Today I have presented in UICC about the contribution of BRCA1 promoter methylation in Pakistani triple negative breast cancer patients. BRCA1 and BRCA2 are the two major genes, breast cancer predisposing genes, if the genes are silenced. The major reason for gene silencing is genetic changes. So we have identified in the Pakistani population the prevalence of about 25% BRCA1/2 mutations. Among these we noted that BRCA1 mutation carriers have a distinct subtype of breast cancer which is triple negative breast cancer. So this a subtype which is very aggressive. Overall the prevalence of triple negative in the Pakistani population is higher than the West which is 30% in Pakistan and in the West is about 12-20%.

So we noted 37% of triple negative breast cancer women harboured BRCA1 mutations whereas 67% of breast cancer women with BRCA1 mutation only display triple negative breast cancer. So there must be another mechanism of gene silencing which is BRCA1 promoter methylation. Only two studies are conducted from Asia, one is from India, a smaller study on 50 cases, and the second is from [1:24], it includes cases of 150. So these were smaller studies and they also included BRCA1/2 mutation carriers and they did not stratify triple negative versus non-triple negative breast cancer cases. So we conducted the first study of its type in the Pakistani population to investigate the contribution of BRCA1 promoter methylation in triple negative and to correlate with the pathological features.

Breast cancer is the major cancer in Pakistan. Overall in the world about two million new cancer cases are being diagnosed and about 0.7 million of these individuals die from this disease. There is a disproportionate mortality ratio in the developing world and Pakistan has one of the highest mortality to incidence ratios in Asia. So the majority of Pakistani women are presenting at an advanced stage and at a younger age. Therefore it is very important to identify or to design a non-invasive assay for Pakistani women so that we could just predict that an individual is at higher risk as compared to another individual.

For this purpose we started a study in our database in a tertiary care cancer hospital, Shaukat Khanum Memorial Cancer Hospital. We included 385 breast cancer patients, 131 triple negative, the remaining 254 patients non-triple negative, and 107 healthy controls. All these patients were negative for BRCA1/2 mutations. We performed a methylation sensitive high resolution assay by system and we included all samples three times and also included methylation standards just to validate our results. More than 76% of our study population were diagnosed within the first year of their presentation when they were recruited so thereby minimising any kind of survival bias.

What we noted, overall the contribution of BRCA1 methylation in breast cancer patients is about 19% and in the control it’s 13%. When we stratified into different risk parameters, among early onset cases it was higher, about 23%, but even higher in triple negative cases – up to 30% - then non-triple negative which Is 14% and healthy controls which was about 13%. We also noted that the higher prevalence was identified among breast cancers presenting with the higher tumour grade, that is grade 3, as compared to grade 2 and grade 1. Also PR negative tumours have higher methylation than PR positive breast cancer tumours. But we did not identify any other parameters like age, ethnicity, BMI, parity, ER status or HER2 status, we did not find any correlation.

Then we performed a test of multi logistic regression model in which we noted that triple negative breast cancer was independently associated with BRCA1 promoter methylation in our population.

So, in conclusion, this was the largest study we conducted from Asia in which we investigated the contribution of BRCA1 promoter methylation in Pakistani triple negative breast cancer. The prevalence of constitutional BRCA1 promoter methylation was twofold higher than in non-triple negative. So based on these findings we suggest that this BRCA1 promoter methylation, this is just a simple blood test, it could be used as a pre-invasive tool, pre-invasive diagnostic test, to predict who is at risk to develop triple negative breast cancer.

How do you offer BRCA screening in Pakistan, and where does it sit with international guidelines?

In Shaukat Khanum Memorial Cancer Hospital we started BRCA screening back in 2001. We started a project in collaboration with German cancer research centre in Heidelberg in which we screened our patients. We transferred the technology from the German cancer research centre back to Pakistan. I did my PhD from the German cancer research centre then we transferred the technology to Shaukat Khanum. In Shaukat Khanum since 2001 we are conducting patient screening who are at risk in a research-based setting until 2018. So all patients who were at risk, younger age of breast cancer presentation or those with a familial breast cancer or breast and ovarian cancer, even ovarian cancer, all those patients were screened for BRCA1 and BRCA2.

If a mutation was identified in those individuals, then we offered cascade genetic testing to the at risk individuals. Everything was performed and offered free of cost. Shaukat Khanum Memorial Cancer Hospital supported that study and based on that knowledge over a period of the last 18 years, we identified some founder mutations. Founder mutations are ethnic-specific mutations, if that mutation was identified in one of the leaders or founders it becomes prevalent to the whole of that ethnic group. So we identified there are some specific mutations in the north, some specific mutations in the south and based off geographic region and the caste we could predict what are the possible mutations.

So based on that, of our more than 1,000 families, we have designed an assay including 26 Pakistani-specific mutations. We are offering it as a diagnostic test so any patient anywhere in Pakistan, or even those sitting abroad, could get that sample tested and within one week the results are being shared with their clinicians.

Is there anything else you would like to add?

Breast cancer is the most common invasive malignancy among Pakistani females. It is estimated at one out of nine Pakistani females will be diagnosed with breast cancer. The majority of Pakistani women are presenting at an advanced stage and at a younger age but there is a 16 month delay. There was a study conducted in Pakistan, in Sindh, which showed that the patient presentation with symptoms and presenting to the doctor it takes 16 months. This is a huge delay. So efforts should be made for increased breast cancer awareness. So for this Shaukat Khanum every year in October there is a breast cancer awareness month in which we give talks to the general public and also on television and there is also a media campaign for the awareness of this disease. This is a treatable disease; the survival rate is higher than any other cancer but the main thing is if there is any sign, any symptom, so an individual notices then she should immediately consult a certified, a qualified, doctor, not the quacks or any other person who has no idea about this disease.

This is not a contagious disease, there is another misconception in our population that a patient even sharing food that could spread to another individual. This is not a contagious disease. And especially females are the centre and the nucleus of any family so they are really important as a wife, as a daughter, as a mother, for the wellbeing, upbringing of the children and the education of the children. So healthy women are important for a healthy society and that is only possible with increased cancer awareness.

Shaukat Khanum Memorial Cancer Hospital is offering free treatment, more than 75% of patients are getting free treatment. So now there are three cancer hospitals - Shaukat Khanum Memorial Cancer Hospital and Research Centre in Lahore, the second one is in Peshawar and the third one will be opened soon, by 2025. So our patients, whoever has any symptoms, there are free walk-in clinics, they can go to the walk-in clinic for their check-up and if there is any suspicion then the doctor would suggest some tests. Based on those tests a patient could be diagnosed or if the patient is diagnosed then the individual will get early treatment. If the patient is not having any kind of cancer then that will be a sign of relief for the individual, then he or she has no need to worry about it.