate the impact of duration of combined SSRI use (total number of prescriptions dispensed), cumulative dose (total dosage received) and timing of use (two or more years, two to seven years and more than seven years prior to index date) on the risk of breast cancer.

RESULTS

Overall, SSRI use was not associated with an increased risk of breast cancer regardless of our definition of cumulative use (total number of prescriptions dispensed and total dosage). In addition, our results indicate that prolonged SSRI use does not have a latent effect on breast cancer risk. Also, our findings are not suggestive of an increased risk of breast cancer with the use of individual SSRIs.

CONCLUSIONS

Our study improved upon most previous studies by having a longer follow-up period, a larger sample size of long-term SSRI users and consideration of risk during specific exposure time windows that take latency into account. Given the potential health benefits of using SSRIs, our results suggest that the issue of breast cancer risk may no longer be a concern for women requiring long-term SSRIs.

Tricyclic antidepressants and the incidence of certain cancers: a study using the GPRD

Background:

Several studies suggest links between cancer and tricyclic antidepressant use.

Methods:

A case–control study using the General Practice Research Database examined whether previous tricyclic usage was associated with reduced incidence of brain (with glioma as a sub-category), breast, colorectal, lung and prostate cancers. Conditional logistic regression adjusted for age, gender, general practice, depression, smoking, body mass index, alcohol use and non-steroidal anti-inflammatory drug use.

Results:

A total of 31 953 cancers were identified, each matched with up to two controls. We found a statistically significant reduction in tricyclic prescriptions compared with controls in glioma (odds ratio (OR) =0.59, 95% confidence interval (CI)=0.42–0.81) and colorectal cancer patients (OR=0.84, CI=0.75–0.94). These effects were dose-dependent (P-values for trend, glioma=0.0005, colorectal=0.001) and time-dependant (P-values for trend glioma=0.0005, colorectal=0.0086). The effects were cancer-type specific, with lung, breast and prostate cancers largely unaffected by antidepressant use.

Conclusion:

The biologically plausible, specific and dose- and time-dependant inverse association that we have found suggests that tricyclics may have potential for prevention of both colorectal cancer and glioma.

Incidence of cancer and antidepressant medication: record linkage study

The consumption of antidepressants, especially selective serotonine reuptake inhibitors (SSRI) has been increasing. Because a large fraction of the population is exposed, even a small excess of risk with respect to cancer should be considered. We carried out a record linkage study in Finland utilizing nationwide databases of reimbursed medication and cancer. The study population included all antidepressant drug (AD) users in Finland who had purchased at least 1 prescription between 1998 and 2005, and who had no cancer diagnosis at the date of first purchase. A control population without AD usage (matched by age and sex) was also included. Data consisted of 418,588 pairs of individuals that cumulated 3.3 million person-years with an average of 4.0 years of follow-up. 19,365 cancer cases were observed. The most frequent cancers were breast, prostate, lung, colon, and brain cancer. In general, only few associations between the utilization of AD and cancer could be detected. Over four years exposure to AD showed a weak association with increased colon and breast cancer incidence, which could have been caused by bias. As conclusion, no clear evidence of neither beneficial nor harmful association between usage of antidepressant and cancer was found.

Antidepressant medication use and breast cancer risk

PURPOSE

Most epidemiologic studies have detected no association between prior use of antidepressant medications and breast cancer risk. Despite the uniform conclusion, there is a continuous rise in the proportion of women using antidepressants, lending support to further monitoring of disease effects.

METHODS

We conducted a population-based case-control study among 2908 incident breast cancer cases diagnosed from 2003 to 2006, and 2927 control women from Wisconsin. Associations between antidepressant use and breast cancer risk were evaluated using multivariable logistic regression.

RESULTS

The association between use of antidepressant medications and breast cancer risk was null (OR = 0.89, 95%CI 0.78-1.01). When stratified by type of antidepressant, use of selective-serotonin reuptake inhibitors (SSRIs) resulted in a similar risk overall (OR = 0.85, 95%CI 0.72-1.00) and among former and currents users. There were no associations between other types of antidepressant classes and breast cancer risk. In assessing risks among the five most commonly used antidepressants, we detected no association with fluoxetine, sertraline, venlafaxine, or buproprion hydrochloride. There was a reduction in breast cancer risk of 36% (OR = 0.64, 95%CI 0.45-0.92) among users of paroxetine hydrochloride. When stratified by body mass index, there was a reduction in risk associated with antidepressant users who were not overweight (OR = 0.73, 95% CI 0.60-0.90), but this association was null in overweight women (p-interaction = 0.04).

