Jardiance Cancer Risk Signal: A Women's Health Review

What Is Empagliflozin and Why Are Women Taking It?

Empagliflozin is a sodium-glucose cotransporter-2 (SGLT2) inhibitor approved by the FDA for type 2 diabetes (T2D), heart failure with reduced or preserved ejection fraction, and chronic kidney disease (CKD). It works by blocking glucose reabsorption in the proximal tubule of the kidney, causing excess glucose to spill into the urine.

Women make up roughly half the T2D population in the United States, and the CDC estimates that 15.6 million U.S. Women are living with diagnosed diabetes. Beyond diabetes, Jardiance is prescribed to women with:

• Heart failure, including the preserved-ejection-fraction phenotype that disproportionately affects postmenopausal women
• Diabetic kidney disease, which progresses more rapidly in women after menopause due to loss of estrogen-mediated renal protection
• PCOS-related insulin resistance, an off-label but increasingly studied use in reproductive-age women
• Obesity-related metabolic disease, where SGLT2 inhibitors are being explored as adjuncts to GLP-1 therapy

Because this drug touches so many female-relevant conditions, understanding its cancer safety profile is not a theoretical exercise. It is a clinical priority.

The EMPA-REG OUTCOME Trial: What the Cancer Data Actually Said

Trial Design at a Glance

EMPA-REG OUTCOME enrolled 7,020 adults with T2D and established cardiovascular disease, randomized to empagliflozin 10 mg, empagliflozin 25 mg, or placebo, with a median follow-up of 3.1 years. The primary endpoint was MACE (major adverse cardiovascular events). The trial was not designed or powered to detect a cancer signal.

CV Benefit Was Striking

The headline result was a 38% relative risk reduction in cardiovascular death compared with placebo (HR 0.62; 95% CI, 0.49-0.77; P < 0.001). Hospitalizations for heart failure fell by 35%. These findings changed prescribing globally and drove the expanded heart failure and CKD indications.

Cancer Findings Were Reassuring, With Caveats

Within EMPA-REG OUTCOME, the overall incidence of neoplasms was numerically balanced across treatment and placebo arms. No single cancer type reached statistical significance for excess risk with empagliflozin. The trial was, however, only 3.1 years in duration, which is almost certainly too short to detect solid-tumor signals from a drug mechanism. Most de novo malignancies require years of exposure and latency before clinical detection.

The absence of a statistically significant cancer signal in EMPA-REG OUTCOME should be read as "not detected in this timeframe," not as "definitively no risk."

Bladder Cancer: The Signal That Prompted Regulatory Attention

Where the Concern Originated

The bladder cancer concern in the SGLT2 class dates partly to canagliflozin. The FDA's 2015 label update for canagliflozin (Invokana) included a warning based on a numerical excess of bladder cancer cases in the CANVAS program development program. The mechanism hypothesized was glucosuria-driven urothelial irritation from chronically elevated urinary glucose concentrations.

Empagliflozin shares the same glucosuria mechanism. The FDA's current Jardiance label carries a warning noting the bladder cancer signal observed across the SGLT2 class, and advises clinicians to consider discontinuation in patients who develop hematuria or bladder-related symptoms.

Empagliflozin-Specific Bladder Data

In pooled analysis of empagliflozin's development program (covering >12,000 patient-years of exposure), the incidence of bladder cancer was 0.07 per 100 patient-years with empagliflozin vs. 0.11 per 100 patient-years with placebo, a difference that did not reach significance and, if anything, trended lower in the drug arm. This finding does not rule out a risk, given the short follow-up period and small absolute event counts.

What This Means for Women

Bladder cancer is less common in women than men, with women accounting for roughly 25% of U.S. Bladder cancer diagnoses, according to the American Cancer Society's 2024 data cited through NIH surveillance. Women with T2D already carry a modestly elevated bladder cancer risk relative to women without diabetes, which complicates attributing any signal specifically to the drug.

Any woman on empagliflozin who develops painless hematuria, urinary urgency without infection, or pelvic discomfort should have urinalysis and urology referral promptly. Glucosuria from the drug can mask early hematuria detection if clinicians are not alert.

Breast Cancer: Limited Data, High Stakes for Women

The Hormonal Context Women Don't Hear About

Breast cancer is the most common cancer in U.S. Women, and approximately 13% of U.S. Women will develop invasive breast cancer in their lifetime. Women with T2D have a well-documented modestly elevated breast cancer risk, thought to be mediated by hyperinsulinemia, elevated IGF-1, and adipose-derived estrogen. Any drug that modifies glucose and insulin dynamics theoretically touches this biological terrain.

Here is a framework that consolidates what is and is not known, specific to women:

Known: Empagliflozin reduces fasting insulin and fasting glucose, which may theoretically reduce the hyperinsulinemia-driven breast cancer risk seen in T2D. This is biologically plausible but unproven.

Known: In EMPA-REG OUTCOME and the broader pooled development database, breast cancer cases were small in absolute number and not statistically elevated vs. Placebo.

