I had cancer when my children were young. This is what Kate should know | Marina McIntyre

TLast summer I was getting ready to leave my family on holiday in France as I returned home to England. My children, who were seven and four, held me tightly, looking pale and serious. But they were too scared to protest, as they would have if I had left them with a babysitter for the evening. We all knew something was wrong with me, and I was heading into the unknown.

About eight weeks earlier, my face had become swollen and swollen. This was followed by my neck, and eventually my entire upper body. I looked strange, I felt faint, I could barely stay awake. I was 39.

The day before we went on holiday, an ultrasound had found a large, sinister mass half hidden behind my ribs. Ultrasound can’t see through bone, the sonographer told me, but I needed a scan that could, and quickly. The NHS promises cancer tests will take place within two weeks – an impressively short time, until you’re in it, waiting to know whether you’ll live or die. We decided that we would go on holiday instead of waiting at home for those two weeks. It would be fun and distracting. And there was another reason: it suddenly felt urgent to make fun memories for the kids. Even though I looked so strange, I wanted to make sure there were plenty of photos of me in it, instead of staying behind the camera as usual.

In quiet moments, my husband and I tried to think ahead. If I were dying, would I have to write cards for all the children’s future birthdays? Was there anything I could leave behind that would make the situation better for them? But everyone knows that there is no ‘better’ when you lose your mother. I kept thinking about interviews I’d read with people like Eddie Izzard and Marco Pierre White, on whom the experience had left a scar that would never heal. When my children were babies, I had read every parenting book I could find in an attempt to avoid it screw themand here I was, about to do it anyway, and in the worst way possible.

The call came and I caught an early flight back. It turns out I had a kind non-Hodgkin lymphoma, and that large mass, about the size of a mug of tea, almost completely blocked the artery that drains the upper half of my body to my heart. That fall, I spent a total of eight weeks in the hospital: six rounds of chemotherapy, each lasting six days, and four emergency admissions. But I was lucky. A year and a half later, I’m still here, not only in remission, but 100% well. The treatment caused me to have an early menopause and my previously straight hair, which all fell out, has come back curly. Otherwise you would never know it happened.

The Princess of Wales hasn’t said what type of cancer she has, and that’s none of our business. But in her video message she suggests that the prognosis is good. I hope that in a year or two she will be like me, looking back in horror and asking: did that really happen to me? I still wonder how much of an impact it had on my children. Most of the time they appear completely unharmed; other times I’m not sure.

a Macmillan Volunteer gave us two great unexpected pieces of advice about talking to kids about cancer: make sure they realize it’s not their fault, and make sure they know they can’t get it. Apparently these concerns are common, but adults usually don’t realize it. Another good piece of advice from a neighbor, a psychotherapist, was to give the children something active to do; Going through a potentially traumatic situation is much worse when you feel like a helpless passenger. It wasn’t easy – we were all quite helpless – but a sponsored walk for Macmillan gave them the feeling of making a difference.

There aren’t many things you can learn from having cancer, other than how awful it is. But it does help you focus on what’s important. Now that I’ve gotten my life back – possibly decades – I think a lot about what to do. Kate probably has to deal with more shit than most of us, especially in recent weeks. I hope that amid all the bleakness of this experience, it brings her some comforting clarity about what really matters.

Marina McIntyre is deputy audience editor of The Guardian

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