In just a few weeks, I'm having both of my breasts removed. At the age of 31. Why? Because it's the only reasonable option I have to dramatically reduce the risk of getting a disease that could kill me.
Cancer has already taken several members of my family: my grandma, my great grandmother and two of my aunts. The final straw was my mum, Sue, who died in March from ovarian cancer.
In February this year, when I was caring for my mum during the last few weeks of her life, I received the news I'd been dreading.
I found out I'm a carrier of the BRCA1 gene mutation. This "faulty gene" can be passed on through generations and significantly increases the risk of developing cancer. This gene means I have an 80 per cent risk of developing breast cancer and a 50% risk of developing ovarian cancer in my lifetime.
My brother Stephen is also a carrier. But our discovery came too late for my sister Lindsay. She found a lump in her breast which turned out to be an aggressive form of cancer in December last year, just months before our mum died. This summer, Lindsay finished her course of chemotherapy and radiotherapy, had a single mastectomy and is currently waiting to complete the removal of her remaining breast.
Though my impending mastectomy is, of course, on my mind, my key focus is elsewhere as I prepare to join the rebellion against cancer and take on Stand Up To Cancer's Great Canoe Challenge. Next week I'll be joining a host of cancer survivors and celebrities as they take to the water and paddle 120 miles in five days - all in the name of game-changing cancer research.
I'll be paired with TV personality and Liberty X star Michelle Heaton, an incredibly strong woman who has herself undergone a preventative double mastectomy after discovering she carries the BRCA2 gene which increases her risk of breast cancer.
This summer was my last with my body in full health. I'm living this year to the best of my ability - I've taken part in a boxing event and travelled across Europe with the Transcontinental Bike Race, so to take part in the Great Canoe Challenge was a no-brainer. With all that's happening, I feel compelled to do all I can to raise awareness. I wish to be an advocate for families living with a history of cancer, so they might be aware of their choices if they too are at high risk.
Having a double mastectomy was an immediate and obvious decision for me. Of course I have researched to see if there are other routes available, but right now this is currently the best option. My sister wishes she could have been given the same choices, but we were too late to receive our BRCA status.
Thankfully I'm not worried about what I'll look like after the mastectomy - I care more about longevity and health, and optimising that as best I can. But I know it's going to be a very difficult winter ahead.
And the decisions don't end there. Due to my ovarian cancer risk, I'll hopefully be starting fertility treatment at the end of this year to give me the best chance of one day having a family.
I'm not ready yet, but I'll be having another major operation to remove my ovaries and fallopian tubes before I'm 40, so it's important that I do this now. Every day I waiver between apprehension, annoyance and complete frustration by everything that I'm facing, but I'm determined that it will not be cancer that kills me.
Josephine is taking part in Stand Up To Cancer's Great Canoe Challenge. Stand Up To Cancer is a joint national fundraising campaign from Cancer Research UK and Channel 4.The challenge is taking place from Monday 25 September - Friday 29 September. For more information visit: standuptocancer.org.uk/canoe, to support the Paddlers and donate £5 or £10 text CANOE5 or CANOE10 to 70404*, or donate online at standuptocancer.org.uk/canoe