Dr Rachael Natrajan always knew that she wanted to pursue some kind of scientific career, but she wasn’t sure what exactly. At school, she enjoyed chemistry and biology; at university, she initially did a joint degree in genetics and zoology. But it was while she was still an undergraduate at Leeds University that she began to think seriously about pursuing a career in cancer research.

“I got quite engrossed in the genetics aspect of my degree, and learning about how defects in your DNA can cause disease,” she says. “And then while I was doing my degree, my mother was diagnosed with breast cancer. So that was my main driving force.”

Today, Dr Natrajan works at The Institute of Cancer Research (ICR), London, where she heads up the functional genomic team in the Breast Cancer Now Toby Robins Research Centre. In laywoman’s terms, this means that her team investigates how the effectiveness of breast cancer treatment is influenced by individual women’s genes.

“We’re focused on looking at particularly aggressive forms of breast cancer,” she explains. “The question we’re working on is: why don’t some patients respond to treatment?”

Many women “are still alive 10 years down the line from having breast cancer,” Dr Natrajan notes. “So why do some women still die from the disease?”

In practice, this means that Dr Natrajan and her team spend a lot of time looking at the make-up of DNA within patients’ tumours, and monitoring how that DNA evolves and “how it responds to chemotherapy or endocrine therapy or similar treatments.” If they can see that a patient’s genetic information is changing over time, they may be able to use that to identify new drugs that could be effective treatments.

The ICR is one of the most prominent and influential cancer research bodies in the world, and is partnered with a neighbouring hospital, the Royal Marsden in Chelsea. This means that Dr Natrajan and other cancer researchers at the ICR are able to practice what she describes as a “bench” – as in laboratory bench – “to bedside” approach, whereby patients who are undergoing treatment at the Royal Marsden can have biopsies and tumours analysed at the ICR’s labs next door.

“What we are doing is taking a small proportion of the patient’s tumour that’s removed during surgery, or through a biopsy, and then we can grow that in the lab next door,” Dr Natrajan says. These days, she says, “you can grow a patient’s tumour relatively successfully in the lab to do real-time experiments”.

Growing a new tumour in the lab allows Dr Natrajan’s team to “test how the patients might respond to the therapy that they’re currently getting, or new therapies based on the genetic makeup of their tumours.” In other words, it allows them to try out experimental new treatments without putting the patient themselves at risk.

In 2012, Dr Natrajan was awarded a career development fellowship to start her own lab within the breast cancer division at the ICR, which she says was “one of the proudest moments” of her working life.

“You always have that thought in your mind that you want to be at the top,” she says. “But you know that not that many people make it. So that was a good moment for me, to realise that someone believed in me.”

In general, she says, breast cancer research is a good place for women scientists who want to reach ‘the top’: “It’s not like in physics where you just see men.” She estimates that the more junior levels of breast cancer research have a roughly 50/50 male/female split, and says that she works alongside many other women in senior positions.

Nevertheless, like all areas of science, the most senior levels of cancer research do tend to be male-dominated. Dr Natrajan is reluctant to attribute this to some fundamental flaw in the scientific community so much as she sees it as a reflection of society at large: “There are gender biases in other professions as well.” And she’s keen to encourage more women to pursue careers as breast cancer researchers. “It is very rewarding and exciting.”

It’s not a perfect profession, but what is? Dr Natrajan says she struggles to switch off, “because you’re constantly thinking about the experiments you’re doing, and how you’re going to translate them into patient benefit. It’s not a 9-to-5 job – you carry this stuff with you wherever you go.”

But, she says, she wouldn’t trade it for anything else. “As a breast cancer researcher, you know you’re making a difference to patients’ lives,” she says. “You’re contributing to something really important.

“That’s something that you can carry around with you on a day-to-day basis and it gets you out of bed in the morning. Even when you’re having a really rubbish day, you know you’re doing something worthwhile.”

The Woman of the Week series is part of Stylist’s Visible Women campaign, dedicated to raising the profiles of brilliant women past and present. See more Visible Women stories here.

Images: Nicola Tree for the Institute of Cancer Research, London / Getty Images