I remember the day my father called me to give me the terrible news. I could not believe that it was my own mother affected by a disease with such a frightening name. Remembering the spelling so I could Google it was hard enough. I was only at the end of my first year of medical school and thought it was normal that I had never heard of it. I soon realised that it was too rare to be covered in lectures. In the few hours after my father’s call I discovered that uterine sarcomas account for 1 % of uterine cancers [1], and uterine cancer in turn makes up only 2.5 % of cancer diagnoses [2]. I could not find a specific incidence rate for her cancer, because no one was ever sure of the diagnosis. Suddenly, I realised that the challenges my family was going to face to receive appropriate care were greater than the ones we would have faced had this cancer been more common.

A rare disease is defined by the European Union as a “disease that affects less than 5 in 10,000 people” [3]. There are between 6000 and 8000 rare diseases [3]. Collectively, they are common: in the UK 1 in 17 people will be affected by a rare disease at some point in their life [3]. Rare diseases are heterogeneous: they can result from a single gene mutation, often inherited, or from a combination of environmental and genetic factors.

On the broad spectrum of cancer patients, my mother was fortunate in that her tumour was at least operable. However, her treatment journey is a microcosm of the battle people with rare diseases face. The gynaecologist in my city was brutally honest in stating that he had no experience carrying out the required operation. The best person to do so was 430 miles away in Milan, and we would have to wait a month before he became available. The other option was to opt for immediate surgery locally. But how does one weigh up the value of a surgeon with experience of a rare cancer against the risk of giving a rapidly proliferating cancer an extra month to grow? I will never know if we made the right decision by opting to wait and travel to Milan. If we had chosen to act immediately perhaps my mother’s metastases would have come earlier, later, or not at all. Unfortunately that is the world in which sufferers of rare diseases and their families must live - a world of hypotheticals. No evidence exists to direct patient or clinician down a particular path.

I remember looking up the Italian guidelines on leiomyosarcoma management. I had just spent weeks learning the Scottish equivalents for common diseases for my exams: management of an acute MI, therapy adjustment for asthma. I naively expected the same level of detail for my mother’s disease. The guidelines can be broadly paraphrased as: “We do not know which chemotherapy works best for uterine sarcomas. Here are a list of drugs you should try in any order.” Given the paucity of evidence and recommendations, I could not blame the oncologist for his reticence to initiate chemotherapy. Equally, I do not blame him for being unaware of the existence of the final chemotherapy agent she received. After all, when my father found about this drug, he agreed to read up on it. He was of further assistance when it became apparent that this drug was not immediately available for people like my mother on the Italian national health service. He made enquiries and arranged its delivery to the local hospital, although the process took three months. Three months my mum did not have.

If I develop a rare condition at the same age my mother was diagnosed, it would be the year 2050. I hope that by then, a family with a relative affected by a rare condition will not have to envy those of people affected by common conditions. I hope that guidelines will be published by professional bodies for a greater number of rare diseases. I hope there will be more multi-centred, multi-national randomised controlled trials and greater resources for treatment, both in terms of drugs and skilled professionals. I hope they will be readily accessible temporally and geographically. Most of all, I hope that nobody ever feels that same sense of fear I felt the first time I realised my mother’s cancer was rare.

Written informed consent was obtained from my Father as my Mother’s next of kin for publication of this Letter. A copy of the written consent is available for review by the Editor of this journal.