The same week in which Barbara Clark, a 49-year-old nurse, launched her battle to be treated with Herceptin - the drug that offers the best chance of survival for women with a certain very aggressive form of breast cancer - I was in a chemo lounge waiting for my second dose of this see-through fluid.

Usual blood test, and then nothing. By the time I'd read the papers, and sewn 12 name-tags into school uniforms, I figured something was up. I went to the reception area. Discomfited faces. Also Peter Ostler, the consultant oncologist, looking annoyed. "I'm so sorry," the American nurse said. "This one is three hours past its expiry. I can't give it to you."

"How did this happen?" Dr Ostler asked.

Behind us, another nurse was disposing of the small square plastic bag, complete with contents. "Wow," I whistled, "what did that just cost?" Dr Ostler, who loves figures, started tapping: "Uh, £2,000 or so." The American nurse looked like she was reliving Vietnam. "God, that's terrible," she said. "It came off hold too early." (In non-medical speak, this translates roughly as, "The pharmacy took it out of the fridge too soon.")

And then the crucial phrase: "Are you OK to come in again for it tomorrow, Dina?"

You see, for me, bags of Herceptin can just be flushed down a sink. I'm swimming in the stuff. To get her dosage, though, Barbara Clark had to threaten her local health authority with the European court of human rights. And why?

Like one in five breast cancer sufferers, Clark and I are Her-2 node positive. This means that the breast cancer we have, which has spread out of our breast and into our lymph glands, produces the protein Her-2. It grows faster, and is more likely to recur, than other cancers. There didn't used to be anything to prevent our kind of tumour from returning, but Herceptin does it - it inhibits cancer growth. This can be the difference between death and life for around 5,000 British women each year.

At a convention of 15,000 cancer specialists in Florida this past summer, the results of a trial on this drug were revealed to a hushed audience. These were the best results anybody in that room, in that field, had seen: the sharpest reduction in mortality rates.

Just one hitch, though, for British patients. Roche, the makers of the drug, hadn't applied for the right licence for Herceptin yet; it wouldn't be authorised on the NHS, and nobody knew what the private-health insurers would do.

I got Herceptin because my canny, fighting doctor went to my insurance company and talked about press coverage and the company agreed to pay straight away.

Every time I see him these days, Ostler talks about Herceptin. He mainly treats NHS patients, and the ethical implications trouble him: "Do I tell a woman she should be getting this drug, but sorry, you can't have it?" On Tuesday this week, Barbara Clark won her fight to be treated with Herceptin, and surprise, on Wednesday, the health secretary Patricia Hewitt announced that the drug will now be available for any woman who might benefit.

So Ostler's cock-a-hoop, right? "The announcement's carefully worded," he says. "They haven't allocated extra funds for it. So where's the money going to come from? Each primary-care trust will have to find the money for it from their existing budgets - by cutting spending somewhere else. If, like us, and all the primary-care trusts round here, you are completely over-extended already, how's that supposed to work?".