Cancer Treatment and Bone Density: Why a DEXA Scan Is Essential During and After Chemotherapy and Hormone Therapy

Cancer treatment saves lives, but many of the most effective therapies carry a hidden cost to your skeletal health. Chemotherapy, hormone-blocking drugs, and long-term corticosteroid use can all accelerate bone mineral density loss, sometimes at rates far exceeding normal ageing.

Quick answer: If you are undergoing or have completed cancer treatment, a DEXA bone density scan can reveal whether your bones have been affected. NICE guidelines recommend baseline DEXA scans before starting aromatase inhibitors for breast cancer and during androgen deprivation therapy for prostate cancer. Early detection means early intervention, and that can prevent fractures years down the line.

For many patients, bone health is an afterthought during treatment. The focus, understandably, is on the cancer itself. But studies show that certain treatments can reduce bone mineral density by 1 to 5 per cent within the first year alone, and without monitoring, this damage often goes unnoticed until a fracture occurs.

This guide explains exactly how the most common cancer treatments affect your bones, what NICE recommends for monitoring, and what your DEXA results mean in the context of cancer care.

Your bones are living tissue, constantly breaking down old bone and building new bone in a process called remodelling. Healthy bone remodelling depends on a balance between osteoclasts (cells that break down bone) and osteoblasts (cells that build new bone). Several cancer treatments disrupt this balance, tipping the scales toward bone loss.

The mechanisms vary by treatment type. Some drugs directly suppress osteoblast activity, reducing new bone formation. Others strip away the protective hormones, primarily oestrogen and testosterone, that help maintain bone density throughout adult life. Corticosteroids, prescribed alongside many chemotherapy regimens, accelerate bone breakdown through multiple pathways at once.

What makes this particularly important is that the bone loss is often silent. You will not feel your bone mineral density declining. The first sign may be a fragility fracture, a break that occurs from a minor fall or even a cough, that could have been prevented with earlier detection.

A bone density DEXA scan measures your bone mineral density with precision, identifying loss before it reaches the fracture threshold. For cancer patients, this makes DEXA scanning a clinical tool, not a screening luxury.

Chemotherapy drugs target rapidly dividing cancer cells, but they can also damage the cells responsible for bone formation. Research published in Supportive Care in Cancer found that premenopausal women receiving chemotherapy for early-stage breast cancer experienced lumbar spine bone mineral density reductions of 1 to 4 per cent during treatment.

For hormone-receptor-negative breast cancer patients, the losses can be steeper. One study demonstrated an average bone mineral density reduction of 5.1 per cent at the lumbar spine within six months of completing chemotherapy. A 10 per cent reduction in bone mineral density, roughly equivalent to one standard deviation on a DEXA scan, doubles to triples your fracture risk.

Chemotherapy also frequently triggers premature menopause in women under 50. The sudden loss of oestrogen production magnifies the direct skeletal effects of the drugs, creating a compounding problem. Women who enter treatment-induced menopause may lose bone density at rates comparable to those seen in natural menopause but compressed into a much shorter timeframe.

Men undergoing chemotherapy are not immune either. Platinum-based regimens, commonly used for testicular and lung cancers, have been linked to reduced testosterone levels and measurable declines in bone density.

If you are currently receiving or have recently completed chemotherapy, a DEXA scan provides a clear baseline or follow-up measurement. Understanding where your bone density stands allows your oncologist and GP to act before a fracture occurs. You can learn more about how DEXA scanning works and what the process involves.

Aromatase inhibitors, including letrozole, anastrozole, and exemestane, are prescribed to postmenopausal women with hormone-receptor-positive breast cancer. These drugs work by blocking the enzyme aromatase, which converts androgens into oestrogen. By suppressing oestrogen production to near-zero levels, they starve the cancer of the hormone it needs to grow.

The trade-off is significant bone loss. Oestrogen plays a critical role in maintaining bone density, and its near-total suppression accelerates osteoclast activity. Studies have consistently shown annual bone mineral density losses of 1 to 3 per cent at the lumbar spine and hip in women taking aromatase inhibitors, rates substantially higher than those seen during normal postmenopausal ageing.

