Is it bad luck that Sarah Ferguson has been diagnosed with breast cancer and melanoma, are they connected?

Melanoma is a type of skin cancer that originates in the pigment-producing cells called melanocytes. Caught early, the chance of a long-term cure is very high. Cancer Research UK states that over 85% will be cancer-free at 10 years after surgical removal. The prognosis, very much depends on how early it has been picked up. As The Duchess of York would have been undergoing regular check-ups for her breast cancer, let's hope it has been picked up at an early stage.

About 17,000 people are diagnosed with melanoma every year in the UK, but the annual incidence has tripled since the 90s. This trend is thought to be associated with sunbathing and the availability of affordable holidays in the sun, especially among young people. Sun burning as a young adult is the most significant risk factor for melanoma later in life. Sarah Ferguson also has fair skin and is red-headed, which makes the skin more sensitive to sun damage and hence melanoma. The Duchess has also enjoyed skiing holidays and outdoor activities where the intensity of Ultraviolet (UV) Radiation Exposure would have been high.

Is there a link between breast cancer and melanoma?

Genetics: About 10% of melanomas are caused by certain genetic factors, most commonly a mutated gene called CDKN2A. Although inheriting this gene can also increase the risk of pancreatic cancer, there is no increased risk of breast cancer. Very rarely, the lifetime risk of melanoma can be increased by a mutated gene called BRCA2. This is the gene made famous by Angelina Jolie, who opted for a double mastectomy to prevent a substantially increased risk of breast cancer. Although the details of The Duchess's breast cancer are not publically known, the fact that she had a single reconstructed mastectomy and no chemotherapy makes this genetic factor unlikely. The majority of women I see in my practice with the BRCA mutation are usually very young and have an aggressive form of breast cancer called triple-negative, which requires intensive chemotherapy.

Vitamin D: There certainly may be a lifestyle-related issue which could explain the link. The risk of both breast cancers and melanoma is significantly increased by vitamin D deficiency. Although we think of vitamin D as only helping bones, it has many other functions in the body, including enhancing immunity against infection and cancer. Although The Duchess may have enjoyed the sun in her younger years, being a redhead, she may well have kept in the shade in recent years. Vitamin D has a half-life of 6 weeks, meaning that, without supplementation or sunlight exposure, within 3 months blood levels dropping to one-quarter of what they should be. This explains studies showing that over 50% of people from the UK have suboptimal levels of vitamin D, especially in December and March.

There is also good evidence to suggest that people with low vitamin D after melanoma surgery have an increased the risk of relapse later in life.  I am sure The Duchess's doctors will be measuring her vitamin D levels, although it's still surprising how few doctors across the UK would do this routinely. Studies have shown that people who continue sensible sun exposure, often against their physicians' advice, have lower relapse rates. As well as dietary measures, I personally would advise patients to take a good quality vitamin D supplement, preferably one with probiotics and prebiotics, which increases absorption and bioavailability, but do accept that further large-scale randomised trials are required to confirm this recommendation.

In conclusion, this double cancer diagnosis must be very distressing for The Duchess but hopefully they have been both picked up at a curable stage. On top of the excellent medical treatments she most certainly have received, there is an increasing body of evidence to suggest that lifestyle and dietary strategies could reduce her risks of relapse further particularly exercising three hours a week, eating a healthy mainly plant based diet, reducing alcohol intake and maintaining adequate vitamin D levels.