How long do I have?
We need to talk about it
Warning: we are going to talk about the numbers of life expectancy for people with metastatic breast cancer.
When talking about my experience with cancer, I only mention numbers when asked directly; I realised that some people prefer not to be haunted by them, and that is ok. In the last appointment, my oncologist mentioned that there are many women that never ask, and don’t want to know, their prognosis.
If you don’t want to know the numbers, this article is not for you. If you are curious about them, I hope it will give you some insight about what they really mean.
If you've ever had to ask this question, you know what I'm talking about. It's the scene that appears in films and series when a character is told that they have an incurable disease.
«What's the prognosis?» was the first question I asked the oncologist, after learning that I had metastases in my bones. I had the scene prepared, trained, and the list of questions on my mobile phone.
In the (few) days before my appointment, I read everything I could find on the subject. The first result of a google search took my breath away: the 5-year survival rate for people with metastatic breast cancer was 28 per cent, at the time, according to the American Cancer Society.
Then I discovered the MONALEESA results, the clinical trial for ribociclib, the treatment my doctor had mentioned on the phone. This study followed, for six years and seven months, 668 women with metastatic breast cancer who had not previously received systemic therapy for advanced disease.
In this study, half the women took ribociclib and letrozole (an oestrogen blocker), and the other half a placebo and letrozole. During the study, 181 women died in the first group and 219 in the second. In the group taking ribociclib, the five-year survival rate was 52.3 per cent and the overall survival median was 63.9 months, 12.5 months more than the placebo group. The relative risk (hazard ratio) was 0.76, which means that the risk of death with ribociclib was 24 per cent lower. The article concludes that treatment with ribociclib and letrozole has a significant benefit on overall survival compared to letrozole alone.
When I finally got to the appointment and asked my question, the doctor said that the median survival time was seven years1.
I also learned that, by definition, metastatic breast cancer is not curable (it's called stage IV, the last stage). I realised that treatment is done «forever», and that when the first treatment stops working or becomes very toxic, with serious side effects, they try another one.
I'm not a number
The five-year survival rate and the median survival time are very useful for comparing the effectiveness of treatments, but they can be (even more) frightening when we don't know what they mean or how they are calculated.
Let's start with the definitions. In a given group/study:
The five-year survival rate tells us the percentage of people who are still alive five years after the diagnosis.
The median overall survival tells us the time after which half of the people are still alive.
But when we apply these figures to an individual, it's important to consider some assumptions:
Statistics don't take into account how each individual responds to treatment. They don't take into account individual factors such as age, state of health or immune system, or genetics.
Survival rates and survival times are calculated from the moment of diagnosis or treatment - and not everyone is diagnosed or treated at the same stage of the disease. Some people, like me, discover metastases by chance (and thanks to the care of the team of doctors), and others discover metastases when symptoms appear, and may be at a more advanced stage.
The median is the middle number of a set of numbers placed in order of magnitude. In the case of these studies, it's as if they put the survival time of all the women in ascending order and chose the middle number. Using seven years as an example, the median overall survival means that half of the women lived between zero and seven years and, and the other half lived more than seven years. And how much longer? We don’t know. The results are updated as the years go by, and more people take the medication - ribociclib was approved in the US and EU in 2017.
In the case of ribociclib, the initial studies were carried out with a daily dose of 600mg (21 days of treatment and a 7-day break), but a study from 2023 indicated that a dose of 400mg could improve tolerability to the drug without compromising its efficacy. Maybe with a reduced dose, it will be possible to take ribociclib for longer.
Research continues, and every year new treatments bring more time and quality of life to people with advanced cancer. A few examples are: genetic studies of mutations, individualised treatments, target therapies, immunotherapy/vaccines and nanotechnology.
When statistics become emotional
When I started looking at the numbers, I remembered why I never liked statistics: I know that the probability of a dice landing on a certain number is always the same, but I don't feel like it is. If I get a six, twice, I feel it's less likely that I'll get a six the third time.
Statistics don’t feel real, they seem to portray something that happens to other people.
When I saw, in the ribociclib study, that the doctors considered an extra year to be a significant benefit, I was sceptical about the data analysis. Significant benefit? One year? Not really.
The emotional reaction to these figures differs with each person's world-view, beliefs and life experience. It's very different for a twenty-year-old starting out in life, a mum of young children, or a middle-aged woman with no children (like me).
When I first learned the number, I felt I still had time - I’m optimistic and not very good at long-term planning. Good news sticks to me more than bad news. Just a few days ago, on an online group, I was told that the University of Wisconsin Madison is studying outliers/long-term survivors of breast cancer, and about a woman who has been living with metastatic breast cancer for 36 years — and she has been on my mind ever since.
But I suspected that time would go by fast and, as I write this, a year and a half(!) has passed.
Knowing my number has changed the way I see the world, and it inspired the name of this publication. It has brought me sadness, discouragement and anxiety, but also acceptance, trust and peace. This experience awoke in me the feeling that whatever time I have left, it will be enough, that it is already enough. Maybe this will change, as the clock keeps ticking, but I hope it doesn’t.
By adding the 63.9 months from the ribociclib study with the 23.9 months from a new study for trastuzumab deruxtecan, a possible second-line treatment for my case.
My breast cancer is luminal subtype A - positive for the oestrogen (ER) and progesterone (PR) receptors and low human epidermal growth factor receptor 2 (HER2). My first line of treatment includes ribociclib, letrozole, goserrelin and denosumab (you can find here what each of these do).
I can see some people not wanting to know and others feeling they have to know. Thank you for sharing this and for holding on to the chance of outliers.
You’ve written about such a difficult topic with such hope and sensitivity. Thank you ♥️