NICE guideline 80 on early and locally advanced breast cancer is clear on this point: patients starting adjuvant aromatase inhibitor treatment should have a baseline DEXA scan to assess bone mineral density. The same applies to women experiencing treatment-induced menopause or starting ovarian ablation or suppression therapy.

Despite the clarity of this guidance, a clinical audit found that only 38 per cent of eligible patients received a baseline DEXA scan before starting aromatase inhibitor therapy. That means roughly six in ten women began a bone-depleting medication without knowing their starting bone density.

If you have been prescribed an aromatase inhibitor and have not yet had a DEXA scan, requesting one is a straightforward step that gives both you and your clinical team the information needed to protect your bones during treatment.

Androgen deprivation therapy reduces testosterone to castration levels, either through medications (GnRH agonists or antagonists) or surgical orchidectomy. For men with prostate cancer, ADT can slow or halt tumour progression. But testosterone, like oestrogen in women, is essential for maintaining bone mineral density.

Men receiving ADT face a 20 to 30 per cent increase in fracture risk, with the spine, hip, and wrist most commonly affected. The rate of bone loss during ADT has been compared to that seen during early menopause, with measurable declines detectable within the first 6 to 12 months of treatment.

NICE recommends fracture risk assessment and DEXA scanning before starting ADT, with ongoing monitoring for men on long-term treatment. Yearly DEXA scans are often advised to track the trajectory of bone loss and guide decisions about protective interventions.

Bisphosphonates and denosumab have both been shown to prevent or reverse bone loss during ADT. In clinical trials, denosumab reduced the incidence of new vertebral fractures by 62 per cent in men receiving ADT. Lifestyle measures, including weight-bearing exercise, adequate calcium intake (1,000 to 1,200 mg daily), and vitamin D supplementation (10 to 20 micrograms daily), form the foundation of bone protection alongside medication.

The key point is that bone loss during ADT is treatable when caught early. A DEXA scan before or shortly after starting therapy gives your clinical team the baseline they need to act.

Corticosteroids such as prednisolone and dexamethasone are used extensively in cancer care. They reduce inflammation, manage nausea during chemotherapy, and form part of treatment protocols for blood cancers including lymphoma and myeloma. Many patients take them for weeks, months, or even years.

Glucocorticoid-induced osteoporosis is the most common form of secondary osteoporosis, and it can develop rapidly. Corticosteroids suppress osteoblast function (reducing new bone formation), increase osteoclast activity (accelerating bone breakdown), and impair calcium absorption from the gut, creating a triple threat to skeletal health.

The Royal Osteoporosis Society recommends that anyone expected to take oral corticosteroids for three months or longer at a dose equivalent to 7.5 mg or more of prednisolone daily should be assessed for fracture risk. For those over 70, or with a prior fragility fracture, preventive treatment should be considered from the outset.

We covered how several common medications affect bone density in our guide to medications that cause bone loss and when you need a DEXA scan. Corticosteroids rank among the most significant offenders, and cancer patients are often exposed to higher doses than the general population.

If you are taking corticosteroids as part of your cancer treatment, a DEXA scan can quantify whether bone loss has occurred and help your team decide whether bone-protective medication is warranted.

The timing of DEXA scans depends on your specific treatment, your age, and your existing risk factors. Based on NICE and Royal Osteoporosis Society guidance, the general framework covers several key scenarios.

Before starting aromatase inhibitors for breast cancer, a baseline DEXA scan is recommended. Follow-up scans are typically repeated every one to two years while on treatment.

Before or shortly after beginning androgen deprivation therapy for prostate cancer, a baseline DEXA scan is advised. Annual monitoring is standard for men on long-term ADT.

If you are prescribed oral corticosteroids for three months or longer at doses equivalent to 7.5 mg or more of prednisolone daily, a DEXA scan should be arranged. Repeat scanning is usually recommended after 12 to 24 months.

After completing chemotherapy, particularly if you experienced treatment-induced menopause or received platinum-based regimens, a DEXA scan within 12 months of completing treatment provides valuable follow-up data.

