It wasn't me.

In her forties and before she met P’s eldest brother, my Spanish sister-in-law discovered she had breast cancer. That diagnosis was more than eight years ago and today she’s doing great. Better than great. She’s a breezy, happy, no-messing, fun-seeking, beer-drinking, chain-smoking, newly retired heroine, and she was on brilliant form when we went to visit her and my brother-in-law in Madrid last weekend. ‘You get the hot flushes, yes?’ she said, thrusting a fan into my hand moments after we landed. She winked at me knowingly, smoothly opening her own fan and delicately waving it in front of her face in a single, seamless flick of the wrist. I returned the wink, trying to mimic her super-cool fanning manoeuvre but instead getting one of the prongs caught in my little finger and only extending it to what looked like a lacy, black slice of pizza. I was nervous; the clumsy Jedi Cancer Youngling to her Jedi Cancer Master.

It was a daft moment, really, but in that simple exchange of winks, I knew that she understood everything I’ve felt this past year; all the stuff I’ve kept between me and Mr Marbles; all the feelings I’ve not been able to explain to my family; all the things I’ve not quite managed to describe on this blog. She just got it. No deep conversations, no tears, no confused Spanglish. Just a wink and a smile and a flick of a fan that said, ‘Yep, I know.’ (Or perhaps, ‘The force is strong with you’. Whatever.)

The Spanglish route, however, was admittedly a more fun method of sharing our cancer stories, particularly since our respective Lynch boys have peskily ensured that the best we know of each other’s languages is ‘are you stupid or what?’ (her) and ‘Cariño, he encogido a los niños’ (me). ‘So, cheemoferathy,’ she said, gallantly pronouncing the word better than I dare say I can in my mother tongue. ‘Awful?’ I raised my eyebrows in confirmation. ‘Yep. Hell.’ She agreed. ‘Depression, too, no?’ We bobbed our heads like a pair of nodding dogs after three too many cervezas. ‘And children? Is not possible?’ (Insert obligatory nobody-expects-the-Spanish-inquisition gag here.) I shrugged, trotting out my now-standard line that P and I are happy enough, actually, and that life’s just taken us down a different path, is all. ‘Yes, we are lucky to have these men. I never really want to be a mother anyway,’ she said, as I caught our boys eavesdropping from the other side of the table, each with what looked suspiciously like an adoring glint in their eye. ‘But you are okay,’ she continued, in what I think was a statement rather than a question. ‘When you arrive in the airport, I see your skin and I see your hair and I think, yes, you are fine; you are brave.’ (See, the force is strong with me.) I gave her a cuddle, opting to swerve the mention of my hair and rest my usual routine of inflicting the hairdryer treatment on anyone who dares mention it.

As our conversation went on, though, it became eerily clear how similar our stories were, despite the almost-twenty-year gap in our ages at diagnosis. Left breast? Check. Stage three? Check. Oestrogen receptive? Check. No family history? Check. We talked of finding the lumps we each assumed were cysts; hers in the shower, mine in bed with P. I talked about Smiley Surgeon and his early advice to eat watercress and cherries. She talked about her oncologist and his insistence that she should only eat red meat once in a while, drink a glass of red wine every day, have regular massages and to keep herself stress-free. ‘Ah, that’s my favourite piece of advice,’ I said; though, oddly, it was my local shopkeeper rather than my oncologist who offered it to me. ‘What you need to do, dear,’ she insisted to me and Mum when I first made it the twenty yards to her store after chemo #1, ‘is remove all stress from your life. Work, money, worries, everything. Let everyone else take care of that. You just concentrate on you.’ It’s fortunate that I was in a position to do that. My super-supportive company signed me off immediately, P took all the financial stuff in hand (not altogether a bad thing for a girl with an iTunes-and-handbag habit like mine), and my folks looked after the running of the flat whenever they were here. Everything just got done. The only stress I had was the one the tumour inflicted on me which, frankly, was rather enough worry in the first place. Pre-cancer, however, my sister-in-law and I shared another similarity. Around a year before we happened upon the evil activity beneath our left nipples, we both experienced a pretty rough ride in our jobs – the kind that finds you tetchy and sleep-deprived and makes you row with your husband for forcing you out of bed in the mornings.

‘That kind of stress causes the cancer,’ asserted my sister-in-law. I found myself half-heartedly agreeing out of politeness. She saw straight through me. ‘No, no, it’s true,’ she assured me. ‘My oncologist says it.’ Now I’ve only had a handful of sessions with my oncologist, but there’s no way I can imagine him telling me that stress causes cancer (not unless he’s suddenly started writing headlines for the Daily Mail) no more than I can imagine him telling me to have a G&T every morning or that a diet of chocolate fondue is a fast-track to better health. (Hell, I only squeezed the watercress and cherries advice out of Smiley Surgeon through nagging and eyelash fluttering.) But hers clearly believes it. As does she. And that’s where our stories differ.

It’s funny how a bit of sea can separate two countries’ conclusions about The Bullshit. On this side of the channel, it seems, we’re far more careful about the semantics. Just as ‘no trace of cancer’ is acceptable where ‘cancer free’ isn’t, I’m sure most British-based doctors would tap-dance around the statement that stress ‘causes’ cancer. And, from what I’ve gathered from my sister-in-law, Spanish oncologists place much more emphasis than their British counterparts on lifestyle and stress and attitude and positive thinking – those strange unquantifiables that can’t be measured through a blood test. To my mind, that’s a bloody risky strategy. We’re supposed to be able to control stress, lowering it as we would our cholesterol. So if stress leads to cancer, does that make those of us who have it responsible? If we can't maintain a positive attitude, does that mean we're making things worse?

It’s a funny one, this stress lark. Though I think there’s only a very tenuous medical connection between stress and good health (in that some say it can weaken the immune system), I don’t doubt that it plays a part. I have no basis to back it up but, at the risk of getting all new-age on you (I’m in Glasto training, remember), I’m a big believer in the link between the mental and the physical. Even at a simple level – blushing when you’re embarrassed. Shaking when you’re nervous. Working yourself up to the point of puke on the morning of your driving test. Getting butterflies in your stomach before a first date. But suggesting that stress causes cancer? Sheesh. If that were the case, there’d be a chemo carriage on every underground train.

The problem, I think, is that it’s human nature to search for answers. Why did this happen to me? Is it something I did wrong? What could I have done differently? So attributing stress to cancer might just be a case of finding an answer where there isn’t one. And granted, in occasional moments of rage, I’ve blamed The Bullshit on my getting wound up by everything from shouty bosses to estate agents to bad referees to Kerry Katona. But in reality, I can’t believe that. (Though I do think there’s a direct correlation between my improved health and no longer buying OK! magazine.) I can’t believe it because that would make the cancer my fault. And there are plenty of things I’ll take responsibility for – the pink nail varnish on our white bedlinen, clogging up the Sky+ with episodes of Hollyoaks, having once had a crush on Mick Hucknall – but The Bullshit just ain’t one of them. And tough as it is to come to terms with having nothing to blame it all on but a crappy combination of oestrogen and shit luck, that’s just the way it’s going to have to be. Que sera sera.