We need a better understanding of the biomarkers that allow the life-saving early detection of cancer.
A few weeks ago, I read an article about cancer survival rate  (in Polish) and the development/wealth of a country. Interestingly, for some cancers, like prostate, there is up to 50% difference in survival rate in wealthy countries (e.g. USA, Australia, Poland) compared to “medium” developed countries (e.g. Turkey, China). Notably, however, for the most deadly cancers (less than 20% survival rate), there was not much difference across the world. I was especially surprised to see that for prostate cancer, the 5-year survival rate was almost 100%, compared to a dramatically lower 50% in wealthy vs medium-wealthy countries.
This reminded me of a research proposal I wrote back in 2013. It was about mapping the differences in prostate cancer and different stages of its development, and I became familiar with the good and bad sides of the Prostate Specific Antigen (PSA) test.
The PSA test is a non-invasive blood test used to detect a biomarker called prostate specific antigen, which tends to be elevated in prostate cancer. 
According to the NIH, until 2008 this test was commonly recommended to men over 50, allowing widespread early detection of prostate cancer. Now, we know that elevated PSA levels can actually occur during many different non-life-threatening conditions, which results in false-positive diagnoses (indicating a disease that is not there). Simultaneously, the test missed some cases of prostate cancer due to the natural variability and complexity of prostate cancer.  In fact, some researchers argued that only 1 death per 1000 men between ages 55–69 could be prevented with the PSA test, while over 100 men out of 1000 receive a false positive result, leading to unnecessary biopsy, surgery and over-treatment. 
In 2016, Ben Stiller wrote a Medium post recounting his personal encounter with prostate cancer and the PSA test. Despite the controversy surrounding the test, it potentially saved his life. This speaks to the great advantage and life saving potential of early detection of cancers.
There is a clear survival advantage of being in a country that supports the means for early detection, diagnosis and treatment.  That’s why huge research efforts go into discovering new biomarkers for cancer and other diseases. While thousands are being found in early stage research, only a few dozen at most are researched in clinics, due to the challenges associated with the reliability of biomarker-based diagnosis like the PSA test.
The main difficulty in dealing with cancer is that it is not one disease, but a series of many conditions that differ by their molecular profile.
In fact, two tumours in one patient can be totally different from each other. This causes great variation in the development, malignancy, metastatic potential and response to treatment of cancers. It’s highly challenging to find biomarkers that unambiguously indicate the type and stage of cancers.
Of course, it seems like a single biomarker is not enough to do the job of early detection. Recently, the “new” biomarkers tests are in fact combination of several proteins or molecules, whose collective information provides a highly accurate result. By observing multiple elements at the same time, we increase our chances of unambiguously identifying diseases, as well as tailoring specifically a treatment to a person (an approach called personalised medicine).
By observing multiple elements at the same time, we increase our chances of unambiguously identifying diseases, as well as tailoring specifically a treatment to a person.
Since I started to think seriously about my own research agenda a few years ago, I dreamed of making a device that would allow in-home rapid detection of biomarkers. We’re still a long way from there, but seeing this article reminds me it’s actually a very valid goal for researchers and provide less developed countries with the means to face cancer.
 Infographic: Onkologia (Accessed on 8.2.2018)
 NIH Factsheet on Prostate Cancer, National Institute of Health (Accessed on 20.2.2018)
 Chen et al. 2017 Scientific Reports 7 Article number: 40003 (DOI)