Should I Take Hormone Therapy After Breast Cancer If I Am Over 70?

Do I need hormone therapy after breast cancer if I am over 70?

Endocrine therapy is commonly recommended after surgery for hormone receptor-positive breast cancer, but being over 70 does not create one answer for everyone. The American Cancer Society describes hormone therapy as a treatment used after surgery to lower recurrence risk.

The useful question is not, “Am I too old for this?” It is, “What does this treatment change for this cancer, in this life?” Tumor size, nodal status, estrogen-receptor status, planned radiation, and the chance of recurrence shape the cancer side of that answer. Bone strength, clotting history, uterine history, cardiovascular health, other illnesses, and daily function shape the person side.

The evidence in older adults has limits. A 2023 npj Breast Cancer review reports that only 3,972 of 88,023 women in a tamoxifen meta-analysis were age 70 or older. That gap matters. A relative reduction can sound large while the absolute gain for a low-risk person remains small.

The same 2023 review reports that non-breast-cancer mortality often exceeds breast-cancer mortality in older women with favorable-risk tumors. This does not make breast cancer unimportant. It makes competing health risks part of an honest estimate of benefit.

Can I refuse tamoxifen or an aromatase inhibitor after a lumpectomy?

Yes, a person can decline endocrine therapy after lumpectomy, and the decision belongs in a shared conversation with the oncology team. Declining is not the same as having no plan. It means understanding what recurrence protection is being left behind, what other treatments are part of the plan, and what follow-up will look like.

In a 2022 Annals of Surgical Oncology study from Memorial Sloan Kettering Cancer Center, 968 women age 70 or older had pT1-2, estrogen receptor-positive breast cancer treated with lumpectomy without radiotherapy. At a median follow-up of 53 months in the 2022 study, the 5-year locoregional recurrence rate was 3.1% among those with high endocrine-therapy adherence, 14.7% with low adherence, and 17.9% with no endocrine therapy.

Those figures are not a universal forecast. They describe a defined group that omitted radiation. Still, they show a hard truth: when endocrine therapy carries more of the recurrence-prevention burden, taking it inconsistently can look much closer to not taking it than to taking it steadily.

There is another trade-off. The National Cancer Institute reports that tamoxifen was linked more often with blood clots, uterine cancer or polyps, vaginal bleeding, and muscle cramps in a phase III comparison, while exemestane was linked with slightly more bone fractures. A drug choice is not a contest between a safe option and a dangerous one. It is a choice between different risks.

Joint stiffness and pain from aromatase inhibitors can be severe enough for some people to stop treatment, according to the American Cancer Society. The same source describes switching to tamoxifen as one approach clinicians use when pain blocks completion of therapy. A stopped treatment should start a conversation, not end one.

How much does endocrine therapy lower my recurrence risk at my age?

Endocrine therapy can lower recurrence risk at older ages, but the amount that matters is the absolute reduction for a specific cancer and treatment plan. The 2023 npj Breast Cancer review reports that, among the age-70-and-older subgroup in a meta-analysis, the annual event rate was 5.7% without tamoxifen and 3.3% with tamoxifen. The same 2023 review reports a hazard ratio of 0.49 for that subgroup.

Relative risk is the shape of the change. Absolute risk is the weight of it. Both belong on the table.

The 2023 review also summarizes CALGB 9343, which included 636 women age 70 or older with T1, node-negative, estrogen-receptor-positive cancer. At 10 years in that trial, local recurrence was 2% with radiation plus endocrine therapy and 10% with endocrine therapy alone; breast-cancer death was 1% in each group. That comparison addresses radiation added to endocrine therapy. It does not show what happens when endocrine therapy itself is omitted.

For postmenopausal patients choosing between drug classes, harms belong beside benefits. A 2011 Journal of the National Cancer Institute meta-analysis of seven randomized trials involving 30,023 patients found that longer aromatase-inhibitor use had higher odds of bone fracture than tamoxifen, with an odds ratio of 1.47 and a number needed to harm of 46. The same 2011 analysis found higher cardiovascular-disease odds with aromatase inhibitors, at 1.26, and lower odds of venous thrombosis, at 0.55, and endometrial carcinoma, at 0.34.

The practical task is to put the benefit and the burden in the same frame. A person with substantial recurrence risk and manageable side effects can see a different balance from a person with a favorable-risk tumor, fragile bones, painful joints, or a serious competing illness. Treatment length has meaning only when the person can live with the treatment.