Survivorship Isn’t Just Surviving: Why Post-Cancer Weight Gain Matters

When people generally picture someone going through breast cancer treatment, they often imagine fatigue, hair loss and weight loss. But many women undergoing treatment gain weight, often with little or no warning. When women receive a diagnosis of breast cancer, weight gain is a side effect that often isn’t discussed.

Weight gain after breast cancer is not just a cosmetic concern. It’s a serious health issue that has been linked to cancer recurrence and a higher risk of chronic illnesses like heart disease and type 2 diabetes.

Yet, there is no clear clinical pathway or health professional whose role it is to help women with breast cancer to manage weight gain during or after treatment. This silence can have lasting consequences for a woman’s health and well-being.

According to the Australian Institute for Health and Welfare, breast cancer was estimated to be the most commonly diagnosed cancer in Australia in 2021. Thankfully, survivorship rates are increasing. However, if we truly care about survivorship, we need to move beyond just treating cancer. We need to support cancer survivors, during treatment and beyond recovery.

The Hidden Struggle: Weight Gain After Breast Cancer

Breast cancer treatment can disrupt the body in many ways. Chemotherapy, hormone therapy, and steroids can all interfere with metabolism, increase fat mass, reduce muscle mass and cause fatigue that limits physical activity. Emotional stress, changes to appetite and taste preferences, treatment-induced menopause and altered daily routines can make the issue worse.

Despite this, many women go into treatment assuming they will lose weight. When the scales begin to climb, it comes as an unwelcome shock. Yet, research by Professor Vance and colleagues shows that 50-96% of women undergoing treatment for breast cancer will gain weight. Women are rarely warned this might happen. And when it does, they’re often left to wonder: why didn’t anyone tell me?

Weight gain during cancer treatment isn’t just common: it is also significant. Weight gain has been linked to cancer recurrence. It also places additional strain on the heart, liver, and metabolic system. Yet in the current healthcare system (both in Australia and worldwide), there’s no clear consensus on who should manage this risk. Should it be the oncologist whose focus is on removing the cancer? Or your GP, who may not have the time or expertise in nutrition and lifestyle medicine? Or someone else entirely, such as a nutritionist or dietician?

This lack of coordinated care means that weight gain too often falls through the cracks.

A recent study by clinician researchers from the Netherlands reinforces this concern, calling for lifestyle interventions to become a core part of survivorship care. Such a program would provide tailored support in nutrition, physical activity, behaviour change, and mental health, and ideally be covered by Medicare to ensure accessibility. This model could transform outcomes for breast cancer survivors but it doesn’t yet exist in most countries, including Australia.

Currently, most women find themselves navigating recovery alone, expected to adjust to a ‘new normal’ without the guidance or support they need, unless they have the financial means to pay out-of-pocket for nutrition and exercise services.

It is not just about the scales (it’s a whole-person health issue)

Weight gain during breast cancer treatment is not about aesthetics, body shaming, or placing blame. It is about recognising how weight intersects with survivorship, especially as survivorship rates increase.

Women recovering from breast cancer have often been through surgery, radiation, chemotherapy, and hormone treatment. Their bodies feel unfamiliar, their routines are disrupted. Their confidence can be shaken. When weight gain happens, it can trigger another layer of distress, especially when no one has explained that it may happen. The conversation about weight needs to be reframed, not as a number on a scale, but as part of a woman’s overall health, wellbeing, and survivorship.

There is also an opportunity here. Professor Demark-Wahnefried has described the period following a cancer diagnosis as a ‘teachable moment’, a time when women may be more receptive to lifestyle changes that support long-term health. But this opportunity is missed if it isn’t met with coordinated support.

There is growing recognition that survivorship care needs to be more than a closing chapter, it can be a new beginning. We need to ask what it would look like if weight management and prevention were embedded into the cancer journey from the start. What if we trained healthcare providers to have these conversations compassionately and proactively? What if we funded lifestyle interventions as part of routine cancer care?

It is time to rethink how we approach breast cancer survivorship. We need to move beyond the goal of ‘no evidence of disease’ to consider what it means to live well after cancer. That means integrated care, where nutrition, exercise and mental wellbeing are acknowledged as vital as follow-up scans. It also means ensuring these services are accessible, not just to those who can pay for private healthcare, but to every woman who survives breast cancer, wherever she lives.

Written by Lisa Hanlon, Clinical Nutritionist