After moving to London last year and registering with a local GP, I received a letter in December inviting me to be screened for cervical cancer. The NHS Cervical Screening Programme offers screening to all women aged between 25 and 64. I'm 25, so on the day of my appointment the nurse assumed I was being tested for the very first time.

But this wasn't my first smear test. What the nurse didn't know was that I'm Portuguese. Back home most of my friends have also been screened, not as part of any formal screening programme but because in Portugal gynaecologists advise women to be screened every year from their late teens onwards.

Why aren't women under 25 screened in England, I wondered. Were the Portuguese doctors wrong when they advised me to be screened at an earlier age?

According to the World Health Organisation, cervical cancer is the second most common cancer in women worldwide after breast cancer. Treatment can be gruelling and around 288,000 women die of the disease every year.

Effective screening is clearly vital, so why is there such a big discrepancy in prevention strategies, even within Europe? Is it a scientific, an economic or a political decision?

Screening is a balance between risks and benefits. "In younger women screening is less effective, cervical changes are more common and they often return to normal without treatment, " says Hazel Nunn, senior health information manager at Cancer Research UK. As with other types of screening, there's a risk of false positives (or "overdiagnosis"), leading to unnecessary, invasive treatment.

In 2007, 70 women under 25 were diagnosed with cervical cancer in the UK. There were a further 265 cases in women aged between 25 and 29.

"It isn't clear exactly at which age women should begin screening," Nunn added, "which is why there are differences in the screening programmes across the UK." In Scotland, Northern Ireland and Wales, screening starts at 20.

You may wonder, as I now do, about the scientific evidence on which cancer screening programmes are based.

The issue is obviously a concern for Jo's Cervical Cancer Trust, a UK charity committed to help improve the diagnosis of cervical cancer and the understanding of how it can be prevented. Robert Music, director of the trust, said we need a "greater investment on improving access to cancer screening programmes".

Other questions have occurred to me about the prevention programme. A vaccine against HPV, the virus that causes cervical cancer, is now available and will be given to schoolgirls. Will this be effectively integrated in the screening programme?

Why did countries like the UK choose the Cervarix vaccine whereas others chose Gardasil? Why are men vaccinated in some countries but not in others? You may wonder, as I did, whether lobbying from the pharmaceutical industry has played a part.

Virtually all cases of cervical cancer are linked to the human papillomavirus – an apparently preventable viral infection that deserves more attention. This particularly applies to Sub-Saharan Africa (about 80% of cervical cancer cases occur in developing countries). HPV may not be as alarming as HIV, but changing sexual behaviours to prevent one could easily contribute to preventing the other.

Are there any cervical screening programmes in Africa? And will other countries follow Rwanda's lead and adopt the vaccine?

Depending on where you live, you may or may not be able to follow the best scientific advice to avoid this disease. But at the moment, it feels as though these decisions are in the hands of policymakers, not scientists.

To summarise, these are the main questions I aim to answer:

• Should women under 25 be screened?

• What is the incidence of false positives and unnecessary treatment for cervical cancer?

• What is the difference between the Gardasil and the Cervarix vaccines?

• Should men be vaccinated?

• Would it be cost-effective to run screening and vaccination programmes in tandem?

• Are any cervical screening programmes running in Africa?

• Can HPV cause other types of cancer?

Whether you are female or male, a teenager or a parent, I look forward to reading your feedback, which I will do my best to put to the experts. The more thoughts we share, the more we'll get to grips with this tricky problem.

Débora Miranda is a science journalism MA student at City University London and will be investigating these questions for her final project. In the next few weeks she will interview experts and post updates assessing the evidence and comparing prevention strategies. All her source material will be posted on her website cancer-screening.net. She can be contacted via email on cancerscreeningproject@gmail.com and on Twitter @debmir