Commentary: Don't overlook Stage 0 cancer. It could be your earliest warning sign

CNA

30-04-2025

LONDON: At 71, Tina Knowles – the fashion designer, businesswoman, and mother of Beyonce – made headlines not for her career, but for a deeply personal revelation: Her breast cancer diagnosis. In 2023, a routine mammogram uncovered two tumours in her left breast, one benign and the other malignant. Diagnosed with Stage 1 breast cancer, she underwent surgery and is now cancer-free.
Knowles had initially hesitated to share her story, even considering leaving it out of her upcoming memoir Matriarch. A private person by nature, she ultimately chose to speak out to educate and inspire others – especially women balancing busy lives – about the critical importance of regular screenings.
Knowles candidly revealed that her cancer might have been caught even earlier, at Stage 0, if she hadn't missed a mammogram during the COVID pandemic. Like many, she delayed rescheduling, and it wasn't until nearly four years later that she returned for screening.
Her sister, a breast cancer survivor herself, reminded her that if she had stayed on schedule, doctors might have detected her cancer before it had begun to invade surrounding tissue.
Thankfully, Knowles' tumour was small and slow-growing. Still, the experience shook her and reinforced a message she now shares widely: Early detection saves lives.
IS 'STAGE 0 CANCER' CANCER?
Knowles' story opens the door to an important medical conversation: What exactly is Stage 0 cancer, and why does it matter?
Stage 0, often called 'carcinoma in situ', is the earliest form of cancer. The Latin phrase in situ means 'in its original place', and that's exactly where these abnormal cells remain – they haven't yet spread to nearby tissue or other parts of the body. In breast cancer, the most common type of Stage 0 is ductal carcinoma in situ (DCIS), where abnormal cells are confined to the milk ducts.
Because Stage 0 cancers rarely cause symptoms or lumps, they're usually detected through screening – most often, a mammogram. In fact, the breast is where Stage 0 is most commonly diagnosed, thanks to the effectiveness of these screening programmes.
But Stage 0 cancer is not unique to the breast. Similar early, non-invasive changes can be found in other organs, such as the cervix (cervical intraepithelial neoplasia) or the colon (certain types of polyps).
There's a growing debate in the medical community about whether Stage 0 cancers should be labelled as 'cancer' at all. Some experts argue that terms like 'pre-cancer' or 'non-invasive cancer' might better reflect the low risk posed by these abnormal cells. Others caution that, while not invasive yet, some Stage 0 cancers can become dangerous over time, especially if left untreated.
Research suggests that up to 40 per cent of untreated DCIS cases may eventually develop into invasive breast cancer, although the risk in any given year is relatively low at around 3 per cent. Because we currently lack a reliable way to predict which cases will progress, most doctors recommend treatment such as surgery to remove abnormal cells.
POWER OF EARLY DETECTION
Treatment for Stage 0 cancer is typically less aggressive than for more advanced stages, but it's still personalised. In breast cancer, options often include:
Lumpectomy – surgery to remove only the affected area
Mastectomy – removal of the entire breast
Radiation therapy – often recommended after lumpectomy to reduce the risk of recurrence
Hormone therapy – for cancers that have hormone receptors, medication may be used to lower future risk.
However, some experts are exploring a different approach: Active surveillance. This strategy involves closely monitoring low-grade lesions without immediate treatment. While promising for some patients, it's still controversial since there's always a risk the cancer could progress silently.
The prognosis for Stage 0 cancer is overwhelmingly positive. The five-year survival rate for Stage 0 breast cancer approaches 99 per cent and most people diagnosed at this stage will never experience a recurrence.
This remarkable outcome is a testament to the power of early detection and effective treatment. However, the rise in Stage 0 diagnoses also raises questions about so-called over-diagnosis and over-treatment and whether this means some people are undergoing unnecessary procedures for abnormalities that might never have caused harm.
ROUTINE CARE IS IMPORTANT
Despite its early stage, a diagnosis of Stage 0 cancer can carry a heavy emotional toll. There's comfort in knowing the cancer was caught early but also anxiety about what might have happened if it hadn't. Many patients struggle with the uncertainty of whether treatment was necessary or whether watchful waiting would have been safe.
Knowles, for instance, spoke of disbelief, fear and the emotional rollercoaster that followed her diagnosis. She credits her daughters and friends for getting her through, providing love, laughter and perspective in a frightening time. Her openness underscores how vital it is to have a strong support system and a healthcare team that encourages open dialogue.
Mammograms and other screening tools like colonoscopies are vital for catching cancers at the earliest, most treatable stages. While the increase in Stage 0 diagnoses has fuelled debate about over-treatment, it's clear that early detection gives people options and a chance at a cure before cancer becomes more aggressive.
My research team is working to develop more effective methods for distinguishing which early abnormalities truly require treatment and which can be safely monitored. Until those tools are widely available, public health experts continue to stress one clear message: Stay up to date with recommended screenings.
Knowles' story is more than a celebrity health headline, it's a powerful reminder that prioritising routine care can change the course of your life. Stage 0 cancer represents a rare window of opportunity: A chance to intervene early, often with excellent outcomes. But it also requires careful decision-making, emotional resilience and support.
The message is simple and urgent: Take care of yourself. Reschedule that appointment. Get screened. It might just save your life.