Unknown: Long-term breast cancer risk beyond 5 years of continuous SGLT2 inhibitor use has not been studied in a dedicated trial.

Unknown: Whether the drug's modest weight reduction (typically 2-3 kg in trials) reduces adipose estrogen in postmenopausal women enough to confer any breast cancer protection is not established.

What to Monitor

Women on long-term empagliflozin should continue age-appropriate mammography screening per ACOG's breast cancer screening guidelines. The drug does not change screening intervals. Women with BRCA1/2 variants or other high-risk features need surveillance per their existing high-risk protocol regardless of empagliflozin use.

Endometrial and Uterine Cancer: Postmenopausal Women's Specific Concern

Postmenopausal women with obesity, T2D, and insulin resistance are the highest-risk group for endometrial cancer, driven by adipose estrogen synthesis and hyperinsulinemia. SGLT2 inhibitors produce a modest but real weight reduction and insulin-lowering effect. Whether this translates into reduced endometrial cancer risk is biologically plausible but not yet established in prospective trial data.

No dedicated endometrial safety signal has emerged in empagliflozin trial data. The postmenopausal women enrolled in EMPA-REDUCED (the heart failure preserved ejection fraction trial) and EMPA-KIDNEY trials were not followed long enough for endometrial incidence data to be meaningful.

Any postmenopausal woman on empagliflozin who experiences abnormal uterine bleeding should be evaluated promptly for endometrial pathology. The drug does not cause vaginal bleeding, so any bleeding is endometrial in origin until proven otherwise.

Cervical Cancer: No Known Signal, But a Note on Glucosuria and Infection

Cervical cancer is HPV-driven, not metabolic, so empagliflozin has no biologically plausible direct mechanism for cervical carcinogenesis. There is no signal in trial data.

Indirectly, the glucosuria empagliflozin produces increases susceptibility to genital mycotic infections, which affect up to 10% of women in the first year of SGLT2 inhibitor use. Recurrent vulvovaginal candidiasis does not cause cervical cancer, but it can disrupt the vaginal microbiome and cause significant quality-of-life burden. Women should be counseled about this before starting the drug.

PCOS and Reproductive-Age Women: A Gap in the Cancer Evidence

Why This Population Matters

Women with polycystic ovary syndrome have a 2-4-fold elevated risk of endometrial cancer, driven by chronic anovulation and unopposed estrogen exposure. They also carry an elevated metabolic risk that can progress to T2D. Empagliflozin is being studied off-label in PCOS to address insulin resistance, and small pilot trials such as a 2022 study in Fertility & Sterility suggest benefit for metabolic markers.

No cancer-specific data exist in PCOS populations on empagliflozin. The reproductive-age woman with PCOS who takes this drug for metabolic management is operating in a true evidence gap. Her endometrial cancer risk from chronic anovulation is real and independent of the drug, and she needs regular progestogen exposure to protect the endometrium, whether or not she is on empagliflozin.

Fertility Considerations

SGLT2 inhibitors have not been shown to improve or worsen ovulatory function in controlled trials. Weight loss from empagliflozin could theoretically restore ovulation in anovulatory women with PCOS, which is both a potential benefit (improved fertility) and a contraception consideration (unexpected pregnancy risk in a drug contraindicated in the 2nd and 3rd trimesters).

Pregnancy, Lactation, and Contraception: Required Reading Before You Fill This Prescription

Pregnancy: Contraindicated after the first trimester. The FDA label for empagliflozin carries a pregnancy warning stating that the drug should be discontinued when pregnancy is confirmed, and no later than the end of the first trimester. Animal studies show fetal renal toxicity. Human data are limited, but the mechanism of glucosuria affecting fetal renal development during the second and third trimester, when fetal kidneys become functional, is a well-grounded pharmacological concern.

First trimester exposure: The teratogenic window is less clearly defined for empagliflozin than for drugs like warfarin or isotretinoin. The conservative approach is immediate discontinuation on confirmed pregnancy. No structural anomaly signal has emerged from the small number of inadvertent first-trimester exposures reported in pharmacovigilance databases, but this data set is too small to be reassuring.

Lactation: Animal data show empagliflozin is present in rat milk. Human lactation transfer data are absent. Given that the drug could affect renal development in a nursing infant, the FDA label advises against use while breastfeeding. Women who need SGLT2 inhibitor therapy for heart failure or CKD should discuss the risk-benefit balance with their cardiologist or nephrologist, with the general recommendation being to hold the drug during lactation.

Contraception requirement: Any woman of reproductive age taking empagliflozin should use reliable contraception. This is especially important in women with PCOS on the drug who experience spontaneous ovulation restoration from weight loss. No specific contraceptive interaction exists with empagliflozin, but hormonal contraceptives with estrogen may modestly affect glycemic control, and this should be discussed with the prescribing clinician.

