Burden of metastatic breast cancer

Each year, there are approximately 1.7 million new cases of breast cancer (Globocan, 2012), translating into over 460,000 new cases in Europe alone (Stewart & Wild, 2014). Of these patients, roughly one third will go on to develop metastatic breast cancer (mBC) and 6% will have an initial diagnosis of, or de novo, mBC (O’Shaughnessy, 2005). This represents a significant population of largely incurable patients. In the USA, it was estimated that 154,794 women were living with mBC in 2017. Although there was a predicted increase in mBC prevalence of 17% between 2000 and 2010, and a projected increase of 31% between 2010 and 2020, it is believed this is largely due to improved survival rates. This appears to be particularly apparent in younger patients (aged 15–49 years) diagnosed with de novo mBC with a doubling of 5-year relative survival rates (18% to 36%) between 1992–1994 and 2005–2012 (Mariotto et al., 2017). However, improved mortality rates have not been observed across all mBC patient groups and the 5-year survival rate has remained at approximately 20% over the past 15 years (Sant et al., 2003; Cardoso et al., 2012; Vondeling et al., 2018). In fact, the median survival time following mBC diagnosis is just 2–4 years (Mosher et al., 2012).

"Although I stay as positive as possible, there is always the horrible doubt of  'what if’ and 'when'"

mBC patient

(Global Status of Advanced/Metastatic Breast Cancer 2005–2015 Decade Report, 2016)

While data from the USA shows an increasing number of people are living with mBC, its incidence may be stable. Between 1990 and 2014, the incidence of breast cancer in the Netherlands increased from 34.6/100,000 to 82.7/100,000 women. However, over the same period, the incidence of mBC did not change (6.7/100,000 and 6.8/100,000, respectively) with the observed changes in incidence largely a consequence of increased diagnosis of early breast cancer (Vondeling et al., 2018).

mBC and quality of life

The burden of mBC has a significant impact on patients’ well-being and quality of life, especially around the time of diagnosis and towards the end of their life. The physical and psychosocial burden of mBC must not be underestimated with eight out of 10 women with mBC indicating that quality of life is the area with the greatest need of improvement (Here & Now, Novartis, 2013). However, discussions around quality of life frequently remain vague and insufficient to meet patients’ needs (Danesh et al., 2014). Unfortunately, fear among patients can prevent them from asking more questions and getting the comfort they need. This ongoing need is reflected in EQ-5D quality of life data suggesting that patients with mBC did not see an improvement in quality of life between 2004 and 2012 despite ongoing treatment developments. This suggests that while additional therapies were required to improve patient outcomes, it is critical that additional aspects of patient care such as adverse event management and psychosocial support are addressed (Global Status of Advanced/Metastatic Breast Cancer 2005–2015 Decade Report, 2016).

Emotional burden of mBC

The emotional impact of mBC is substantial and found to be worse than a diagnosis of early breast cancer. Perhaps unsurprisingly, younger patients (<50 years of age) and those who were more recently diagnosed with mBC reported a greater emotional impact than patients who were older or who had lived with mBC for some time (Hurvitz et al., 2013). In a survey across 13 countries, 55–80% of respondents reporting feelings of fear, depression, confusion, anger and loneliness at the time of diagnosis (Mayer et al., 2010).

Feelings reported by women with metastatic breast cancer.

Figure 1: Feelings reported by women with mBC (Mayer, 2010; Global Status of Advanced/Metastatic Breast Cancer 2005–2015 Decade Report, 2016).

With the majority of patients receiving a diagnosis of mBC experiencing significant emotional distress, it is imperative that appropriate support is provided. If insufficiently supported, manageable emotional episodes can escalate. In one study of 173 patients with mBC, 61% of women who were identified as distressed at baseline had clinically significant anxiety or depressive symptoms just one week later (Mosher et al., 2012). Depression and anxiety can have a substantial impact on patients’ quality of life. However, the impact doesn’t end there as they can also affect patients’ coping mechanisms and potentially their treatment outcomes through reduced treatment compliance (Kissane et al., 2004). 

A diagnosis of mBC can also result in patients feeling isolated and having a reduced self-identity. Women who worked and had active careers may struggle with being unable to work due to prolonged sick leave or forced retirement with many reporting feeling useless in society. Similar experiences were reported for women with important family and domestic roles due to a diminished ability to fulfil the tasks they previously performed (Luoma & Hakamies-Blomqvist, 2004). These enforced changes to a patient’s day-to-day life can have a significant effect on women’s self-identity as a mother and partner, especially among families with younger children (Global Status of Advanced/Metastatic Breast Cancer 2005–2015 Decade Report, 2016). A reduced ability to work or fulfil typically daily routines can also lead to social isolation as confidence and comfort levels are diminished, especially if treatment results in changes of appearance such as alopecia.

Physical burden of mBC

A significant number of patients with mBC also experience physical discomfort in their daily lives as a consequence of their disease. In a survey of 158 women with mBC and 146 caregivers, pain that interfered with their daily life was reported by half of respondents, while half suffered from discomfort and anxiety (Here & Now, Novartis, 2013). Quality of sleep has also been shown to be reduced in patients with mBC, possibly because of the pain (Mystakidou et al., 2007). One survey of patients found that 70% suffered from sleep disturbance (Mosher et al., 2013).

A frequently overlooked, but severe, symptom of mBC is reduced sexual interest and sexual dysfunction (Cleeland et al., 2014). Reduced sexual function can impact physical, emotional and social well-being and promote depressive symptoms in both the patient and their partner (Milbury & Badr, 2013). Effective communication, and the use of tools and techniques to support this, can help improve sexual function and help alleviate this substantial burden. However, the approach taken may need to be tailored to the individuals to ensure it is effective for both partners as well as consider any cultural sensitivities that may be apparent (Au et al., 2013; Milbury & Badr, 2013).