CONCLUSIONS

Surveillance of health risks associated with antidepressant medications continues to be of public health importance, though these medications are not likely to be associated with breast cancer risk.

Use of common medications and breast cancer risk

Prescription and over-the-counter medications are widely used in the United States and many western countries. More than two-thirds of women ages >45 years, who are at greatest risk for breast cancer, take prescription medication. In light of the ubiquitous nature of medication use and the fact that breast cancer remains the most common cancer in women, research on the role of medication use in breast cancer etiology is warranted. We summarize the epidemiologic evidence on the association between breast cancer risk and use of common medications, including antibiotics, antidepressants, statins, antihypertensives, and nonsteroidal anti-inflammatory drugs. Overall, there is little evidence that would implicate the use of antibiotics, antidepressants, statins, and antihypertensives in the etiology of breast cancer. Although several prospective studies and a randomized low-dose aspirin chemoprevention trial have not shown lower risk of breast cancer among aspirin users, most studies that have examined the potential chemoprotective effect of nonsteroidal anti-inflammatory drugs have shown significant risk reductions for regular and prolonged use of these drugs. The existing literature on the role of medication use in breast carcinogenesis is complicated. Interpretation of the evidence is hampered due to major methodologic differences across studies, including exposure assessment, exposure classification, and adjustment for potential confounding variables. These differences largely stem from the fact that the majority of articles on this topic represent secondary data analyses from studies with inadequate information on exposure or confounders. Thus, future epidemiologic studies specifically designed to study these ubiquitous and biologically plausible exposures are warranted.

Breast cancer recurrence risk in relation to antidepressant use after diagnosis

BACKGROUND

While laboratory data suggest that antidepressants may promote mammary tumor growth, there has been little research investigating whether antidepressant use after breast cancer diagnosis is associated with the risk of breast cancer recurrence.

METHODS

We conducted a retrospective cohort study within Group Health, an integrated healthcare delivery system in Washington state. Women diagnosed with a first primary invasive, stage I, IIA, or IIB, unilateral breast carcinoma between 1990-1994 (aged>or=65 years) and 1996-1999 (aged>or=18 years) were eligible for the study (N=1306). Recurrence within 5-year of diagnosis was ascertained by medical chart review. We used the pharmacy database to identify antidepressant dispensings from Group Health pharmacies. We used multiple Cox regression to estimate the hazard ratio for recurrence and breast cancer mortality, comparing users and non-users of antidepressant medications. Results for recurrence were examined separately in users and non-users of tamoxifen.

RESULTS

We did not observe an association between antidepressant use after breast cancer diagnosis and the risk of recurrence either in general (hazard ratio for any antidepressant use: 0.8; 95% confidence interval: 0.5-1.4) or for specific types of antidepressant medication. Risk of death from breast cancer did not differ between non-users and users of antidepressants.

CONCLUSIONS

The results of this study suggest that women who use antidepressants after breast cancer diagnosis do not have an increased risk of recurrence or mortality.

Use of antidepressants and risk of lung cancer

OBJECTIVE

To evaluate the effect of antidepressant use on lung cancer risk.

METHODS

We conducted a case-control study nested in a cohort of patients 40-84 year-old in 1995-2004, without a prior diagnosis of cancer using The Health Improvement Network (THIN) database in the UK. Cases comprised 4,336 patients with a first diagnosis of primary lung cancer. A sample of 10,000 controls was frequency-matched to the cases for age, sex, and the calendar year of diagnosis. The index date for exposure definition was one year before the diagnosis for cases and one year before a random date for controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using conditional logistic regression models adjusted for potential confounders.

RESULTS

Selective serotonin reuptake inhibitor (SSRI) use during the year preceding the index date with treatment duration of at least one year had an OR of 0.59 (95% CI 0.41, 0.86). The corresponding OR was 1.23 (95% CI 0.96, 1.58) for tricyclic antidepressants (TCAs).

CONCLUSIONS

SSRI use did not increase the lung cancer risk and might be associated with a reduced risk. However, residual confounding might explain the apparent protective effect found for SSRI use, as well as the marginally elevated risk observed among TCA users.