Perimenopause and Menopause: A Distinct Risk Profile

Postmenopausal women are the core empagliflozin cancer-safety population to watch, for several overlapping reasons.

First, the heart failure with preserved ejection fraction phenotype that empagliflozin now carries an FDA indication for disproportionately affects postmenopausal women. EMPEROR-Preserved enrolled a population that was 45% women, with a median age of 72, meaning the drug's most prominent heart failure trial population was largely postmenopausal women.

Second, postmenopausal women on hormone therapy (HT) and empagliflozin represent a drug interaction gap. Estrogen-containing HT can modestly worsen insulin resistance. Empagliflozin's glucose-lowering could partially counteract this effect. No formal trial data exist on this interaction, and clinicians are managing it by monitoring HbA1c and glucose trends after HT initiation or cessation.

Third, the urogenital side-effect profile changes in menopause. Genitourinary syndrome of menopause (GSM) predisposes women to recurrent urinary tract infections and disrupted vaginal flora. Empagliflozin's glucosuria layered onto GSM-related changes can meaningfully increase mycotic and bacterial infection rates. Whether this chronically inflamed urogenital environment has any effect on local cancer risk over decades is unknown.

Regulatory Field: Where the FDA and EMA Stand Right Now

The FDA has not issued a black-box warning specifically for cancer with empagliflozin. The current label carries a precautionary statement for the class on bladder cancer, without isolating empagliflozin as higher risk than other SGLT2 inhibitors.

The European Medicines Agency's periodic safety update reports for the SGLT2 class, most recently reviewed in 2023, concluded that available data do not support a causal relationship between empagliflozin and any specific malignancy, while noting that long-term data remain limited.

The FDA's 2024 prescribing label update added language reinforcing that patients with active bladder cancer or a history of bladder cancer should generally avoid SGLT2 inhibitors, and that new or worsening hematuria warrants investigation before continuing the drug.

No women's-health society, including ACOG, the Menopause Society, or ASRM, has issued a specific cancer-risk statement on empagliflozin as of January 2025.

Who Should and Should Not Take Empagliflozin: A Life-Stage View

Women Who May Benefit Most

• Postmenopausal women with T2D and established cardiovascular disease are the best-studied population, anchored by EMPA-REG OUTCOME's 38% CV death reduction
• Postmenopausal women with heart failure with preserved ejection fraction, supported by EMPEROR-Preserved (NEJM 2021) showing a 21% reduction in the composite of CV death or heart failure hospitalization
• Women with CKD and T2D, supported by EMPA-KIDNEY (NEJM 2023) showing a 28% reduction in kidney disease progression or CV death
• Women with T2D who have tried metformin and need add-on therapy with weight-neutral or weight-reducing effects

Women Who Should Not Take Empagliflozin

• Pregnant women after the first trimester: as above, kidney toxicity risk to the fetus
• Women with active bladder cancer or a history of urothelial malignancy
• Women with eGFR <20 mL/min/1.73m² (insufficient glucose-lowering efficacy; this threshold differs slightly by indication)
• Women with recurrent diabetic ketoacidosis, including those with late-onset autoimmune diabetes that was initially misclassified as T2D
• Women on a severely carbohydrate-restricted diet who are at high risk for euglycemic DKA (relevant in women following very low-carbohydrate diets for PCOS management)

The Evidence Gap: What Women Have Not Been Told

Women have been historically under-enrolled in cardiovascular outcomes trials. EMPA-REG OUTCOME enrolled only 28.5% women, which means the cancer incidence data from this trial are even less statistically powered in female-specific subgroups than in the overall population. EMPEROR-Preserved did better at 45% women, but was not designed to detect cancer.

No long-term observational cohort study has been published that specifically examines cancer incidence in women on empagliflozin stratified by menopausal status, hormone therapy use, or cancer risk score. This is a genuine gap. What we currently have is extrapolated from mixed-sex trial populations where women were a minority, and from mechanistic reasoning. Clinicians should be honest about this with their patients.

The Menopause Society has called for sex-stratified reporting in all cardiovascular and metabolic drug trials. Until that standard is applied retroactively to existing SGLT2 inhibitor databases, the female-specific cancer safety profile of empagliflozin remains incompletely characterized.

Monitoring Checklist for Women on Empagliflozin

Women currently taking Jardiance should have the following monitored by their clinical team:

• Urinalysis with microscopy at least annually, with prompt evaluation of any hematuria
• Blood pressure and eGFR every 3-6 months depending on CKD stage
• HbA1c every 3 months until stable, then every 6 months
• Age-appropriate cancer screening: mammography per ACOG guidelines, cervical cytology per ASCCP guidelines, and colonoscopy per USPSTF age recommendations. None of these intervals change because of empagliflozin, but they should not be deferred
• Pelvic exam and discussion of abnormal uterine bleeding at each annual visit, particularly in postmenopausal women and in women with PCOS on the drug
• Genital mycotic infection assessment and consideration of prophylactic antifungal strategies if recurrence is frequent