If you have additional risk factors, including a family history of osteoporosis, low body weight, a history of smoking, or previous fragility fractures, your clinical team may recommend earlier or more frequent scanning.

The goal is not to add anxiety to an already demanding treatment journey. It is to ensure that bone health does not become a casualty of the treatment that saved your life.

A DEXA scan produces a T-score that compares your bone mineral density to that of a healthy 30-year-old adult, the age at which bone density peaks. A T-score of 0 is average. A T-score between -1.0 and -2.5 indicates osteopenia (lower than normal bone density). A T-score of -2.5 or below indicates osteoporosis.

For cancer patients, the T-score tells you where you stand, but the rate of change matters just as much. If a baseline scan before treatment showed a T-score of -0.5 and a follow-up scan 18 months later shows -1.8, the absolute number might still fall within the osteopenia range, but the speed of decline is clinically significant and may warrant intervention.

Your Z-score, which compares your bone density to others of the same age and sex, can also be informative. A Z-score below -2.0 suggests that bone loss is occurring at a rate faster than expected for your demographic, and in the context of cancer treatment, this often points directly to treatment-related causes.

If your results show meaningful bone loss, your team has several options. Bisphosphonates (such as alendronic acid or zoledronic acid) can slow or reverse bone loss. Denosumab, a targeted injection given every six months, is another effective option, particularly for patients who cannot tolerate bisphosphonates. Lifestyle modifications, including resistance exercise, adequate protein intake, calcium, and vitamin D, support bone health alongside medication.

Recovery is possible. Bone density can stabilise and, in some cases, improve after cancer treatment ends, particularly with appropriate intervention. Serial DEXA scans every one to two years allow you and your clinical team to track that recovery with objective data.

Can chemotherapy cause osteoporosis?

Yes. Chemotherapy can directly damage bone-forming cells and may trigger premature menopause, both of which accelerate bone loss. The extent depends on the drugs used, the duration of treatment, and your age. A DEXA scan can detect whether clinically significant bone loss has occurred.

Does everyone on cancer treatment need a DEXA scan?

Not necessarily, but NICE specifically recommends baseline DEXA scans for patients starting aromatase inhibitors, those on androgen deprivation therapy, and anyone on long-term corticosteroids. If your treatment falls outside these categories but you have other risk factors, such as family history of osteoporosis or low body weight, discuss DEXA scanning with your oncologist.

How soon after treatment should I get a DEXA scan?

Ideally, a baseline scan is performed before or at the start of treatment. If that did not happen, a scan within 6 to 12 months of completing treatment provides a useful reference point. Follow-up scans are typically repeated every one to two years.

Can bone density recover after cancer treatment?

In many cases, yes. Once hormone-suppressing treatments are stopped, some bone recovery can occur naturally. Bone-protective medications, exercise, and nutritional support can further improve outcomes. Serial DEXA scans track this recovery over time.

Is a DEXA scan safe during or after cancer treatment?

A DEXA scan uses an extremely low dose of radiation, roughly equivalent to one to two days of natural background radiation. It is considered safe for cancer patients and can be repeated as often as clinically needed.

What is the difference between a T-score and a Z-score?

A T-score compares your bone density to that of a healthy 30-year-old. A Z-score compares it to people of your own age and sex. Both are useful, but a low Z-score in a cancer patient often highlights treatment-related bone loss specifically. For a detailed explanation, read our guide to DEXA T-scores and Z-scores.

If you are undergoing or have completed cancer treatment and want to understand how your bones have been affected, a DEXA bone density scan provides the clinical data you and your treatment team need.

At DEXA London, our Harley Street clinic offers medical-grade DEXA scanning with results reviewed by Dr Emil Gadimali. Whether you need a baseline scan before starting treatment or a follow-up after completing a course of chemotherapy or hormone therapy, we provide detailed, consultant-reviewed reports that your oncologist can use to guide your care.

To book your DEXA bone density scan, call us on 0207 637 8227 or visit our booking page. Appointments are typically available within a few days, and the scan itself takes around 10 to 15 minutes.