Depression, quality of life and breast cancer: a review of the literature

Depression is misdiagnosed and undertreated among breast cancer population. Risk factors for depression in the 5 years after diagnosis are related more to the patient rather than to the disease or its treatment. The breast cancer stage (early and advanced) is not statistically significant in terms of rates of psychosocial distress except for recurrence. Risk factors of depression might impair quality of life such as fatigue, past history or recent episode of depression after the onset of cancer, cognitive attitudes of helplessness/hopelessness, resignation. Body image impairment from mastectomy and sexuality aftermath generates higher rates of mood disorders. The link between increased risk of breast cancer and depression is controversial among the literature. Some studies suggest a protective factor, others find a relation between stress, immunity and cancer occurrence or even mortality. Breast cancer survivors report a higher prevalence of mild to moderate depression with a lower quality of life in all areas except for family functioning. Treatment of depression in breast cancer women improves their quality of life and may increase longevity. Antidepressant medications remain the cornerstone of depression treatment. The hypothetical link between their prescription and increased breast cancer risk is not supported by literature's data.

SSRI use and breast cancer risk by hormone receptor status

BACKGROUND

There is little evidence linking the use of selective serotonin reuptake inhibitors (SSRIs) with increased breast cancer risk, but one study has found an association with estrogen receptor negative (ER-) and progesterone receptor negative (PR-) tumors.

METHODS

We used data collected on 820 invasive breast cancer cases and 2852 hospitalized controls collected from 1990 through 2006. Information on medication use and other variables was collected by nurse interviewers. We used unconditional logistic regression analyses to evaluate the association between regular SSRI use (use at least 4 times/week for at least 3 months) and breast cancer risk overall and by subtype defined by hormone receptor status.

RESULTS

The odds ratio for all breast cancer was not elevated among regular users of SSRIs (OR = 0.89, 95% CI 0.62-1.29). None of the odds ratios varied from 1.0 in any category of hormone receptor status. Among women aged 55 and over, the odds ratios were increased for ER- (OR = 1.84, 95% CI 0.66-5.16), PR- (OR = 1.85, 95% CI 0.80-4.27), and ER-PR- (OR = 2.10, 95% CI 0.73-6.02) tumors, but these estimates were compatible with chance.

CONCLUSION

We found no association between SSRI use and breast cancer risk, overall or by hormone receptor status. Odds ratios were elevated in older women, particularly for ER- and PR- tumors, but the confidence intervals were compatible with no association.

Traditional nonsteroidal anti-inflammatory drugs and postmenopausal hormone therapy: a drug-drug interaction?

BACKGROUND

Suppression of prostacyclin (PGI2) is implicated in the cardiovascular hazard from inhibitors of cyclooxygenase (COX)-2. Furthermore, estrogen confers atheroprotection via COX-2-dependent PGI2 in mice, raising the possibility that COX inhibitors may undermine the cardioprotection, suggested by observational studies, of endogenous or exogenous estrogens.

METHODS AND FINDINGS

To identify an interaction between hormone therapy (HT) and COX inhibition, we measured a priori the association between concomitant nonsteroidal anti-inflammatory drugs (NSAIDs), excluding aspirin, in peri- and postmenopausal women on HT and the incidence of myocardial infarction (MI) in a population-based epidemiological study. The odds ratio (OR) of MI in 1,673 individuals and 7,005 controls was increased from 0.66 (95% confidence interval [CI] 0.50-0.88) when taking HT in the absence of traditional (t)NSAIDs to 1.50 (95% CI 0.85-2.64) when taking the combination of HT and tNSAIDs, resulting in a significant (p < 0.002) interaction. The OR when taking aspirin at doses of 150 mg/d or more was 1.41 (95% CI 0.47-4.22). However, a similar interaction was not observed with other commonly used drugs, including lower doses of aspirin, which target preferentially COX-1.

CONCLUSIONS

Whether estrogens confer cardioprotection remains controversial. Such a benefit was observed only in perimenopausal women in the only large randomized trial designed to address this issue. Should such a benefit exist, these results raise the possibility that COX inhibitors may undermine the cardioprotective effects of HT.

Review of the epidemiological literature on antidepressant use and breast cancer risk

Based on evidence that antidepressants increase levels of prolactin and may promote the growth of mammary tumor cells, there has been concern that the use of these drugs may increase the risk of breast cancer. This article reviews the epidemiological evidence on the relationship between breast cancer risk and the use of the selective serotonin reuptake inhibitors, the tricyclic antidepressants and other antidepressants. Overall, the evidence does not support the hypothesis that the use of antidepressants increases the risk of breast cancer. There is a dearth of data on long-term selective serotonin reuptake inhibitor use. Since these drugs are commonly used, it is prudent public health policy to monitor breast cancer incidence among women using this class of drug for long durations.

Antidepressant use in ambulatory cancer patients

Antidepressants are among the most commonly used medications, and they are frequently prescribed for cancer patients. Several dozen antidepressants are available, and they work through at least seven distinct mechanisms. These agents are used primarily to treat depressive and anxiety symptoms and have proven efficacy in treating hot flashes and as adjuvant analgesics. Side effects and drug interactions are frequent with these agents, and proper assessment and monitoring are crucial.

Use of antidepressant medications in relation to the incidence of breast cancer

Although associations have been reported between antidepressant use and risk of breast cancer, the findings have been inconsistent. We conducted a population-based case-control study among women enrolled in Group Health Cooperative (GHC), a health maintenance organization in Washington State. Women with a first primary breast cancer diagnosed between 1990 and 2001 were identified (N = 2904) and five controls were selected for each case (N = 14396). Information on antidepressant use was ascertained through the GHC pharmacy database and on breast cancer risk factors and screening mammograms from GHC records. Prior to one year before diagnosis of breast cancer, about 20% of cases and controls had used tricyclic antidepressants (adjusted odds ratio = 1.06, 95% CI 0.94-1.19) and 6% of each group had used selective serotonin reuptake inhibitors (OR = 0.98, 95% CI 0.80-1.18). There also were no differences between cases and controls with regard to the number of prescriptions filled or the timing of use. Taken as a whole, the results from this and other studies to date do not indicate an altered risk of breast cancer associated with the use of antidepressants overall, by class, or for individual antidepressants.

Antidepressant use and breast cancer risk

BACKGROUND

Antidepressants are among the most commonly prescribed drugs in the United States. Laboratory studies suggest that because certain antidepressants increase prolactin levels that they may also increase breast cancer risk. However, human studies evaluating use of antidepressants in relation to breast cancer risk have yielded inconsistent results.

METHODS

A population-based case-control study consisting of 975 breast cancer cases 65-79 years of age diagnosed from 1997-1999 and 1007 age and residence-matched controls was conducted in western Washington State. Detailed information on antidepressant use was obtained through structured in-person interviews. Logistic regression was performed to analyze the relationship between antidepressant use and breast cancer risk.

RESULTS

Overall, there was no association between ever use of antidepressants and breast cancer risk (odds ratio [OR] = 1.2, 95% confidence interval [95% CI]: 0.9-1.6). When evaluated separately, tricyclic antidepressants (TCA), selective serotonin reuptake inhibitors (SSRI), and triazolopyridines were each not associated with breast cancer risk. However, risk varied by hormone receptor status. Compared to never users, ever users of SSRIs had elevated risks of progesterone receptor (PR) negative and estrogen receptor (ER) positive/PR-negative breast cancers (OR = 1.8, 95% CI: 1.1-3.6 and OR = 2.0, 95% CI: 1.1-3.8, respectively), but not of tumors with other hormone receptor profiles.

CONCLUSIONS

Based on these results and those of previous studies, there is limited evidence that any type of antidepressant use is associated with breast cancer risk overall. SSRIs may elevate risks of PR- and ER+/PR- tumors, though further studies are needed to confirm these associations.

Use of selective serotonin reuptake inhibitors and the risk of breast cancer

Selective serotonin reuptake inhibitors (SSRIs) were introduced in 1987 and, by 1997, were prescribed to 58% of Americans receiving outpatient treatment for depression. In 1992, a study reported that one of the SSRIs, fluoxetine, accelerated the growth of mammary tumors in rodents. By use of data from 1988 to 2002 from their hospital-based, case-control surveillance study, the authors examined the relation between use of SSRIs and risk of breast cancer. Nurse interviewers administered standard questionnaires to patients admitted to hospitals in three US centers to obtain information on demographic, medical, and lifestyle factors and to elicit a history of drug use, including antidepressants. Cases comprised 2,138 women with primary invasive breast cancer, and controls comprised 2,858 women admitted with nonmalignant diagnoses unrelated to SSRI use. The authors used multivariate conditional logistic regression models to estimate odds ratios for breast cancer among regular users of SSRIs compared with nonusers. The odds ratio was 1.1 (95% confidence interval: 0.8, 1.7) for regular use of SSRIs and 0.7 (95% confidence interval: 0.4, 1.5) for use of 4 or more years. Odds ratios were not elevated for any specific SSRI. These data provide some assurance that the use of SSRIs does not increase the risk of breast cancer.